一平浪盐矿产蛋白酶嗜盐古菌的鉴定及其酶学性质

从分离自一平浪盐矿的嗜盐古菌中筛选产胞外蛋白酶菌株,并对所产蛋白酶的酶学性质进行初步研究。结果表明,2株高产胞外蛋白酶嗜盐古菌YPL20和YPL26为盐矿盐古球菌（Halococcus salifodinae）。YPL20胞外蛋白酶最适反应条件为50℃,p H9.0和0 mol/L Na Cl。YPL26胞外蛋白酶最适反应条件为50℃,p H7.0⁹.0和2.5 mol/L Na Cl。它们具有良好的热稳定性、酸碱稳定性和盐度耐受性。Mn²⁺、Ca²⁺对YPL20和YPL26的蛋白酶活性均有促进作用,而Cu²⁺、Zn²⁺均有抑制作用。丝氨酸蛋白酶抑制剂完全抑制YPL20和YPL26的蛋白酶活性,说明YPL20和YPL26的胞外蛋白酶是丝氨酸蛋白酶。 

Identification of halophilic archaea producing protease from Yipinglang salt mine and its enzymatic properties

Haloarchaeal strains isolated from Yipinglang salt mine were screened for extracellular protease production.Their enzyme properties were studied.The results showed that YPL20 and YPL26 showed the highest protease activity, and were identified as Halococcus salifodinae strains.The maximal protease activity of YPL20 occurred at 50℃, p H9.0, and 0 mol/L Na Cl.The YPL26 protease exhibited optimal activity at 50℃, p H7.0⁹.0, and 2.5 mol/L Na Cl.The YPL20 and YPL26proteases were highly stable over wide ranges of temperatures, p H values and Na Cl concentrations.Mn²⁺and Ca²⁺significantly enhanced protease activity of YPL20 and YPL26.Cu²⁺and Zn²⁺significantly inhibited the protease activities.The protease activities were completely inhibited by serine protease inhibitor, indicating that YPL20 and YPL26 proteases may be serine proteases.