Bacteria of the Black Sea Are Producers of Proteolytic Enzymes

Abstract

Despite the fact that in recent years there has been a certain enhancing interest in the study of marine microorganisms, nevertheless, marine bacteria as producers of biologically active substances, in particular enzymes, are still poorly studied. The marine biota is significantly different from the terrestrial one; therefore, there is a high probability of detecting in the marine environment different from terrestrial bacteria producers of enzymes with unique specificity and activity, for the needs of modern biotechnology. Proteolytic enzymes play an important role in these studies. Since the majority of microbial producers are characterized by a number of serious deficiencies, in particular, most of the elastase producers described in the literature are pathogenic for humans, the search for new, effective producers continues to be an urgent problem, given that highly active producers of proteolytic enzymes, in particular elastase, are generally absent in Ukraine. In this regard, the purpose of this work was to screen microorganisms isolated from the Black Sea for the presence of effective producers of proteolytic enzymes. Methods. We used methods of determining proteolytic (caseinilytic, elastolytic, fibrinolytic, fibrinogenolytic) activity. Results. The study of the enzymatic activity of the isolates showed that on the 10th day of cultivation in the supernatant of the culture liquid, caseinolytic activity was not detected only in one isolate 56, whereas very insignificant activity was observed in isolates 7, 20, and 50. The maximum activity was detected in isolate 247 (0.2 units/mL), and lower one - in isolates 46 (0.16 U/mL), 52 (0.15 U/mL), 51 (0.135 U/mL), 54 (0.08 U/mL), and 44 (0.05 U/mL). Of the 10 studied isolates, elastase activity was found only in four of them. The highest activity was found in isolates 51 and 54 (20.83 and 19.96 U/mL, respectively). Lower levels of activity (15.62 U/mL and 12.15 U/mL, respectively) were shown by isolates 52 and 247. The studied isolates also differed in their ability to hydrolyze fibrin and fibrinogen. T e highest fi brinolytic activity (2.33 U/mL) was found in isolates 46 and 54, significantly lower in isolate 20 (0.5 U/mL) and isolate 44 (0.33 U/mL). The rest isolates did not show fibrinolytic activity. As for fibrinogenolytic activity, it was noted in 6 studied cultures. The highest levels of activity were observed in isolate 51 (1.16 U/mL). Lower activity was found in isolates 54 (0.66 U/mL), 7 (0.5 U/mL), and 247 (0.33 U/mL). In isolate 50, it was minimal (0.083 U/mL). Conclusions. No correlation was found between elastase, fibrinolytic and fibrinogenic activity in the studied isolates. Thus, isolates 51, 54 and, to a lesser extent, 52 and 247 synthesize elastase activity. The highest fibrinolytic activity was in isolates 46 and 54, and fibrinogenolytic activity was in isolate 51. It was shown that the Black Sea is rich in marine bacterial species, which can be effective producers of a number of practically important enzymes, in particular, proteolytic ones with specificity to elastin, fibrin, and fibrinogen, which can be promising for implementation in biotechnological processes.