Abdel-Fattah Azza M, El-Gamal Mamdouh S, Ismail Siham A, Emran Mohamed A, Hashem Amal M
Department of Chemistry of Natural and Microbial Products, Division of Pharmaceutical and Drug Industries Research, National Research Centre, Giza, Egypt.
Department of Botany and Microbiology, Faculty of Science (Boys), Al-Azhar University, Cairo, Egypt.
J Genet Eng Biotechnol. 2018 Dec;16(2):311-318. doi: 10.1016/j.jgeb.2018.05.005. Epub 2018 May 28.
Keratinase are proteolytic enzymes which have gained much attention to convert keratinous wastes that cause huge environmental pollution problems. Ten microbial isolates were screened for their keratinase production. The most potent isolate produce 25.2 U/ml under static condition and was primarily identified by partial 16s rRNA gene sequence as ALW1. Optimization studies for the fermentation conditions increased the keratinase biosynthesis to 72.2 U/ml (2.9-fold). The crude extracellular keratinase was optimally active at pH 8.0 and temperature 65 °C with 0.7% soluble keratin as substrate. The produced ALW1 keratinase exhibited a good stability over pH range from 7 to 9 and over a temperature range 50-60 °C for almost 90 min. The crude enzyme solution was able to degrade native feather up to 63% in redox free system.
角蛋白酶是一种蛋白水解酶，因其能转化造成巨大环境污染问题的角蛋白废弃物而备受关注。筛选了10株微生物菌株以检测它们产生角蛋白酶的能力。最具潜力的菌株在静态条件下产生25.2 U/ml的角蛋白酶，通过部分16s rRNA基因序列初步鉴定为ALW1。对发酵条件的优化研究使角蛋白酶的生物合成量增加到72.2 U/ml（提高了2.9倍）。粗制的细胞外角蛋白酶以0.7%的可溶性角蛋白为底物时，在pH 8.0和温度65°C下活性最佳。所产生的ALW1角蛋白酶在pH 7至9的范围内以及50 - 60°C的温度范围内表现出良好的稳定性，可持续近90分钟。在无氧化还原体系中，粗酶溶液能够降解高达63%的天然羽毛。
