EFFICIENCY OF KERATINASE ENZYME PRODUCING BACTERIA ISOLATED FROM SOIL OF POULTRY FARMING FOR DEGRADATION OF CHICKEN FEATHER

Abstract

In each year, Thailand has a large amount of feather left from the process of chicken meat production. Burning or land filling of those feathers can cause the air pollution. However, feather wastes can be potential used as substrates for digestible protein production by feather degrading microorganisms. This study, therefore, aimed to investigate the ability in feather degradation of 18 bacteria isolated (PSRU 1 –    PSRU 18) from soil in Pathum poultry farm, Phitsanulok Province, which produced clear zone in skim milk agar plate. It was found that all bacteria were grown on raw feathers minimal medium and could degrade chicken feather in different levels. Further, gram strain, morphological studies and biochemical assays were used to identify the isolated feather degrading bacteria. The results showed 18 strains including, 9 isolates of Staphylococcus sp., 7 isolates of Bacillus sp., and 2 isolates of Corynebacterium sp.. The first three of high efficiency bacteria were selected to study the effects of temperature (30, 37, 40, 50 and 60°C) and pH values (4.5, 6.0, 7.5, 9.0, and 10.5) on degradation ability. The isolate PSRU 11 possessed 73.60% of degradation at 37°C and pH 7.5. Based on molecular identification, isolates PSRU 8, PSRU 11 and PSRU 12 were closely related to Bacillus cereus, B. subtilis and B. siamensis, respectively. The results from this study are likely to be applied for reducing feather wastes and could be a potential application in the production of protein source for animal feed.