Keratinolytic Protease Production by Bacillus amyloliquefaciens 6B Using Feather Meal as Substrate and Application of Feather Hydrolysate as Organic Nitrogen Input for Agricultural Soil

• Published in: Waste and biomass valorization Vol. 5; no. 4; pp. 595 - 605
• Main Authors: Bose, Anjali, Pathan, Shabnam, Pathak, Khyati, Keharia, Haresh
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-08-2014
• Subjects: Engineering; Environment; Environmental Engineering/Biotechnology; Industrial Pollution Prevention; Original Paper; Renewable and Green Energy; Waste Management/Waste Technology; Surfactin; Feather degrading; Nitrogenous soil input; Solvent tolerant serine protease
• ISSN: 1877-2641; 1877-265X
• DOI: 10.1007/s12649-013-9272-5

Feather waste, a by-product of poultry processing sectors, contains a large quantity of hard to degrade
keratin
that pose great threat to the environment and mankind. Thus, development of a biotechnological approach to use such waste as substrate for enzyme production with its subsequent conversion to nitrogenous soil input is the main aim of the present investigation. Thirteen proteolytic bacteria were isolated from feather dump soil, amongst which
Bacillus amyloliquefaciens
6B (JQ904625) was found to completely degrade native feather in shortest time period (24 h) and thus selected for further investigation. Upon optimization of process parameters, the maximum enzyme yield (610.13 U/ml) was obtained after 12 h of fermentation at 37 °C using a medium containing 0.5 % (w/v) feather meal and 0.5 % (w/v) xylose at pH 8.0. The keratinolytic protease 6B exhibited optimum activity at 50 °C and pH 8.0. The enzyme exhibited significant stability in presence of solvents, surfactants and bleach-oxidant, suggesting its potential use in industries. Furthermore, the strain could produce antifungal metabolites which could inhibit the growth of fungal phytopathogens in the same conditions observed for keratinolytic enzyme production. Consequently, feather hydrolysates resulting from the microbial conversion of feather keratin might be utilized as a bioactive agricultural nitrogen input. Thus, degradation of bird feather using a soil bacterial isolate with simultaneous production of solvent and detergent tolerant keratinolytic protease, offers a cost-effective technology for industrial protease production, while adding value to poultry feather waste.