深海产低温脂肪酶菌株Dspro004的诱变育种

The Mutagenic Breeding of a cold-adapted lipase producing strain Dspro004 from deep sea

从一株深海环境中筛选到的产低温脂肪酶菌株Dspro004出发,对其进行了紫外诱变筛选,以期获得高产脂肪酶的突变菌株。实验结果表明,选择致死率为81%的诱变剂量,获得了一株能稳定遗传的正突变株UM3,该突变株酶活力可达2540～2710 U/mg,比出发菌株提高约34%～39%。酶学性质研究表明,该酶的最适作用温度为30℃,最适作用pH值8.5。在低于30℃、pH值7～8的条件下放置12 h后,酶活可保持在70%以上,显示出较好的稳定性。

A strain Dspro004 producing cold-adapted lipase was isolated from the deep sea sediment. In order to obtain the high-yield lipase strain, the stain Dspro004 was treated by UV-treatment. One positive mutation, UM3, was obtained when the lethality rate was 81% mutagen dosage. The lipase activity of UM3 was increased to 2540 -2710 U/rag, with about 34 -39% more than the starting strain. The optimal temperature and pH for the activity of UM3 were 30~C and 8.5, respectively. The residual activity of UM3 were higher than 70% after 12 h incubation at temperatures below 30~C , or pH 7 ~ 8. The results showed that the UM3 lipase has better thermo-stability and pH-stability.