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  • Enzymatic depolymerization of industrial lignins by laccase‐mediator systems in 1,4‐dioxane/water
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-19
    Justine Dillies; Céline Vivien; Mickael Chevalier; Alexandre Rulence; Gabrielle Châtaigné; Christophe Flahaut; Vincent Senez; Renato Froidevaux

    Lignin is the second most abundant polymer after cellulose in lignocellulosic biomass. Its aromatic composition and recalcitrant nature make its valorization a major challenge for obtaining low molecular weight (LMW) aromatics compounds with high value‐added from the enzymatic depolymerization of industrial lignins. Oxidation reaction of lignin polymer using laccases alone remains inefficient. Therefore, researches are focused on the use of laccase‐mediator system (LMS) to facilitate enzymatic depolymerization. Until today the LMS system was studied using water soluble lignin only (commercial lignins, modified lignins or lignin model compounds). This work reports a study of three LMS systems to depolymerize the three major industrial lignins (Organosolv lignin, Kraft lignin and Sodium Lignosulfonate). We show that an enzymatic depolymerization of these lignins can be achieved by LMS using laccase from Trametes versicolor, 2,2′‐Azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) diammonium salt (ABTS) as mediator and a cosolvent (25 % of 1,4‐dioxane) to enhance the solubilization of lignins.

  • Purification and characterization of chitinase from Paenibacillus sp
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-19
    Jinghe Du; Shan Duan; Jianyin Miao; Miaomiao Zhai; Yong Cao

    The chitinase‐producing bacteria Paenibacillus sp. was isolated from soil samples. The chitinase was purified successively by ammonia sulfate fractional precipitation followed by chromatography on DEAE 52‐Cellulose column and then on Sephadex G‐75 column. The chitinase has a molecular weight of ca. 30 kDa as measured by SDS‐PAGE electrophoresis. Its optimum pH is 4.5 and its optimum temperature is 50 °C with colloidal chitin as a substrate. The enzyme is stable below 45 °C and in pH ranges between 4.5 and 5.5. It is activated by glucosamine, glucose, N‐acetylglucosamine, and metal ions including Ca2+, Fe2+, Fe3+, and Ni2+. It is inhibited by SDS, H2O2, ascorbic acid, Cu2+, Mg2+, Ba2+, Sn2+, Cr3+, and K+. With colloidal chitin as substrate, the Km and the Vmax of the chitinase are 4.28 mg/ml and 14.29 μg/(min·ml) respectively, while the end products of the enzymatic hydrolysis are 14.33% monomer and 85.67% dimer of N‐acetylglucosamine. The viscosity of carboxymethyl chitin (CM‐chitin) decreased rapidly at the initial stages when subjected to chitinase hydrolysis, which indicates that the chitinase acts in an endo‐splitting pattern.

  • A comprehensive review on microbial L‐asparaginase: Bioprocessing, characterization and industrial applications
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-18
    Subhash Chand; Richi V. Mahajan; Jai Prakash Prasad; Debendra K. Sahoo; Kanti Nandan Mihooliya; Mahesh S. Dhar; Girish Sharma

    L‐asparaginase (E.C. is a vital enzyme which hydrolyzes L‐asparagine to L‐aspartic acid and ammonia. This property of L‐asparaginase inhibits the protein synthesis in cancer cells, making L‐asparaginase a mainstay of pediatric chemotherapy practices to treat acute lymphoblastic leukemia (ALL) patients. L‐asparaginase is also recognized as one of important food processing agent. The removal of asparagine by L‐asparaginase leads to the reduction of acrylamide formation in fried food items. L‐asparaginase is produced by various organisms including animals, plants and microorganisms, however, only microorganisms which produce a substantial amount of this enzyme are of commercial significance. The commercial L‐asparaginase for healthcare applications is chiefly derived from E. coli and Erwinia chrysanthemi. A high rate of hypersensitivity and adverse reactions limits the long term clinical use of L‐asparaginase. Present review provides thorough information on microbial L‐asparaginase bioprocess optimization including submerged fermentation (SmF) and solid state fermentation (SSF) for L‐asparaginase production, downstream purification, its characterization and issues related to the clinical application including toxicity and hypersensitivity. Here we have highlighted the bioprocess techniques which can produce improved and economically viable yields of L‐asparaginase from promising microbial sources in the current scenario where there is an urgent need for alternate L‐asparaginase with less adverse effects.

  • 更新日期:2020-01-17
  • A sensitive amperometric detection of neurotransmitter acetylcholine using carbon dot‐modified carbon paste electrode
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-15
    Onur Can Bodur; Saliha Dinç; Mustafa Özmen; Fatma Arslan

    Acetylcholine is a neurotransmitter which is located at the intersections of the nerve and muscles in the lymph nodes of the internal organs motor systems and in various parts of the central nervous system. Decrease of acetylcholine in brain is associated with Alzheimer‘s disease. That is why it is an important agent for this disease. In this study, a bienzymatic biosensor system with acetylcholine esterase and choline oxidase was prepared with carbon paste electrode modified with carbon nano Dot‐(3‐Aminopropyl) triethoxysilane (CDs‐APTES) for determination of the amount of acetylcholine. Acetylcholine esterase and choline oxidase enzymes were immobilized onto modified carbon paste electrode by cross‐linking with glutaraldehyde. Determination of acetylcholine was carried out by the oxidation of enzymatically produced H2O2 at 0.4 V vs. Ag/AgCl. The effect of temperature, pH and substrate concentration on the acetylcholine response of the prepared biosensor was investigated. In addition, the optimum CDs‐APTES amount, the linear operating range of the biosensor and the interference effect were also investigated.

  • Statistical analysis of the crystallinity index of nanocellulose produced from Kraft pulp via controlled enzymatic hydrolysis
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-13
    Ruan Stevan Almeida Ribeiro; Ninoska Bojorge; Nei Pereira Junior

    Enzymatic hydrolysis processes can change the physical characteristics of nanocellulose derived from Kraft pulp. Among these attributes are its crystallinity index and dimensions. In this study, we determined the optimal conditions under which nanocellulose could be produced enzymatically with the greatest increase of the crystallinity index relative to its initial state. Application of Central Composite Rotatable Design (CCRD) statistical analysis to the experiments was employed to direct an increase the crystallinity index in 10% at the 24‐hour hydrolysis time. Upon establishment of ideal levels of starting material and enzyme, reactions were carried out at hydrolysis times of 24, 48, and 72 h under these ideal parameters. The effectiveness of deagglomeration was demonstrated by measuring the hydrodynamic diameter of the particles by dynamic light scattering (DLS). Scanning electron microscopy was performed on four samples, the original material, kraft pulp, and hydrolyzed biomaterials at 72 h in the ideal parameters. The hydrolyzed material with the best statistical data, revealing a fiber diameter of 180 nm, disclosing to be biomaterial with nanocellulose dimensions.

  • Continuous flow reactor based with an immobilised biocatalyst for the continuous enzymatic transesterification of crude coconut oil
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-12
    Juliana L. Santana; Juliana M. Oliveira; Jamily S. Nascimento; Silvana Mattedi; Laiza C. Krause; Lisiane S. Freitas; Eliane B. Cavalcanti; Matheus M. Pereira; Álvaro S. Lima; Cleide M. F. Soares

    Here, we have assessed the use one packed bed or two packed bed reactors in series in which Burkholderia cepacia lipase (BCL) was immobilised on protic ionic liquid (PIL)‐modified silica and used as a biocatalyst for the transesterification of crude coconut oil. Reaction parameters including volumetric flow, temperature and molar ratio were evaluated. The conversion of transesterification reaction products (ethyl esters) were determined using gas chromatography and the quantities of intermediate products (diglyceride and monoglyceride) were assessed using high performance liquid chromatography. Packed bed reactors in series produced ethyl esters with the greatest efficiency, achieving 65.27% conversion after 96 h at a volumetric flow rate of 0.50 mL min−1 at 40°C and a 1:9 molar ratio of oil to ethanol. Further, within the first 24 h of the reaction, increased monoglyceride (54.5%) production was observed. Molecular docking analyses were performed to evaluate the catalytic step of coconut oil transesterification in the presence of BCL. Molecular docking analysis showed that triglycerides have a higher affinity energy (‐5.7 kcal mol−1) than the smallest monoglyceride (‐6.0 kcal mol−1), therefore BCL catalyzes the conversion of triglycerides rather than monoglycerides, which is consistent with experimental results.

