Advanced Level State Biotech Hub, Microbial Biotechnology Research Laboratory, Department of Biochemistry, Manipur University, Canchipur, India.
J Basic Microbiol. 2019 Jan;59(1):4-13. doi: 10.1002/jobm.201800434. Epub 2018 Oct 24.
Feathers account for 5-7% of the total weight of chicken have become one of the major pollutants due to their recalcitrant nature. Feather which is constituted of 90% keratin can be a good source of peptides, amino acids, and minerals for use as organic fertilizer. Traditional feather degradation methods consume large amount of energy and reduces the overall quality of the proteins. However, degradation of keratin by keratinolytic bacteria may represent as an alternative for the development of cheap, cost effective, eco-friendly, and easily available nitrogen (N) and minerals rich source as potential organic fertilizers. Keratinase enzymes from bacteria are serine-type proteases showing optimal activity at pH 6 to 9 and 30 to 50 °C. Mechanism of degradation includes, sulfitolysis, proteolysis, followed by deamination. Keratinolytic bacteria showing antagonism against important plant pathogens may act as biocontrol agent. Feather hydrolyzate can also be employed as nitrogenous fertilizers for plant growth. Tryptophan release from the feather degradation can act as precursor for plant phytohormone, indole-3-acetic acid (IAA). Solubilization of inorganic phosphate (P) by keratinolytic bacteria may further elevate the growth of plant. Application of hydrolyzate increases the water holding capacity, N, carbon (C) and mineral content of the soil. It elevates protein, amino acids, and chlorophyll content of plant. Feather hydrolyzate enhances seed germination and growth of plant. Soil application further increases the population of beneficial bacteria. The use of keratinolytic bacteria having antagonistic and plant growth promoting activities, and feather hydrolyzate can emerge as sustainable and alternative tools to promote and improve organic farming, agro-ecosystem, environment, human health, and soil biological activities.
羽毛占鸡总重量的 5-7%，由于其难降解的特性，已成为主要污染物之一。羽毛由 90%角蛋白组成，可作为多肽、氨基酸和矿物质的良好来源，可用作有机肥料。传统的羽毛降解方法消耗大量能源，降低了蛋白质的整体质量。然而，角蛋白降解菌对角蛋白的降解可能是开发廉价、经济高效、环保且易于获得的富含氮（N）和矿物质的新型有机肥料的替代方法。细菌来源的角蛋白酶属于丝氨酸蛋白酶，在 pH6-9 和 30-50°C 时具有最佳活性。降解机制包括亚硫酸盐解、蛋白水解，然后脱氨。对重要植物病原菌具有拮抗作用的角蛋白降解菌可以作为生物防治剂。羽毛水解物也可用作植物生长的氮素肥料。羽毛降解产生的色氨酸可作为植物植物激素吲哚-3-乙酸（IAA）的前体。角蛋白降解菌对无机磷酸盐（P）的溶解作用可进一步提高植物的生长。水解物的应用增加了土壤的持水能力、N、C 和矿物质含量。它提高了植物的蛋白质、氨基酸和叶绿素含量。羽毛水解物促进了植物的种子萌发和生长。土壤施用进一步增加了有益细菌的数量。具有拮抗和促进植物生长活性的角蛋白降解菌及其水解物的应用，有望成为促进和改善有机农业、农业生态系统、环境、人类健康和土壤生物活性的可持续替代工具。
