当前期刊: Biochemical Engineering Journal Go to current issue    加入关注   
显示样式:        排序: 导出
我的关注
我的收藏
您暂时未登录!
登录
  • The biosynthesis of cadmium selenide quantum dots by Rhodotorula mucilaginosa PA-1 for photocatalysis
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-15
    Kai Cao; Miao-Miao Chen; Fang-Yuan Chang; Yuan-Yuan Cheng; Li-Jiao Tian; Fei Li; Guo-Zhi Deng; Chao Wu
    更新日期:2020-01-15
  • A genomic integration platform for heterologous cargo encapsulation in 1,2-propanediol utilization bacterial microcompartments
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-14
    Taylor M. Nichols; Nolan W. Kennedy; Danielle Tullman-Ercek
    更新日期:2020-01-15
  • Identifying prokaryotes and eukaryotes disintegrated by a high-pressure jet device for excess activated sludge reduction
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-14
    Hiroyuki Yoshino; Tomoyuki Hori; Masaaki Hosomi; Akihiko Terada
    更新日期:2020-01-14
  • A Dynamic EFM-Based Model for Antibody Producing Cell Lines and Model Based Evaluation of Fed-Batch Processes
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-13
    Denizhan Yilmaz; Satish J. Parulekar; Ali Cinar

    Based on elementary flux mode (EFM) analysis, a novel approach is presented for monoclonal antibody (MAb) production by GS-CHO cells. A kinetic model is developed on the basis of a set of macro-reactions, which can predict the time-dependent concentrations of metabolites, cell growth, and MAb productivity over a range of culture conditions. The model incorporates energy metabolism with biomass and MAb formation, with the specific ATP production rate being decided by the central carbon metabolism and used for estimation of biomass and MAb synthesis rates. The reaction rate expressions are represented by Michaelis-Menten kinetics based on extracellular metabolite concentrations, which determine ATP production by glycolysis and respiratory chain. Glutamine and asparagine are considered as regulatory metabolites for GS-CHO cells. Glutamine determines asparagine utilization route and energetic state of cells, while asparagine regulates the uptake rates of aspartate and glutamate. The model was calibrated for glutamine-free and glutamine-available cases and validated for fed-batch cultures supplied with glutamine. Unoptimized fed-batch cultures have been simulated for daily and constant feeding. The model predictions are in good agreement with the experimental data reported in literature.

    更新日期:2020-01-14
  • 更新日期:2020-01-09
  • Forced aeration promotes high production and productivity of infective conidia from Metarhizium robertsii in solid-state fermentation
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-08
    Fernando Méndez-González; Octavio Loera; Gerardo Saucedo-Castañeda; Ernesto Favela-Torres
    更新日期:2020-01-08
  • Integration of metabolomic and transcriptomic profiles of hiPSCs-derived hepatocytes in a microfluidic environment
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-07
    Mathieu Danoy; Stephane Poulain; Rachid Jelalli; Francoise Gilard; Sachi Kato; Charles Plessy; Taketomo Kido; Atsushi Miyajima; Yasuyuki Sakai; Eric Leclerc

    The differentiation of human induced pluripotent stem cells (hiPSCs) into functional hepatocytes has the potential to solve the shortage of human primary liver cells and would be of use in drug screening. In this frame, we developed a hiPSCs maturation strategy in microfluidic biochips, using a liver-on-chip approach, a promising technology mimicking in vivo physiology. Hepato-like tissues differentiated in biochips presented advanced liver features, including ALB and CYP3A4 expressing cells. The metabolomics and transcriptomics profiles of hepato-likes cells differentiated either in biochips or Petri dishes were integrated to compare their functionalities. The multi-omics analysis revealed 41 metabolites and 302 genes differentially expressed. Overall, biochip environment lead to higher degree of hepatic differentiation demonstrated by an increase in the metabolic production of lipids, fatty acids and biliary acids, which was confirmed at the transcriptome level by the modulation of expression for genes involved in related signaling pathways. This observation was correlated with higher production of fructose in biochips, together with down-regulation of genes engaged in glycolysis. In parallel, increased activity of the Krebs cycle, pentose phosphate shuttle, and fatty acid beta oxidation was observed in tissues cultured in Petri. Besides, the modulation of nitrogen metabolism was observed in transcriptomic data and confirmed by an intense production of glutamine, putrescine and creatinine and by the higher consumption of spermidine measured in Petri.

    更新日期:2020-01-07
  • Lycopene Production from Glucose, Fatty acid and Waste Cooking Oil by Metabolically Engineered Escherichia coli
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-07
    Na Liu; Bo Liu; Gaoyan Wang; Ya-Hue Valerie Soong; Yong Tao; Weifeng Liu; Dongming Xie
    更新日期:2020-01-07
  • 更新日期:2020-01-07
  • The optimization on distributions of flow field and suspended solids in a full-scale high-rate clarifier using computational fluid dynamics
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-07
    Qi Xu; Keke Xiao; Qiongxiang Wu; Hui Wang; Sha Liang; Wenbo Yu; Shuangyi Tao; Huijie Hou; Bingchuan Liu; Jingping Hu; Jiakuan Yang
    更新日期:2020-01-07
  • Engineering of supramolecular nanoreactors by assembly of multiple enzymes for ATP regeneration in vitro
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-03
    Xing Zhang; Xiangwei Cui; Su Shen; Zhimin Li

    The assembly of multiple enzymes has received increasing attention due to the promising application in improving biocatalytic process. In this study, supramolecular nanoreactors were engineered by assembly of polyphosphate kinase (PPK) and bifunctional glutathione synthetase (GshF) for adenosine triphosphate (ATP) regeneration in vitro. Tetrameric PPK and dimeric GshF were first self-assembled via peptide-peptide interaction of fused leucine zipper domains to form multienzyme complexes (MECs) with plate-like morphology. Further, under the driving force of polymerization of PPK driven by substrate polyphosphate (polyP), MECs were assembled into multienzyme nanoreactors (MENRs) with branch-like morphology. MENRs were applied to a two-enzyme cascade reaction in vitro. The ATP regeneration efficiency of MENRs system was 57% higher than that of unassembled enzymes mixture, and the thermal stability was improved by 46%. When reused for ATP regeneration, the assemblies retained more than 70% of the initial activity even after seven cycles. This is the first report in which an artificial complex was constructed by substrate-driven assembly of multiple enzymes for cascade reaction. The strategy demonstrated potential application of multienzyme assembly in synthetic biotechnology and nanotechnology.

