中文摘要：

为促进嗜盐微生物及其所产蛋白酶的工业应用，采用脱脂奶粉培养基从我国天津近海盐田富集筛选得到产蛋白酶中度嗜盐菌株SY-7. 通过对其形态特征、生理生化、16S rRNA基因序列及系统进化树进行分析，确定菌株的分类地位. 利用Plackett-Burman（PB）设计和响应面优化法（Response surface methodology）优化其发酵条件. 结果表明：菌株SY-7为革兰氏阳性菌，最适生长温度为30 ℃、最适生长pH 7.5，最适NaCl为10%. 16S rRNA基因序列分析显示，菌株SY-7与Thalassobacillus devorans亲缘性最近，16S rRNA基因序列相似性为98.88%. 利用PB设计从众多影响因素中筛选出影响较大的3个因素：葡萄糖含量、接种量和装液量；再利用响应面法中的杂合设计进行优化，通过拟合得到响应曲面函数，获得了最佳的产酶条件. 在该实验条件下酶活从870 U/mL提高到1 390 U/mL，实际酶活力达到理论预测值的98.3%，优化效果较好. 图2 表5 参19

英文摘要：

A protease-producing strain SY-7 was screened by skim milk agar method from Tianjin offshore salt pan of China. The strain was identified by morphological, biochemical and physiological and phylogentic analysis, and the fermentation conditions for protease-producing were optimized by Plackett-Burman （PB） design and response surface methodology. Strain SY-7 was Gram^-positive, and it grew best at 30 ℃, pH 7.5 and with the presence of 10% NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain belonged to the genus Thalassobacillus, and had the highest similarity （98.88%） with T. devorans. Three statistically significant parameters （quantity of glucose, liquid volume and inoculum volume） were determined by PB design. With the hybrid design, response surfaces were optimized and response surface function was obtained. The production of protease increased significantly to 1 390 U/mL from 870 U/mL under the optimal levels of the fermentation conditions. The test data of enzyme activity reached 98.3% of the calculated data, indicating that the optimization was effective. Fig 2, Tab 5, Ref 19