  • Overexpression of stilbene synthase genes to modulate the properties of plants and plant cell cultures
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-11
    Konstantin V. Kiselev; Alexandra S. Dubrovina

    Plant stilbenes have attracted special attention, since they possess valuable health benefits and improve plant resistance to environmental stresses. Stilbenes are synthesized via the phenylpropanoid pathway, where stilbene synthase (STS, EC directly catalyzes the formation of t‐resveratrol (monomeric stilbene). This review discusses the features of using STS genes in genetic engineering and plant biotechnology with the purpose to increase plant resistance to environmental stresses and to modify secondary metabolite production.

  • High‐performance detection of an abdominal aortic aneurysm biomarker by immunosensing
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-09
    Shikui Guo; Yuejin Li; Rougang Li; Peng Zhang; Yongzhi Wang; Subash C.B. Gopinath; Kunmei Gong; Ping Wan
  • Novel surface plasmon resonance biosensor that uses full‐length Det7 phage tail protein for rapid and selective detection of Salmonella enterica serovar Typhimurium
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-08
    Seok Hywan Hyeon; Woon Ki Lim; Hae Ja Shin

    We report a novel surface plasmon resonance (SPR) biosensor that uses the full‐length Det7 phage tail protein (Det7T) to rapidly and selectively detect Salmonella enterica serovar Typhimurium. Det7T, which was obtained using recombinant protein expression and purification in Escherichia coli, demonstrated a size of ∼75 kDa upon SDS‐PAGE and was homotrimeric in its native structure. Micro‐agglutination and TEM data revealed that the protein specifically bound to the host, S. Typhimurium, but not to non‐host E. coli K‐12 cells. The observed protein agglutination occurred over a concentration range of 0.8∼24.6 μg/ml. The Det7T proteins were immobilized on gold‐coated surfaces using amine‐coupling to generate a novel Det7T‐functionalized SPR biosensor, wherein the specific binding of these proteins with bacteria was detected by SPR. We observed rapid detection of (∼ 20 min) and typical binding kinetics with S. Typhimurium in the range of 5 × 104–5 × 107 CFU/ml, but not with E. coli at any tested concentration, indicating that the sensor exhibited recognition specificity. Similar binding was observed with 10% apple juice spiked with S. Typhimurium, suggesting that this strategy provides promise for the rapid, real‐time and selective monitoring of target microorganisms in the environment, and thus has great potential for supporting health by enabling early disease prevention.

  • Hyperthermophilic flavin reductase from Sulfolobus solfataricus P2: Production and biochemical characterization
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-09-11
    Gokhan Gun; Rahmi Imamoglu; Ozge Tatli; Yuda Yurum; Ahmet Tarik Baykal; Gizem Dinler‐Doganay

    Nicotinamide adenine dinucleotide phosphate (NAD(P)H)‐flavin oxidoreductases (flavin reductases) catalyze the reduction of flavin by NAD(P)H and provide the reduced form of flavin mononucleotide (FMN) to flavin‐dependent monooxygenases. Based on bioinformatics analysis, we identified a putative flavin reductase gene, sso2055, in the genome of hyperthermophilic archaeon Sulfolobus solfataricus P2, and further cloned this target sequence into an expression vector. The cloned flavin reductase (EC. was purified to homogeneity and characterized further. The purified enzyme exists as a monomer of 17.8 kDa, free of chromogenic cofactors. Homology modeling revealed this enzyme as a TIM barrel, which is also supported by circular dichroism measurements revealing a beta‐sheet rich content. The optimal pH for SSO2055 activity was pH 6.5 in phosphate buffer and the highest activity observed was at 120 °C within the measurable temperature. We showed that this enzyme can use FMN and flavin adenine dinucleotide (FAD) as a substrate to generate their reduced forms. The purified enzyme is predicted to be a potential flavin reductase of flavin‐dependent monooxygenases that could be involved in the biodesulfurization process of S. solfataricus P2.

  • Construction of a fusion anti‐caries DNA vaccine in transgenic tomato plants for PAcA gene and cholera toxin B subunit
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-05
    Guohui Bai; Yuan Tian; Jiayuan Wu; Yu Gu; Zhu Chen; Fengjiao Zeng; Jianguo Liu

    Chronic bacterial infections in the oral cavity influence the development of dental caries. Mutans streptococci are the major pathogenic cause of dental caries. The World Health Organization (WHO) ranks dental caries, cancer, and cardiovascular diseases as the three major global diseases that need urgent preventative and curative measures. However, substantial evidence suggests that traditional prevention and treatment strategies are inefficient in reducing the prevalence of dental caries. For protection against caries, it is important to develop effective vaccines that induce anticolonizing immunity against Streptococcus mutans infections. In the present investigation, we constructed a fusion anti‐caries DNA vaccine (PAcA‐ctxB) through fusing A region of cell surface protein PAc (PAcA) coding gene of mutans streptococci with cholera toxin B subunit coding gene (CTB). Afterward, the plasmids were integrated into tomato genomes through agrobacterium‐mediated plant transformation technology. The presence of transgenes in the tomato genome was confirmed by PCR, β‐glucuronidase gene (GUS), and western blot. The expression of genes was confirmed at transcription and protein level. Altogether, the results presented herein showed that transgenic tomatoes may provide a useful system for the production of human caries antigen.

  • Aflatoxin B1 removal by three bacterial strains and optimization of fermentation process parameters
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-09-03
    Mengge Ning; Shujie Zhang; Yanli Xie; Wei Wang; Yajun Gao

    Aflatoxin B1 (AFB1) removing bacterial strains were isolated from different habitats that were easily contaminated by AFB1. Furthermore, the composition of the fermentation medium and conditions of fermentation process were optimized, including carbon source, nitrogen source, metal ions, temperature, initial pH value, inoculation volume, and culture broth volume. Using coumarin as the sole carbon and energy source, we primarily screened 31 strains, and 10 strains were found to be capable to remove AFB1. Among them, the highest removal rate of 71.91% appeared in those isolated from rotten wood (poplar). Strains XY1, XY3, and T6 were carried out to identify, and the results were Klebsiella sp., Klebsiella pneumonia, and Pantoea sp., respectively. Corn cob powder and tryptone can significantly increase the AFB1 removal activity of these strains. The AFB1 removal activity of Klebsiella sp.XY1 and K. pneumonia XY3 can be enhanced by Ca2+, and those of Pantoea sp. T6 can be enhanced by Cu2+. Temperature and initial pH were positively correlated with the AFB1 removal activity of these strains in a certain range. This study not only provides reference for the screening and application of AFB1 removing bacteria, but also provides a basis for possible application in the food and feed industry.

