Response surface methodology for optimization of medium components in submerged culture of Aspergillus flavus for enhanced heparinase production

Abstract

Aims: Aim of the study was to develop a medium for optimal heparinase production with a strain of Aspergillus flavus (MTCC-8654) by using a multidimensional statistical approach.

Methods and results: Statistical optimization of intracellular heparinase production by A. flavus, a new isolate, was investigated. Plackett-Burman design was used to evaluate the affect of medium constituents on heparinase yield. The experimental results showed that the production of heparinase was dependent upon heparin, the inducer; chitin, structurally similar to heparin and NH(4)NO(3,) the nitrogen source. A central composite design was applied to derive a statistical model for optimizing the composition of the fermentation medium for the production of heparinase enzyme. The optimum fermentation medium consisted of (g l(-1)) Mannitol, 8.0; NH(4)NO(3), 2.5; K(2)HPO(4), 2.5; Na(2)HPO(4), 2.5; MgSO(4).7H(2)O, 0.5; Chitin, 17.1; Heparin, 0.6; trace salt solution (NaMoO(4).2H(2)O, CoCl(2).6H(2)O, CuSO(4).5H(2)O, FeSO(4).7H(2)O, CaCl(2)), 10(-4) mol l(-1).

Conclusions: A 2.37-fold increase in heparinase production was achieved in economic and effective manner by the application of statistical designs in medium optimization.

Significance and impact of the study: Heparinase production was doubled by statistical optimization in a cost-effective manner. This heparinase can find application in pharmaceutical industry and for the generation of low-molecular-weight heparins, active as antithrombotic and antitumour agents.