Amylolytic activity of <i>Bacillus subtilis</i> isolates obtained from wildlife microbiota

Abstract

At present, the study of the enzymatic potential of Bacillus subtilis bacteria is in demand due to the fact that probiotic and enzymatic preparations are created on their basis for their use in animal husbandry. The results of the study of amylolytic activity of 10 isolates of B. subtilis bacteria isolated from wildlife microbiota for amylopectin are presented. Determination of bacterial enzyme activity was performed by the Schomodi-Nelson method. The supernatants of the culture liquid of the 1st, 2nd, 3rd, and 7th day cultures were taken as enzyme preparation. Isolates with high qualitative indices were examined quantitatively using a spectrophotometer. The two isolates with the best performance were selected. Protein concentration was determined by the Bradford method. In addition to studying supernatants of isolates that showed extracellular enzymatic activity, studies were performed on intracellular enzymes. Cell destruction was performed using an ultrasonic disintegrator, in which the dissolved sediment was contained in a glass vial in a flask with ice. The best qualitative indicators were found in B. subtilis 2SP and B. subtilis 5SP isolates, which had high amylopectin activity from day one, so further quantitative studies were continued with them. Protein concentrations in the above isolates progressed by the days of seeding. The specific activity also increased accordingly and on day 7, the B. subtilis 2SP isolate was 2.75 units/mg, B. subtilis 5SP 2.67 units/mg. The study of the activity of intracellular enzymes in these isolates confirmed similar qualitative indicators. Two B. subtilis isolates were selected as promising for the development of enzyme preparations isolated from the microbiota of wild animals of the Far North.