Kleerebezem R, Hulshoff Pol L W, Lettinga G
Subdepartment of Environmental Technology, Department of Agricultural, Environmental and Systems Technology, Wageningen Agricultural University, 6703 HD Wageningen, The Netherlands.
Appl Environ Microbiol. 1999 Mar;65(3):1161-7. doi: 10.1128/AEM.65.3.1161-1167.1999.
The effects of acetate, benzoate, and periods without substrate on the anaerobic degradation of terephthalate (1, 4-benzene-dicarboxylate) by a syntrophic methanogenic culture were studied. The culture had been enriched on terephthalate and was capable of benzoate degradation without a lag phase. When incubated with a mixture of benzoate and terephthalate, subsequent degradation with preference for benzoate was observed. Both benzoate and acetate inhibited the anaerobic degradation of terephthalate. The observed inhibition is partially irreversible, resulting in a decrease (or even a complete loss) of the terephthalate-degrading activity after complete degradation of benzoate or acetate. Irreversible inhibition was characteristic for terephthalate degradation only because the inhibition of benzoate degradation by acetate could well be described by reversible noncompetitive product inhibition. Terephthalate degradation was furthermore irreversibly inhibited by periods without substrate of only a few hours. The inhibition of terephthalate degradation due to periods without substrate could be overcome through incubation of the culture with a mixture of benzoate and terephthalate. In this case no influence of a period without substrate was observed. Based on these observations it is postulated that decarboxylation of terephthalate, resulting in the formation of benzoate, is strictly dependent on the concomitant fermentation of benzoate. In the presence of higher concentrations of benzoate, however, benzoate is the favored substrate over terephthalate, and the culture loses its ability to degrade terephthalate. In order to overcome the inhibition of terephthalate degradation by benzoate and acetate, a two-stage reactor system is suggested for the treatment of wastewater generated during terephthalic acid production.
研究了乙酸盐、苯甲酸盐以及无底物阶段对一种互营产甲烷培养物厌氧降解对苯二甲酸（1,4 - 苯二甲酸酯）的影响。该培养物已在对苯二甲酸上富集，并且能够在无延滞期的情况下降解苯甲酸盐。当与苯甲酸盐和对苯二甲酸的混合物一起培养时，观察到随后优先降解苯甲酸盐。苯甲酸盐和乙酸盐均抑制对苯二甲酸的厌氧降解。观察到的抑制作用部分是不可逆的，导致在苯甲酸盐或乙酸盐完全降解后对苯二甲酸降解活性降低（甚至完全丧失）。不可逆抑制仅为对苯二甲酸降解所特有，因为乙酸盐对苯甲酸盐降解的抑制可以很好地用可逆非竞争性产物抑制来描述。此外，仅几小时的无底物阶段就会不可逆地抑制对苯二甲酸的降解。通过将培养物与苯甲酸盐和对苯二甲酸的混合物一起培养，可以克服因无底物阶段导致的对苯二甲酸降解抑制。在这种情况下，未观察到无底物阶段的影响。基于这些观察结果，推测对苯二甲酸的脱羧形成苯甲酸盐严格依赖于苯甲酸盐的伴随发酵。然而，在较高浓度的苯甲酸盐存在下，苯甲酸盐比对苯二甲酸更受青睐，并且培养物失去了降解对苯二甲酸的能力。为了克服苯甲酸盐和乙酸盐对苯二甲酸降解的抑制，建议采用两级反应器系统处理对苯二甲酸生产过程中产生的废水。