    更新日期:2020-01-04
  • Fermentative Oxidation of Butane in Bubble Column Reactors
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-03
    G. Sluyter; J. Kleber; F. Perz; B. Grund; S. Leuchs; S. Sieberz; P. Bubenheim; O. Thum; A. Liese

    Butane is an abundant side product of oil and gas production and is mostly burned for energy and heat production. The alkane monooxygenase enzyme system AlkBGT expressed in E. coli offers a robust model system with a fast butane uptake for microbial oxidation at low temperatures (25 – 40 °C) and pressures (1.1 – 1.5 bar). The process is established in a two liter bubble column under strict safety requirements obligatory for butane/air mixtures. Detailed characterization of the transport limited process regarding the relevant process parameters gassing rate / superficial velocity (0.25 – 1.5 L·min-1/ 0.8 – 5 cm·s-1), butane content (14 – 28 % v/v), pressure as well as temperature is carried out. Classical kLa-transferability is shown inside the selected process window. The determined optimum (1.5 L·min-1/ 5 cm·s-1; 1.5 bar; 35 °C and 14 % v/v) is validated and a first scale up to 5 L is approximated. The potential is discussed as a first step to a fermentative oxidation of butane on industrial scale.

    更新日期:2020-01-04
  • Process development to obtain a cocktail containing cell-wall degrading enzymes with insecticidal activity from Beauveria bassiana
    Biochem. Eng. J. (IF 3.371) Pub Date : 2020-01-02
    Eliana A. Alves; Silvana Schmaltz; Marcus V. Tres; Giovani L. Zabot; Raquel C. Kuhn; Marcio A. Mazutti

    In this work was presented a strategy to produce, to concentrate and to apply a cocktail containing cell-wall degrading enzymes. The novelties and the differences of this study from the others lie in the fact of defining the entire production process of a second generation biopesticide and in addition, an enzyme cocktail will be produced and not a single enzyme as usually studied. Enzymes were produced by solid-state fermentation using Beauveria bassiana fungus and the enzymes concentration was carried out using ultrafiltration membranes. Enzymatic cocktail was used as bioinsecticide for Phereoeca uterella biocontrol. The fermentation increased the enzyme activities in 10% for exocellulase, 63% for endocellulase, 60% for chitinase and 61% for β-1,3-glucanase. During the step of membrane concentration, was possible to obtain a purification factor of 6.19 for exocellulase, 18.01 for endocellulase, 22.27 for β-1,3-glucanase and 25.07 for chitinase. Finally, the application of permeate and retentate fractions in Phereoeca uterella larvae showed better results in the permeate fraction, results that agreed with the highest enzymatic activity of cocktail.

    更新日期:2020-01-02
  • Investigating microbial fuel cell aided bio-remediation of mixed phenolic contaminants under oxic and anoxic environments
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-12-31
    Nishat Khan; Abdul Hakeem Anwer; Anees Ahmad; Suhail Sabir; Mohammad Zain Khan
    更新日期:2019-12-31
  • Membrane Type Comparison and Modification to Modulate Sample Flow in Paper Diagnostics
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-12-28
    Dorin Harpaz; Evgeni Eltzov; Tim Axelrod; Robert S. Marks; Alfred I.Y. Tok
    更新日期:2019-12-29
  • Up-concentration of succinic acid, lactic acid, and ethanol fermentations broths by forward osmosis
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-12-26
    Jon Garcia-Aguirre; Merlin Alvarado-Morales; Ioannis A. Fotidis; Irini Angelidaki

    The potential of Forward Osmosis (FO) technology to up-concentrate succinic acid (HSuc), lactic acid (HLac), and ethanol (Eth) from fermentation broths was investigated. The aforementioned molecules were obtained from two residual resources (biopulp and algal biomass) via anaerobic fermentation. HLac and Eth were produced from biopulp and HSuc was produced from macroalgal biomass hydrolysate. Herein, HLac, Eth, and HSuc titers of 14.98 ± 0.76, 19.11 ± 0.51 and 38.8 ± 0.32 g L-1 were obtained respectively. After treatment with centrifugation, FO was applied to the treated broths using a thin film composite hollow fibre (TFHF) membrane. Best results were obtained with the HSuc fermentation broth using NaCl 5.0 M as draw solution. Final HSuc titer of 186.7 ± 9.3 g L-1 and water removal of 85% were attained. Findings in this work highlight a novel application of TFHF membranes.

    更新日期:2019-12-27
  • Impact of exogenous acetate on ethanol formation and gene transcription for key enzymes in Clostridium autoethanogenum grown on CO
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-12-19
    Huijuan Xu; Cuiyi Liang; Xiaoyan Chen; Jingliang Xu; Qiang Yu; Yu Zhang; Zhenhong Yuan

    Gas fermentation using C1 substrate (CO or CO2) is a novel and attractive technology for ethanol production. Clostridium autoethanogenum, a promising gas fermentation strain, can grow on 100% CO and produce acetate and ethanol through the Wood-Ljungdahl pathway. Like other autotrophic acetogens, C. autoethanogenum produces ethanol primarily via the reduction of acetyl-CoA. In this study, we demonstrated that ethanol was also formed via acetate reduction. 13C-labeled acetate was employed to investigate the conversion of acetate in C. autoethanogenum during its autotrophic growth on CO. The addition of exogenous acetate can improve ethanol production in C. autoethanogenum, 13C abundance in ethanol increased significantly with the increase of exogenous 13C-labeled acetate, confirming that acetate can be transformed to ethanol. Moreover, transcriptional analysis of genes encoding phosphotransacetylase(pta), aldehyde:ferredoxin oxidoreductase(aor), carbon monoxide dehydrogenase(codh) and alcohol dehydrogenase(adh) in C. autoethanogenum revealed their differential expression under varied exogenous acetate levels. Among these genes, pta gene was down-regulated due to its involvement in acetate formation, whereas aor gene CAETHG_0102, codh gene CAETHG_3005, adh genes CAETHG_1841 and CAETHG_1813 were found to be highly up-regulated at higher levels of exogenous acetate, suggesting that they may play important roles in the conversion of acetate to ethanol.

