Abstract:
The objective of the present study was, production of keratinolytic protease (s) through solid state fermentation using bacteria isolated from traditional leather processing stagnant ponds (Ponds are in use for last several years). Samples were collected from four different locations of Sebaha, North Gondar and isolated casein proteolytic bacteria. Partial purification enzymes was carried out using 80% saturated ammonium sulfate. Morphological and biochemical techniques were used to characterize the bacteria. Four isolated Bacillus species from two different regions showed highest proteolytic activity ranging from 26.7 U/ml (Bacillus strain Hs-3), 23 U/ml (Bacillus strain ms-1), 21.1 U/ml (Bacillus strain ms-2), 17.1 U/ml (Bacillus strain Hs-1). The optimum pH for protease production and stability of Bacillus species were 7 and 8 respectively. The optimum temperature for isolates ms-1 and ms-2 was found to be 37 °C, whereas for isolate Hs-1 and Hs-3, was at 30 °C. Maximum enzyme activity was observed at 0.2M NaCl. The optimum production time was 48 hours, Bacillus spp. grown best in wheat bran and rice bran carbon sources and at 1:3 ratio of media to moisture content showed highest enzymatic activity. Proteolytic activity of crude enzyme tested with and without traditional fruit extract (Lagenaria abyssinica) were compared and tested on various substrates. Complete dehairing of cattle hide after 24h of incubation and complete removal of blood stains was only observed with Bacillus spp. Hs-3 crude enzyme along with fruit juice. The present study suggests that, the two isolates should be further characterized and optimized for pure enzyme production.
