Optimization of process parameters for alkaline protease production under solid-state fermentation by Thermoactinomyces thalpophilus PEE 14

Abstract

Production parameters of extracellular alkaline protease employing our laboratory isolate Thermoactinomyces thalpophilus PEE 14 under solid-state fermentation (SSF) were optimized. Wheat bran the best substrate among the 15 substrates used for optimization, showed the highest activity (1620 PU/g). The physical and chemical parameters were also optimized. The maximum enzyme activity under optimum conditions was obtained with incubation period 72 h, incubation temperature 55ºC, initial pH 10, inoculum level 20%, level of salt solution 2:10 and initial moisture level 80%. Increase of enzyme activity by 60% (2576 PU/g) was observed when compared with the unoptimized conditions.