  • Diagnosing ovarian cancer by identifying SCC‐antigen on a multiwalled carbon nanotube‐modified dielectrode sensor
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-09-12
    Ting Liang; Qiuzhi Qu; Yuhua Chang; Subash Chandra Bose Gopinath; Xian Tong Liu

    Ovarian cancer starts in the ovaries in its earlier stages and then spreads to the pelvis, uterus, and abdominal region. The success of an ovarian cancer treatment depends on the stage of the cancer and the diagnostic system. Squamous cell carcinoma antigen (SCC‐Ag) is one of the most efficient cancer biomarkers, and elevated levels of SCC‐Ag in ovarian cancer cells have been used to identify ovarian cancer. Carbon is a potential material for biosensing applications due to its thermal, electrical, and physical properties. Multiwalled carbon nanotubes (MWCNTs) are carbon‐based materials that can be used here to detect SCC‐Ag. Anti‐SCC‐Ag antibody was immobilized on the amine‐modified MWCNT dielectric sensing surface to detect SCC‐Ag. The uniformity of the surface structure was measured with a 3D nanoprofiler, and the results confirmed the detection of SCC‐Ag at ∼80 pM. The specific detection of SCC‐Ag was confirmed with two control proteins (factor IX and human serum albumin), and the system did not show biofouling. This experimental set‐up with MWCNTs a dielectric sensing surface can lead to the detection of ovarian cancer in its initial stages.

  • Electropermeabilization of metastatic chondrosarcoma cells from primary cell culture
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-09-18
    Olga Michel; Piotr Błasiak; Jolanta Saczko; Julita Kulbacka; Małgorzata Drąg‐Zalesińska; Adam Rzechonek

    Primary cell cultures are challenging, but reliable model reflecting tumor response in vitro. The study was designed to examine if the increased electropermeabilization can overcame initial drug insensitivity in chondrosarcoma cells from lung metastasis. We established a primary cell culture and evaluated the cytotoxic impact of four drugs—cisplatin (CDDP), camptothecin, 2‐methoxyestradiol, and leucovorin calcium (LeuCa). After determination of parameters allowing for electropermeabilization, we performed electrochemotherapy in vitro with the least toxic drugs—CDDP and LeuCa. Although combining CDDP and leucovorin together increased their toxicity and supported apoptosis, application of pulsed electric fields (PEFs) brought no advantage for their efficacy. The study emphasizes the need for introduction of primary cell cultures into studies on pulse electric fields as model frequently less sensitive to PEF‐based treatments than continuous cell lines.

  • Calcium ion induced thermodynamic stability, bisubstrate specificity, and differential organic solvent tolerance of a predominantly β‐sheet serine protease from Bacillus aquimaris VITP4
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-09-30
    Chittoor Jabeena Thaz; Gurunathan Jayaraman

    The present study was aimed to get insights on the role of calcium ions on the thermodynamic stability, substrate specificity, and organic solvent compatibility of the extracellular protease produced by Bacillus aquimaris VITP4. Presence of Ca2+enhanced the activity of the enzyme in the temperature range of 30–60 °C and increased the half‐life from 164 to 234 Min. Circular dichroism experiments indicated that the temperature of half‐denaturation (Tm) of the protease increased from 76 to 86 °C. As judged by fluorescence emission profiles, the overall fold of the enzyme around the tryptophan residues could be similar. Further, thermal inactivation experiments revealed that the enzyme followed first order kinetics, with increase in energy for inactivation (Eai) by 24.2 ± 1.2 kJ mol −1 in the presence of Ca2+. Studies with synthetic peptides as well as with bovine serum albumin signified preferential hydrolysis of the peptide bonds at the C‐terminus of alanine residues (with a kcat/KM of 141,400 M−1 Sec−1) and at the C‐terminus of arginine residues with a lower specificity (72,400 M−1 Sec−1), indicating bisubstrate specificity of the enzyme. The enzyme was found to be compatible with organic solvents (50%, v/v) such as acetonitrile and butanol, indicating possible application under demanding nonaqueous conditions.

  • Developing an l‐threonine‐producing strain from wild‐type Escherichia coli by modifying the glucose uptake, glyoxylate shunt, and l‐threonine biosynthetic pathway
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-09-16
    Lifei Zhu; Yu Fang; Zhixiang Ding; Shuyan Zhang; Xiaoyuan Wang

    Wild‐type Escherichia coli MG1655 usually does not accumulate l‐threonine. In this study, the effects of 13 genes related to the glucose uptake, glycolysis, TCA cycle, l‐threonine biosynthesis, or their regulation on l‐threonine accumulation in E. coli MG1655 were investigated. Sixteen E. coli mutant strains were constructed by chromosomal deletion or overexpression of one or more genes of rsd, ptsG, ptsH, ptsI, crr, galP, glk, iclR, and gltA; the plasmid pFW01‐thrA*BC‐rhtC harboring the key genes for l‐threonine biosynthesis and secretion was introduced into these mutants. The analyses on cell growth, glucose consumption, and l‐threonine production of these recombinant strains showed that most of these strains could accumulate l‐threonine, and the highest yield was obtained in WMZ016/pFW01‐thrA*BC‐rhtC. WMZ016 was derived from MG1655 by deleting crr and iclR and enhancing the expression of gltA. WMZ016/pFW01‐thrA*BC‐rhtC could produce 17.98 g/L l‐threonine with a yield of 0.346 g/g glucose, whereas the control strain MG1655/pFW01‐thrA*BC‐rhtC could only produce 0.68 g/L l‐threonine. In addition, WMZ016/pFW01‐thrA*BC‐rhtC could tolerate the high concentration of glucose and produced no detectable by‐products; therefore, it should be an ideal platform strain for further development. The results indicate that manipulating the glucose uptake and TCA cycle could efficiently increase l‐threonine production in E. coli.

  • Phosphorylated abacavir analogue (ABC‐1) has ameliorative action against Newcastle disease virus induced pathogenesis in chicken
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-10-23
    K. A. Suresh; K. C. Venkata Subbaiah; C. Thirunavukkarasu; S. Chennakesavulu; A. Rachamallu; Naga Raju Chamarti; Rajendra Wudayagiri; Lokanatha Valluru

    Newcastle disease virus (NDV) causes huge economic loss to the poultry industry due to high mortality and morbidity. The present study aimed to assess the protective role of novel phosphorylated analogue ABC‐1 in vivo in NDV‐infected chickens through the inhibition of fusion protein. Both NDV‐induced oxidative damage and protective role of novel phosphorylated ABC‐1 were evaluated in vital organs such as the liver and lung of chickens. Enzyme linked immunosorbent assay (ELISA) results showed that protein oxidation and nitration levels were significantly raised in NDV‐infected tissues compared to healthy controls, whereas these levels were reduced significantly (P < 0.05) in birds treated with phosphorylated compounds compared to the NDV‐infected group alone. Additional investigation with double immunofluorescence showed that the large amount of immuno colocalization and Western blot analysis also confirmed this observation through its band pattern in NDV‐infected birds compared to healthy birds, whereas these alterations were reduced in treatment with novel phosphorylated ABC‐1. The expression of fusion glycoprotein was studied by immuno colocalization, PCR, and flow cytometry, and results demonstrated that the novel phosphorylated analogues reduced the expression of fusion glycoprotein. These results put forth that novel phosphorylated ABC‐1 protects chickens from NDV‐induced pathogenesis, protein oxidation/nitration, and exerts potent antiviral activity.

  • Optimization of penicillin G acylase immobilized on glutaraldehyde‐modified titanium dioxide
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-03
    Zhangjun Chen; Zhenbin Chen; Chunli Liu; Xudong Wang; Yongshan Zhou; Runtian Wang

    In this work, TiO2, which was modified by glutaraldehyde, was adopted as the carrier; the penicillin G acylase (PGA) was immobilized and the influence of immobilized conditions, such as pH of solution, the concentration of PGA, the immobilization temperature, and the reaction time, on the catalytic performance of the immobilized PGA was investigated and optimized. During this process, potassium penicillin G (PG) was chosen as substrate, and the quantity of 6‐aminopenicillanic acid (6‐APA) produced by PG at the temperature of 25 °C for 3 Min in neutral solution was conscripted as the evaluation foundation, indexes, containing the loading capacity (ELC), the activity (EA), and activity retention rate (EAR), were calculated based on quantities of produced 6‐APA and compared with finding out the suitable conditions. Results showed that when the solution pH, PGA concentration, immobilization temperature, and reaction time were 8.0, 2.5% (v/v), 35 °C, and 24 H, respectively, ELC, EA, and EAR presented optimal values of 9,190 U, 14,969 U/g, and 88.5% relatedly. After that, the stability and reusability of immobilized PGA were studied, and the results documented that the pH resistance, thermal stability, and storage stability of immobilized PGA were significantly improved. This work provided technique support for the practical application of immobilized PGA carrier.