    更新日期:2019-12-20
  • Mathematical modelingof ethanol production from glycerol by Enterobacter aerogenes concerning the influence of impurities, substrate, and product concentration
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-12-19
    Juli Novianto Sunarno; Poonsuk Prasertsan; Wiriya Duangsuwan; Prawit Kongjan; Benjamas Cheirsilp

    The application of biodiesel derived crude glycerol for ethanol production using Enterobacter aerogenes TISTR 1468 involved multiple interactions among substrate (glycerol), impurities (methanol) and product (ethanol and acetic acid). A mathematical model based on Monod and Luedeking-Piret models were established to simulate the cell performance in the presence of inhibitors. The Monod model was modified by adding the inhibition factors in terms of critical concentration (C*Ac< C*EtOH< C*MeOH< C*Gly) and its inhibition degree (ni) (nGly>nMeOH>nAc>nEtOH with the values of 119.06, 13.33, 1 and 0.0383, respectively). The Luedeking-Piret model confirmed that ethanol and acetic acid were predominantly growth-associated products. Glycerol up to 24.31 g/L and 31.32 g/L were optimum for cell growth and ethanol productivity, respectively. The cell performance was affected by methanol even at its lowest concentration tested (7.92 g/L). The applicability of the new two-phase growth model during the growth phase and stationary phase in the crude glycerol medium was validated and proved accurate (r2> 0.98).

    更新日期:2019-12-19
  • Suppression of time-dependent decay by controlling the redox balance of human induced pluripotent stem cells suspended in a cryopreservation solution
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-12-10
    Masashi Kagihiro, Kazuhiro Fukumori, Ikki Horiguchi, Mee-Hae Kim, Masahiro Kino-oka

    To scale-up a filling process in a cell manufacturing system, the impact of the processing time on the final product quality should be evaluated. It is known that the suspended cells in a cryopreservation solution are subjected to various types of stress factors, which eventually results in apoptotic or necrotic death. In this study, the aim was to investigate a critical factor of cell decay in human induced pluripotent stem cells suspended in a cryopreservation solution and to propose a methodology to maintain the viability of cells for a longer filling process time. Based on experimental results, it was determined that the accumulation of intracellular reactive oxygen species induces apoptosis of cells suspended in a cryopreservation solution. In addition, treatment with an antioxidant or a low-temperature condition was effective in suppressing the induction of apoptosis and subsequent cell death. In particular, the treatment at low temperature was able to maintain the attachment efficiency of suspended cells at a higher level compared to the treatment with antioxidants. The appropriate control of redox balance in cells suspended in a cryopreservation solution could improve the viability of cells in the filling process and lead to the successful lot size expansion of cell manufacturing systems.

    更新日期:2019-12-11
  • THE APPLICATION OF NOVEL MAGNETICALLY COUPLED MIXER DRIVES IN BIOREACTORS OF UP TO 15 m3
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-12-05
    Arturs Suleiko, Juris Vanags, Marina Konuhova, Konstantins Dubencovs, Oskars Grigs

    We introduce a novel magnetically coupled mixer drive for biotechnological, pharmaceutical and chemical applications requiring high-grade aseptic conditions. The proposed design enables its application in larger volume bioreactors compared to traditional magnetic drives, due to a possibility of introducing higher power quantities per individual rotor, while ensuring higher mixing intensity. In the following study, we provide information on the design aspects of the novel magnetic drive and demonstrate the principles behind both theoretical and experimental maximal torque and other key working parameter evaluation. Based on the mentioned principles, magnetic mixer drives were developed for laboratory (5 dm3) and pilot-scale (15 m3) bioreactors. The specific power inputs relative to the agitation rates for the mentioned mixers were experimentally determined in water for two impeller types: six-bladed Rushton and three-bladed Pitched-blade turbines. The performance of the novel magnetic drive was evaluated during Kluyveromyces marxianus cultivations utilizing whey (a well known byproduct of the dairy industry) as the main substrate source in the 15 m3 bioreactor. The obtained results show that the novel magnetic drive can be successfully applied in 15 m3 bioreactors, while providing sufficient mixing of the cultivation broth for biomass growth.

    更新日期:2019-12-05
  • A simple and efficient model for calculating Fixed Capital Investment and Utilities consumption of large-scale Biotransformation processes
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-12-05
    Endrit Dheskali, Apostolis Koutinas, Ioannis K. Kookos

    Environmental concerns and the depletion of fossil resources are the major factors that boost modern society towards bio-based and circular economy. To this end, the development of mathematical tools that can be used to perform rapid comparative analysis across multiple technology options is necessary. The aim of this work is to present a simple and accurate mathematical model, which describes the economics of the bioreaction section of a typical biotransformation technology. The functional dependency of fixed capital investment (FCI) and utilities consumption from parameters determined experimentally is developed using a regression model. The proposed model, which consists only of three equations, can be used to compare the economic performance of different bio-based technologies that could potentially reach commercialization. More specifically, it can be used to estimate, at the early stages of process development, the effect of final broth concentration (titer), fermentation time and aeration rate on overall process economics.

    更新日期:2019-12-05
  • Exploring the production of citric acid with Yarrowia lipolytica using corn wet milling products as alternative low-cost fermentation media
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-12-04
    Ema Cavallo, Matías Nobile, Patricia Cerrutti, María Laura Foresti
    更新日期:2019-12-04
  • Long-term acclimatization of sludge microbiome for treatment of high-strength organic solid waste in anaerobic membrane bioreactor
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-30
    Tomohiro Inaba, Tomo Aoyagi, Tomoyuki Hori, Amine Charfi, Changwon Suh, Jonghoon Lee, Yuya Sato, Atsushi Ogata, Hidenobu Aizawa, Hiroshi Habe
    更新日期:2019-11-30
  • Support Vector and Locally Weighted regressions to monitor monoclonal antibody glycosylation during CHO cell culture processes, an enhanced alternative to Partial Least Squares regression
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-29
    Daniel Arturo Zavala-Ortiz, Bruno Ebel, Meng-Yao Li, Dulce María Barradas-Dermitz, Patricia Margaret Hayward-Jones, María Guadalupe Aguilar-Uscanga, Annie Marc, Emmanuel Guedon
    更新日期:2019-11-30
  • Estimation of volumetric mass transfer coefficient (kLa) - Review of classical approaches and contribution of a novel methodology
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-26
    Magdalini Aroniada, Sofia Maina, Apostolis Koutinas, Ioannis K. Kookos

    The volumetric mass transfer coefficient, usually denoted by kLa, is an important parameter for both the design, scale-up and monitoring of aerated bioreactors. Significant research efforts have been expended over the last decades in order to develop reliable and easy to apply methodologies for determining kLa using aeration experiment and fast oxygen (polarographic) probes. These methodologies have been reviewed in this study followed by the presentation of a new and promising methodology for kLa determination, which can be used when data from step experiments are not available. Step and aeration experiments have been carried out in laboratory scale bioreactors and the experimental data were used for the validation of the proposed methodology and also to critically assess all alternative methodologies for estimating kLa.

