Environmental biodegradation of haloarchaea-produced poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in activated sludge----中国科学院微生物研究所

科研成果

论文题目:	Environmental biodegradation of haloarchaea-produced poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in activated sludge
作者:	Liu Xiao-Bin, Wu Lin-Ping, Hou Jing, Chen Jun-Yu, Han Jing, and Xiang Hua*.
联系作者:
刊物名称:	Applied microbiology and biotechnology
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年份:	2016
影响因子:	3.848
论文下载:	http://link.springer.com/article/10.1007%2Fs00253-016-7528-2
摘要:	Novel poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) copolymers produced by haloarchaea are excellent candidate biomaterials. However, there is no report hitherto focusing on the biodegradation of PHBHV synthesized by haloarchaea. In this study, an environmental biodegradation of haloarchaea-produced PHBHV films, with 10~60 mol% 3-hydroxyvalerate (3HV) composition and different microchemical structures, was studied in nutrition-depleted activated sludge. The changes in mass, molar mass, chemical composition, thermal properties, and surface morphology were monitored. The mass and molar mass of each film decreased significantly, while the PHA monomer composition remained unchanged with time. Interestingly, the sample of random copolymer PHBHV-2 (R-PHBHV-2) (3HV, 30 mol%) had the lowest crystallinity and was degraded faster than R-PHBHV-3 containing the highest 3HV content or the higher-order copolymer PHBHV-1 (O-PHBHV-1) possessing the highest surface roughness. The order of biodegradation rate was in the opposite trend to the degree of crystallizability of the films. Meanwhile, thermal degradation temperature of most films decreased after biodegradation. Additionally, the surface erosion of films was confirmed by scanning electron microscopy. The dominant bacteria probably responsible for the degradation process were identified in the activated sludge. It was inferred that the degradation rate of haloarchaea-produced PHBHV films mainly depended on sample crystallinity, which was determined by monomer composition and microchemical structure and in turn strongly influenced surface morphology.