化工学报2016，Vol.67Issue(10)：4431-4438,8.DOI:10.11949/j.issn.0438-1157.20160085
pH 对嗜盐混合菌发酵挥发性有机酸混合物合成PHA 的影响
Influence of pH on PHA production by halophilic sludge fermenting mixed VFAs substrate
摘要
Abstract
Polyhydroxyalkanoates (PHA) production by halophilic mixed microbial cultures (MMCs) draw a lot of attention because of great advantages, such as free sterilization, easily extraction and high production. In this study, halophilic MMC was used to investigate the effect of pH on PHA production in the mixed VFAs fermentation process. The results indicated that there was no significant influence on PHA production in the pH range of 6.5—8.2. PHA production rate and substrate utilization rate would be inhibited in lower or higher pH conditions. PHA yield was influenced by pH in the systems, but different influencing mechanism existed in acidic condition and alkaline condition. Alkaline environment led to higher dissociation degree of VFAs. Then more energy needed as substrates being absorbed, which further led to the decrease of VFAs absorption rate. This affect was obvious when pH raised to 9.2. Molecular-state VFAs changed intracellular pH in the acidic condition. Then, the lower activity of related enzymes and protein resulted in slower substrate utilization. Energy consumption of substrate utilization and microbial metabolism reduced when pH=5.2, resulting in the decrease of intracellular PHA degradation and the increase of PHA yield. The pH value had little influence on PHA component. And HV accounted for 34.9%—38.3% of PHA weight when the initial pH between 5.2 and 10.2. This study would be a guide for PHA production using mixed VFAs as carbon source by halophilic MMCs.关键词
聚羟基脂肪酸酯/pH/挥发性脂肪酸/嗜盐混合菌Key words
polyhydroxyalkanoate/pH/volatile fatty acid/halophilic mixed microbial cultures分类
资源环境引用本文复制引用
崔有为,张宏宇..pH 对嗜盐混合菌发酵挥发性有机酸混合物合成PHA 的影响[J].化工学报,2016,67(10):4431-4438,8.基金项目
国家自然科学基金项目(51478011，51178004)；北京市自然科学基金项目(8132013)；北京市属高等学校高层次人才引进与培养计划项目。@@@@Foundation item：supported by the National Natural Science Foundation of China (51478011,51178004), theNatural Science Foundation of Beijing (8132013) and the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions （51478011，51178004）