    更新日期:2019-11-27
  • Development of an enzyme-functionalized immunosensor for measuring maturation-inducing hormone in fish
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-26
    Haiyun Wu, Yusuke Saito, Yasutoshi Yoshiura, Hitoshi Ohnuki, Hideaki Endo

    In modern aquaculture, simple and rapid methods of predicting fish ovulation are needed to produce seedlings in a stable and efficient manner. Ovulation time is variable due to environmental and physiological factors, while 17α,20β-dihydroxy-4-pregnen-3-one (DHP), an indicator of ovulation, increases its concentration rapidly just before spawning. In this paper, we developed a biosensor system in which immune and enzymatic reaction assays were combined to monitor DHP levels with low environmental loads. We attempted to quantify DHP by analyzing the decrease rate in the output current after the immunoreaction using the amperometric method as a transfer inhibition degree of the enzyme-generated electrons generated by the formation of the antigen-antibody complex. DHP standard samples were measured under investigated optimal conditions and a specific response with a good linear correlation was obtained between the current decrease rate of the sensor system and the DHP concentration in a range of 7.81∼500 pg ml-1. Further, DHP levels in goldfish (Carassius auratus) during the ovulation period obtained using the sensor system were compared with those of using the conventional method (ELISA) and a good correlation was obtained. These findings suggest that the proposed sensor system can detect DHP quickly and easily compared with the conventional method.

    更新日期:2019-11-27
  • Simulation and economic assessment of large-scale enzymatic N-acetyllactosamine manufacture
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-26
    M. Karimi Alavijeh, A.S. Meyer, S. Gras, S.E. Kentish

    N-acetyllactosamine (LacNAc) is an important lactose-derived molecule which can act as an effective prebiotic. In this study a process for the enzymatic synthesis and downstream purification of LacNAc was designed based on the use of thermostable β-galactosidases from Bacillus circulans (BgaD-D), Thermus thermophilus HB27 or Pyrococcus furiosus (CelB) respectively. Four configurations for the purification stage were simulated; anion-exchange chromatography, an activated charcoal-Celite column, N-acetylglucosamine (GlcNAc) crystallization and an activated charcoal-Celite column, as well as selective crystallization. While the enzyme CelB has greater stability at higher temperatures, this enzyme gives a lower LacNAc yield, leading to significant capital investment. For the design based on the BgaD-D biocatalyst and anion exchange chromatography, recovery of GlcNAc improved the project profitability when the GlcNAc price was greater than $10 per kg. GlcNAc was the main contributor to the raw material costs for most processes, although methanol contributed 72% of these costs for the process based on an activated charcoal column. The use of a crystallizer for GlcNAc separation before this column, reduced this methanol consumption by 73%. The use of selective crystallization proved the best approach, reducing the minimum LacNAc sales price to $2 per gram. The plant was more economic when the acceptor to donor ratio was reduced from 10 to 4 and the lactose concentration increased from 50 mM to 550 mM.

    更新日期:2019-11-27
  • Altered Clostridia response in extractive ABE fermentation with solvents of different nature
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-22
    H. González-Peñas, G. Eibes, T.A. Lu-Chau, M.T. Moreira, J.M. Lema

    Solvents with opposite characteristics in terms of biocompatibility towards Clostridium acetobutylicum and butanol extraction capacity: vegetable oils, 2-butyl-1-octanol and oleyl alcohol were tested in batch extractive fermentations. Concentration profiles of substrate, intermediate and final products were compared with a control (solvent-free) fermentation. By concomitantly removing the inhibitory products, the total initial substrate was completely consumed with both solvents, while about 70% of the substrate was consumed in the solvent-free batch fermentation. Overproduction of butanol attained 60% and 100% with vegetable oil and 2-butyl-1-octanol respectively. Surprisingly, in the case of 2B1O extractive fermentation, a 46% increase of butanol yield (mass of butanol per mass of glucose consumed) was also observed, as well as the doubling of the ratio for the main metabolites (butanol to acetone). However, with this solvent, a longer lag phase compared to solvent free or vegetable oil extractive fermentation was observed, although the extraction capacity of butanol improved significantly due to the higher partition coefficient. Based on these results, differences between solvents go beyond what is expected from thermodynamics (liquid-liquid extraction). Culture metabolism and/or membrane polarity related functions appear to be influenced by the presence of 2B1O. In this context, possible mechanisms for these effects are discussed.

    更新日期:2019-11-22
  • 更新日期:2019-11-22
  • Denitrification behavior in a woodchip-packed bioreactor with gradient filling for nitrate-contaminated water treatment
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-21
    Jiamin Zhao, Qiaochong He, Nan Chen, Tong Peng, Chuanping Feng
    更新日期:2019-11-22
  • Surface Residues Serine 69 and Arginine 194 of Metagenome-Derived Lipase Influence Catalytic Activity
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-19
    Fatma Feyza Özgen, Nurcan Vardar-Yel, Owen Scott Roth, Lersa Sayyad Shahbaz, Gönül Vardar-Schara
    更新日期:2019-11-19
  • Metabolic Pathway Analysis and Dynamic Macroscopic Model Development for Lovastatin Production by Monascus purpureus Using Metabolic Footprinting Concept
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-18
    A. Seenivasan, J. Satya Eswari, P. Sankar, S.N. Gummadi, T. Panda, Ch. Venkateswarlu
    更新日期:2019-11-18
  • Evaluation of methane degradation performance in microbial gas-phase reactions using effectively immobilized methanotrophs
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-18
    Yan-Yu Chen, Masahito Ishikawa, Risa Suzuki, Hidehiro Ito, Toshiaki Kamachi, Katsutoshi Hori

    The removal of atmospheric methane by methanotrophs is a potential strategy for mitigating global warming. However, due to the low mass transfer of methane to methanotrophic cells, the conventional bioprocesses require active gas-supply with high energy consumption. This study aimed to evaluate methane degradation performance in microbial gas-phase reactions using effectively immobilized Methylococcus capsulatus (Bath) cells. Cell immobilization was achieved by freeze-thaw treatment and a simple filtration process. The methane degradation rate was much faster in the gas-phase reaction than in the aqueous-phase reaction with stirring. The efficiency of methane degradation was almost the same between the gas-phase reaction using gel-entrapped cells and the static aqueous reaction using a cell suspension. The results of this study will facilitate the development of a high-efficiency and low-energy bioprocess for methane removal.

