Exploitation of chicken feather waste as a plant growth promoting agent using keratinase producing novel isolate Paenibacillus woosongensis TKB2

Abstract

Abstract A potent feather degrading bacterium was isolated from soil and it was identified as Paenibacillus woosongensis TKB2 on the basis of morphological, biochemical and as well as 16S rDNA sequence characteristics. The physico-chemical cultural condition for keratinase (principal feather degrading enzyme) production by the isolate was optimized following OVAT (one variable at a time) protocol. It was found that the bacterium produced highest amount of keratinase at 0.75% (w/v) raw feather as sole substrate, 2% (v/v) inoculums, pH 8.5, incubation temperature 30 °C, 5% (w/v) sodium chloride and other mineral components like 0.05% K 2 HPO 4 , 0.025% MgSO 4 and 0.02% CaCO 3 (w/v). The filter sterilized fermented hydrolysate has the ability to promote significantly the germination of seeds (germination rate 87.5%) and growth of Bengal gram ( Cicer arietinum ) seedlings. It induces the nodule formation (3 fold) and increased soil fertility by altering N, P, K and the C/N ratio by 1.2 fold. This also enhanced the quantity of free living nitrogen fixers (2 fold) and phosphate solubilizers (5.8 fold) in comparison to the control soil. Thus the enzymatic feather hydrolysate can be exploited as a useful biological fertilizer in future.