  • Lutein upregulates the PGC‐1α, NRF1, and TFAM expression by AMPK activation and downregulates ROS to maintain mtDNA integrity and mitochondrial biogenesis in hyperglycemic ARPE‐19 cells and rat retina
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-10-24
    Hemalatha Nanjaiah; Baskaran Vallikannan

    Hyperglycemia (HG) affects cellular organelle including mitochondrion in retina that diminishes mitochondrial biogenesis by downregulation of nuclear transcription factors peroxisome proliferator‐activated receptor‐γ coactivator‐1 (PGC‐1α) and mitochondrial transcription factor A (TFAM). Mitochondrial dysfunction has been linked to diabetic retinopathy (DR). Carotenoids reported to modulate mitochondrial biogenesis in HG. Aim of the study was to explore the role of lutein, oxidized lutein (purified upon UV oxidation of lutein) and drug metformin, on mitochondrial biogenesis in HG‐induced ARPE‐19 cells and rat retina. Results showed higher uptake of lutein and oxidized lutein in ARPE‐19 cells and rat retina of HG group than the control groups. Further, lutein and oxidized lutein augmented the AMPK phosphorylation and activation of mitochondrion signaling molecule TFAM (protein expression) and mRNA expression of PGC‐1α, TFAM, and nuclear respiratory factor 1 (responsible for mitochondria biogenesis) along with lowered reactive oxygen species in HG compared with control and metformin groups. Higher mRNA expression of nicotinamide adenine dinucleotide dehydrogenase subunits mt‐ND1, mt‐ND4, mt‐ND6, and cytochrome C that aid maintenance of mtDNA integrity was also evidenced. To conclude, lutein and oxidized lutein found to upsurge mitochondrial biogenesis in ARPE‐19 cells and rat retina under HG, which may be due to upregulation of AMPK phosphorylation. Finally, lutein and oxidized lutein may provide a therapeutic basis to ameliorate HG‐induced DR.

  • Production and characterization of multifacet exopolysaccharide from an agricultural isolate, Bacillus subtilis
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-10-16
    Bhavana V. Mohite; Sunil H. Koli; Jamatsing D. Rajput; Vikas S. Patil; Tarun Agarwal; Satish V. Patil

    This study aims to explore the fermentative production and physicochemical properties of an exopolysaccharide (EPS) produced from agricultural isolate, Bacillus subtilis S1 in submerged culture. The structural characterization (Ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy, and 13C Nuclear magnetic resonance spectrometry) revealed that the EPS is an acidic heteropolymer consisting of glucose, glucuronic acid, pyruvic acid, and succinic acid. The non‐Newtonian shear thickening nature of EPS with a 1.55 × 107 Da molecular weight is confirmed by rheology analysis. The extracted EPS was 61.3% amorphous with partial crystallinity (38.7%) as confirmed by X‐ray diffraction analysis. The EPS shows two‐step decomposition and thermal stability up to 300 °C as confirmed by thermogravimetric analysis and differential scanning calorimetry analysis. The EPS has a small Z‐average particle size (74.29 nm), high porosity (92.99%), high water holding (92.39%), and absorption capacity (1,198%). The biocompatible nature is confirmed by cytotoxic testing on the human keratinocytes cell line. The demonstrated unique characteristics of Bacillus EPS presents it as a choice of biomaterial for diverse applications.

  • Protective effect of glycyrrhizic acid on cerebral ischemia/reperfusion injury via inhibiting HMGB1‐mediated TLR4/NF‐κB pathway
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-10-10
    Sunhong Yan; Chuanqin Fang; Lei Cao; Long Wang; Jing Du; Yue Sun; Xuanxia Tong; Ying Lu; Xiaosan Wu

    Cerebral ischemia is caused by various disorders, such as stroke, myocardial infarction, or peripheral vascular disease. The purpose of this paper was to investigate the effects of glycyrrhizic acid (GA) on cerebral ischemia/reperfusion (I/R) injury. Middle cerebral artery occlusion was established to evaluate the effects of GA on cerebral ischemia. In this study, our results showed that GA could dramatically decrease cerebral edema, reduce the neurological deficits, and smaller brain infarct volume was found in the GA treatment group. In serum and brain tissue, GA also increased superoxide dismutase activity. In addition, in serum and brain tissue, GA also dramatically inhibited the secretion of inflammatory cytokines, including interleukin‐1β (IL‐1β), IL‐6, and tumor necrosis factor‐α. Moreover, GA inhibited the expressions of high‐mobility group protein box‐1 (HMGB1)‐mediated TLR4/NF‐κB pathway. Our data determined that GA may provide protective effect on the I/R‐induced cerebral ischemia disease.

  • Development of an automated flow‐based spectrophotometric immunoassay for continuous detection of zearalenone
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-08
    Jongjit Jantra; Kinga Zór; Melanie Sanders; Sarah De Saeger; Martin Hedström; Bo Mattiasson
  • 更新日期:2020-01-08
  • Effect of detoxification methods on ABE production from corn stover hydrolysate by Clostridium acetobutylicum CICC 8016
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-06
    Fengqin Wang; Yuheng Dong; Xiang Cheng; Hui Xie; Andong Song; Zhanying Zhang

    In this study, effects of different single biomass‐derived inhibitors on acetone‐butanol‐ethanol (ABE) production by Clostridium acetobutylicum CICC 8016 were firstly investigated. The results showed that formic acid, coumaric acid and furfural at 0.5 g/L (sodium formate equivalent) inhibited ABE production. Furthermore, corn stover hydrolysate media were prepared following dilute acid pretreatment, enzymatic hydrolysis and detoxification with different methods. Among overliming, steam stripping, acetone‐ethyl ether extraction and ion exchange with five anion resins, adsorption with resin D301 showed the highest efficiency for inhibitor removal (99‐100% of phenolics and 87–99% of sugar degradation products). Without detoxification, ABE production were lower than 1.0 g/L from 28.1 g/L sugars while ABE production with medium detoxified by D301 resin achieved higher ABE concentrations and yields than control with synthetic medium. Correlation analysis further revealed that formic acid, coumaric acid and total phenolics were the major compounds inhibiting ABE production. The results also showed that single detoxification method was sufficient to detoxify the hydrolysate for ABE production at the pretreatment conditions used in this study.

