Study on the Conditions for Producing Cellulase by Liquid Fermentation with Aspergillus niger HQ-1

[Objective] The study aimed to discuss the optimum condition for producing cellulase by liquid fermentation of Aspergillus niger HQ-1.[Method] With 1 strain of A.niger HQ-1 with higher activity of producing cellulase as the original srtain,the optimum conditions for liquid fermentation of A.niger HQ-1 to produce cellulase was studied primarily through the single factor experiments and orthogonal tests and the activities of CMCase and FPAase were measured.[Result] The factors influencing the production of CMCase and FPAase by liquid fermentation of A,niger HQ-1 were in order were the content of compound carbon origin,the ratio of 2 kinds of carbon,the content of nitrogen and the liquid volume in flask.The optimal medium of producing CMCase was as follows:15‰ bran+corn stalk powder(1∶1),2.0‰ NH4Cl,other components as same as Mandel's medium.The optimal medium of producing FPAase was as follows:20‰ bran+corn stalk powder(1∶1),1.5‰ NH4Cl,others were as same as Mandel's medium.For both medium,the optimum pH was 5.0 and medium volume was 50 ml/250 ml triangle flask.The activities of CMCase and FPAase reached 525.2 and 217.6 IU respectively after culturing for 4 d under 30 ℃ and 170 r/min.[Conclusion] This study provided some technique reference for the research and development of producing cellulase strain.