Enzymatic potential of the indigenous microbiota of the intestine of rainbow trout Parasalmo mykiss (=Oncorhynchus)

Abstract

This paper is devoted to finding the scientific support for the development of commercial aquaculture. The article presents the results of examining the microbiocenosis of the commodity trout (Parasalmo mykiss) intestine. It was revealed that members of the genus Pseudomonas preveil in the microbiocenosis of the aquaculture intestinal contents. A small number of lactic acid bacteria, representing autochthonous microbiota and rare types of bacteria, such as coagulase-negative Staphylococcus spp. and Clostridium spp. being the components of fish allochthonous microbiota were discovered. Lactic acid bacteria were not found on the mucous membrane of the intestinal tract, due to the weak attachment of microorganisms in fish exposed to stress. The enzyme product was obtained from the bacteria with proteolytic activity in order to introduce this supplement as a feed probiotic into the artificial diets of cultivated fish. The advantage of the developed product is that the raw material (source) for its production are the bacteria isolated from rainbow trout intestine from experimental cage farms. The maximum activity of selected proteases was observed at bacterial concentration xio8 cells/ml. Proteolytic activity in the enzyme product from bacteria of the genus Pseudomonas spp. is higher than in the enzyme product obtained from the primary culture of E. coli.Antibiotic resistance of the selected isolates from Pseudomonas spp. Cefotaxime, which is recommended to use for prevention of bacterial infections when forming the broodstock was determined. Pseudomonas showed high sensitivity to a number of broad-spectrum antibiotics, such as ciprofloxacin, gentamicin. The obtained results of microbiological research can be used to develop the strategy of antibacterial therapy in fish farming.