摘要
为揭示碳源浓度对微生物发酵产氢及铁还原特征的影响,研究了发酵产氢型Fe(Ⅲ)还原菌JX1-25以不同浓度葡萄糖为唯一碳源时对Fe(Ⅲ)的还原特征、培养体系氢气分压及p H值,探讨了微生物产氢过程与Fe(Ⅲ)还原过程的关系,以及Fe(Ⅲ)还原过程对体系碳源电子消耗的贡献。结果表明:菌株JX1-25利用0.25、0.5、2、4、8、16 mmol·L-1葡萄糖为碳源还原Fe(Ⅲ)时,Fe(Ⅲ)还原率分别达到6.81%、12.47%、56.69%、97.71%、96.86%、99.77%;Fe(Ⅲ)还原潜势(a)、铁还原最大反应速率(Vmax)与氢气分压峰值(pp H2max)均随着体系葡萄糖浓度的升高而升高,而体系p H值随之降低;Fe(Ⅲ)还原过程消耗电子占体系葡萄糖提供电子的比例为2.02%~9.69%,产氢过程对体系葡萄糖提供电子的消耗比例为13.74%~19.45%。CCA分析发现菌株JX1-25利用不同浓度葡萄糖的Fe(Ⅲ)还原过程与产氢过程存在一定的相关性,pp H2max与a、Vmax呈显著正相关关系,与达到最大反应速率对应的时间(TVmax)和体系最低p H值(pHmin)呈显著负相关关系。
Fermentative Fe(Ⅲ)reducing microorganism as a facultative anaerobe can reduce Fe(Ⅲ)to Fe(Ⅱ)by using the intermediates of glucose metabolism as an electron donor. However, the effects of carbon source concentrations on microbial hydrogen production and Fe(Ⅲ)reduction were unclear. A 30-d anaerobic pure incubation experiment with Fe(Ⅲ)reducing bacteria JX1-25 was conducted to investigate the effects of glucose concentrations on Fe(Ⅲ)reduction, p H and hydrogen partial pressure. When glucose was the sole carbon source, Fe(Ⅲ)reduction rates by the strain JX1-25 were 6.81%, 12.47%, 56.69%, 97.71%, 96.86% and 99.77% for 0.25, 0.5, 2, 4, 8mmol·L-1and 16 mmol·L-1glucose, respectively. The Fe(Ⅲ) reduction potential(a) and maximum reduction rate(Vmax)and hydrogen pressure peak(pp H2max)increased with increasing glucose concentrations. Electron consumption percentages of microbial Fe(Ⅲ)reduction and hydrogen production were respectively 2.02%~9.69% and 13.74%~19.45% at different concentrations of glucose. Glucose at 4 mmol·L-1was able to satisfy the demand of Fe(Ⅲ)reduction. Canonical correspondence analysis(CCA)indicated that there was to some extent correlation between microbial Fe(Ⅲ)reduction and hydrogen production, in which the strain JX1-25 used glucose as carbon source. The peak of hydrogen partial pressure(pp H2max)had an extremely significant positive correlation with a and Vmaxbut a negative correlation with the time to the maximum reduction rate(TVmax)and the minimum p H value of the incubation system(p Hmin).
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2015年第4期722-727,共6页
Journal of Agro-Environment Science
基金
国家自然科学基金面上项目(41171204)
关键词
葡萄糖浓度
发酵产氢
Fe(Ⅲ)还原
电子消耗比例
glucose concentration
fermentative hydrogen production
Fe(Ⅲ)reduction
electron consumption ratio
