豆豉纤溶酶对枯草杆菌WB800的影响

Influence of Douchi Fibrinolytic Enzyme on Bacillus subtilis WB800

[目的]研究豆豉纤维酶(DFE)在枯草杆菌WB800中的生理功能。[方法]以能够合成DFE的重组菌株WB800/pBE3.DFE为试验菌株,研究其产孢率和在各外界胁迫下的耐受性。[结果]菌株WB800/pBE3和WB800/pBE3.DFE在产孢培养基中发酵24 h后,菌株WB800/pBE3.DFE的产孢率仅比对照菌株高9.6%;继续发酵至48 h,菌株WB800/pBE3.DFE的产孢率提高到了83.3%,而对照菌株的产孢率只有57.0%。表明DFE可以提高枯草杆菌的产孢率。在酸性、NaCl、高温、H2O2胁迫下,菌株WB800/pBE3.DFE的耐受性要高于对照菌株。可见,DFE很可能通过调节产孢机制来提高枯草杆菌的耐受性。[结论]该研究初步揭示了DFE在枯草杆菌中的生理功能,为DFE的应用奠定了理论基础。

[Objective]The research aimed to study the physiological function of douchi fibrinolytic enzyme（DFE） in Bacillus subtilis WB800.[Method]The recombinant strain WB800/pBE3.DFE which could synthetize DFE was as the experimental strain.The sporulation rate and tolerance on every external stress were studied.[Result]After WB800/pBE3 and WB800/pBE3.DFE were cultivated 24 h in the sporulation medium,the sporulation rate of WB800/pBE3.DFE was only 9.6% higher than that of control strain.When continued to ferment to 48 h,the sporulation rate of WB800/pBE3.DFE increased to 83.3%,but the sporulation rate of control strain was only 57.0%.It showed that DFE could improve the sporulation rate of Bacillus subtilis.Under the compelling of acidity,NaCl,high temperature and H2O2,the tolerance of WB800/pBE3.DFE was higher than that of control strain.It was thus clear that DFE was possible to improve the tolerance of Bacillus subtilis by regulating the sporulation mechanism.[Conclusion]The research revealed initially the physiological function of DFE in Bacillus subtilis,which laid the theory basis for the application of DFE.