The effect of anaerobic–aerobic and feast–famine cultivation pattern on bacterial diversity during poly-β-hydroxybutyrate production from domestic sewage sludge

Liu, Changli; Liu, Di; Qi, Yingjie; Zhang, Ying; Liu, Xi; Zhao, Min

The effect of anaerobic–aerobic and feast–famine cultivation pattern on bacterial diversity during poly-β-hydroxybutyrate production from domestic sewage sludge

2016

The main objective of this work was to investigate the influence of different oxygen supply patterns on poly-β-hydroxybutyrate (PHB) yield and bacterial community diversity. The anaerobic–aerobic (A/O) sequencing batch reactors (SBR1) and feast–famine (F/F) SBR2 were used to cultivate activated sludge to produce PHB. The mixed microbial communities were collected and analyzed after 3 months cultivation. The PHB maximum yield was 64 wt% in SBR1 and 53 wt% in SBR2. Pyrosequencing analysis 16S rRNA gene of two microbial communities indicated there were nine and four bacterial phyla in SBR1 and SBR2, respectively. Specifically, Proteobacteria (36.4 % of the total bacterial community), Actinobacteria (19.7 %), Acidobacteria (14.1 %), Firmicutes (4.4 %), Bacteroidetes (1.7 %), Cyanobacteria/Chloroplast (1.5 %), TM7 (0.8 %), Gemmatimonadetes (0.2 %), and Nitrospirae (0.1 %) were present in SBR1. Proteobacteria (94.2 %), Bacteroidetes (2.9 %), Firmicutes (1.9 %), and Actinobacteria (0.7 %) were present in SBR2. Our results indicated the SBR1 fermentation system was more stable than that of SBR2 for PHB accumulation.

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