MUTAGENIC STRAIN IMPROVEMENT OF ASPERGILLUS NIGER (MBL-1511) AND OPTIMIZATION OF CULTURAL CONDITIONS FOR BOOSTED LIPOLYTIC POTENTIAL THROUGH SUBMERGED FERMENTATION

摘要

In present study an isolated hyper producer of Aspergillus niger (MBL-1511) was treated for sodium azide mutagenesis. Results showed 147.27 % enhanced extracellular lipase activity after 150 minutes of sodium azide treatment. Wild and mutant hyper lipase producer strains were exploited to submerged fermentation (SmF). Brassica meal as an additive agro waste product to the basal medium was optimized. Experimental conditions optima were 10% inoculum size, 30oC temperature, 96 h rate of fermentation and pH 6 for maximum lipases production. Molasses and Ammonium nitrate were optimized as the best carbon and nitrogen sources (0.6% and 0.4%) w/v respectively and sunflower oil 1% (v/v) as better inducer. Finally, an effective mutant [MBL-1511SA-4(150 min)] having of 176.10% enhanced extracellular lipases production over wild (MBL-1511) strain was acquired.