Competition and coexistence of sulfate-reducing bacteria, acetogens and methanogens in a lab-scale anaerobic bioreactor as affected by changing substrate to sulfate ratio

作者：Shabir Ahmad Dar, Robbert Kleerebezem, Alfons J. M. Stams, J. Gijs Kuenen, Gerard Muyzer · 发表于：Applied Microbiology and Biotechnology · 年份：2008 · DOI：10.1007/s00253-008-1391-8 · 被引用次数：302 · 研究领域：Wastewater Treatment and Nitrogen Removal、Anaerobic Digestion and Biogas Production、Microbial Community Ecology and Physiology

The microbial population structure and function of natural anaerobic communities maintained in lab-scale continuously stirred tank reactors at different lactate to sulfate ratios and in the absence of sulfate were analyzed using an integrated approach of molecular techniques and chemical analysis. The population structure, determined by denaturing gradient gel electrophoresis and by the use of oligonucleotide probes, was linked to the functional changes in the reactors. At the influent lactate to sulfate molar ratio of 0.35 mol mol(-1), i.e., electron donor limitation, lactate oxidation was mainly carried out by incompletely oxidizing sulfate-reducing bacteria, which formed 80-85% of the total bacterial population. Desulfomicrobium- and Desulfovibrio-like species were the most abundant sulfate-reducing bacteria. Acetogens and methanogenic Archaea were mostly outcompeted, although less than 2% of an acetogenic population could still be observed at this limiting concentration of lactate. In the near absence of sulfate (i.e., at very high lactate/sulfate ratio), acetogens and methanogenic Archaea were the dominant microbial communities. Acetogenic bacteria represented by Dendrosporobacter quercicolus-like species formed more than 70% of the population, while methanogenic bacteria related to uncultured Archaea comprising about 10-15% of the microbial community. At an influent lactate to sulfate molar ratio of 2 mol mol(-1), i.e., under sulfate-limiting conditions, a different met...