EVALUATION OF BIODEGRADING POTENTIAL OF KERATINOPHILIC MICROFLORA OF RAJASTHAN

Abstract

newline Nature has provided the planet earth with a variety of beneficial organisms. newlineSoil is considered as a well-known source for the growth of microorganisms and newlinekeratinophilic microflora (fungi and bacteria) are the nature s gifts and the biggest newlinegroup of the organisms which have the capability to degrade the keratinous waste. newlineBeing the second populated country, the huge amount of keratinous waste is newlinegenerated in India. Keratinous waste are considered as the environmental pollutants newlineand produced mostly from the poultry farms, slaughterhouses and leather industries. newlineThe keratinous waste are dumped, buried, used for landfilling or incinerated and newlinethese all action increases the threats of environmental hazards, pollution, negatively newlineinfluence the public health and increase greenhouse gases concentration. The newlinekeratin-degradation ability of keratinophilic microflora has been credited with the newlineproduction of the microbial keratinase enzyme and biodegradation takes place newline(enzymatic degradation). Keratinase is the industrially significant enzyme which newlineoffers bioconversion of keratinous waste, utilization as animal feed supplements, newlinedehairing agents in tannery in eco-friendly way from the leather, detergent and newlinetextile industries. newlineIn the present study, the keratinophilic microflora was isolated from semi newlinearid region of Rajasthan, India. This research have reported the successful isolation newlineof keratinophilic microflora, molecular characterization, screening of keratinolytic newlineactivity, nutritional and physiological, estimation of keratin degradation, keratinase newlineenzyme activity and SDS-PAGE of keratinophilic fungi and keratinophilic bacteria. newline161 isolates of keratinophilic fungi and 36 isolates of keratinophilic bacteria have newlinebeen isolated from the soil of Rajasthan. The occurrence of genus Trichophyton newline(22.36%) was highest in soil samples followed by Chrysosporium (21.74%) by hair newlinebaiting technique. Among the keratinophilic bacteria occurrence of genus Bacillus newlinewas highest in the soil samples. newline newlineThe keratinophilic isolates were screened for the keratinolytic activity on newlineFeather Meal Agar Medium (FMA) and Basal Salt Medium (BSM). The isolates, newlinewhich showed the maximum feather degradation, were molecularly characterized. newlineThe 18S rRNA nucleotide sequences of five keratinophilic fungi were duly newlinedeposited for annotation and obtained accession numbers (KU560574, KU560575, newlineKU560576, KU605806 and KU605807) from NCBI GenBank (USA). The 16S newlinerRNA nucleotide sequence of one keratinophilic bacteria was duly deposited for newlineannotation and obtained accession number (KX443709) from NCBI GenBank newline(USA). newlineThe following isolates were processed for keratinous substrate degradation newlineby weight loss method and keratinase enzyme production: Keratinophilic fungi: - newlineAphanoascus arxii, Arthroderma multifidum, Chrysosporium queenslandicum, newlineChrysosporium zonatum and Uncinocarpus queenslandicus; Keratinophilic newlinebacteria: Bacillus licheiniformis AST10, Bacillus megaterium AST11, Bacillus newlinesubtilis AST28, Bacillus licheniformis AST29 and Bacillus pumilus AST35. newlineThe rate of degradation of keratinous waste was faster for chicken feather as newlinecompared to human hair, animal hair and human nail clipping. Scanning Electron newlineMicroscopic (SEM) micrographs showed the degradation of chicken feather shaft newlineand barbs and breakdown of the chicken feather structure by the keratinophilic newlinemicroflora. All the fungal isolates showed good keratinase production in Basal newlineMedium at pH 7.0 and at 28oC on twelfth day of incubation and all the bacterial newlineisolates showed good keratinase production in Basal Medium at pH 7.0 and at 37oC newlineon sixth day of incubation. The molecular weight of keratinase of Arthroderma newlinemultifidum TKKASa and Bacillus megaterium AST11 was estimated to be in range newlineof ~41 kDa to ~43 kDa. newlineThus in nutshell, it can be put forth that the present strains of keratinophilic newlinefungi and keratinophilic bacteria have high keratinolytic potential and capable to newlinedegrade the keratinous substrates.