    更新日期:2019-11-18
  • Recent Advances of Enzymatic Reactions in Ionic Liquids: Part II
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-09
    Amal A.M. Elgharbawy, Muhammad Moniruzzaman, Masahiro Goto
    更新日期:2019-11-18
  • A ClpS-based N-terminal Amino Acid Binding Reagent with Improved Thermostability and Selectivity
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-17
    Jennifer Tullman, Makenzie Christensen, Zvi Kelman, John P. Marino

    Realization of binding reagents that can perform high-fidelity, sequential recognition and detection of amino acids is important for the success of many proposed approaches for single-molecule protein sequencing. Towards this purpose, a variant of the Agrobacterium tumefaciens protein ClpS was previously engineered with improved binding affinity for phenylalanine at the N-terminus of a peptide. In this study, this variant was further engineered for attributes necessary for robust application as a biotechnology reagent such as increased thermostability and improved selectivity under different buffer conditions. The stabilized variant was further characterized in terms of selectivity for the N-terminal residue in the context of different peptides with varying residues at positions 2 (P2) and 3 (P3). The implication of the study for the use of ClpS based reagents in peptide sequencing technologies are described.

    更新日期:2019-11-18
  • Feasibility of enhancing production of 5-hydroxymethylfurfural using deep eutectic solvents as reaction media in a high-pressure reactor
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-17
    Wei-Chuan Chen, Yin-Chen Lin, I-Ming Chu, Li-Fen Wang, Shen-Long Tsai, Yu-Hong Wei

    5-hydroxymethylfurfural (HMF) is a versatile biomass-derived chemical for synthesizing useful compounds. In this work an attempt is made to produce HMF by developing a low-cost process for doing that using cellulosic waste and deep eutectic solvents (DESs). The most effective DES was choline chloride/citric acid (ChCl/citric acid, 2/1), which provided a greater glucose conversion percentage (around 100 mol%), HMF yield (8 mol%), and HMF selectivity (8 %) than other DESs with 0.1 g of pure glucose. To increase the HMF yield further, the species of catalyst, reaction time and reaction temperature were varied. The highest glucose conversion percentage (91.76 mol%), HMF yield (15.02 g/g) and HMF selectivity (8%) were obtained with a reaction time of five minutes, a reaction temperature of 130 ℃, sulfuric acid as the catalyst, and a ChCl/citric acid ratio of the DES of 2/1. These optimal conditions were used with the enzymatic hydrolysate of pretreated wood dusts as a substrate. The experimental results thus obtained revealed a glucose conversion percentage, HMF yield and HMF selectivity of 34.86 mol%, 16.46 g/g and 67.43 %, respectively, under these conditions. These results reveal that using enzymatic hydrolysate from pretreated wood in the production of HMF can yield approximately as much (16.46 g/g) as the use of pure glucose, indicating that this low-cost process may be commercially feasible.

    更新日期:2019-11-18
  • Estimating Capital Investment and Facility Footprint in Cell Therapy Facilities
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-17
    Tania D Pereira Chilima, Fabien Moncaubeig, Suzanne S. Farid

    Estimations of the facility footprint and fixed capital investment (FCI) of cell therapy (CT) facilities need to consider the unique features of the single-use technologies (SUTs) selected for CT manufacture (e.g. cleanroom containment requirement, capacity, automation) and the product nature that impacts scale-out versus scale-up approaches. A novel detailed factorial methodology is proposed for estimating FCI and footprint for bespoke stick-built cell therapy facilities that accounts for technology-specific factors for key cell culture technologies as well as the implications of SUTs, open versus closed operations and the commercialisation scenario selected. This was used to derive benchmark values for short-cut cost and area factors for typical cell therapy facilities according to the technologies selected. The results provide project-specific ratios for equipment purchase costs to facility footprint (area factor) and for FCI to total equipment purchase costs (cost factor or “Lang” factor). Area factors ($/m2) were 675-6,815 and the cost factors were 2.3-8.5 for a Greenfield project in a medium-developed country. The case study shows that that for the same output facility footprints and FCI values are on average 6 times higher for autologous processes than allogeneic processes. This is attributed to economies of scale achieved with scale-up for allogeneic cell therapy manufacture. This study can be used to predict the commercial FCI and facility footprint during early stages of process development.

    更新日期:2019-11-18
  • Antimicrobial warnericin RK peptide functionalized GaAs/AlGaAs biosensor for highly sensitive and selective detection of Legionella pneumophila
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-15
    M. Amirul Islam, Walid M. Hassen, Azam F. Tayabali, Jan J. Dubowski

    Detection of pathogenic Legionella pneumophila by culture-based methods is not efficient in predicting outbreaks of the Legionnaires’ disease. The main problem is the relatively slow time-to-result and the inability of some culture media to support the growth of viable bacteria. One strategy to alleviate these issues is developing biosensors functionalized with mammalian antibodies designed to capture bacteria. However, mammalian antibodies are known to suffer from batch-to-batch variations, as well as limited stability, which reduce the consistent utility of antibody-based biosensors. In an attempt to address this problem, we investigated antimicrobial peptides (AMP) for capture of L. pneumophila with GaAs/AlGaAs biochips. The Fourier-transform infrared spectroscopy measurements revealed that the peptides were covalently immobilized on the 1-ethyl-3-(-3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide activated –COOH terminals of mercaptohexadecanoic acid self-assembled monolayer functionalized GaAs surface. The efficiency of the specific interaction between the peptide and L. pneumophila, E. coli, B. subtilis and P. fluorescens was investigated with fluorescence microscopy and a digital photocorrosion GaAs/AlGaAs biosensor. We found that the warnericin RK peptides exhibited ∼5 times greater binding affinity towards L. pneumophila than to the other bacteria investigated. Furthermore, detection level as low as 103 CFU/mL was possible with the proposed biosensor architecture. We argue that a biosensor based on warnericin RK AMP peptides offers an attractive alternative solution in comparison to antibody-based devices towards detection of L. pneumophila.

    更新日期:2019-11-15
  • Towards in situ continuous feeding via controlled release of complete nutrients for fed-batch culture of animal cells
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-15
    Jyoti Rawat, Mugdha Gadgil

    Small-scale culture of animal cells in suspension is of importance for many applications. At a small-scale, fed-batch is achieved either by manual bolus feeding or the use of liquid handling robots. In this study, we report an alternate application of a hydrogel for in situ continuous delivery of a nutrient feed comprising 18 amino acids, vitamins, antioxidants, and trace elements. We show that amino acid release is sustained for at least seven days. Importantly, release rates of individual amino acids can be independently modulated by changing their loading. We demonstrate the application of this hydrogel for complete in situ feeding of nutrients to a suspension adapted CHO cell line expressing IgG leading to 2.7-fold and 4-fold improvement in integral viable cell density (IVCD) and volumetric productivity respectively. This is similar to improvements obtained by bolus liquid feeding. Further, supplying glucose from the same hydrogel to eliminate manual feeding led to a 1.8-fold increase in IVCD accompanied by a 3-fold increase in volumetric productivity as compared to batch culture. In summary, this study provides a proof-of-concept that hydrogels can enable completely closed in situ feeding for mammalian cell culture requiring no external intervention. Such continuous in situ delivery can potentially enable closed culture systems maintaining nutrients at low levels mimicking physiological concentrations.

