Elmén J, Pan W, Leung S Y, Magyarosy A, Keasling J D
Department of Chemical Engineering, University of California, Berkeley, California 94720-1462, USA.
Biotechnol Bioeng. 1997 Jul 5;55(1):82-90. doi: 10.1002/(SICI)1097-0290(19970705)55:1<82::AID-BIT10>3.0.CO;2-5.
Groundwater from a xylene-contaminated acquifer was enriched in the laboratory in the presence of toluene, xylenes, ethylbenzene, and benzene. A pure culture that degrades toluene and m-xylene under nitrate-reducing conditions was isolated. Fatty acid analysis, 16S rRNA sequencing, and morphological traits indicate that the isolate was a strain of Azoarcus tolulyticus. The kinetics of toluene degradation under nitrate-reducing conditions by this isolate was determined. Nitrate reduction does not proceed beyond nitrite. Nitrate and toluene are substrate limiting at low concentrations, whereas toluene, nitrate, and nitrite are inhibitory at high concentrations. Several inhibition models were compared to experimental data to represent inhibition by these substrates. A kinetic model for toluene and nitrate degradation as well as for cell growth and nitrite production was developed and compared to experimental data. The results of this work may find important application in the remediation of groundwater aquifers contaminated with aromatic hydrocarbons.
从受二甲苯污染的含水层采集的地下水在甲苯、二甲苯、乙苯和苯存在的情况下于实验室中进行富集培养。分离出一种在硝酸盐还原条件下降解甲苯和间二甲苯的纯培养物。脂肪酸分析、16S rRNA测序和形态特征表明该分离物是甲苯分解偶氮弧菌菌株。测定了该分离物在硝酸盐还原条件下甲苯降解的动力学。硝酸盐还原不会超过亚硝酸盐阶段。硝酸盐和甲苯在低浓度时是底物限制因素，而甲苯、硝酸盐和亚硝酸盐在高浓度时具有抑制作用。将几种抑制模型与实验数据进行比较，以体现这些底物的抑制作用。建立了甲苯和硝酸盐降解以及细胞生长和亚硝酸盐产生的动力学模型，并与实验数据进行比较。这项工作的结果可能在修复受芳烃污染的地下水含水层方面有重要应用。
