Effect of the probiotic preparation “Ecoflor” on the activities of glycosidase in the intestines of starlet

Probiotics are used in aquaculture to maintain a stable digestive tract and microflora. These preparations contain a complex of live bacteria, usually lacto- and bifidobacteria. They regulate the microbiocenosis of the digestive tract and make a significant contribution to nutrient assimilation. The effect of different dosages of Ecoflor on the activity of glycosidases (amylase and maltase) in the intestinal mucosa and chyme of sterlet was studied. This probiotic is a consortium of strains of lacto- and bifidobacteria: B. bifidum, B. longum and L. acidophilus, L. casei, L. plantarum, immobilized on carbon-mineral sorbent SUMS-1. The experiment was conducted at the experimental base of the I.D. Papanin Institute for Biology of Inland Waters. Fish were divided into 4 groups: control and three experimental groups, to which probiotic was added to the feed in the amount of 2, 4, 6 g/kg. Samples were taken from 5 individuals from each group before and on 7, 14, and 21 days of the experiment. To obtain enzymatically active preparations, the intestines of fish were freed from fat on ice bath glass. After cutting, chyme was collected with a spatula and scraper, then the mucous membrane was removed. The obtained suspensions of chyme and intestinal mucosa were homogenized with Ringer’s solution pH 7.5 (103 mMNaCl, 1.9 mMCl, 0.45 mM CaCl 2 , 1.4 mM MgSO 4 ) at 0-4°C, for cold-blooded animals, at a dilution of 1:50. Amylase activity was determined by the Smith-Roy method, as modified at a wavelength of 560 nm. The maltase activity was determined by the glucose oxidase method using a set of reagents for glucose determination in biological fluids (AGAT-MED LLC, Russia), the optical density was determined at a wavelength of 505 nm. The activity of both studied enzymes was found to increase in the mucous membrane and chyme of sterlet after one week of experimental feeding. In the following periods of observation the stimulating effect of the preparation only on the secretory activity of maltase was recorded. The dependence of the drug efficiency on the enzyme activity on the dosage was shown.