UHT乳中产耐高温脂肪酶嗜冷菌的研究

STUDIES OF PSYCHROPHILIES PRODUCING THERMOTOLERANT LIPASESIN UHT MILK

从牛乳中筛选到1株产耐高温脂肪酶的嗜冷菌株DW-A,通过对其形态学及生理生化特性的研究,鉴定该菌株为脆弱假单胞菌(P.fragis)。对其生长特性进行了研究,菌株DW-A在发酵液体培养基中振荡培养时,0h～12h为生长延迟期,12h～36h为对数生长期,36h～84h为稳定期,84h后为衰亡期;最适生长温度为20℃;最适作用pH值为7.0;最适培养液NaCl浓度为0%～1%。

A strain producing Heatproof lipases of Psychrophilies was isolated from milk. The morphological and physiological properties of this strain were studied. According to Bergey,s Munual of Determinative Bacteriology, the strain was identified to be P. fragis. The lag phase of the growth curve of DW - A was in 0 - 12h,log phase was in 12 - 36h, stationary phase was in 36 - 84h, decline phase was after 84h,when DW - A was shaking - cultured in fermentation liquid medium. Its optimum growth temperature was 20% ;the optimum growth pH was 7.0; and the optimum salinity ranges from 0 to 1% Nacl concentration.