Ma Qinyuan, Zhang Ya Ning, Zheng Xue, Luan Fang, Han Ping, Zhang Xianghe, Yin Yanmiao, Wang Xiaoxiao, Gao Xiuzhen
School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China.
Front Microbiol. 2022 Mar 14;13:794738. doi: 10.3389/fmicb.2022.794738. eCollection 2022.
Wool keratin is difficult to degrade as comparing to feathers because of its tough secondary structure. In order to develop an approach for high-value utilization of wool fiber waste by keratinolytic microorganisms, which is produced from shearing, weaving, and industrial processing of wool, screening of wool-degrading bacterium with high degradation efficiency were performed in this study. To this end, YQ20 was identified and characterized. The optimized conditions for wool degradation were pH 9.0 and 37°C with 20% liquid volume of Erlenmeyer flask. After fermentation, 15 essential amino acids were detected when wool fiber waste was fermented. The total amino acids produced from 1% wool per hour were 13.7 mg/L. The concentration was 8.6-fold higher than that produced by the strain BBE11-1, which had previously been reported to have the highest wool-degrading capacity. Our study reports the first strain that exhibits efficient wool degradation and yields higher concentrations of amino acids than previously reported strains. Whole-genome sequencing indicated that there were 18 keratinase-like genes in the genome of YQ20, which exhibited a long evolutionary distance from those of . Therefore, YQ20 may have applications in the environmentally friendly management of wool waste as fertilizer in agriculture.
与羽毛相比，羊毛角蛋白因其坚韧的二级结构而难以降解。为了开发一种利用角蛋白分解微生物对羊毛纤维废料进行高价值利用的方法，这些废料产生于羊毛的剪毛、织造和工业加工过程，本研究开展了高效降解羊毛细菌的筛选工作。为此，对YQ20进行了鉴定和表征。羊毛降解的优化条件为pH 9.0、37°C以及三角瓶液体体积为20%。发酵后，对羊毛纤维废料进行发酵时检测到15种必需氨基酸。每小时从1%的羊毛中产生的总氨基酸量为13.7 mg/L。该浓度比先前报道的具有最高羊毛降解能力的BBE11-1菌株产生的浓度高8.6倍。我们的研究报道了首个表现出高效羊毛降解能力且产生的氨基酸浓度高于先前报道菌株的菌株。全基因组测序表明，YQ20基因组中有18个类角蛋白酶基因，与其他菌株的类角蛋白酶基因进化距离较远。因此，YQ20在羊毛废料作为农业肥料的环境友好管理方面可能具有应用价值。
