Separating Keratinase Producer Bacteria from the Soil of Poultry Farms and Optimization of the Conditions for Maximum Enzyme Production

Abstract

Feather is considered one of the environmental pollutant factors that can be hydrolyzed by bacteria and fungi. About 90% of the full weight of a feather consists of keratin. The structure of feather is very difficult to break down. Some bacteria in the presence of keratin-contained substrates are able to produce the keratinase enzyme to hydrolyze keratin. A total of 15 soil samples were collected from the poultry farms around Marvdasht city. 7 bacterial strains were grown in feather filled environment. 5 isolates that showed a clear analysis were selected and identified using biochemical tests and molecular methods. The bacterial DNA contents were sequenced and were assigned certain numbers in GenBank as new strains. Then, every fifth bacteria were also evaluated for the production of keratinase. All strains belonged to different strains of Bacillus. Five strains were able to completely degrade feather. Bacillus cereus SKH1 had the maximum enzyme activity, 17.12 (Unit/ml/min). Different strains of Bacillus in this study showed the ability to produce keratinase in the presence of keratin. Keratinase measurement showed that all 5 strains are potentially able to treat feather-contained waste.