互营烃降解菌系M82的脂肪酸降解特性

Degradation of fatty acid by syntrophic hydrocarbondegrading consortium M82

摘要:

摘要:【目的】通过分子生态学手段筛选适合互营烃降解菌Syntrophus sp．生长的非烃碳源。【方法】利用实验室驯化获得的正十六烷烃降解产甲烷菌系M82为接种物，添加不同碳源(正十二烷二元酸、正十四烷二元酸、正十六烷烃、十六烷酸钠、乳酸钠和丙酸钠)传代培养，通过PCR-DGGE和qPCR技术研究不同碳源条件下Syntrophaceae科细菌的丰度与变化趋势;利用T-RFLP方法分析古菌群落结构。【结果】菌系M82可以利用多种脂肪酸生长并产生甲烷，但是细菌群落结构发生了变化，只在添加正十二烷二元酸和正十四烷二元酸的培养液中检测到了代表Syntrophaceae细菌的条带，并且每毫升菌液中Syntrophaceae细菌的log丰度分别达到7.4和7.6，比添加其它几种非烃碳源的实验组丰度高2－3个单位。古菌群落结构主要由乙酸营养型产甲烷古菌(Methanosaeta)和氢营养型产甲烷古菌(Methanoculleus)组成。【结论】Syntrophus sp．细菌可以利用正十二烷二元酸和正十四烷二元酸这两种非烃碳源生长，这为我们定向分离互营烃降解菌和研究起始烃降解机制和代谢机理提供了依据。

Abstract:

Abstract:［Objective］Using molecular ecology methods，we screened non-hydrocarbon carbon sources suitable for growth of syntrophic hydrocarbon-degrading Syntrophus sp.［Methods］ The acclimated methanogenic hexadecane-degrading consortium M82 was subcultured with dodecanedioic acid，tetradecanedioic acid，hexadecanoic acid，propionate and lactate． PCR-DGGE and qPCＲ were used to analyze the abundance and quantity of syntrophaceae using different carbon sources．The T-RFLP was applied to analyze archaeal community．［Results］ The consortium M82 could grow and produce methane using a variety of fatty acids that also resulted in the change in bacterial microbial community structure．Syntrophaceae bacterial stripe was obviously detected in the culture added additional dodecanedioic acid and tetradecanedioic acid．Furthermore，the results show that the logarithmic abundance of Syntrophaceae was 7.4 and 7.6 in per milliliter culture in the two enrichment cultures respectively，which were 2－3 units higher than these in other cultures．The archaeal community structure was mainly composed of acetoclastic methanogens Methanosaeta and hydrogenotrophic methanogens Methanoculleus in all culture．［Conclusion］ Syntrophus sp．can use non-hydrocarbon carbon source ( dodecanedioic acid and tetradecanedioic acid) as substrate to grow，which provides valuable information to isolate syntrophic hydrocarbon bacteria，and reveal the molecular mechanism of syntrophic hydrocarbon degradation．