Isolation and identification of extracellular keratinase producing bacteria from soil

Abstract

Feathers, horns, cows skin are by product waste of cows skin, poultry and skin processing plants and produced in huge amount of waste every year. This horns, skin hair, chicken feather waste can be modified to make animal dietary protein. This conversion can be done by Keratinolytic bacteria, High protein content of keratin waste can be used as a good source of protein and amino acids by systemic recycling. Feather recycling can provides a cheap and alternative protein feed stuff. Further this can be used for many other purposes more likely animals feed fish feed. Some Bacteria, Fungi and Actinomycetes have been reported to produce keratinase in the presence of keratin substrate. In the present study Keratinase producing bacteria was isolated from soil and their Keratinolytic enzyme production was investigated. Soil sample was collected from Hazaribagh skin processing site Dhaka, Bangladesh, an organic waste dumping site. Soil samples were inoculated in eight nutrient broth media enriched with hair horns, feather powder and inoculated bacteria was isolated from soil sample. Only two organisms were able to degrade hair horns and feather powder indicating that these isolates produced Keratinase enzyme. In this study it was observed that keratinase and protease activity were detected in the culture supernatant and optimal medium for extracellular production of keratinase and protease is Keratin powder milk media at pH (7.5) and temperature (37oC). There was complete degradation of keratin after 168 hour of incubation in rotary shaking incubator 150 RPM at 37oC. Finally, biochemical test was done to identify the organism and it was found to be Bacillus licheniformis.