Optimization of process variables for enhanced production of urease by indigenous Aspergillus niger strains through response surface methodology

Publication date: Available online 13 June 2019Source: Biocatalysis and Agricultural BiotechnologyAuthor(s): Yasir Mehmood Khan, Hira Munir, Zahid AnwarAbstractUrease is one of the important enzymes secreted by microorganisms in the soil, but can also be produced by microbial fermentation. The present study aimed to explore optimum conditions for maximum urease enzyme production from wheat straw by applying a statistical approach, response surface methodology (RSM), under the solid-state fermentation process. Eight different local strains of Aspergillus niger were screened for the production of urease enzyme. Fermentation profile revealed that all the strains showed activity but two strains BMB-02 NSJ and BMB-05 G displayed the higher activity as compared to the other strains. Therefore, two strains explicitly BMB-02 NSJ and BMB-05 G were shortlisted for further optimization studies. Different process parameters including incubation time, temperature, and pH were optimized for urease production. The result showed that both strains of A. niger (BMB0-02 NSJ and BMB-05 G) displayed maximum enzyme activity at 144 h (6 days), 35 °C, and pH 9.0, respectively. Moreover, RSM was employed to optimize the different parameters such as biomass, inoculum size, nitrogen content and moisture for both strains. Optimal enzyme conditions for BMB-02 NSJ were biomass, inoculum size, nitrogen, and moisture of 10 g, 5 mL, 0.5 g and 250% ratio to biomass, respectively, whereas biom...
Source: Biocatalysis and Agricultural Biotechnology - Category: Biotechnology Source Type: research