  • Expression of ESAT‐6 antigen from Mycobacterium tuberculosis in broccoli: An edible plant
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2020-01-02
    Kiran Saba; Muhammad Sameeullah; Asba Asghar; Johanna Gottschamel; Sara Latif; Andreas Günter Lössl; Bushra Mirza; Osman Mirza; Mohammad Tahir Waheed
  • Establishment of hairy root cultures by Agrobacterium Rhizogenes mediated transformation of Trachyspermum ammi L. for the efficient production of thymol
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-31
    Ramtin Vamenani; Ali Pakdin‐Parizi; Maryam Mortazavi; Zahra Gholami

    Trachyspermum ammi is an important medicinal plant that contains bioactive compound namely thymol. In the study, T. ammi was transformed by Agrobacterium rhizogenes strains. Seedling stem explants were inoculated with A. rhizogenes strains A4, LBA 9402, ATCC 15834 and the effect of different co‐cultivation media along with incorporation of acetosyringone (100µM) were evaluated comparatively on the frequency of hairy root induction. Polymerase chain reaction (PCR) using rolB and virD specific primers were served to confirm the transformed root. All strains established hairy root with various frequency among which strain ATCC 15834 was significantly the most efficient strain for hairy root induction (84.3%). Half strength B5 medium and incorporation of acetosiryngone (100µM) were also significantly optimal for hairy root induction. Hairy roots culture induced by ATCC 15834 using half strength B5 liquid medium supplemented with 30 g/l sucrose indicated the highest accumulation of biomass (99.05 g/l FW and 10.95 g/l DW) and thymol content (11.30 mg g−1 DM) at 20 days. Nearly 4.9‐fold and 5.3‐fold increment of biomass and thymol acumulation was observed respectively at 20 days in comparison with the untransformed control roots. The current results showed the potential of hairy root cultures for the biosynthesis of thymol for the first time.

  • Modulation of the competition between renaturation and aggregation of lysozyme by additive mixtures
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-29
    Zeinab Takalloo; Forouzan Niknaddaf; S. Shirin Shahangian; Akbar Heydari; Saman Hosseinkhani; Reza H. Sajedi
  • Improvement of R‐2‐(4‐hydroxyphenoxy) propionic acid biosynthesis of Beauveria bassiana by combined mutagenesis
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-29
    Hai‐Feng Hu; Hai‐Yan Zhou; Gao‐Ping Cheng; Ya‐Ping Xue; Yuan‐Shan Wang; Yu‐Guo Zheng
  • Synergetic engineering of central carbon and nitrogen metabolism for the production of N‐acetylglucosamine in Bacillus subtilis
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-29
    Tengfei Niu; Xueqin Lv; Zhenmin Liu; Jianghua Li; Guocheng Du; Long Liu
  • 更新日期:2019-12-30
  • Optimized production of Poly γ‐glutamic acid (γ‐PGA) using Bacillus licheniformis and its application as cryoprotectant for probiotics
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-27
    Janifer Raj Xavier; Mrithula Mahalakshmi Madhankumar; Gopalan Natarajan; Karna Venkata Ramana; Anil Dutt Semwal

    Bacteria produce Poly γ‐glutamic acid (γ‐PGA), a polymer of L or D ‐ glutamic acid as a defense response and have gained importance due to their applications in food and pharmaceutical industry. In the present investigation, production of γ‐PGA using cost effective carbon substrate, characterization of the produced polymer and its application as cryoprotectant for selected freeze dried probiotic bacteria were investigated. Central composite rotatable design of response surface methodology (RSM) was used to study the main and the interactive effects of medium components: rice bran and casein peptone concentration. Rice bran at 35 percent (w/v) and casein peptone at 7.5 percent (w/v) were found to be optimal at an initial pH of 7.5 and incubation temperature of 37°C for 48 h produced 8.2 g/L γ‐PGA on dry weight basis. The thermal properties such as melting temperature, heat of fusion and thermal stability were also studied. 10 percent (w/v) of γ‐PGA with 10 percent of sodium alginate (w/v) protected viability of Bifidiobacterium bifidum NCDC 235, B. adolescentis NCDC 236 during freeze drying at ‐80˚C for 48 h. The γ‐PGA synthesized by the reported bacterium with GRAS status is suitable for food and biomedical applications.

  • EZH2 enhances expression of CCL5 to promote recruitment of macrophages and invasion in lung cancer
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-19
    Lilong Xia; Xinhai Zhu; Lei Zhang; Yanhui Xu; Guoping Chen; Jing Luo

    EZH2 (Enhancer of zeste homolog 2) regulates epigenetic gene silencing and functions as critical regulators in various tumor progression. Macrophages infiltration promotes cancer development via stimulating tumor cell migration and invasion. However, the effect of EZH2 on macrophages infiltration, cell invasion and migration of lung cancer remains to be investigated. In this study, we found that knockdown of EZH2 inhibited macrophages chemotaxis and decreased chemokine ligand 5 (CCL5). Wound‐healing and transwell assays results showed that migration and invasion of lung cancer cells was inhibited by EZH2 deletion. Moreover, EZH2 over‐expression increased CCL5 expression. Loss‐of functional assay indicated that the promotion ability of EZH2 on macrophages chemotaxis was inhibited by CCL5 knockdown. Mechanistically, the promotion ability of EZH2 on cell migration and invasion of lung cancer was also inhibited by CCL5 knockdown. In vivo subcutaneous xenotransplanted tumor model also revealed that silence of EZH2 suppressed lung cancer metastasis and macrophages infiltration via regulation of CCL5. In conclusion, our findings indicated that EZH2 promoted lung cancer metastasis and macrophages infiltration via up‐regulation of CCL5, which might be the underlying mechanism of EZH2‐induced lung cancer cell progression.

  • Icariin alleviates hypoxia‐induced damage in MC3T3‐E1 cells by down‐regulating TALNEC2
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-17
    Weiguo Wang; Jian Xin; Wenming Chen; Lizhong Jing; Peng Zhang

    Osteonecrosis is a harmful musculoskeletal disease. We aims to detect the effects of Icariin (ICA) in MC3T3‐E1 cell.

  • In vivo formation of spherical and rod lead nanoparticles in root cells of water velvet (Azolla pinnata)
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-10
    Jiraporn Chumpol, Sineenat Siri

    Several plant species survive in the metal‐contaminated environment by minimization of detrimental effects of metal exposure and cellular accumulation, but little is known about their capability to transform the uptake metal ions into nanoparticles, especially in non‐spherical shapes. This work firstly reported the in vivo formation of spherical and rod‐shaped lead nanoparticles (PbNPs) from the uptake lead ions in root cells of water velvet (Azolla pinnata). The energy dispersive X‐ray fluorescence analysis revealed the high level of lead (67.21 ± 0.70%) and the modulated levels of sulfur, potassium, and calcium in the treated roots. Fourier transform infrared spectroscopy spectral analysis suggested the changes of biochemical constituents in Pb‐treated roots, including carbohydrates, organic compounds, proteins, and nucleic acids. Transmission electron microscope (TEM) images revealed the formation of spherical, short rod, and long rod PbNPs dominantly in epidermal, cortical, and vascular cells in the plant roots, respectively. The analyses of energy‐dispersive X‐ray spectroscopy, high resolution TEM, and selected area diffraction TEM indicated the body‐centered tetragonal lattice of PbONPs in the root cells.

  • The antioxidant 2,3‐dichloro,5,8‐dihydroxy,1,4‐naphthoquinone inhibits acetyl‐cholinesterase activity and amyloid β42 aggregation: A dual target therapeutic candidate compound for the treatment of Alzheimer's disease
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-09
    Imen Khelifi, Audrey Tourrette, Zohra Dhouafli, Jalloul Bouajilaj, Thomas Efferth, Sara Abdelfatah, Riadh Ksouri, El Akrem Hayouni

    Alzheimer's disease is characterized by amyloid β aggregation and cholinergic neurodegeneration. In the present study, pure DDN (2,3‐dichloro‐5,8‐dihydroxy‐1,4‐naphthoquinone) was examined, for the first time, for its dual potential as inhibitor of acetylcholinesterase (AChE) and Aβ42 aggregation. Such investigation was encouraged by the in vitro high antioxidant potential of DDN. Indeed, it revealed interesting antioxidant activity with IC50 values of 9.8 and 4.3 µM for ABTS and reducing power, respectively.

