A high-yield strain of PHAs, Bacillus sp. PB-3 was isolated from waste activated sludge by Nile red staining and fluorescence microscopy screening. Gas chromatography analysis indicated that the intracellular production of the strain was polyhydroxybutyrate ( PHB). Furthermore, medium composition and fermentation factors were investigated and optimized. The optimal carbon and nitrogen sources were glucose(12 g/L) and beef paste(2 g/L) , respectively. The optimal cultivation conditions were pH 7. 5 , 37 ℃ for 48 h, and 80 mL medium at an agitation rate of 200 r/min. Under the fermentation conditions, the yield of PHB was raised to 32. 09% (w/w) , 30% higher than that before optimized.%通过尼罗红染色法结合荧光显微镜镜检,从废弃活性污泥中分离得到1株高产聚羟基脂肪酸酯(PHAs)的菌株Bacillus sp.PB -3,经气相色谱法鉴定该菌株胞内产物为聚β-羟基丁酸酯(PHB).对培养基成分及发酵条件优化后,获得最佳培养方案:12 g/L的葡萄糖为C源,2 g/L的牛肉膏为N源,初始pH7.5,培养基装液量80 mL,转速为200 r/min,37℃培养48 h,PHB质量分数可达菌体干质量的32.09％,比优化前提高30％.
展开▼
