当前位置: X-MOL 学术Res. Microbiol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Cross-correlating analyses of mineral-associated microorganisms in an unsaturated packed bed flow-through column test; cell number, activity and EPS
Research in Microbiology ( IF 2.6 ) Pub Date : 2020-09-21 , DOI: 10.1016/j.resmic.2020.09.002
Didi X Makaula 1 , Robert J Huddy 2 , Marijke A Fagan-Endres 1 , Susan T L Harrison 2
Affiliation  

In heap bioleaching and waste-rock dumps, complex microbial communities exist in the flowing and interstitial liquid phases and mineral surface-associated biofilms, often embedded in extracellular polymeric substances (EPS). Microbial activity in the interstitial phase and mineral ore surface facilitates mineral degradation, resulting in either metal recovery or acidic, metal -bearing drainage from sulfidic waste-rock. Determining microbial presence and activity through microorganisms leaving the heap or dump has severe limitations. Hence, increasingly the ore-bed is sampled to quantify and characterise this. Here, methods for cell detachment and quantification, microbial activity measurement on the mineral surface and evaluation of EPS, quantitatively and biochemically, were refined and validated to assess microbial presence, using mineral coated beads in continuous flow-through columns. Number of wash steps required were assessed over increasing colonisation times over 30 days. Microbial cells colonising the mineral surface, pre- and post-washing were visualised by scanning electron microscopy (SEM) and their activity quantified by isothermal microcalorimetry (IMC). Using IMC, detachment and enumeration of detached cells, we demonstrated that 6–8 washes provided a reliable estimation of mineral-associated microorganisms, with less than 10% of cells or microbial activity associated with the surface following treatment. This allowed consolidated refinement of the protocol using traditional detachment method, SEM and IMC to provide correlative data. Extraction of EPS in a complete flow-through system is reported for the first time and the biochemical composition was similar to those reported under batch bioleaching conditions.



中文翻译:

在不饱和填充床流通柱测试中对矿物相关微生物的互相关分析;细胞数,活性和EPS

在堆生物浸出和废物堆放场中,复杂的微生物群落存在于流动和间隙液相以及矿物表面相关的生物膜中,通常嵌入细胞外聚合物(EPS)中。间隙相和矿物表面中的微生物活动促进矿物降解,从而导致金属回收或酸性,含金属的金属从硫化waste石中排出。通过离开堆或堆的微生物来确定微生物的存在和活性具有严重的局限性。因此,越来越多的矿床被采样以对其进行量化和表征。在此,对细胞分离和定量,矿物表面微生物活性测量以及EPS定量和生化评估的方法进行了完善和验证,以评估微生物的存在,在连续的流通柱中使用矿物涂层的珠子。在超过30天的定植时间内,评估所需的洗涤步骤数。通过扫描电子显微镜(SEM)观察定居在矿物表面,洗前和洗后的微生物细胞,并通过等温微量热(IMC)定量其活性。使用IMC,分离的细胞的分离和计数,我们证明6-8次洗涤可以可靠地估计与矿物质有关的微生物,处理后与表面相关的细胞或微生物活性不到10%。这允许使用传统的分离方法,SEM和IMC对协议进行合并优化,以提供相关数据。

更新日期:2020-11-09
down
wechat
bug