Microbial and enzymatic degradation of keratin waste is more preferred over various conventional approaches which are costly and not environmentally suitable. Diverse niches are auspicious for the discovery of new microorganisms. To discover novel keratinolytic bacteria, 60 isolates from different poultry dumping sites were initially screened, and among these found a potent keratinolytic isolate (NKSP-7) that displayed higher feather-degrading ability. The selected isolate was identified as Bacillus sp. NKSP-7 based on 16S rDNA sequencing as well as physiochemical and morphological characteristics. The strain NKSP-7 showed complete hydrolysis of native chicken feathers (10 g/L) in nutrient medium after 24 h of incubation at 37 °C under agitation (150 rev/min) and produced thermostable extracellular keratinase. The crude enzyme displayed maximal keratinolytic activity (34.7 U/mL) in phosphate buffer of pH 7.0, and at 60 °C using keratin azure as a substrate. Keratinolytic enzyme showed stability at 20-65 °C for 4 h over the pH range of 5.5-8.0. No obvious inhibitory influence was perceived by cations, organic solvents, EDTA, and detergents. Whereas, enzyme activity was enhanced by adding β-mercaptoethanol, Na+, Cd2+, and Mn2+. All these notable features of keratinase make it a promising candidate for various industrial applications especially for dehairing process in leather industry, bioconversion of poultry waste, and in detergents formulations.

中文翻译：

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新分离的芽孢杆菌属菌种的角质分解酶介导的难降解家禽羽毛废物的生物降解。NKSP-7在深层发酵下。

角蛋白废料的微生物和酶促降解优于昂贵且不适合环境的各种常规方法。多样的生态位对于发现新的微生物是吉祥的。为了发现新颖的角化蛋白分解细菌，最初筛选了来自不同家禽倾倒场所的60种分离物，其中发现了一种具有较强羽毛降解能力的强力角化蛋白分离物（NKSP-7）。选择的分离物被鉴定为芽孢杆菌。NKSP-7基于16S rDNA测序以及理化和形态学特征。NKSP-7菌株在37°C搅拌（150 rev / min）孵育24小时后，在营养培养基中显示天然鸡毛（10 g / L）完全水解，并产生热稳定的细胞外角蛋白酶。粗酶在pH 7.0的磷酸盐缓冲液中以及在60°C（以角蛋白天蓝色为底物）下显示出最大的角蛋白分解活性（34.7 U / mL）。角质蛋白分解酶在5.5-8.0的pH范围内在20-65°C的温度下显示4个小时的稳定性。阳离子，有机溶剂，EDTA和去污剂没有明显的抑制作用。而通过添加β-巯基乙醇，Na +，Cd2 +和Mn2 +可以增强酶的活性。角蛋白酶的所有这些显着特征使其成为各种工业应用的有前途的候选者，尤其是在皮革工业中的脱毛过程，家禽废物的生物转化以及洗涤剂配方中。阳离子，有机溶剂，EDTA和去污剂没有明显的抑制作用。而通过添加β-巯基乙醇，Na +，Cd2 +和Mn2 +可以增强酶的活性。角蛋白酶的所有这些显着特征使其成为各种工业应用的有前途的候选者，尤其是在皮革工业中的脱毛过程，家禽废物的生物转化以及洗涤剂配方中。阳离子，有机溶剂，EDTA和去污剂没有明显的抑制作用。而通过添加β-巯基乙醇，Na +，Cd2 +和Mn2 +可以增强酶的活性。角蛋白酶的所有这些显着特征使其成为各种工业应用的有前途的候选者，尤其是皮革工业中的脱毛工艺，家禽废物的生物转化以及洗涤剂配方中。