混合电子供体对好氧非光合微生物菌群固碳效率影响的析因实验分析

通过混合电子供体析因实验,定量描述了Na2S、NaNO2、Na2S2O3 3种无机物的用量和比例与非光合微生物固碳量之间的关系,并分析了3种电子供体之间的两两交互作用.最后,通过16S rDNA V3区DGGE图谱分析,研究了不同混合电子供体对固碳微生物群落结构的影响.结果表明,电子供体析因实验的模型具有较好的拟合度,...

Effect evaluation of different electron donors on CO2 fixation by a non-photosynthetic microbial community under aerobic conditions using factorial design

Carbon dioxide is one of the main greenhouse gases, but it is also the most abundant carbon source, so that its recycle and reuse has become an important issue. In our experiment, a factorial design was used to demonstrate the interaction effects of different electron donors on CO₂ fixation by a non-photosynthetic microbial community under aerobic conditions, and PCR-DGGE technology was applied to analyze the changes of microbial community structure during CO₂ fixing with different electron donors. The results showed that the factorial design models were of high quality to predict the CO₂ fixation efficiency of the non-photosynthetic microbial community. Na₂S and Na₂S₂O₃ could each enhance its CO₂ fixation efficiency, and the positive effect was reinforced when both were present. NaNO₂ as added electron donor could significantly enhance CO₂ fixation, but this effect was competitively inhibited when Na₂S₂O₃ or Na₂S was added to the medium. The DGGE patterns revealed significant differences among microbial communities cultivated with various electron donors, demonstrating changes of CO₂ fixation efficiency at the molecular level. Nitrobacteria, which were predominant when pre-incubated under conditions in which NH⁺₄ was sole electron donor, disappeared in general when other electron donors were added, but many other strains which grow well in the medium with different electron donors appeared. Some of them might fix CO₂ efficiently, but some of them might compete with the bacteria which can fix CO₂.