海南近海水域产碱性蛋白酶菌株的分离筛选及发酵条件优化

【背景】微生物蛋白酶在工业生物技术上具有广阔的应用前景。在微生物蛋白酶中，碱性蛋白酶占全球酶总产量的50%以上，获取产碱性蛋白酶的新微生物资源意义重要。【目的】在海南近海贝类养殖基地海泥中筛选获得高产碱性蛋白酶的菌株，对其生长特性进行探究并优化菌株产酶条件，获得新的蛋白酶生产资源。【方法】以酪素培养基为筛选培养基，采用形态学结合系统发育分析鉴定菌株，通过响应面实验优化菌株的产酶条件。【结果】筛选获得一株高产碱性蛋白酶的菌株F3，鉴定为粘质沙雷氏菌（Serratia marcescens）。菌株在最优产酶条件下发酵酶活达到（339.36±4.30） U/mL。【结论】筛选获得的菌株粘质沙雷氏菌F3有较好的产碱性蛋白酶的能力。

Isolation and screening of alkaline protease-producing strains from Hainan offshore areas and optimization of the fermentation conditions

Background] Microbial proteases have broad application prospects in industrial biotechnology. Among microbial proteases, alkaline proteases account for more than 50% of the world''s total enzyme production. It is of great significance to explore new microbial resources that synthesize alkaline proteases. Objective] Strains with high production of alkaline proteases were screened from the sea mud of Hainan offshore shellfish breeding base and their growth characteristics were explored. Moreover, the conditions for the enzyme production were optimized. Thereby, new protease-producing resources were obtained. Methods] Casein medium was employed for screening the protease producers and the yielded strain was identified by morphological and phylogenetic analysis. The enzyme production conditions of the strain were optimized by response surface methodology. Results] Strain F3 with high production of alkaline protease was screened out and identified as Serratia marcescens. The enzyme activity in the fermentation broth of the strain was up to (339.36±4.30) U/mL under the optimal conditions. Conclusion] S. marcescens F3 has strong ability to produce alkaline protease.