  • Metabolic engineering strategies for consolidated production of lactic acid from lignocellulosic biomass
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-08
    Roberto Mazzoli

    Lactic acid (LA) is one the most requested molecules by the chemical industry. Current expansion of LA market is mainly driven by its application as building block for the synthesis of polylactide (PLA), i.e. a family of biodegradable and biocompatible plastic polymers. PLA can potentially replace oil‐derived polymers as general purpose plastic, but current LA price makes PLA not cost‐competitive with traditional plastics. Nowadays, LA is mainly produced by fermentation of expensive starchy biomass. Hopefully, cheaper lignocellulosic feedstock could be used in future 2nd generation biorefinery processes. However, most efficient natural LA producers cannot ferment lignocellulose without prior biomass saccharification. Metabolic engineering may develop improved microorganisms that feature both efficient biomass hydrolysis and LA production, thus supporting consolidated bioprocessing (CBP), that is one‐pot fermentation, of lignocellulose to LA. CBP could dramatically reduce LA production cost thus contributing to the expansion of more environmental sustainable plastics and commodity chemicals. The present review presents an overview of “recombinant cellulolytic strategies”, mainly consisting in introducing cellulase systems in native producers of LA, and “native cellulolytic strategies” aimed at improving LA production in natural cellulolytic microorganisms. Issues and perspectives of these approaches will be discussed.

  • Glucose‐methanol based fed batch fermentation for the production of recombinant human interferon gamma (rhIFN‐γ) and evaluation of its antitumor potential
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-06
    Ashish A Prabhu, Jadi Praveen Kumar, Biman B. Mandal, Venkata Dasu Veeranki

    Squamous cell carcinoma (SCC) is non‐melanoma skin cancer, which is very common in patients having T‐cell immunosuppressant drugs. Anti‐cancerous agents such as cytokines shown effective response on SCC. Human interferon‐gamma (hIFN‐γ) a type II cytokines are having potent antiproliferative, and immunomodulatory effects. In the current study, the fed‐batch cultivation of recombinant Pichia pastoris was carried out, and its effect on cell biomass production, recombinant human interferon‐gamma (rhIFN‐γ) production, and the overflow metabolites was estimated. Pichia pastoris GS115 strain co‐expressed with 6‐phosphogluconolactonase (SOL3) and ribulose‐phosphate 3‐epimerase (RPE1) gene (GS115/rhIFN‐γ/SR) resulted in 60 mg L−1 of rhIFN‐γ production which was two‐fold higher as compared to the production from GS115/rhIFN‐γ strain. The anti‐proliferative potential of rhIFN‐γ was examined on the human squamous carcinoma (A431) cell lines. Cells treated with 80 ng mL−1 of rhIFN‐γ exhibited 50% growth inhibition by enhancing the production of intracellular reactive oxygen species (ROS) levels and disrupting membrane integrity. Our findings highlight a state of art process development strategy for the high‐level production of rhIFN‐γ and its potential application as a therapeutic drug in squamous cell carcinoma therapy.

  • Epigallocatechin 3‐gallate attenuates arthritis by regulating Nrf2, HO‐1, and cytokine levels in an experimental arthritis model
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-05
    Ahmet Karatas, Adile Ferda Dagli, Cemal Orhan, Hasan Gencoglu, Metin Ozgen, Nurhan Sahin, Kazim Sahin, Suleyman Serdar Koca
  • Acaciain peptidase: The first South American pollen peptidase potentially involved in respiratory allergy
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-03
    Cristina Barcia, Ana Sofia Coelho, Sonia Barberis, Paula Veríssimo
  • Biochemical characterization of an organic solvent‐tolerant glycosyltransferase from Bacillus licheniformis PI15 with potential application for raspberry ketone glycoside production
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-03
    Bingfeng Li, Bo Fan, Jingping Fan, Siyuan Chang, Xin Pan, Yinan Wang, Yaming Wu, Junsong Song, Xuejun He
  • MicroRNA‐144 relieves chronic constriction injury‐induced neuropathic pain via targeting RASA1
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-12-03
    Xianjie Zhang, Hongli Guo, An Xie, Ou Liao, Feng Ju, YuKai Zhou
  • 更新日期:2019-12-04
  • Metabolic flux analysis of Saccharomyces cerevisiae during redox potential‐controlled very‐high‐gravity ethanol fermentation
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-30
    Yishuang Zhang, Yen‐Han Lin

    A previously published genome‐scale metabolic model namely iFF708 was modified to depict the metabolic flux distribution within Saccharomyces cerevisiae grown under redox potential‐controlled very‐high‐gravity condition. The following modifications were made: electron transport chain (ETC) and oxidative phosphorylation, proton gradient and ATP transportation, and malate‐aspartate shuttle. With these modifications, this model could describe the experimental data collected from the above‐mentioned ethanol fermentation. As a result, the simulation unveiled that P/O ratio is critical under micro‐aerobic conditions and the malate‐aspartate shuttle is inactivated due to the shortage of electron transport across mitochondria. In other words, the limited supply of oxygen supresses the functionality of oxidative phosphorylation, TCA cycle and ETC. In terms of glycolytic pathway, fluxes coming from glucose‐6‐phosphate and pyruvate nodes are insensitive to the changes of fermentation redox potential. As initial glucose concentration is greater than 250 g/L, the interactive effect between initial glucose concentration and redox potential level becomes noticeable.

  • Liposoluble compounds from Ganoderma lipsiense grown on solid red rice medium with antiparasitic and antibacterial properties
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-27
    Tania Maria Costa, Juliana Lenzi, Camila Jeriani Paganelli, Hercílio Higino da Silva Filho, Michele Debiasi Alberton, Lorena Benathar Ballod Tavares, Débora de Oliveira
  • Production of polyhydroxyalkanoates by halotolerant bacteria with volatile fatty acids from food waste as carbon source
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-27
    Pan Wang, Xi Teng Chen, Yin Quan Qiu, Xiao Fei Liang, Meng Meng Cheng, Yong Jing Wang, Lian Hai Ren
  • Effect of phenolic compounds from the rind of Punica granatum on the Activity of three metabolism‐related enzymes
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-25
    Farid A. Badria, Mohamed H. Ahmed, Hala M. Aldesouki

    Enzyme activity modulation by synthetic compounds provide strategies combining the inhibitory and therapeutic mode of action of the confirmed inhibitors. However, natural modulators could offer a valuable alternative for synthetic ones for the treatment of different chronic diseases (diabetes, hypertension, cancer); due to the numerous side effects of the latter. In vitro screening assays were conducted for Punica granatum rind methanolic extract against three metabolism‐related enzymes; α‐amylase, tyrosinase and hyaluronidase. The obtained results showed that the examined extract retained high multi‐target inhibition with inhibition percentages 31.5±1.3%, 75.9±4.7%, 68.5±5.3% against α‐amylase, tyrosinase and hyaluronidase, respectively. Bio‐guided fractionation of P. granatum rind extract revealed that quercetin is the major active compound with inhibitory activities; 54.3±2.7%, 94.2±3.5%, 90.9±2.7% against α‐amylase, tyrosinase and hyaluronidase, respectively. Kinetic studies of showed that quercetin inhibition was non‐competitive, un‐competitive and competitive for α‐amylase, tyrosinase and hyaluronidase, respectively. The molecular docking of quercetin with α‐amylase and hyaluronidase showed high binding energy with different bonds stabilizing the ligand‐protein complex. Compiling all obtained results led to conclude that both P. granatum rind extract and quercetin have multi‐target activities with potential therapeutic applications in many metabolic disorders.

  • Biobutanol production from sugarcane bagasse by Clostridium beijerinckii strains
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-23
    Saraswathi Narayanasamy, Kit Lun Chan, Hui Cai, Ahmad Hilman Bin Abdul Razak, Boon Keat Tay, Huang Miao

    Acetone‐butanol‐ethanol (ABE) fermentation was performed with sugarcane bagasse hydrolysate using Clostridium beijerinckii strains. A cost‐effective sugarcane bagasse medium (SCB medium) was developed with no enzymatic hydrolysis and no supplementation of extra carbon source or expensive nitrogen source. One of the Clostridium beijerinckii strains studied was able to produce butanol with butanol productivity of 1.23 g/L/d with butanol yield of 0.18 g/g of sugars from the developed medium. High utilization rate of both glucose and xylose was observed in SCB medium during ABE fermentation. This study shows that sugarcane bagasse is a promising substrate for cellulosic biobutanol production.

