Chitinolyticbacter meiyuanensis SYBC-H1几丁质酶的性质及在虾皮水解中的作用

Enzyme Characterization of a New Strain of Chitinase

以一株产几丁质酶细菌Chitinolyticbacter meiyuanensisSYBC-H1为材料,对几丁质酶进行了分离纯化及酶学性质研究。通过硫酸铵沉淀、DEAE-cellulose阴离子交换介质和SephadexG-100分子筛层析柱处理其所产几丁质酶,获取纯度为95%以上的几丁质酶。酶学性质表明,该酶的最适温度为40℃,最适pH值为6.5,在50℃以下较为稳定,在pH值为5.0时最稳定,β-巯基乙醇有利于防止半胱氨酸氧化而增加几丁质酶稳定性,EDTA可增加该酶稳定性,Na+,K+对几丁质酶有明显的激活作用,Zn2+,Mn2+,Fe2+,Fe3+对几丁质酶有较大的抑制作用。SYBC-H1几丁质酶可把虾皮水解为N-乙酰氨基葡萄糖,水解率为21.8%。

Chitinase from a new isolated strain Chitinolyticbacter meiyuanensis SYBC-H1 was purified and characterized in this study.Chitinase of more than 95% purity was obtained after ammonium sulfate precipitation,DEAE-32 negative chromatography and Sephadex G-100 sieve chromatography.The results of enzyme properties indicated that its optimal pH and temperature was 40℃ and 6.5,respectively.Chitinase exposed to temperature lower than 50℃ was stable and it is most stable at pH 5.0.Its stability was promoted with the addition of mercaptoethanol and EDTA.Moreover,the chitinase activity was apparently stimulated by Na＋ and K＋,while inhibited by Zn2＋,Mn2＋,Fe2＋ and Fe3＋.The shrimp crust was hydrolyzed into acetylglucosamine by Chitinase from SYBC-H1,and the hydrolysis rate achieved at 21.8%.