ABSTRACT
Effects of main environmental factors, such as temperature, pH , metal ions and anions, on expression and activity of bacterial extracellular car bonic anhydrase(CA) were studied, exemplified by a bacterium named GLRT102Ca, wh ich was separated from karst ecosystems of Southwest China. The results showed that the tested strain could express different activity of extracellular carboni c anhydrase within the scope of experimental temperature (10℃~50℃) and pH (5. 5~9.0). The activity of extracellular carbonic anhydrase was higher at tempera ture of 20℃~30℃ and at neutral and alkaline trending condition. Moreover, the expression of activity of extracellular carbonic anhydrase could be generally p romoted at the experimental range of concentration of 4 kinds of metal ions such as Ca2+, Mg2+, Zn2+ and Co2+, along with 8 kinds of ani ons such as SO2-_4, H_2PO-_4, NO-_3, NO-_2, Cl-,Br-, I- and HCO-_3. This research provides a cert ain theoretical basis for further study on the role of microbial CA in karst pro cesses.