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从南极普里兹湾深海沉积物中筛选到一株产低温脂肪酶的菌株7195, 细菌学形态鉴定及16S rDNA 序列分析表明该菌株属于嗜冷杆菌属( Psychrobacter) 。生长特性研究表明该菌株属于耐冷菌, 其最适生长温度范围为5~ 15??C, 7195 菌株能利用多种碳、氮源产酶。粗酶液经硫酸铵盐析、DEAE cellulose- 52 柱层析进行初步分离纯化后进行酶学性质的研究。该菌株所分泌的脂肪酶最适作用温度为30??C, 最适pH 值为9. 0, 对热敏感, 60??C 热处理10min 剩余酶活为30%, 是典型的低温酶。Ca2+ 、Mn2+ 、 Cu2+ 对该酶有较为明显的激活作用, 而Co2+ 、Zn2+ 、Hg2+ 、Rb2+ 、Cd2+ 、Fe3+ 、EDTA 则能抑制酶活, 此外该脂肪酶能在高浓度的 SDS、CHAPS、Triton X- 100、Tween 80、Tween20 等变性剂中表现出较好的稳定性。

英文摘要:

A strain 7195, which produces cold- adapted lipase, was isolated from the deep sea sediment of Prydz Bay, Antarctic. The morphology identification and 16S rDNA sequence analysis showed that it belonged to genus Psychrobacter. The optimal growth temperature of the Psychrobacter sp. 7195 was 5~ 15?? , indicating it was a psychrophile bacter ium. The strain could utilize various single carbonaceous and n-i trogenous substances and produce lipase. The optimal and highest temperatures for enzyme producing were 20?? and 30?? respectively. The enzyme purification was performed by ammonium sulfate fractionation and anion exchange chromatography with DEAE cellulose- 52. It was sensitive to high temperature. The optimal temperature and pH value for the lipase activity were 30??C and 9. 0 respectively. These results indicated that they were typical alkaline cold- adapted enzymes. The activities of them were stimulated by Ca2+ , Mn2+ , Cu2+ and were inhibited by Zn2+ 、 Hg2+ 、Rb2+ 、Cd2+ , Co2+ , Fe3+ and EDTA. The cold- adapted lipase showed better resistance to inactivation of 1% detergents such as SDS, CHAPS, etc.

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