Grbić-Galić D, Churchman-Eisel N, Mraković I
Department of Civil Engineering, Stanford University, California 94305-4020.
J Appl Bacteriol. 1990 Aug;69(2):247-60. doi: 10.1111/j.1365-2672.1990.tb01516.x.
Methanogenic microbial consortia, originally enriched from anaerobic sewage sludge with ferulic acid or styrene (vinylbenzene) as sole organic carbon and energy sources, were used to study transformation of styrene under strictly anaerobic conditions. Styrene, which was added as the substrate in a range of concentrations from 0.1 to 10 mmol/l, was extensively degraded but no methane production was observed during incubation for eight months. The addition of yeast extract during the enrichment stage completely inhibited degradation of styrene. Gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS), high performance liquid chromatography (HPLC) analyses of the culture fluid, and GC analyses of the anaerobic headspace, indicated that the transformation of this arylalkene was initiated through an oxidation-reduction reaction and that the favoured mechanism was most likely the addition of water across the double bond in the alkenyl side-chain. The degradation proceeded through to carbon dioxide, the final product. Benzoic acid and phenol were transient compounds found in highest concentrations in the spent culture fluid and are suggested as the key intermediates of the transformation process. The tentative routes of anaerobic transformation partially overlap with those previously proposed for aromatic hydrocarbons such as toluene. Several pure cultures, which were tentatively identified as Clostridium spp. and Enterobacter spp., were isolated from the styrene-degrading consortia. Two of these cultures were demonstrated to grow on styrene as sole carbon and energy source. Additionally, a pure culture of Enterobacter cloacae DG-6 (ATCC 35929) which had been isolated previously from the ferulate-degrading consortium, was shown to degrade styrene through to carbon dioxide.
产甲烷微生物群落最初是从厌氧污水污泥中富集而来，以阿魏酸或苯乙烯（乙烯基苯）作为唯一的有机碳源和能源，用于研究在严格厌氧条件下苯乙烯的转化。苯乙烯作为底物添加，浓度范围为0.1至10 mmol/l，被大量降解，但在八个月的培养过程中未观察到甲烷产生。在富集阶段添加酵母提取物完全抑制了苯乙烯的降解。对培养液进行气相色谱（GC）、气相色谱/质谱（GC/MS）、高效液相色谱（HPLC）分析，以及对厌氧顶空进行GC分析，表明这种芳基烯烃的转化是通过氧化还原反应启动的，最可能的有利机制是在烯基侧链的双键上加水。降解过程一直进行到最终产物二氧化碳。苯甲酸和苯酚是在废培养液中发现的浓度最高的瞬态化合物，被认为是转化过程的关键中间体。厌氧转化的暂定途径与先前提出的甲苯等芳烃的途径部分重叠。从苯乙烯降解菌群中分离出几种纯培养物，初步鉴定为梭菌属和肠杆菌属。其中两种培养物被证明能以苯乙烯作为唯一的碳源和能源生长。此外，先前从阿魏酸降解菌群中分离出的阴沟肠杆菌DG-6（ATCC 35929）纯培养物，被证明能将苯乙烯降解为二氧化碳。
