Argentina’s geothermal areas are niches of a rich microbial diversity. In 2020, species of Bacillus cytotoxicus were isolated for the first time from these types of pristine natural areas. Bacillus cytotoxicus strains demonstrated the capability to grow and degrade chicken feathers with the concomitant production of proteases with keratinolytic activity, enzymes that have multitude of industrial applications. The aim of this research was to study the production of the proteolytic enzymes and its characterization. Also, feather protein hydrolysates produced during fermentation were characterized. Among the thermotolerant strains isolated from the Domuyo geothermal area (Neuquén province, Argentina), Bacillus cytotoxicus LT-1 and Oll-15 were selected and put through submerged cultures using feather wastes as sole carbon, nitrogen, and energy source in order to obtain proteolytic enzymes and protein hydrolysates. Complete degradation of feathers was achieved after 48 h. Zymograms demonstrated the presence of several proteolytic enzymes with an estimated molecular weight between 50 and > 120 kDa. Optimum pH and temperatures of Bacillus cytotoxicus LT-1 crude extract were 7.0 and 40 °C, meanwhile for Oll-15 were 7.0 and 50 °C. Crude extracts were inhibited by EDTA and 1,10 phenanthroline indicating the presence of metalloproteases. Feather protein hydrolysates showed an interesting antioxidant potential measured through radical-scavenging and Fe3+-reducing activities. This work represents an initial approach on the study of the biotechnological potential of proteases produced by Bacillus cytotoxicus. The results demonstrated the importance of continuous search for new biocatalysts with new characteristics and enzymes to be able to cope with the demands in the market.

中文翻译：

---

角质分解细菌细胞毒芽孢杆菌作为具有抗氧化活性的新型蛋白酶和羽毛蛋白水解物的来源

阿根廷的地热区具有丰富的微生物多样性。2020 年，首次从这些类型的原始自然区域分离出细胞毒芽孢杆菌。细胞毒性芽孢杆菌菌株显示出能够生长和降解鸡毛，同时产生具有角质溶解活性的蛋白酶，这些酶具有多种工业应用。本研究的目的是研究蛋白水解酶的产生及其表征。此外，对发酵过程中产生的羽毛蛋白水解物进行了表征。在从 Domuyo 地热区（阿根廷内乌肯省）分离的耐热菌株中，选择了细胞毒芽孢杆菌 LT-1 和 Oll-15，并使用羽毛废料作为唯一的碳、氮、和能量来源以获得蛋白水解酶和蛋白水解物。48 小时后羽毛完全降解。酶谱表明存在几种估计分子量介于 50 和 > 120 kDa 之间的蛋白水解酶。细胞毒芽孢杆菌 LT-1 粗提物的最佳 pH 值和温度分别为 7.0 和 40 °C，而 Oll-15 的最佳 pH 值和温度为 7.0 和 50 °C。粗提取物被 EDTA 和 1,10 菲咯啉抑制，表明存在金属蛋白酶。羽毛蛋白水解物显示出一种有趣的抗氧化潜力，可通过自由基清除和 Fe3+ 还原活性进行测量。这项工作代表了研究细胞毒性芽孢杆菌产生的蛋白酶的生物技术潜力的初步方法。