适于非水相催化用细菌脂肪酶基本性质的研究

对假单胞菌产脂肪酶的基本酶学性质进行了研究．该酶水解油脂时的最适作用ｐＨ为９．０，最适作用温度为４５℃；在ｐＨ７．０～１０．０范围内稳定，在６０℃以下热稳定性良好．Ｋ＋、Ｃａ２＋、Ｍｇ２＋等金属离子对酶有明显的激活作用，而Ｈｇ２＋、Ｃｕ２＋、Ｓｎ２＋等重金属离子却对酶有较强的抑制作用；几种表面活性剂和胆汁盐均使酶发生不同程度的失活．该酶在水解油脂时表现出１，３－位置专一性，且对不同种类和来源的油脂水解作用速率不同

Enzymic Properties of a Bacterial Lipase Suitable for Biocatalysis in Nonaqueous Media

The enzymic properties of the lipase produced by a Pseudomonas sp.strain were investigated.The isolated enzyme had an optimum pH of 9 0 and showed maximum activity at 45℃ in triglyceride hydrolysis.It was fairly stable in a pH range of 7 0～10 0,and at temperature below 60℃.Its activity was significantly improved in the presence of K +,Ca 2+ ,Mg 2+ ,and was severely inhibited by Hg 2+ ,Cu 2+ ,Sn 2+ .The surfactants and bile salts tested also had negative effect to the enzyme activity.The lipase attacked triglycerides at 1,3 position specifically;its hydrolysis rates varied significantly among a wide variety of lipid substrates,and in general it hydrolyzed plant oils faster than animal oils,and hydrolyzed synthetic lipids faster than natural lipids.