  • Systemic lupus erythematosus: possible localization of trypsin‐like and metalloprotease active centers in the protein sequence of the monoclonal light chain (NGTA2‐Me‐pro‐Tr)
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-20
    Anna M. Timofeeva, Georgy A. Nevinsky

    It was previously shown that several monoclonal light chains (MLChs) corresponding to the phagemid library of recombinant peripheral blood lymphocyte immunoglobulin light chains of patients with systemic lupus erythematosus (SLE) specifically hydrolyze only myelin basic protein (MBP). Canonical enzymes usually have only one active site catalyzing some kind of chemical reaction. It was shown previously that in contrast to classical enzymes, preparations of one of the light chains (NGTA2‐Me‐pro‐Tr) showed two optimal pH values, two optimal concentrations of metal ions and two Km values for MBP. One protease active site of NGTA2‐Me‐pro‐Tr was trypsin‐like, while second one is metal‐dependent. In this article a search for protein sequences of NGTA2‐Me‐pro‐Tr responsible for catalytic functions was carried out. We performed for the first time, analysis of the homology of the protein sequence of NGTA2‐Me‐pro‐Tr with those of several classical Zn2+‐ and Ca2+‐dependent, as well as human serine proteases. The analysis allowed us to identify the protein sequences of NGTA2‐Me‐pro‐Tr responsible for serine‐like activity, the binding of MBP, chelation of metal ions and catalysis directly. The data obtained are summarized using hypothetical models of the structure of the two active centers of a very unusual light chain of antibodies. The findings obtained may be very important for understanding possible structure of active centers of very unusual light chain of antibodies possessing several enzymatic activities.

  • Optimization, kinetics and radioprotective potential of a heteropolysaccharide from L. rhamnosus RVPI
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-20
    Anushri Umesh, Pradeepa, Anushree Manjunath, Chithralekha Salian, Manasadeepika, Manu Suvarna, Vidya Shimoga Muddappa

    The probiotic potential of Lactobacillus rhamnosus RVP1 isolated from Sardinella longiceps was investigated in vitro. The bacterium exhibited highest tolerance at low pH, high bile salt concentration and demonstrated good antioxidant activity, hydrophobicity and inhibited both gram‐negative and gram‐positive indicator bacteria. To aid in process design and to unravel the fermentation kinetics, response surface methodology was devised to optimize the EPS production from L. rhamnosus and mechanistic models were developed to describe the fermentation kinetics. The optimum pH, dextrose and peptone concentrations for EPS production were 7.07, 19.995 g/L and 23.4 g/L, respectively, with a predicted yield of 724 mg/L. The actual yield under these conditions was 708±29 mg/L which was within the 95% confidence interval. The simulated mechanistic model fit the experimental values with a high degree of correlation with R2 = 0.99, 0.96 and 0.97 for the logistic growth, substrate consumption and EPS production and degradation curves respectively. The kinetic constants μ_max = 0.29 hr−1, Xmax = 3.44 g/L, kf = 348 mg of EPS/ g of dry biomass and kd = 0.53 hr−1 were derived from the model. The EPS administration improved the survival of irradiated mice by 50% proving it radioprotective potential and showed positive effects on structural integrity of intestinal tissue.

  • One‐pot lipase‐catalyzed esterification of ε‐caprolactone with methyl‐D‐glucopyranoside and its elongation with free 6‐hydroxyhexanoate monomer units
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-19
    Muhammad Naziz Saat, Mohamad Suffian Mohamad Annuar

    One‐pot synthesis of sugar functionalized oligomeric caprolactone was carried out by lipase‐catalyzed esterification of ε‐caprolactone (ECL) with methyl‐D‐glucopyranoside (MGP) followed by the elongation of functionalized oligomer chain. Functionalization was performed in a custom‐fabricated glass reactor equipped with Rushton turbine impeller and controlled temperature at 60°C using tert‐butanol as reaction medium. The overall reaction steps include MGP esterification of ECL monomer and its subsequent elongation by free 6‐hydroxyhexanoate monomer units. A ping‐pong bi‐bi mechanism without ternary complex was proposed for esterification of ECL and MGP with apparent values of kinetic constant namely maximal velocity (Vmax), Michaelis constant for MGP (KmMGP) and Michaelis constant for ECL (KmECL) at 3.848 × 10−3 M h−1, 8.189 × 10−2 M and 6.050 M, respectively. Chain propagation step of MGP‐functionalized ECL oligomer exhibits the properties of living polymerization mechanism. Linear relationship between conversion (%) and number average molecular weight, Mn (g mol−1) of functionalized oligomer was observed. Synthesized functionalized oligomer showed narrow range of molecular weight from 1,400 to 1,600 g mol−1 with more than 90 % conversion achieved. Structural analysis confirmed the presence of covalent bond between the hydroxyl group in MGP with carboxyl end group of ECL oligomer.

  • HMGA2 gene polymorphisms and Wilms tumor susceptibility in Chinese children: a four‐center case‐control study
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-19
    Jiwen Cheng, Zhenjian Zhuo, Liu Yang, Pu Zhao, Jiao Zhang, Haixia Zhou, Jing He, Peng Li

    Wilms tumor is a kidney malignancy that typically occurs in children. Aberrant expression of HMGA2 gene is commonly seen in many malignant tumors. Yet, HMGA2 gene polymorphisms on Wilms tumor risk is not established. We carried out the first four‐center case‐control study with 355 patients and 1070 controls to assess the association of HMGA2 polymorphisms (rs6581658 A>G, rs8756 A>C, and rs968697 T>C) with Wilms tumor risk. All of these three polymorphisms in single could not impact Wilms tumor risk. Stratified analysis revealed a contributing Wilms tumor risk role of rs968697 TC/CC in subgroup of male [TC/CC vs. TT: adjusted odds ratio (OR) = 1.46, 95% confidence interval (CI) = 1.03‐2.08, P = 0.035]. However, we found that presence of 1–3 protective genotypes were less likely to develop tumor in subgroup of female (adjusted OR = 0.69, 95% CI = 0.48‐0.99, P = 0.045). Our findings suggest that HMGA2 gene polymorphisms might influence Wilms tumor predisposition in a weak manner, under certain circumstances. The current study represents the first one to explore the relationship between HMGA2 gene polymorphisms and Wilms tumor risk. We firstly demonstrated that rs6581658 A>G, rs8756 A>C, and rs968697 T>C could not impact Wilms tumor risk, respectively. We shed light on the participation of HMGA2 gene polymorphisms in the risk of Wilms tumor, under certain circumstances.

  • Biochar reduces nutrient loss and improves microbial biomass of composted cattle manure and maize straw
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-19
    Ayodeji Bello, Liting Deng, Siyuan Sheng, Xin Jiang, Wei Yang, Qingxin Meng, Xiaotong Wu, Yue Han, Haifeng Zhu, Xiuhong Xu

    In this study, nutrient loss, the direct and indirect relationship between period, compost types, temperature, total nitrogen (TN), nitrate nitrogen (NO3−‐N), ammonia nitrogen (NH4+‐N), microbial biomass carbon (MBC) and nitrogen (MBN) were investigated during composting of cattle manure‐maize straw mixture. This study findings revealed that biochar addition lowered NH4+‐N but did not increase NO3−‐N concentrations unlike no biochar piles during composting. The first‐order kinetic models showed that biochar accelerated organic matter (OM) degradation, improved N mineralization, consequently reducing TN losses by 13.6% and OM losses by 12.66%. Transformation ratio of MBC/MBN, coupled with other chemical components of the entire microbial community suggested a shift in the microbial succession and diversity during composting from the dominant bacteria and actinomycetes to fungi. The Structural equation model and path coefficient revealed temperature to be the main factor mediating the evolution of MBC and MBN in composting. The physicochemical variables, phytotoxicity and final product quality revealed that biochar incorporation to the composting feedstock is an ideal material for mitigating problems of TN and OM losses in composting and ultimately enhancing the fertility potential of the final compost product.

