Identification of the newly isolated staphylococcus lentus SLKr1 as a keratinase enzyme producing bacteria

Feathers, a largely wastes produced in poultry industries represents a rich insoluble protein resource containing over 90% keratins. The aim of this study was to analyze and characterize the diversity of keratinase producing bacteria in broiler chicken litter house. A total of 10 gram samples were cultured in skim milk agar. The isolates were cultured on keratine and Azokeratin agar medium using keratin as the sole source of carbon to isolate keratinolytic microbes. The colonies with high feather hydrolyzing ability were subjected to identification by microscopic observation, biochemical characterization and molecular analysis. The results showed that among a total of 10 bacterial strains obtained from skim milk agar plates with proteolytic activity, only four bacteria were capable of degrading keratin. According to the biochemical and morphological characters, the isolated strain was grouped under the genus of Coccus (Staphylococcus). Based on 16S rRNA typing and phylogenetic analysis this strain was identified as Staphylococcus lentus SLKr1 and according to diameter clear zone on keratin agar medium, exhibited higher level of keratinolytic activity among other isolated strains. Staphylococcus lentus SLKr1 as a new keratinase producing bacteria also possessed high caseinase activity but was negative in amylase, lecithinase, cellulase and gelatinase production. Taken together, these results suggest Staphylococcus lentus SLKr1, a new keratinase producing bacteria with high keratinolytic activities which have the potential use in industrial biotechnology.