深海适冷假交替单孢菌Pseudoaltermonas sp.SM9913产适冷蛋白酶的条件优化

对深海适冷假交替单孢菌Pseudoaltermonas sp．SM9913适冷蛋白酶的发酵产酶条件进行了优化．研究结果表明，在发酵培养基中添加一定量柠檬酸钠有利于提高产酶；较难分解利用的氮源，如豆粕、豆粉，能诱导适冷蛋白酶合成，而较易吸收利用的氮源，如豆粕水解液、蛋白胨、尿素、铵盐等，对产酶有抑制作用；添加表面活性剂吐温80和SDS能促进酶向胞外的分泌；钙、镁离子促进产酶，锌、铜、铁离子对产酶有抑制作用；发酵产酶是好氧过程，装液量较少对产酶比较有利；发酵培养基初始pH7．0～8．0利于产酶．在优化后的发酵条件下，Pseudoaltermonas sp．SM9913产适冷蛋白酶量较原来提高了约65％，为适冷蛋白酶向着工业化生产应用提供了基础数据．

Optimization of cold-adapted protease fermentation by benthal psychrotrophic Pseudoaltermonas sp.SM9913

Fermentation conditions of cold-adapted protease by benthal psychrotrophic Pseudoaltermonas sp. SM9913 were optimized. The results showed that citrate would increase the production of protease. If bean-bits and bean-cake powders were added to the media as nitrogen sources, the yield of protease increased. While the nitrogen source that could be absorbed easily, such as bean-bits hydrolysate, peptone, urea and ammonium, restrained the production of protease. Ca 2+, Mg 2+ stimulated the strain to secret protease, whereas Zn 2+, Cu 2+, Fe 2+ had negative effects. Surface-active agents, Tween 80 and SDS, could increase the production of protease. Oxygen was strictly needed in fermentation, less liquid culture medium was beneficial for production of protease. The initial pH of the medium between 7.0 and 8.0 was suitable for protease production. Under such fermentation optimization the yield of protease increased by about 65%.