Optimization of polyhydroxybutyrate (PHB) production by excess activated sludge and microbial community analysis.
In this study, a high value-added and biodegradable thermoplastic, polyhydroxybutyrate (PHB), was produced by excess activated sludge. The effects of the nutritional condition, aeration mode, sodium acetate concentration and initial pH value on PHB accumulation in the activated sludge were investigated. The maximum PHB content and PHB yield of 67.0% (dry cell weight) and 0.740gCODgCOD(-1) (COD: chemical oxygen demand), respectively, were attained by the sludge in the presence of 6.0gL(-1) sodium acetate, with an initial pH value of 7.0 and intermittent aeration. The analysis of the polymerase chain reaction (PCR)-denaturing gradient-gel-electrophoresis (DGGE) sequencing indicated that the microbial community of the sludge was significantly different during the process of PHB accumulation. Three PHB-accumulating microorganisms, which were affiliated with the Thauera, Dechloromonas and Competibacter lineages, were found in the excess activated sludge under different operating conditions for PHB accumulation.
Liu
Zhenggui
Z
Environmental Science Research Center, College of Oceanography and Environmental Science, Xiamen University, Xiamen 361005, PR China.
Wang
Yuanpeng
Y
He
Ning
N
Huang
Jiale
J
Zhu
Kang
K
Shao
Wenyao
W
Wang
Haitao
H
Yuan
Weilong
W
Li
Qingbiao
Q
D000332:Aerobiosis; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D003001:Cloning, Molecular; D003470:Culture Media; D004247:DNA / Q000737:chemistry / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D006863:Hydrogen-Ion Concentration; D006885:Hydroxybutyrates / Q000737:chemistry*; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D010802:Phylogeny; D011091:Polyesters / Q000737:chemistry*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology*; D014871:Water Microbiology; D000094122:Polyhydroxybutyrates
D002244:Carbon; D003470:Culture Media; D004247:DNA; D006885:Hydroxybutyrates; D009584:Nitrogen; D010758:Phosphorus; D011091:Polyesters; D012722:Sewage; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates