Feathers, rich in keratin, are usually the unused by-products of poultry industries. In addition, the cast-off X-ray films serve as secondary sources of silver, and the traditional method of silver extraction from this source is costly and not eco-friendly. Therefore, the current study focuses on protease production using a freshwater bacterium Chryseobacterium cucumeris SARJS-2, aiming to convert these wastes into useful products. The protease production was optimized by one-factor-at-a-time (OFAT), followed by Plackett Burman design (PBD) and response surface methodology (RSM). The protease production got enhanced by more than two folds after the statistical optimisation. Upon partial purification, the enzyme activity increased by approximately three folds. The protease was active in the range of temperatures from 25 to 75 °C, but the optimum temperature was recorded as 35 °C. The protease exhibited detergent compatibility and organic solvent stability. The detergent compatibility suggests the protease could be a detergent additive. It was also found that the presence of Fe⁺² enhanced protease activity. The protease was tested for stain removal, feather degradation and silver recovery applications. It was found that the protease could efficiently remove stains of blood and tomato sauce. In addition, the protease was found to be a successful candidate for feather degradation, thereby feather-hydrolysate production which has prominent roles as nature-friendly fertilizer and animal feed ingredient. The protease also degraded gelatin from the X-ray films to release the silver-halides for silver recovery. The results recommend that the SARJS-2 protease is a potential candidate for use in eco-friendly applications in various industrial sectors.

羽毛富含角蛋白，通常是家禽业未使用的副产品。此外，废弃的X射线胶片是银的二次来源，而从该来源提取银的传统方法成本高昂且不环保。因此，目前的研究重点是利用淡水细菌黄瓜黄杆菌SARJS-2生产蛋白酶，旨在将这些废物转化为有用的产品。蛋白酶生产通过一次一因素 (OFAT) 进行优化，然后采用 Plackett Burman 设计 (PBD) 和响应面方法 (RSM)。经过统计优化后，蛋白酶产量提高了两倍以上。部分纯化后，酶活性增加了大约三倍。该蛋白酶在25至75℃的温度范围内具有活性，但最适温度为35℃。该蛋白酶表现出洗涤剂相容性和有机溶剂稳定性。洗涤剂相容性表明蛋白酶可以作为洗涤剂添加剂。还发现Fe ⁺²的存在增强了蛋白酶活性。该蛋白酶经过了去污、羽毛降解和银回收应用的测试。研究发现，该蛋白酶可以有效去除血迹和番茄酱污渍。此外，该蛋白酶被发现是羽毛降解的成功候选者，从而产生羽毛水解产物，其作为自然友好型肥料和动物饲料成分具有突出的作用。蛋白酶还降解 X 射线胶片上的明胶，释放卤化银以回收银。结果表明，SARJS-2 蛋白酶是各种工业领域环保应用的潜在候选者。