以富含蛋白质的浮萍作为有机氮源，接种一株通过自然筛选而得的新颖菌株Serratia sp. SYBC H，进行微生物发酵生产稀有的蛋白酶，为浮萍的高值化利用开创一条新途径。先采用单因素实验，研究影响Serratia sp. SYBC H发酵浮萍生产蛋白酶的发酵时间，碳源，C/N比，无机盐，产酶添加剂，结果发现：以小麦粉为碳源，小麦粉与浮萍比例为1:2，NaCl，表面活性剂吐温80，显著促进Serratia sp. SYBC H生产蛋白酶。接着采用正交试验，研究影响Serratia sp. SYBC H生产蛋白酶的发酵培养基的主要组成及其使用量。结果显示，在实验范围内，影响Serratia sp. SYBC H生产蛋白酶的发酵培养基组成及其最佳使用量为小麦粉15 g/L，浮萍30 g/L，吐温80，0.8% (V/V)，NaCl 0.05 mol/L。接种发酵18 h后，蛋白酶的生产值达到最大值，发酵液中最高蛋白酶活达到1459.94 U/mL。

The protease.was produced by microbial fermentation with a novel strain Serratia sp. SYBC H obtained by naturally screening and with protein-rich duckweed as organic nitrogen source, which provided a new approach for the high-valued utilization of duckweed resourceAt first, a single factor method was used to investigate a variety of variables affecting protease production, which contained carbon sources, C/N ratio, inorganic saltsand additives. The results demonstrated that wheat flour as carbon source, the ratio of wheat flour and duckweed as 1:2, NaCl and Tween 80 significantly improved the protease production by Serratia sp. SYBC H fermentation. Then, the orthogonal design was adopted to study the significant variables with levels for the protease production by Serratia sp. SYBC H fermentation. Within the experimental ranges, the significant factors with the optimal level for the maximum protease production by Serratia sp. SYBC H were wheat flour of 15 g/L, duckweek of 30 g/L, Tween 80 of 0.8 % (v/v), and NaCl of 0.05mol/L. The highest protease activity in the supernatant reached 1459.94 U/mL after fermentation for 18 h.

钦州学院引进高层次人才科研启动项目立项基金（2017KYQD117）