    更新日期:2019-11-15
  • Phenomenological modeling of Acutodesmus obliquus microalgae in situ transesterification
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-14
    Kemely B.Z.F. Branco, Wellington Balmant, Elias Trevisan, Dhyogo M. Taher, André B. Mariano, Pedro A. Arroyo

    The aim of this study was to establish a phenomenological model capable of describing the mass transfer and kinetic effects of the in situ transesterification of Acutodesmus obliquus microalgae dry biomass. This model was developed considering the following: homogeneous cell volume and composition; cells agglomerate forming clusters during in situ reaction; the cluster is considered to be formed of internal and external regions; the species concentration in the cluster is described considering multicomponent Langmuir isotherm model; the fatty acids diffusion inside clusters is described by Fick’s Law; mass transfer of the fatty acids between external solid and bulk phases is governed by convection; and reaction occurs homogenously in the bulk phase. Results show that the proposed model fits the experimental data and adequately describes the reaction kinetics and mass transfers between bulk and external solid phases as well as from internal to external solid phases. It was verified that ester production is higher in the initial period of reaction due to the greater availability of lipids, tending to achieve a maximum over time. The mass transfer coefficients values suggest that the alcohol moves towards the solid phase more hardly than the fatty acids are extracted to the bulk phase. Moreover, the Langmuir constants show that the alcohol has higher adsorption strength in the biomass than the esters.

    更新日期:2019-11-14
  • Current advances on biological production of fumaric acid
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-10-12
    Feng Guo, Min Wu, Zhongxue Dai, Shangjie Zhang, Wenming Zhang, Weiliang Dong, Jie Zhou, Min Jiang, Fengxue Xin

    Fumaric acid is an industrially important platform chemical, which has been widely used in food, chemicals, agriculture and pharmaceutical industries. Due to the rising price of raw materials in traditional petrochemical method and demand for sustainable development, fermentative fumaric acid production has attracted great attention. In this context, various strains with enhanced fumaric acid production or elimination of by-products were developed through mutagenesis or metabolic engineering. In addition, renewable organic wastes together with the fermentation process optimization have also been widely investigated. Accordingly, this review will comprehensively summarize the achievements of fermentative fumaric acid production in recent years and major obstacles occurring in industrialization to provide insights and perspective for future microbial fermentation of fumaric acid.

    更新日期:2019-11-13
  • Effect of Flow Intermittency on Lipid Degradation Behavior during In-sewer Purification by the Intermittent Contact Oxidation Process
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-09
    Tiffany Joan Sotelo, Hiroyasu Satoh, Takashi Mino

    Lipid degradation behavior was examined during the Intermittent Contact Oxidation Process (ICOP) for application in in-sewer purification. Lipids are known to accumulate in the sewer environment making the study of its degradation behavior relevant for in-sewer purification. Changes in the lipid substrate during various flow conditions and the subsequent effect of these transformation on the performance of a channel incorporating ICOP were focused on. Biomass was first developed for 84 days in three types of sponges. Oxygen consumption rates, indicative of aerobic lipid degradation, were then observed during three flow conditions which were: extended no flow condition, frequent flow condition, and a combination of extended no flow and frequent flow condition. Oxygen consumption rates decreased over time during extended no flow condition while they were generally similar during frequent flow condition for all sponge types. Lipid samples analyzed after treatment revealed that intermittent flow affected the composition of residual free fatty acid species. Overall, the study provides insights on the effect of flow intermittency on lipid degradation behavior during the application of the ICOP for in-sewer purification.

    更新日期:2019-11-11
  • De novo Biosynthesis of Indole-3-ethanol and Indole-3-ethanol acetate in Engineered Escherichia coli
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-09
    Sijia Kong, Jianbi Zhang, Xun Li, Hong Pan, Daoyi Guo
    更新日期:2019-11-11
  • 更新日期:2019-11-11
  • New dynamic digestion model reactor that mimics gastrointestinal function
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-08
    Zhi-tao Li, Li Zhu, Wen-long Zhang, Xiao-bei Zhan, Min-jie Gao

    A new dynamic model that mimics gastrointestinal function was designed. Elastic and contractile silica gel with gastrointestinal rugae and folds were used to simulate the stomach and large intestine, and silica gel with intestinal folds and villi was utilized to simulate small intestines. Mixing times for Newtonian fluids with Reynolds numbers of 10–5000 and for non-Newtonian fluids with Reynolds numbers of 1–100 were shortened in the new dynamic model bionic gastrointestinal reactor (BGR) compared with those in a traditional stirred tank reactor (STR). Gastric pressure of stomach at different digestion phases in the range 20–220 mm Hg was simulated by adopting different motion models. Maximum force of 0.72 N was observed when using agar beads to mimic solid foods. The folds and villi increased the surface area of the modeled small and large intestine walls by 112% and 52%, respectively. As a result, mixing and grinding in the simulated tract was improved. In the future, BGR can be applied for simulated studies on digestion and metabolism of foods and drugs in a mimetic gastrointestinal tract environment.

    更新日期:2019-11-08
  • The effect of the lipid extraction method used in biodiesel production on the integrated recovery of biodiesel and biogas from Nannochloropsis gaditana, Isochrysis galbana and Arthrospira platensis
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-06
    Álvaro Mendoza, Victoria Morales, Alejandra Sánchez-Bayo, Rosalía Rodríguez-Escudero, Cristina González-Fernández, Luis Fernando Bautista, Gemma Vicente
    更新日期:2019-11-06
  • Enhanced production of microalgal lipids using a heterotrophic marine microalga Thraustochytrium sp. BM2
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-06
    Chun-Yen Chen, Meng-Hsiu Lee, Cheng-Di Dong, Yoong Kit Leong, Jo-Shu Chang

    In this study, the potential of Thraustochytrium sp. BM2 for cost-effective lipid production was investigated. Lipid content and productivity of BM2 reached 76% and 37 mg/L/h when corn steep liquor (12.5 g/L) and glycerol (10 g/L) was used as nitrogen and carbon source respectively. Supplementing an optimal amount of sea salt (2% w/v) further enhanced the lipid content to 79%. The inoculum size and age were also evaluated for their effect on lipid accumulation. A 48-h pre-culture at 0.15 g/L loading further improved the lipid productivity to 43.86 mg/L/h (or 1.052 g/L/d), which is a 340% increase when compared with the control test. Thus, Thraustochytrium sp. BM2 strain could serve as a low-cost and high-lipid-yield heterotrophic lipid producer using glycerol (a by-product of biodiesel manufacturing process) as carbon source and an inexpensive nitrogen source (i.e., corn steep liquor).

