Bhange Khushboo, Chaturvedi Venkatesh, Bhatt Renu
Department of Biotechnology, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, Chhattisgarh, 495009, India.
School of Biotechnology, Banaras Hindu University, Varanasi, U.P., India.
3 Biotech. 2016 Jun;6(1):42. doi: 10.1007/s13205-016-0370-5. Epub 2016 Feb 2.
An efficient keratinolytic strain of Stenorophomonas maltophilia KB13 was isolated from feather disposal site of Bilaspur, Chhattisgarh, India. The strain could metabolize 10 g/l chicken feathers as sole source of carbon and nitrogen. Soluble protein, amino acid, and cysteine content were found to be maximum (690.6 ± 8.7, 688.9 ± 9.12 and 21 ± 0.36 µg/ml, respectively) at late logarithmic phase of growth. Protease and keratinase activity reached its maximum level (103.26 ± 7.09 and 178.5 ± 9.10 U/ml) at the 4th day of incubation. The feather protein hydrolysate (FPH) obtained after degradation of chicken feathers was utilized to reduce hexavalent chromium. About 78.4 ± 2.4 and 63.6 ± 2.2 % reduction of 50 and 100 mg/l Cr(VI), respectively, was observed after 60 min of incubation with FPH. Further, there was no effect of autoclaved FPH on Cr(VI) reduction indicating that any bacterial enzyme was not involved in reduction process. Cr(VI) reduction was significantly inhibited by 10 mm Hg ions indicating the role of sulfur-containing amino acids in reduction process. FTIR analysis confirmed that chromium reduction occurred due to oxidation of amino acids cysteine and cystine. This study shows that FPH arising after feather degradation can be employed as a potential candidate for the reduction of hexavalant chromium.
从印度恰蒂斯加尔邦比拉斯布尔的羽毛处理场分离出了一株高效的嗜麦芽窄食单胞菌KB13角质溶解菌株。该菌株能够将10 g/l鸡毛作为唯一的碳源和氮源进行代谢。在生长对数后期，可溶性蛋白、氨基酸和半胱氨酸含量达到最高（分别为690.6±8.7、688.9±9.12和21±0.36 μg/ml）。蛋白酶和角蛋白酶活性在培养第4天达到最高水平（分别为103.26±7.09和178.5±9.10 U/ml）。鸡毛降解后获得的羽毛蛋白水解物（FPH）被用于还原六价铬。与FPH孵育60分钟后，分别观察到50和100 mg/l Cr(VI)的还原率约为78.4±2.4%和63.6±2.2%。此外，经高压灭菌的FPH对Cr(VI)还原没有影响，这表明还原过程中没有任何细菌酶参与。10 mM Hg离子显著抑制了Cr(VI)的还原，表明含硫氨基酸在还原过程中起作用。傅里叶变换红外光谱（FTIR）分析证实，铬的还原是由于半胱氨酸和胱氨酸氨基酸的氧化所致。这项研究表明，羽毛降解后产生的FPH可作为还原六价铬的潜在候选物。
