The enrichment of an alkaliphilic biofilm consortia capable of the anaerobic degradation of isosaccharinic acid from cellulosic materials incubated within an anthropogenic, hyperalkaline environment.
The enrichment of an alkaliphilic biofilm consortia capable of the anaerobic degradation of isosaccharinic acid from cellulosic materials incubated within an anthropogenic, hyperalkaline environment.
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能够从人为，超碱性环境中孵育的纤维素材料中厌氧降解的碱性生物膜联盟的富集。
DOI：
10.1093/femsec/fiv085
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发表时间：
2015-08
影响因子：
4.2
通讯作者：
Humphreys PN
中科院分区：
文献类型：
--
作者：
Charles CJ;Rout SP;Garratt EJ;Patel K;Laws AP;Humphreys PN
人为的高碱性场所提供了一种类似于为放射性废物提议的水泥质地质处置设施（GDF）的环境。在缺氧、碱性条件下，纤维素废物将水解为一系列以异糖精酸（ISA）为主的纤维素降解产物（CDP）。为了研究水泥质GDF中微生物活动的可能性，将纤维素样品在石灰窑废弃物场地的碱性（约pH 12）厌氧区域进行培养。取回后，这些样品经历了部分碱性水解，并被一个以梭菌属为主的生物膜群落定殖，其中还存在氢营养型、嗜碱的产甲烷菌。当这些样品被用于建立一个以碱性CDP为底物的微宇宙时，群落组成从梭菌属发生了转变，产甲烷菌变得无法检测到，一个由阿里斯氏菌属（Alishewanella sp.）主导的絮凝物群落建立起来。这些絮凝物由嵌入在由细胞外DNA稳定的多糖和蛋白质中的细菌组成。这个群落能够降解所有形式的ISA，超过60%的碳流被引导用于细胞外聚合物（EPS）的生产。这项研究表明，嗜碱微生物群落能够在pH 11的条件下降解与一些放射性废物处置概念相关的CDP。这些群落将大量可降解的碳转移用于EPS的形成，这表明EPS在保护这些群落免受高碱性条件影响方面起着核心作用。
从一个高碱性污染场地分离出了一个能够降解ISA的生物膜形成群落。
从一个高碱性污染场地分离出了一个能够降解ISA的生物膜形成群落。
Anthropogenic hyperalkaline sites provide an environment that is analogous to proposed cementitious geological disposal facilities (GDF) for radioactive waste. Under anoxic, alkaline conditions cellulosic wastes will hydrolyze to a range of cellulose degradation products (CDP) dominated by isosaccharinic acids (ISA). In order to investigate the potential for microbial activity in a cementitious GDF, cellulose samples were incubated in the alkaline (∼pH 12), anaerobic zone of a lime kiln waste site. Following retrieval, these samples had undergone partial alkaline hydrolysis and were colonized by a Clostridia-dominated biofilm community, where hydrogenotrophic, alkaliphilic methanogens were also present. When these samples were used to establish an alkaline CDP fed microcosm, the community shifted away from Clostridia, methanogens became undetectable and a flocculate community dominated by Alishewanella sp. established. These flocs were composed of bacteria embedded in polysaccharides and proteins stabilized by extracellular DNA. This community was able to degrade all forms of ISA with >60% of the carbon flow being channelled into extracellular polymeric substance (EPS) production. This study demonstrated that alkaliphilic microbial communities can degrade the CDP associated with some radioactive waste disposal concepts at pH 11. These communities divert significant amounts of degradable carbon to EPS formation, suggesting that EPS has a central role in the protection of these communities from hyperalkaline conditions. A biofilm forming community able to degrade ISA was isolated from a hyperalkaline contaminated site. A biofilm forming community able to degrade ISA was isolated from a hyperalkaline contaminated site.