    更新日期:2019-11-06
  • Effects of specific pathogen-free porcine platelet-rich plasma activated by the novel activator ectoine on cell proliferation and biological function
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-05
    Chao-Ling Yao, Yung-Wen Chi, Tseng-Ting Kao, Yen-Liang Liu, Tzeon-Jye Chiou, Yi-Ting Lai
    更新日期:2019-11-06
  • The dead cell ratio of bacteria in sludge flocs as an indicator of sludge reduction in sludge ozone process
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-05
    Kurumi Hashimoto, Toru Marushima, Satoshi Nakai, Wataru Nishijima, Hiroshi Motoshige

    A quantitative analytical method to determine the dead cell ratio of bacteria (death ratio) in sludge was developed for evaluating technologies and determining a sufficient amount of ozone for the sludge ozone process. The method with SYTO9 and propidium iodide as staining agents for live and dead cells, respectively, was optimized. The death ratio developed in this study could successfully predict the reduction ratio of the excess sludge in the sludge ozone process with different ozone dosages. Consequently, the death ratio was proven to be a suitable indicator for excess sludge reduction.

    更新日期:2019-11-06
  • 更新日期:2019-11-06
  • Examination of indigenous microalgal species for maximal protein synthesis
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-04
    Chung Hong Tan, Pau Loke Show, Man Kee Lam, Xiaoting Fu, Tau Chuan Ling, Chun-Yen Chen, Jo-Shu Chang
    更新日期:2019-11-04
  • Production of 5-Hydroxymethyl-2-Furan Carboxylic Acid by Serratia marcescens from Crude 5-Hydroxymethylfurfural
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-04
    Tatiana Muñoz, Leidy Y. Rache, Hugo A. Rojas, Gustavo P. Romanelli, José J. Martinez, Rafael Luque
    更新日期:2019-11-04
  • Phenolic and non-phenolic substrates oxidation by laccase at variable oxygen concentrations: selection of bisubstrate kinetic models from polarographic data
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-11-01
    Paula A. Pinto, Irene Fraga, Rui M.F. Bezerra, Albino A. Dias

    Using laccase as a case study, an alternative methodology for discrimination of bisubstrate mechanism types, useful for Bi-Bi reactions when water is one of the products, is presented. A purified enzyme from fungal cultures of Ganoderma resinaceum and two reducing substrates: 2,2´-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and 2,6-dimethoxyphenol (DMP) are used. Kinetic assays of ABTS or DMP oxidation using variable initial concentrations of dioxygen are performed in a closed system and depletion rates of dioxygen are measured using polarography. Seven bisubstrate models based on Michaelis-Menten Bi-Bi mechanisms are applied to the experimental data. Akaike information criterion, a penalized likelihood analysis, and Akaike weights are used for model selection. Results show that the more likely bisubstrate models for ABTS and DMP oxidation are ping-pong and Theorell-Chance, respectively. However, the catalytic efficiency of oxygen reduction to water exhibits similar values, and is compatible with a process relatively independent of reducing substrates and the bisubstrate mechanism type. Finally, Michaelis-Menten constants towards dioxygen, 233 µM with ABTS and 700 µM with DMP, indicate that the soluble electron acceptor available for laccase-catalyzed reactions, is far removed from saturation.

    更新日期:2019-11-01
  • Process simulation-integrated optimization of lignocellulolytic enzyme production
    Biochem. Eng. J. (IF 3.371) Pub Date : 2019-10-31
    Zeynep Yılmaz Serçinoğlu, Nihat Alpagu Sayar

    An optimization workflow is introduced which integrates multi-objective optimization of lignocellulolytic enzyme cocktail ingredients with a bioethanol production process where the enzymes are utilized. The workflow integrates data collection via exploratory experiments, modeling via Kriging, Pareto-based multi-objective optimization, and process simulation. The critical links in the integration are calculation of enzyme cocktail performance and cost. This allows the identification of the best Pareto-optimal result depending on process simulation results. The workflow is demonstrated on a case study involving the production of lignocellulolytic enzymes laccase, β-glucosidase, and carboxymethyl cellulase by a white rot fungus, Pycnoporus sanguineus DMSZ 3024. Concentrations of various carbon and nitrogen sources and culture duration are optimized. Two cases are analyzed: i) where all culture conditions and three enzyme activities are assumed to affect enzyme cost and performance equally; ii) where culture duration and β-glucosidase activity are assumed to respectively affect enzyme cost and performance more significantly compared to the other factors. The integrated optimization workflow identified a shift from a malt extract dominant growth medium in the first case to a yeast extract dominant medium in the second. This shift could not have been identified without the proposed workflow.

    更新日期:2019-11-01
  • A modified method for determination of diffusivities of low molecular substances in non-Newtonian liquids.
    Biochem. Eng. J. (IF 3.371) Pub Date : 2001-05-18
    G Peev,A Nikolova,V Beschkov,G Christov

    A modified method for determination of diffusivities of low molecular substances in non-Newtonian liquids described by the power-law model has been proposed. It is based on the dissolution of Geiss body, with a parameter m=1/3 rotating in an infinite fluid. In this case, the solution of the differential equations of motion and mass transfer is available as an analytical formula for calculating the diffusivity coefficient.The method allows the extension of the variety of media and diffusing species. It has been illustrated with dissolving of gypsum in water and five non-Newtonian liquids. The results obtained have been interpreted taking into account the interaction between calcium ions and polymer molecules of the non-Newtonian system, as well as the heterogeneity of the system near to the dissolving surface.

