耐盐性脂肪酶产生菌的分离、鉴定及紫外线&He-Ne激光复合诱变

Isolation and identifi cation of halo-tolerant bacteria with lipaseproducing activity and breeding by UV & He-Ne laser complex mutagenesis

通过富集、初筛和复筛从榨油厂附近的土壤中分离筛选耐盐脂肪酶产生菌ZF-9,经形态学、生理生化及16S r RNA序列分析,菌株ZF-9被鉴定为醋酸钙不动杆菌(Acinetobacter calcoaceticus),产脂肪酶活力为44 U/m L。为增强该菌株的耐盐和产脂肪酶的能力,对其进行紫外线&He-Ne激光复合诱变,获得遗传稳定性良好的突变株ZF-9-14,其所产脂肪酶的酶活最高可达138 U/m L,此外还可耐受30%浓度的氯化钠。作为一种耐盐且高产脂肪酶的菌,该突变株在食品生产及环境修复等方面有极为广阔的应用前景。

A lipase-producing strain ZF-9, with halo-tolerant ability, was isolated from soil and selected out by enrichment culture, prescreening and rescreening. Through morphological, physiological, biological,and phylogenetic （16S rRNA） characterization, the strain ZF-9 with the lipase activity of 44 U/mL, was identified as Acinetobacter calcoaceticus. In order to enhance its lipase-producing and halo-tolerant ability. The strain was mutated by UV ＆ He-Ne laser complex irradiation. After the mutation, the mutant ZF-9-14 with the highest lipase-producing ability was selected out and tested on its hereditary stability by analysis of variance. As was shown in the result, lipase produced by the mutant ZF-9-14 could reach to 138 U/mL, which was 310% of wild strain. Moreover, compared to the wild strain, the mutant ZF-9-14 could endure higher NaCI concentration. Even in the culture with 30% of NaCI concentration, the lipase still could maintain its ability. Therefore, as a halo-tolerant and high-lipase-producing bacteria, the mutant ZF-9-14 will have a broad application prospects in food production and environment restoration.