Centro de Investigación en Alimentación y Desarrollo, A.C. Carr. Gustavo Enrique Astiazarán No. 46 AP 1735, CP 83000, Hermosillo, Sonora, Mexico.
CIATEJ-Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. Camino Arenero 1227, 45019, Zapopan, JAL, Mexico.
World J Microbiol Biotechnol. 2018 Dec 15;35(1):4. doi: 10.1007/s11274-018-2574-9.
The aim of this research was to study the hydrolytic potential of bacteria isolated from cattle environments of two desert soils in one of the driest and hottest zones in America. A total of 26 points were sampled, 144 strains were isolated, and 50 strains were selected for the characterization of esterase, lipase, protease, and amylase activities and for 16S rRNA identification. Strains of the Bacillus, Pseudomonas, Acinetobacter, Enterobacter, Providencia, Escherichia, and Pantoea genera were identified. Comparisons of the proteolytic activity of the secretome from 14 strains (Bacillus n = 7, Escherichia n = 2; Providencia, Pseudomonas, Enterobacter, Pantoea and Acinetobacter n = 1) were performed. Four strains of Bacillus showed the highest proteolytic activity. These strains were characterized through a comparative analysis of pH and temperature as well as the effects of salt concentration on protease activity. Maximum proteolytic activity occurred in the range of pH 7-9 and temperatures between 50 and 70 °C for B. subtilis WD01, B. tequilensis WS11, B. tequilensis WS13, and B. tequilensis WS14. At a 20% NaCl concentration, the proteolytic activity retained was 71.4%, 65%, and 79.8% for WD01, WS11, and WS13, respectively; the activity of strain WS14 increased with 45% NaCl. Protease production by B. tequilensis WS14 with wheat, fish, and bone flours as low-cost substrates showed no differences between bone and fish flours and showed a decrease in protease production with wheat flour. The proteolytic activity in flour extracts with 20% NaCl was 82%, 75.61% and 38.04% for fish, bone and wheat flours, respectively. Data obtained in this work allow us to propose that strains isolated from environments with extreme conditions have a biotechnological potential.
本研究的目的是研究从美国最干旱和最热地区之一的两种沙漠土壤中分离出的细菌的水解潜力。总共采集了 26 个点的样本，分离出 144 株菌，并选择了 50 株菌用于鉴定酯酶、脂肪酶、蛋白酶和淀粉酶活性以及 16S rRNA 鉴定。鉴定出的菌株包括芽孢杆菌、假单胞菌、不动杆菌、肠杆菌、普罗维登斯菌、大肠杆菌和泛菌属。对 14 株菌（芽孢杆菌 n=7，大肠杆菌 n=2；普罗维登斯菌、假单胞菌、肠杆菌、泛菌属和不动杆菌 n=1）的分泌蛋白酶活性进行了比较。4 株芽孢杆菌显示出最高的蛋白酶活性。通过比较分析 pH 值和温度以及盐浓度对蛋白酶活性的影响，对这些菌株进行了表征。B. subtilis WD01、B. tequilensis WS11、B. tequilensis WS13 和 B. tequilensis WS14 的最适 pH 值范围为 7-9，最适温度范围为 50-70°C。在 20%NaCl 浓度下，WD01、WS11 和 WS13 的蛋白酶活性保留率分别为 71.4%、65%和 79.8%；WS14 菌株的活性随 45%NaCl 增加而增加。B. tequilensis WS14 以小麦、鱼和骨粉作为低成本底物生产蛋白酶时，骨粉和鱼粉之间没有差异，而用小麦粉生产蛋白酶的活性则降低。在含 20%NaCl 的面粉提取物中，鱼粉、骨粉和小麦粉的蛋白酶活性分别为 82%、75.61%和 38.04%。本工作获得的数据表明，从极端环境中分离出的菌株具有生物技术潜力。