    更新日期:2019-11-01
  • Carbon sources affect metabolic capacities of Bacillus species for the production of industrial enzymes: theoretical analyses for serine and neutral proteases and alpha-amylase.
    Biochem. Eng. J. (IF 3.371) Pub Date : 2001-05-18
    P Çalik,T H. Özdamar

    The metabolic fluxes through the central carbon pathways were calculated for the genus Bacillus separately for the enzymes serine alkaline protease (SAP), neutral protease (NP) and alpha-amylase (AMY) on five carbon sources that have different reduction degrees (gamma), to determine the theoretical ultimate limits of the production capacities of Bacillus species and to predict the selective substrate for the media design. Glucose (gamma=4.0), acetate (gamma=4.0), and the TCA cycle organic-acids succinate (gamma=3.5), malate (gamma=3.0), and citrate (gamma=3.0) were selected for the theoretical analyses and comparisons. A detailed mass flux balance-based general stoichiometric model based on the proposed metabolic reaction network starting with the alternative five carbon sources for the synthesis of each enzyme in Bacillus licheniformis that simulates the behaviour of the metabolic pathways with 107 metabolites and 150 reaction fluxes is developed. Highest and lowest specific cell growth rates (&mgr;) were calculated as 1.142 and 0.766h(-1), respectively, when glucose that has the highest degree of reduction and citrate that has the lowest degree of reduction were used as the carbon sources. Highest and lowest SAP, NP and AMY synthesis rates were also obtained, respectively, when glucose and citrate were used. Metabolic capacity analyses showed that the maximum SAP, NP, and AMY synthesis rates were, respectively, 0.0483, 0.0215 and 0.0191mmolg(-1)DWh(-1) when glucose uptake rate was 10mmolg(-1)DWh(-1) and specific growth rate was zero. The amino acid compositions and the molecular weights of the enzyme influence the production yield and selectivity. For SAP and NP oxaloacetate and pyruvate, for AMY oxaloacetate appear to be the critical main branch points. Consequently, for SAP and NP syntheses the fluxes towards the alanine group and aspartate group, and for AMY synthesis the flux towards the aspartate group amino acids need to be high. The results encourage the discussion of the potential strategies for improving productions of SAP, NP and AMY.

    更新日期:2019-11-01
  • Biosorption of gold by immobilized fungal biomass.
    Biochem. Eng. J. (IF 3.371) Pub Date : 2001-05-18
    K -M. Khoo,Y -P. Ting

    The characteristics of polyvinyl alcohol (PVA) and calcium alginate as immobilization matrices were examined and compared for the uptake of gold by a fungal biomass. PVA-immobilized biomass showed superior mechanical strength and chemical stability. In addition, PVA beads were also stable under a wider range of pH (1-13). The lower mass transfer resistance in PVA beads was evident from kinetic studies which showed a significantly shorter period of time for the immobilized PVA beads to achieve 80% gold removal as compared with immobilized alginate beads. Calculated rate constants and maximum rates for the uptake of gold by both immobilized PVA and immobilized alginate biosorbent revealed a much more rapid uptake phenomenon by the former. BET analyses also indicated a larger surface area and larger pore size distribution in PVA beads, further indicating a lower resistance to mass transfer. Gold biosorption in the immobilized PVA bead could be modeled by both the Langmuir and Freundlich adsorption isotherms.

    更新日期:2019-11-01
  • Modelling plasmid instability in batch and continuous fermentors.
    Biochem. Eng. J. (IF 3.371) Pub Date : 2001-05-18
    H R. Baheri,G A. Hill,W J. Roesler

    The probability of complete loss of plasmid material from plasmid bearing cells undergoing active growth has been modelled and incorporated into predictions for the dynamic concentrations of plasmid bearing cells in both batch and continuous flow, stirred tank bioreactors. The new model is based on an extension of the well-used model of Imanaka and Aiba [Ann. New York Acad. Sci. 369 (1981) 1] and is relatively easy to use compared to complex structured models. The new model predicts that both accelerating and decelerating rates of plasmid loss occur in both batch and continuous flow operation, and agrees well with data collected here and published earlier by others.

    更新日期:2019-11-01
  • Whole cell biocatalyst for biodiesel fuel production utilizing Rhizopus oryzae cells immobilized within biomass support particles.
    Biochem. Eng. J. (IF 3.371) Pub Date : 2001-05-18
    K Ban,M Kaieda,T Matsumoto,A Kondo,H Fukuda

    As part of a research program aimed at producing biodiesel fuel from plant oils enzymatically cells of Rhizopus oryzae (R. oryzae) IFO4697 (with a 1,3-positional specificity lipase) immobilized within biomass support particles (BSPs) were investigated for the methanolysis of soybean oil. The R. oryzae cells easily became immobilized within the BSPs during batch operation. To enhance the methanolysis activity of the immobilized cells under the culture conditions used, various substrate-related compounds were added to the culture medium. Among the compounds tested, olive oil or oleic acid was significantly effective. In contrast, no glucose was necessary. Immobilized cells were treated with several organic solvents, but none gave higher activity than untreated cells. When methanolysis was carried out with stepwise additions of methanol using BSP-immobilized cells, in the presence of 15% water the methyl esters (MEs) content in the reaction mixture reached 90% - the same level as that using the extracellular lipase. The process presented here, using a whole cell biocatalyst, is considered to be promising for biodiesel fuel production in industrial applications.

    更新日期:2019-11-01
  • Chemometric optimisation of parameters for biocatalytic reduction of copper ion by a crude enzyme lysate of Saccharomyces cerevisiae grown under catabolic repression conditions.
    Biochem. Eng. J. (IF 3.371) Pub Date : 2001-05-18
    C Bennett Chandran,T V. Subramanian,P Arthur Felse

    The capacity of the microbes to reduce the metal has been demonstrated. The immobilised induced microbes with toxic chemical CuCl(2) was used to reduce the Cu ions as elemental metal and by using the response surface methodology the parameters such as the inducer concentration, the time of inducer addition which are concerned with the growth and formation of specific enzymes and the initial substrate concentration, initial pH of the substrate solution and the time of reaction which are concerned with the biocatalytic reduction of the metal ions were optimised for maximum reduction. The elemental copper reduced and removed experimentally from its ionic state at the optimum conditions was 54.82ppm.

    更新日期:2019-11-01
Contents have been reproduced by permission of the publishers.
导出
全部期刊列表>>
2020新春特辑
限时免费阅读临床医学内容
ACS材料视界
科学报告最新纳米科学与技术研究
清华大学化学系段昊泓
自然科研论文编辑服务
中国科学院大学楚甲祥
中国科学院微生物研究所潘国辉
中国科学院化学研究所
课题组网站
X-MOL
北京大学分子工程苏南研究院
华东师范大学分子机器及功能材料
中山大学化学工程与技术学院
试剂库存
天合科研
down
wechat
bug