通过丁醇富集筛选,从土壤样品中筛选到一株菌株SCH17。经过生理特性和16S rRNA分析,鉴定菌株SCH17属于假单胞菌属。透射电镜显示该菌细胞内聚集了大量颗粒状物质,经过氯仿抽提和核磁共振分析,确认这些颗粒物质是聚β-羟基丁酸(PHB)。通过对碳源和氮源的优化,得到最佳积累PHB的碳源是果糖,氮源是蛋白胨。在该培养基中仅需发酵14 h,菌体干重和PHB含量均达到最大,分别为3.52 g/L和2.69 g/L,PHB含量高达细胞干重的76%。
A novel poly β-hydroxybutyrate(PHB)-accumulating bacterium,strain SCH17,was isolated from soil samples by butanol enrichment.A phylogenetic analysis based on 16S rRNA sequence data indicated that the strain SCH17 was a member of the genus Pseudomonas.Transmission electron mi-crographs showed electron-transparent intracellular granules.The purified sample was extracted from cells with chloroform and was determined as PHB by nuclear magnetic resonance analysis.Pseudomo-nas sp.SCH17 was able to accumulate PHB after growth on various carbon and nitrogen substrates.Fructose and fish peptone were the optimal carbon source and the optimal carbon source,respectively.After grown under the optimal conditions for 14 h,the maximum cell dry weight of 3.52 g/L with the PHB concentration of 2.69 g/L was obtained,and the PHB content was up to 76%.