对于类似鸡毛这样难降解的角蛋白质废物的降解，人们对角蛋白酶的需求不断增长，从而进行了对新潜在细菌角蛋白酶的研究，以生产具有生物活性的高价值产品。本研究报道了从卡纳塔克邦西高止山脉的深山土壤中分离出的一株新型角蛋白酶菌株——嗜酶芽孢杆菌（Bacillus velezensis）株ZBE1，该菌株具有高效的鸡毛角蛋白降解能力，并诱导角蛋白酶的产生。产酶动力学表明，第四天最大角蛋白酶产量为11.65 U/mL，蛋白质浓度为0.61 mg/mL。通过响应曲面法优化了各种影响角蛋白酶产量的理化因子，如接种量、金属离子、碳源和氮源、pH和温度，产酶量增强了3.74倍。通过紫外可见光谱验证了由角蛋白酶作用于鸡毛产生的角蛋白水解物与银（AgNP）和氧化锌（ZnONP）纳米颗粒的合成，并显示了对巴氏杆菌和大肠杆菌等菌的抗菌活性。AgNP和ZnONP还通过ABTS和DPPH的自由基清除活性显示了潜在的抗氧化活性。AgNP和ZnONP对MCF-7乳腺癌细胞系显示了细胞毒活性，IC50分别为5.47µg/ml和62.26µg/ml。对纳米颗粒进行了傅里叶变换红外光谱、扫描电子显微镜与能谱分析、X射线衍射、热重分析和原子力显微镜分析，以阐明其热稳定性、结构和表面特性。本研究表明，角蛋白酶有望在触发生物活性增值产品的生产及生物医学纳米技术领域发挥重要应用。©2023 作者们

The increasing demands of keratinases for biodegradation of recalcitrant keratinaceous waste like chicken feathers has lead to research on newer potential bacterial keratinases to produce high-value products with biological activities. The present study reports a novel keratinolytic bacterium Bacillus velezensis strain ZBE1 isolated from deep forest soil of Western Ghats of Karnataka, which possessed efficient feather keratin degradation capability and induced keratinase production. Production kinetics depicts maximum keratinase production (11.65 U/mL) on 4th day with protein concentration of 0.61 mg/mL. Effect of various physico-chemical factors such as, inoculum size, metal ions, carbon and nitrogen sources, pH and temperature influencing keratinase production were optimized and 3.74 folds enhancement was evidenced through response surface methodology. Silver (AgNP) and zinc oxide (ZnONP) nanoparticles with keratin hydrolysate produced from chicken feathers by the action of keratinase were synthesized and verified with UV-Visible spectroscopy that revealed biological activities like, antibacterial action against Bacillus cereus and Escherichia coli. AgNP and ZnONP also showed potential antioxidant activities through radical scavenging activities by ABTS and DPPH. AgNP and ZnONP revealed cytotoxic effect against MCF-7 breast cancer cell lines with IC50 of 5.47 µg/ml and 62.26 µg/ml respectively. Characterizations of nanoparticles were carried out by Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray, X-ray diffraction, thermogravimetric analysis and atomic force microscopy analysis to elucidate the thermostability, structure and surface attributes. The study suggests the prospective applications of keratinase to trigger the production of bioactive value-added products and significant application in nanotechnology in biomedicine.© 2023 The Author(s).