四脊裸胞壳Dh菌株液体培养条件下淀粉酶的产生及活性影响因子

对虫生真菌四脊裸胞壳(Emericella quadriclineata)Dh菌株产淀粉酶的条件及理化特性进行了研究.在孢子浓度为1.5×106个/mL的PD培养液中恒温(25±1)℃振荡(120 r/min)培养3.5 d,菌丝生物量最大达5.1 mg/mL,产淀粉酶量达272.42 U/mg;培养液初始pH4~6最有利淀粉酶的产生,产酶量为1 377.20~1 528.99 U/mg菌丝.淀粉酶活性在50℃,pH 6.0条件下最高.在pH4~7范围内20℃下处理20 min或在pH4~7范围内37℃下处理1 h酶活较为稳定,保持在65%以上.40℃下处理20 min酶活保持90%以上.60℃和70℃下处理20 min,酶活保持在50%以下.在70℃下处理80 min,剩余酶活仅为11.70%.一定浓度的Cu2+和Ba2+有利于酶活提高;同时Mg2+,Fe2+,Ca2+,NH4+对酶活性的抑制作用依次增强.

Production of Emericella quadriclineata Dh amylase in liquid culture and activity influential factors

Production condition and characteristics of E.quadriclineata Dh strain were studied in this paper.Shaking culture with the liquid containing 1.5×10~(6) connidia per millilitre for 3.5 d at the temperature of(25±1)℃ and 120 r/min resulted in max mycelial of 5.1 mg/mL and amylase yield of 272.42(U/mg).An initial range of pH 4～6 in the liquid culture was the most favorable to amylase production with the yields of 1377.20～1528.99 U/mg.The activity of E.quadriclineata Dh strain amylase was highest at 50 ℃ and pH 6.0.The amylase was considerably stable at pH 4～7 for 20 min at 20 ℃ and at pH 4～7 for 1 h at 37 ℃.The amylase had 90 % of activity for 20 min at 40 ℃,but the activity decreased to 50 % for 20 min at 60 ℃ and 70 ℃.The activity only had 11.70 % after 80 min at 70 ℃.Cu~(2+) and Ba~(2+) could increase the activity of the amylase.Whereas Mg~(2+),Fe~(2+),Ca~(2+),NH~+_(4) could significantly inhibite the activity.