Belchior Silvia G Estevao, Vacca Gabriela
Centro Regional de Investigación y Desarrollo Científico-Tecnológico, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Chubut, Argentina.
Can J Microbiol. 2006 Dec;52(12):1266-71. doi: 10.1139/w06-083.
The aims of this study were to identify a psychrotrophic bacterium, strain CR41, producing a cold adapted protease during growth at low temperatures and to evaluate the ability of the cells to hydrolyze hake fish protein. The strain was isolated from the intestinal tract of hake collected from the San Jorge Gulf (Patagonia, Argentina) and it was identified as Pseudoalteromonas. Growth and fish protein hydrolysis were determined using an aerated simple mineral medium plus 10% fish protein concentrate. Proteolytic activity was measured at 7 and 22 degrees C during culture in the concentrate. Protease production started in the exponential growth phase and reached a maximum during stationary phase. Protease activity at 7 degrees C was lower than at 22 degrees C. After 8 h of incubation, the percentage of hydrolyzed protein was 84% at 7 degrees C and 95% at 22 degrees C. Electrophoresis detection showed that degradation of muscle hake proteins was complete at both temperatures, and in gelatin zymograms extracellular activity showed two proteolytic bands with apparent molecular masses of approximately 31.6 and 62 kDa.
本研究的目的是鉴定一种嗜冷细菌CR41菌株，该菌株在低温生长过程中产生冷适应蛋白酶，并评估其水解无须鳕鱼肉蛋白的能力。该菌株从阿根廷巴塔哥尼亚圣豪尔赫湾捕获的无须鳕鱼肠道中分离得到，鉴定为交替假单胞菌属。使用充气的简单矿物培养基加10%鱼肉浓缩蛋白来测定生长和鱼肉蛋白水解情况。在浓缩蛋白培养过程中于7℃和22℃测定蛋白水解活性。蛋白酶产生于指数生长期，并在稳定期达到最大值。7℃时的蛋白酶活性低于22℃。孵育8小时后，7℃时蛋白水解百分比为84%，22℃时为95%。电泳检测表明，在这两个温度下无须鳕鱼肉蛋白的降解均已完成，在明胶酶谱中，细胞外活性显示出两条蛋白水解带，表观分子量约为31.6 kDa和62 kDa。
