Department of Microbiology, Max Planck Institute for Marine Microbiology, Bremen, Germany.
FEMS Microbiol Ecol. 2010 Mar;71(3):460-8. doi: 10.1111/j.1574-6941.2009.00814.x. Epub 2009 Nov 11.
The identity of the microorganisms capable of anaerobic p-xylene degradation under denitrifying conditions is hitherto unknown. Here, we report highly enriched cultures of freshwater denitrifying bacteria that grow anaerobically with p-xylene as the sole organic carbon source and electron donor. Long curved rods, with 95% 16S rRNA gene sequence identity to Denitratisoma oestradiolicum, dominated the enrichment cultures (>91% of all cells), as detected by phylotype-specific probes. These Rhodocyclaceae microorganisms were distantly related to other denitrifying hydrocarbon-degrading Betaproteobacteria from the Azoarcus-Thauera clade. Complete oxidation p-xylene to CO(2) coupled to denitrification was suggested by quantitative measurements of substrate consumption. Metabolite analysis identified (4-methylbenzyl)succinate and (4-methylphenyl)itaconate, suggesting addition to fumarate as an initial activation reaction.
迄今为止，能够在反硝化条件下进行厌氧对二甲苯降解的微生物的身份尚不清楚。在这里，我们报告了从淡水中富集的能够以对二甲苯作为唯一有机碳源和电子供体进行厌氧生长的反硝化细菌培养物。通过种特异性探针检测，长弯曲杆菌（其 16S rRNA 基因序列与 Denitratisoma oestradiolicum 的同源性高达 95%）是富集培养物中的主要优势菌（占所有细胞的>91%）。这些 Rhodocyclaceae 微生物与 Azoarcus-Thauera 丛的其他反硝化烃降解β-变形菌在系统发育上关系较远。通过对底物消耗的定量测量，表明对二甲苯完全氧化为 CO(2) 与反硝化作用偶联。代谢物分析鉴定了（4-甲基苄基）琥珀酸和（4-甲基苯基）衣康酸，表明其作为初始激活反应添加到富马酸中。
