羽毛角蛋白的生物降解

羽毛角蛋白是自然界中丰富的蛋白资源,由于其难以被解解而造成环境污染,近些年来对它的生物降解及有关角蛋白酶的研究取得了一定进展,对此作一简要综述。     

羊毛角蛋白接枝聚丙烯酸-丙烯酰胺吸水树脂的制备

以废弃羊毛为主要原料,采用溶液聚合法制备了羊毛角蛋白接枝聚丙烯酸-丙烯酰胺高吸水性树脂。详细探讨了羊毛角蛋白含量、丙烯酸比例、反应温度、交联剂和引发剂等条件对合成树脂吸水性能的影响。结果显示,当角蛋白占比为5 wt%,丙烯酸比例为70%,反应温度为70℃,交联剂用量为0.1 wt%,引发剂用量为0.8 wt%时,改性树脂吸水倍率最好。另外,采用红外光谱、全质构仪和吸水速率对角蛋白改性前后的产物进行了结构分析和性能测试。结果显示,羊毛角蛋白的引入可以提高树脂的强度、吸水速率和耐盐能力。     

Screening for a new Streptomyces strain capable of e cient keratin degradation

Keratinous wastes could be degraded by some microorganisms in nature. Native human foot skin （NHFS） was used as sole nitrogen source to screen microorganisms with keratin-degrading capability. From approximately 200 strains, a strain of Streptomyces sp. strain No. 16 was found to possess the strongest keratinolytic activity, and the total activity in the culture was 110 KU/ml with specific activity of 2870 KU/mg protein （KU： keratinase unit）. Substrate specificity test indicated that the crude keratinase could degrade keratin azure, human hair, cock feathers and collagen. The optimal pH of the crude keratinase ranged from 7.5 to 10 and the temperature ranged from 40℃ to 55℃. Metal chelating agent ethylenediamine tetraacetic acid obviously stimulated the keratinolytic activity but suppressed the proteolytic activity. To our knowledge, this is the first report on specific induction of keratinases by NHFS from an actinomycete. Moreover, excellent characteristics of its crude keratinase may lead to the potential application in waste treatment and recovery, poultry and leather industry, medicine, and cosmetic development.     

羽毛角蛋白海绵膜去除气溶胶简

通过添加一定含量增塑剂和冷冻干燥，将羽毛还原法产生的较少被利用的残渣制备成致密多孔具有一定柔韧性的角蛋白膜，不需预处理和交联剂，得率高。甘油添加量对膜的结构影响进行研究后表明，甘油含量5%时机械性能最佳，断裂强度为6.2 MPa，完整性和柔韧性最好，孔隙率最大，兼顾了较好的透气性和对气溶胶的较高去除率。该膜在18℃ 空气流速1 m/s下对大气气溶胶中PM₁₀去除率98%、PM_2.5去除率 39.28% 、PM_1.0去除率 32.97%，在制备口罩材料上具有一定应用潜力。     

羽毛角蛋白的提取及其应用进展

对难降解废弃物羽毛进行再利用的主要方法及其应用领域进行了总结和评述,详细介绍了从羽毛中提取角蛋白的方法,分为机械法、化学法和生物法三方面进行介绍。对羽毛的最新应用领域的方法和效用予以总结,并针对羽毛在吸附剂制备方面的进展作出进一步展望。     

羽毛不可溶角蛋白海绵膜对Cr（Ⅵ）的吸附性能

通过冷冻干燥，将还原法产生的凝胶状不可溶蛋白制备成具有致密孔隙的海绵膜，无需预处理和无交联剂，并研究了其对Cr（Ⅵ）的吸附性能。结果表明，在60℃、固液比12．5g／L、初始浓度100mg／L下最大吸附量为148．8mg／g，吸附过程符合Langmuir型和Freundlich型等温吸附模型，为吸热过程，物理吸附和化学吸附均起到重要作用。     

The oligopeptides production by the feather-degrading bacterium Bacillus methylotrophicus H0北大核心CSCD

Due to the high nutritive value of oligopeptides and the waste of feather resources, this study aimed at screening efficient strains of bacteria able to rapidly degrade feathers and produce large quantities of value-added oligopeptides. In order to assess the potential yield of oligopeptides, the promising strain H0 was selected from 16 feather-degrading microorganisms. To identify the strain, we analyzed the morphological and physiological characteristics of different strains, and carried out a gene sequence analysis of their 16S rRNAs. A single factor experiment was used to promote feather degradation and oligopeptide production, and the characteristics of the oligopeptides produced were also analyzed by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). The strain was identified as Bacillus methylotrophicus. The optimal initial pH and temperature for oligopeptide production were 11 and 40 °C, respectively. After 72 h of fermentation under these optimal conditions, the feathers were almost completely degraded, with a 38.19% of oligopeptides (accounting for 67.53% of the total soluble peptides) and a 11.11% of free amino acids produced. LC-MS/MS analysis indicated that the oligopeptides were mainly short peptides containing 5-10 amino acids, with a molecular mass (Mr) of less than 1 300. Moreover, the peptides were abundant in branched-chain amino acids, that might be responsible for the antioxidant property of the feather hydrolysate. Our results demonstrate the great capability of B. methylotrophicus H0 in feather degradation and oligopeptide production. This research provides a high-quality microorganism resource, and the scientific basis for the development of feather-derived oligopeptide products. © 2018 Science Press. All rights reserved.