Dahlen E P, Rittmann B E
Exponent Failure Analysis Associates, 149 Commonwealth Drive, Menlo Park, California 94025, USA.
Biotechnol Bioeng. 2000 Dec 20;70(6):685-92.
A series of experiments was performed in an aerobic chemostat reactor using a multi-substrate system consisting of acetate, phenol, and 2,4-dichlorophenol (DCP). The phenolic compounds require initial oxygenation reactions, while acetate is oxidized without oxygenations. The biomass completely dechlorinated DCP and utilized all of the substrates simultaneously as electron donors and carbon sources. However, DCP removal was less than for phenol and depended on the solids retention time. A novel substrate-specific yield analysis indicated that true yield values were approximated well by the number of electrons removed in non-oxygenation reactions. Experiments for estimating the kinetic parameters for utilization of the phenolic compounds were designed to eliminate the effects of the key cosubstrates of oxygenation reactions, O2, and the reduced intracellular electron carrier, NADH + H+. The maximum specific rate of substrate utilization, qmax, and the half-maximum rate concentration, K, for phenol and DCP were estimated. The kinetics for DCP were much slower than those for phenol, and the largest effect was a half-maximum rate concentration, which was 19 times larger for DCP. The larger K for DCP explains why DCP removal was low and sensitive to the solids retention time.
在一个需氧恒化器反应器中进行了一系列实验，该反应器使用了由乙酸盐、苯酚和2,4 - 二氯苯酚（DCP）组成的多底物系统。酚类化合物需要初始氧化反应，而乙酸盐在无氧化的情况下被氧化。生物质完全将DCP脱氯，并同时将所有底物用作电子供体和碳源。然而，DCP的去除率低于苯酚，且取决于固体停留时间。一种新颖的底物特异性产率分析表明，真实产率值通过非氧化反应中去除的电子数能很好地近似。为估算酚类化合物利用的动力学参数而设计的实验，旨在消除氧化反应的关键共底物O₂以及还原型细胞内电子载体NADH + H⁺的影响。估算了苯酚和DCP的最大底物利用比速率qmax以及半最大速率浓度K。DCP的动力学比苯酚慢得多，最大的影响是半最大速率浓度，DCP的该值是苯酚的19倍。DCP较大的K值解释了为什么DCP去除率低且对固体停留时间敏感。
