Abstract:

Abstract: To investigate the characteristics and dynamic principle of the bile salt hydrolase produced by Kluyveromyces marxianus M3 from Tibetan Kefir, the single factor and multi levels orthogonal experiments was applied. Enzyme activity was tested under the different contitions:pH4~8, temperature31~43℃, concentration of substrate 4~8mmol/L, and different chemical reagents(SDS、EDTA、carbamide、Cu2+、Mg2+、Ca2+、Fe3+、Al3+、Mn2+ )during 30 min reaction between bile salt hydrolase and substrate. The optimal reaction condition of bile salt hydrolase was pH6.0, concentration of substrate 7mmol/L, temperature37℃. Metal ion of Mn2+、Fe3+、Ca2+ had comparatively large elevation effect on the enzyme activity, and other chemical reagents had few effect on the enzyme activity. The kinetic constant Km of bile salt hydrolase was 2.60 mmol/L. Strain M3 entered the stationary phases after 18~21h. The enzyme activity reached the maxlmum during log phase growth at18h. The experiments results showed the category of dynamic principle was growth couple synthesis type.