title: Production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from excess activated sludge as a promising substitute of pure culture.
abstract: This study aimed to investigate the feasibility and technology to harvest poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) by mixed culture. Copolymer PHBHHx, usually fermented by pure strains, was reported to be synthesized from activated sludge for the first time. Sodium laurate was used as the sole carbon substrate for sludge acclimation and PHBHHx accumulation. Batch experiments were designed to look into the impact of the carbon, nitrogen, phosphorus and oxygen supply on PHBHHx production. The results showed that the acclimated excess sludge was able to produce PHBHHx, and the maximum output (505.6 mg/L PHBHHx containing 6.34 mol% HHx) was achieved with conditions of the continuous aeration, nitrogen and phosphorus limitation, and adequate carbon source implemented by pulse feeding 0.5 g/L sodium laurate every 4h. Moreover, composition and structure of the PHBHHx from sludge were found similar to that from pure culture, according to literature, FTIR and NMR spectra. Finally, high-throughput sequencing technique characterized that phylum Chlorobi and genus Leadbetterella should be critical groups for PHBHHx synthesis in the sludge community.
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Shen
authors.affiliation: College of the Environment and Ecology, Xiamen University, Xiamen 361005, China.
authors.forename: Hongyou
authors.initials: H
authors.lastname: Hu
authors.affiliation: College of the Environment and Ecology, Xiamen University, Xiamen 361005, China.
authors.forename: Hongfang
authors.initials: H
authors.lastname: Ji
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China.
authors.forename: Chuanpan
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China.
authors.forename: Ning
authors.initials: N
authors.lastname: He
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China.
authors.forename: Qingbiao
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China. Electronic address: wypp@xmu.edu.cn.
authors.forename: Yuanpeng
authors.initials: Y
authors.lastname: Wang
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000096:biosynthesis*; D000332:Aerobiosis / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D061249:Batch Cell Culture Techniques; D057919:Biological Oxygen Demand Analysis; D001709:Biotechnology / Q000379:methods*; D002208:Caproates; D002244:Carbon / Q000494:pharmacology; D014644:Genetic Variation; D009584:Nitrogen / Q000494:pharmacology; D010758:Phosphorus / Q000494:pharmacology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D013997:Time Factors; D000094122:Polyhydroxybutyrates
chemical_list: D020155:3-Hydroxybutyric Acid; D002208:Caproates; D002244:Carbon; D009584:Nitrogen; D010758:Phosphorus; D012336:RNA, Ribosomal, 16S; D012722:Sewage; C115940:poly(3-hydroxybutyrate-co-3-hydroxyhexanoate); D000094122:Polyhydroxybutyrates
keywords: Activated sludge; High-throughput sequencing; PHBHHx; Sodium laurate