西南岩溶区土壤细菌胞外碳酸酐酶的稳定性研究  

Study on Stability of Extracellular Carbonic Anhydrase from Soil Bacteria in Karst Areas of Southwest China

作　　者：余龙江[1] 吴云[1] 李为[1] 曾宪东[1] 

机构地区：[1]华中科技大学生命科学与技术学院,中国湖北武汉430074

出　　处：《生命科学研究》2004年第4期365-370,共6页Life Science Research

基　　金：国家自然科学基金重大研究计划项目(90202016);国家自然科学基金面上项目(40152002;40302034);国土资源部岩溶动力学重点实验室资助

摘　　要：分析了来源于西南几个不同类型岩溶地区土壤细菌的胞外碳酸酐酶(CA)活性,发现有不少菌株能够产生分泌胞外CA.以一株编号为GLCa102的菌株为代表,模拟岩溶环境条件,研究其胞外CA的稳定性,结果表明该微生物胞外CA具有良好的热稳定性.偏碱性条件的岩溶土壤环境有利于胞外CA活性的相对稳定.岩溶环境主要金属离子如Ca2+、Mg2+、Zn2+和Co2+等以及阴离子如SO42-、H2PO4-、NO3-、NO2-、Cl-、Br-和I-等在一定浓度范围内可使微生物胞外碳酸酐酶保持50%以上的活性.参照岩溶土壤水体元素背景值,表明岩溶环境的离子含量有利于该微生物胞外CA活性的相对稳定.此研究为深入研究微生物CA在生物岩溶中的作用和地位提供了一定的科学依据.The activity of extracellular carbonic anhydrase (CA) from some soil bacteria in different types of karst area in southwest China was analyzed. It was found that quite a few of strains could produce and secrete extracellular CA. Taking a strain numbered GLCa102 for example, the stability of its extracellular CA was studied through simulating karst environmental conditions. The results showed that the microbial extracellular CA displayed good thermostability. Alkaline condition of karst soil environments was fit for keeping relative stability of extracellular CA. More than 50%of the activity of the microbial extracellular CA could remain under a certain range of concentration of mental ions in karst environment such as Ca2+、Mg2+、Zn2+and Co2+, along with anions such as SO42-、H2PO4-、NO3-、NO2-、Cl-、Br-and I-.According to the background of elements in karst environments, the stability of the microbial extracellular CA could be well maintained in the concentration region of ions in soilwater and karstwater. This research provides scientific basis for further study on the role of microbial CA in biokarst.

关 键 词：岩溶环境 土壤细菌 碳酸酶(CA)活性 稳定性 

分 类 号：S154.3[农业科学—土壤学]