  • Viral IL‐10 promotes cell proliferation and cell cycle progression via JAK2/STAT3 signaling pathway in nasopharyngeal carcinoma cells
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-18
    Yanxin Ren, Jie Yang, Mei Li, Ning Huang, Yun Chen, Xifang Wu, Xiaoli Wang, Shun Qiu, Hu Wang, Xiaojiang Li

    Epstein Barr Virus (EBV) is positively related to the morbidity of nasopharyngeal carcinoma (NPC) in Asia. After infection, EBV can produce several proteins, including viral interleukin‐10 (vIL‐10). But the mechanism by which vIL‐10 contributes to NPC cell proliferation and cell cycle progression is not well understood. In this study, EBV negative and positive cell lines, and the JAK2/STAT3 signal pathway inhibitor AG490 were used to illustrate the role of vIL‐10 in NPC. Cell proliferation and cell cycle were measured by CCK‐8 and flow cytometry. The expression levels of related protein were measured by western blotting. High concentrations of vIL‐10 and IL‐6 were found in the EBV positive patients. The expression level of IL‐6 was positively related to the presence of concentration of vIL‐10. vIL‐10 can promote cancer cell proliferation and G1 to S phase transmission via up‐regulating the IL‐6 protein level by activating the JAK2/STAT3 signal pathway. Furthermore, EBV can induce the formation of cytotoxic T cells whereas vIL‐10 can block the function of cytotoxic T cells. Taken together, these results suggest that vIL‐10 promotes cell proliferation and cell cycle progression via JAK2/STAT3 signaling pathway in NPC.

  • Insights on the current status and advancement of diabetes mellitus type 2 and to avert complications ‐ An overview
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-17
    Ill‐Min Chung, Govindasamy Rajakumar, Umadevi Subramanian, Baskar Venkidasamy, Venkatesan Gopiesh Khanna, Muthu Thiruvengadam

    Type 2 diabetes mellitus type 2 (T2DM) is an endocrine metabolic disorder, occurring worldwide due to aging, advancement in lifestyle by modernization. T2DM is characterized by higher levels of glucose in the blood due to unresponsive secretion of pancreatic insulin and insulin activity or altogether. T2DM, regarded as a powerful genetic susceptible disease that leads to high risk with insulin resistance and β‐cell dysfunction. To manage and overcome type 2 diabetes, physical activity, diet strategies, and other therapeutic medications along with usage of anti‐glycemic agents are developed and attempted appropriate. In the present review, attention has been focused on the understanding of T2DM outcomes, complications with possible management strategies, and pathophysiology of T2DM. Further, a detailed note on anti‐glycemic agents in use, and other possible drugs of choice was discussed in the light of current preventive strategies are presented in this review.

  • Ultrasonic extraction, structural characterization, and bioactivities of nonstarch polysaccharides from red yeast rice
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-14
    Jia Luo, Qiang Sun, Zubing Ma, Jiawen Song, Chunjie Wu, Xiaofang Li
  • 更新日期:2019-11-14
  • Analysis of predicted amino acid biosynthesis in Rv3344c in Mycobacterium tuberculosis H37Rv using bioinformatics tools
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-14
    Khyati Joshi, Swati Meena, Laxman S. Meena

    According to World Health Organization (WHO) report, Mycobacterium tuberculosis H37Rv (M. tuberculosis) affects one‐third population of the world. Emergence of effective treatment/research against this disease is need of the hour. Therefore, we present some important aspects of Rv3344c, which is a PE_PGRS protein. Evidence shows that PE_PGRS proteins show fibronectin binding activity. This protein has affinity for calcium and also shows motifs of GTP‐binding protein. It also shows the presence of sites for ribose‐5‐phosphate binding and motifs of aspartate‐beta‐semialdehyde dehydrogenase, both of which are involved in amino acid biosynthesis. Thus, this protein might be targeted to block the amino acid biosynthesis in M. tuberculosis. This article takes into consideration some important aspects of Rv3344c protein as its function is still unknown. This study includes retrieval of protein sequence database, multiple sequence alignment, protein–protein interaction, epitope prediction, localization, function prediction, phosphorylation site prediction, model building and its validation, ligand‐binding prediction along with mutational analysis. Hence, this study might be an important step in the development of new drugs and treatment of tuberculosis.

  • Expression and purification of soluble and functional fusion protein DAB389IL‐2 into the E. coli strain Rosetta‐gami (DE3)
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-14
    Nasrin Zarkar, Mohammad Ali Nasiri Khalili, Sirus Khodadadi, Mehdi Zeinoddini, Fathollah Ahmadpour

    DAB389IL‐2 (Denileukin diftitox) is considered an immunotoxin, and it is the first immunotoxin approved by Food and Drug Administration. It is used for the treatment of a cutaneous form of T‐cell lymphoma. This fusion protein has two disulfide bonds in its structure that play an essential role in toxicity and functionality of the immunotoxin. Escherichia coli (E. coli) strain BL21 (DE3) is not capable of making disulfide bonds in its reductive cytoplasm, but the E. coli strain Rosetta‐gami (DE3) is a proper strain for the correct expression of the protein due to mutations in glutaredoxin reductase and thioredoxin reductase. In this study, a pET21a vector with the His6‐tag fused at the N‐terminus of DAB389IL‐2 was used to express the soluble immunotoxin in E. coli Rosetta‐gami (DE3). After the purification of the soluble protein by two‐step column chromatographies, the structure of DAB389IL‐2 was analyzed using the Native‐PAGE and circular dichroism methods. In the following, the nuclease activity of soluble DAB389IL‐2 and its cytotoxicity activity were determined. It is concluded that the soluble recombinant protein expressed in the E. coli Rosetta‐gami (DE3) has an intact structure and also functional; hence, this form of immunotoxin could be competitive with its commercial counterparts.

  • Reconstruction and analysis of a three‐compartment genome‐scale metabolic model for Pseudomonas fluorescens
    Biotechnol. Appl. Bioc. (IF 1.559) Pub Date : 2019-11-13
    Xiaoyan Huang, Yen‐Han Lin

    With the versatile metabolic diversity, Pseudomonas fluorescens is a potential candidate in petroleum aromatic hydrocarbon (PAH) bioremediation. Genome‐scale metabolic model (GSMM) can provide systematic information to guide the development of metabolic engineering strategy to improve microbial activity. In this study, the first GSMM for P. fluorescens SBW25 was reconstructed, termed lCW1057. The reconstruction was based on automatic reannotation and manual curation. The periplasmic compartment was constructed to better represent the proton gradient profile. The reconstructed proton transport chain has a P/O ratio at 11/8. Flux balance analysis (FBA) was performed to explore the whole‐cell metabolic flow. The model suggested that instead of EMP pathway, ED pathway was used in glycolytic metabolism of P. fluorescens, indicating that the growth of P. fluorescens is more energy dependent. Furthermore, P. fluorescens can use nitrate as the terminal electron acceptor for the glucose metabolism. The β‐ketoadipate pathway was involved in catechol metabolism. The uptake of oxygen is mandatory for the aromatic ring cleavage. The in silico and in vitro maximum specific growth rate was compared, resulting in 10 % difference when catechol was used as the sole carbon source.

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上海纽约大学William Glover