Shinella zoogloeoides BC026对吡啶的降解特性研究

从首钢焦化厂的污水处理系统中分离1株能以吡啶为唯一碳、氮源的细菌BC026，它具有自絮凝特性，对卡那霉素、氨苄青霉素和壮观霉素具有抗性，可在阿须贝无氮培养基中良好生长.通过16S rRNA序列分析和Biolog微生物鉴定系统鉴定，确定该菌为Shinella zoogloeoides.纯菌对单基质的降解实验表明，在30℃、180 r/min和pH为7的条件下，当投菌量为0.1 g/L时，BC026可在17 h内将400 mg/L吡啶完全降解；在吡啶初始浓度为99～1 806 mg/L的无机盐培养基中，BC026均能保持降解活性，较高初始浓度的吡啶对BC026的生长产生一定抑制，但BC026在适应后对吡啶的降解速率较快；降解最适温度为30～35℃，最适pH为8.BC026对吡啶的代谢途径研究表明：降解的第一步是断开吡啶的2条C—N链，生成氨氮和戊二醛，随后戊二醛被氧化为戊二酸，并最终转化为二氧化碳和水；吡啶中的氮有59.5%转化成氨氮.

Biodegradation of Pyridine by Shinella zoogloeoides BC026

The microbial community structure of beer wastewater treatment plants with hydrolyze-acidification and SBR process was studied by PCR amplification and denaturing gradient gel electrophoresis (DGGE) based 16S rDNA. Activated sludge samples were collected from both hydrolyze-acidification tank and SBR tank at different depth and disposal period. The total DNA was extracted and the 16S rDNA was amplified by universal primer. The microbial community structure was analyzed by denaturing gradient gel electrophoresis, compared with the DGGE band pattern of the screened high efficient bacteria. The PCR products were cloned and sequenced to analyze the microbial community in phylogenic evolution. The DGGE pattern showed that the microbial community in hydrolyze-acidification tank changed with the variation of depth both in microbial structure and population, and at the depth of two-meter the microbial community was relatively rich, the dominant bands were notable. The microbial community in SBR tank at different depths and different disposal periods (precipitation period, inflow period, aeration period) were consistent respectively, but the dominant bands were different. Sequences of y2, 23, 25, 31, h5, 15 yielded high homogeneity with the strains uncultured Thermotogales sp., Comamonas sp. WT OTU1, Agrobacterium tumefaciens, Bacillus subtilis, Bdellovibrio bacteriovorus, Comamonas testosteroni from GenBank. The 16S rDNA sequences of the dominant bands were not completely same with that of the high efficient bacteria, which indicated that the strains screened were not the dominant strains in actual process.