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.