Screening of Chitinolytic Microfungi and Optimization of Parameters for Hyperproduction of Chitinase Through Solid-State Fermentation Technique.

Abstract

This study is intended for the production of chitinase enzyme from locally isolated fungal strains. Out of 10 isolated fungal strains from district Gujrat, Punjab, Pakistan, Aspergillus terreus SB3 (accession number ON738571) was found with maximum chitinolytic potential (80.8 U/mL/min). By applying central composite design (CCD) through response surface methodology (RSM) under solid-state fermentation (SSF), eight nutritional and physical parameters were optimized. Among these, temperature, substrate concentration, and pH were found as significant factors toward chitinase production in the first phase. Moisture and nitrogen source were found as significant factors during second phase of chitinase production. The effect of incubation period, inoculum size, and magnesium source was observed as non-significant. The chitinase activity was successfully enhanced more than 2 folds up to 198.5 U/mL/min at optimized conditions of 35°C temperature, 4.5 pH, 20g substrate concentration, 4-day incubation period, 55% moisture content, 4.5mL inoculum size, 0.25g ammonium sulfate, and 0.30g magnesium sulfate using RSM design. It was also found that Ganoderma lucidum (bracket fungus) has more potential to be used for the production of chitinase compared to fish scales. The present study exhibited Aspergillus terreus SB3 (ON738571) as a potential indigenous strain capable for hyperproduction of chitinase through cheap fermentation technology that might be employed for the eradication of chitin-based sea waste to remove the marine pollution.