Moneto de Ledesma A M, Paraje R, Paglini S
Instituto de Virología Dr. José M. Vanella, Facultad de Ciencias Médicas y Cátedra de Microbiología, Universidad Nacional de Córdoba, Argentina.
Rev Argent Microbiol. 1985;17(2):89-96.
We studied 20 strains of Pseudomonas aeruginosa in its ability to produce proteolytic enzymes. Three different culture media were used: one containing salts and yeast; another one, the dialysed brain-heart-broth fluid and the third, brain-heart-broth. The best was the last one. The purification of the enzymes was performed by precipitation with ammonium sulphate and Sephadex G--100 gel filtration. The number of enzymes acting on casein were demonstrated by means of zymogram previously separated by polyacrylamide gel electrophoresis (Fig. 2). All the strains acted on gelatin and 80% of them on elastin. 80% of the 20 strains studied showed a correlation between the activity on elastin and the activity on casein (Fig. 1). 25% of the strains showed the presence of two enzymes using zymogram and 75% only one enzyme. The results were independent of the culture medium used. Strains recently isolated showed to produce a high level of proteolytic enzymes. When the strains were kept in the laboratory the activity decreased to low levels until almost disappeared (Fig. 1). When the recently isolated strains showed two proteolytic enzymes by zymogram, the less active one disappeared throughout the time when kept in the laboratory. The composition of the purified enzymes were proteic in nature; neither lipoprotein nor glycoprotein were evidenced.
我们研究了20株铜绿假单胞菌产生蛋白水解酶的能力。使用了三种不同的培养基：一种含有盐和酵母；另一种是透析后的脑心浸液肉汤；第三种是脑心浸液肉汤。最好的是最后一种。通过硫酸铵沉淀和Sephadex G - 100凝胶过滤进行酶的纯化。通过先前用聚丙烯酰胺凝胶电泳分离的酶谱图来证明作用于酪蛋白的酶的数量（图2）。所有菌株都能作用于明胶，其中80%能作用于弹性蛋白。在所研究的20株菌株中，80%在弹性蛋白上的活性与在酪蛋白上的活性之间存在相关性（图1）。25%的菌株通过酶谱图显示存在两种酶，75%仅有一种酶。结果与所使用的培养基无关。最近分离的菌株显示出产生高水平的蛋白水解酶。当菌株保存在实验室中时，其活性降低到低水平直至几乎消失（图1）。当最近分离的菌株通过酶谱图显示有两种蛋白水解酶时，活性较低的那种在保存在实验室的过程中逐渐消失。纯化后的酶的成分本质上是蛋白质；未证明有脂蛋白或糖蛋白。
