Department of Microbiology, Dr. Harisingh Gour Vishwavidyalaya (A Central University), Sagar, M.P. 470003, India.
Department of Microbiology, Dr. Harisingh Gour Vishwavidyalaya (A Central University), Sagar, M.P. 470003, India.
Int J Biol Macromol. 2021 Jan 1;166:1046-1056. doi: 10.1016/j.ijbiomac.2020.10.260. Epub 2020 Nov 4.
A newly isolated bacterium producing 55.5 U/mL keratinase on feather meal minimal medium was identified as Ochrobactrum intermedium. Optimization of process parameters by one-variable-at-a-time (OVAT) approach (substrate concentration 0.5% w/v, inoculum size 5% w/v, pH 7.0, 200 rpm for 96 h at 40 °C) resulted in 2.1-fold increase in keratinase secretion (117 U/mL). Keratinase was optimally active at pH 9.0 and 40 °C and was stable at pH 9.0 and 60 °C for 120 min. Calcium ions enhanced keratinase activity (158%) significantly, while it was strongly inhibited by both PMSF and EDTA, indicating it to be a metallo-serine protease. Keratinase degraded native chicken feathers efficiently resulting in 97.9% weight loss along with release of 745.5 μg/mL soluble proteins and 4196.69 μg/mL amino acids. Feather hydrolysate generated by NKIS 1 exhibited significant anti-oxidant and free-radical scavenging activity (90.46%). The present study revealed that O. intermedium NKIS 1 has potential applications in the biodegradation of chicken feathers and the value-addition of poultry waste.
一种新分离的细菌在羽毛粉最小培养基上产生 55.5 U/mL 的角蛋白酶，被鉴定为中间欧文氏菌。通过单变量法（底物浓度 0.5%w/v、接种量 5%w/v、pH 7.0、200 rpm、40°C 下 96 h）对工艺参数进行优化，角蛋白酶的分泌量增加了 2.1 倍（117 U/mL）。角蛋白酶在 pH 9.0 和 40°C 下具有最佳活性，在 pH 9.0 和 60°C 下稳定 120 分钟。钙离子显著增强了角蛋白酶的活性（158%），而 PMSF 和 EDTA 强烈抑制了角蛋白酶的活性，表明它是一种金属丝氨酸蛋白酶。角蛋白酶能有效降解天然鸡羽毛，导致 97.9%的重量损失，同时释放 745.5μg/mL 的可溶性蛋白和 4196.69μg/mL 的氨基酸。NKIS 1 产生的羽毛水解产物具有显著的抗氧化和自由基清除活性（90.46%）。本研究表明，中间欧文氏菌 NKIS 1 具有在鸡羽毛的生物降解和家禽废物的增值方面的应用潜力。
