Studies on potential application of crude keratinase enzyme from Stenotrophomonas sp. for dehairing in leather processing industry

Interpretation :Chicken feathers represent huge pool of waste biomass which can undergo microbial degradation to generate value added products.Chicken feathers can be used as cheap substrate for production of keratinase enzyme which can be effectively used in dehairing of hides.Such enzyme based process is superior over conventional chemical based dehairing process, known to be responsible for pollution of the aquatic ecosystems.Isolation, characterization and identification of keratin degrading bacteria in feather meal broth medium using 0.5% chicken feather as substrate.The effect of various parameters such as temperature; pH and substrate concentration on enzyme activity was assayed.The crude keratinase was evaluated comparatively with conventional chemical based process for dehairing activities with specific references to goat skin and cow hide.Application of bacterial crude keratinase enzyme towards eco-friendly dehairing process was highlighted from Norja-1, which was identified as sp.by combination of 16S rRNA gene based molecular phylogenetic approach and phenotypic characterization.Keratinolytic activity was qualitatively demonstrated by scanning electron microscopic studies and quantitatively by using keratin azure as substrate.The crude keratinase enzyme showed optimum activity at 55°C, pH 9 and 5% substrate concentration.So, the enzyme was considered to be thermo-tolerant and alkaliphilic.Conventional chemical based process generated black spot on hide surface with broken hair while enzyme based process produced hides with better texture and intact hair which may be used further for making other value added products (such as wigs, doll's hair, carpets and mattresses).The dehairing activities of crude keratinase enzyme were demonstrated to be better in comparison to conventional chemical methods and might be useful towards development of pollution free dehairing process for leather processing industries.Presence of enzyme activity at wide range of temperatures (10 to 60°C) and pH (7.4 to 10.7) makes it a potential candidate for possible biotechnological application towards development of eco-friendly cost effective dehairing process in leather industries.