ANAEROBIC DEGRADATION OF TOLUENE AND O-XYLENE BY A METHANOGENIC CONSORTIUM
ANAEROBIC DEGRADATION OF TOLUENE AND O-XYLENE BY A METHANOGENIC CONSORTIUM
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DOI：
10.1128/aem.60.1.313-322.1994
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发表时间：
1994-01-01
影响因子：
4.4
通讯作者：
GRBICGALIC, D
中科院分区：
文献类型：
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作者：
EDWARDS, EA;GRBICGALIC, D
在严格的厌氧条件下，含水层来源的微生物将甲苯和邻二甲苯完全矿化为化学计量比的二氧化碳、甲烷和生物量。接种物的来源是佛罗里达州彭萨科拉被杂酚油污染的沉积物。降解开始前的适应期较长(甲苯降解为100至120天，二甲苯为200至255天)。甲苯和邻二甲苯降解菌的连续转移仍然活跃。细胞密度在2-3年内逐渐增加，稳定在大约每毫升10(9)个细胞。甲苯和邻二甲苯在稳定的混合产甲烷培养物中的降解遵循Monod动力学，当底物浓度超过约700微米时，邻二甲苯和甲苯的降解受到抑制。培养物能降解甲苯或邻二甲苯，但不能降解间二甲苯、对二甲苯、苯、乙苯或萘。在巴氏杀菌或饥饿1年后仍能保持降解活性。甲苯和二甲苯的降解被交替的电子受体氧、硝酸盐和硫酸盐所抑制。此外，添加醋酸盐、H-2、丙酸、甲醇、丙酮、葡萄糖、氨基酸、脂肪酸、蛋白胨和酵母菌等首选底物也可以抑制降解。这些数据表明，天然有机底物或混合污染物的存在可能会抑制甲苯和二甲苯等污染物在受污染部位的厌氧降解。
Toluene and o-xylene were completely mineralized to stoichiometric amounts of carbon dioxide, methane, and biomass by aquifer-derived microorganisms under strictly anaerobic conditions. The source of the inoculum was creosote-contaminated sediment from Pensacola, Fla. The adaptation periods before the onset of degradation were long (100 to 120 days for toluene degradation and 200 to 255 days for oxylene). Successive transfers of the toluene- and o-xylene-degrading cultures remained active. Cell density in the cultures progressively increased over 2 to 3 years to stabilize at approximately 10(9) cells per ml. Degradation of toluene and o-xylene in stable mixed methanogenic cultures followed Monod kinetics, with inhibition noted at substrate concentrations above about 700 muM for o-xylene and 1,800 muM for toluene. The cultures degraded toluene or o-xylene but did not degrade m-xylene, p-xylene, benzene, ethylbenzene, or naphthalene. The degradative activity was retained after pasteurization or after starvation for 1 year. Degradation of toluene and oxylene was inhibited by the alternate electron acceptors oxygen, nitrate, and sulfate. Degradation was also inhibited by the addition of preferred substrates such as acetate, H-2, propionate, methanol, acetone, glucose, amino acids, fatty acids, peptone, and yeast ''tract. These data suggest that the presence of natural organic substrates or cocontaminants may inhibit anaerobic degradation of pollutants such as toluene and oxylene at contaminated sites.