一株产聚-β-羟基脂肪酸酯嗜盐菌的筛选与鉴定

Isolation and Identification of A PHA-accumulating Halophilic Bacterium and Its Growth Characteristics

以大庆地区盐碱土壤为样品经苏丹黑B染色、尼罗蓝染色分离出6株具有聚-β-羟基脂肪酸酯(PHA)合成能力的菌株,选取产量较高的DQ-4进行鉴定,通过细菌形态学鉴定、16S rRNA分析并结合其生理生化特性,将菌株DQ-4鉴定为嗜盐单胞菌(Halomonas sp.)。GC-MS分析表明,菌株DQ-4合成的聚合物具有与PHA标样相似的峰值。FT-IR分析显示,菌株DQ-4合成的聚合物在1 726、2 980、2 934、2 876 cm^(-1)处出现了PHA的特征性吸收峰。因此,将其产物确定为PHA类化合物。菌株DQ-4的最适生长条件,温度38℃、p H值=9、转速160 r·min^(-1)、500 m L锥形瓶的装液量为100 m L,此条件下菌株DQ-4的PHA产量可达5.88 g·L^(-1)。

Six PHA-accumulating strains were isolated with the usage of Sudan black stain,Nile blue staining from saline soil in the region of Daqing,China. Impressing on bacteria morphology salinity resistance,combined with the analysis of the 16 S rRNA,a higher strain named DQ-4 was identified as Halomonas sp.. The product of strain DQ- 4 was similar with PHA standard by GC-MS. The FT-IR spectra of strain DQ-4 had a characteristic sharp absorption band around 1 726,2 980,2 934 and 2 876 cm（-1）. The optimal growth conditions for strains of DQ-4 are 38 ℃ temperature,pH value of 9,the speed of 160 r·min（-1）,and the fluid volume of 100/500 mL in flask with the PHA synthesis of 5.88 g·L（-1）.