Solid-state protease production using anchovy waste meal by moderate halophile Serratia proteamaculans AP-CMST isolated from fish intestine

The possibility of utilising anchovy waste meal as a substrate for protease production by the fish gut isolate Serratia proteamaculans AP-CMST was assessed through solid-state fermentation. A time course for protease production revealed 72 h to be the optimum duration for higher production (146.24 U/g). The most suitable pH, temperature and moisture level observed for higher protease production were pH 7 (123.5 U/g), 30°C (97.22 U/g) and 75% (126.7 U/g), respectively. Protease production by S. proteamaculans AP-CMST was high in medium with added xylose (198.21 U/g), peptone (118.42 U/g), Triton X-100 (152.56 U/g) and manganese sulphate (178.33 U/g) when compared to other tested medium components. The halotolerancy of S. proteamaculans AP-CMST for protease production was 4% sodium chloride (155.65 U/g). Enzyme recovery from fermented anchovy waste meal was greatest (130.52 U/g) when 10% ethyl acetate was used as the extractant, and the optimum time range for extraction was 90–120 min.