THE POSSIBILITY OF INCREASING THE PRODUCTION OF CELLULOLYTIC ENZYMES ISOLATED FROM ANIMALS BY OPTIMIZING THE NUTRIENT MEDIUM

Cellulolytic enzymes are produced by a variety of bacteria and fungi, aerobes or anaerobes, mesophiles or thermophiles, when they grow on lignocellulosic materials, which can be used as a biotransformation agent in the degradation of agricultural biomass and for the creation of feed additives. The production of cellulolytic enzymes by the producing microorganism can be induced by specific substrates, such as lignocellulosic biomass. Despite extensive reports on the production of lignocellulosic enzymes by some fungal and bacterial species, the biotransformation efficiency of agro-industrial wastes remains low. Therefore, continued efforts to screen and isolate new extracellular cellulase producers are important to overcome these challenges. The safety status of enzyme manufacturers is a major concern in the medical, food and animal feed industries. The US Food and Drug Administration considers probiotic microorganisms generally considered safe (GRAS) because they are generally non-toxigenic and non-pathogenic bacteria. In addition, LABs have a long history of use in industrial processes as food starters and biocontrol agents, and as producers of valuable compounds. The goal of our research is bacteria isolated from the gastrointestinal tract of animals and possessing cellulolytic and probiotic properties. It is widely known that these bacteria are fastidious microorganisms that require complex media for growth and therefore cannot directly ferment inexpensive lignocellulosic feedstocks, so bacteria-assisted fermentation of lignocellulose hydrolysates is often reported and is the most developed. Cellulolytic enzymes are important industrial enzymes that are widely used in the production of food, animal feed, pulp, paper and textiles. We attempted to study the potential of locally isolated bacteria from animals as an effective complex bioconversion agent for wheat bran biomass, whey-based yeast extract. Cellulase activity was determined by a calorimetric method based on the determination of reducing sugars (RS) formed by the action of enzymes of the cellulolytic complex on the substrate – Na-CMC. The method is based on the quantitative determination of reducing sugars formed as a result of the action of the cellulase enzyme on the substrate sodium salt of carboxymethylcellulose (Na-CMC) at a temperature of 50 °C. The amount of reducing sugars was determined using the Somogyi-Nelson method. Our optimized whey-based medium was used as a culture medium. At the same time, cellulase activity was 0.233±0.0025 units/ml and 0.193±0.0018 units/ml. When optimizing the cultivation environment of Bacillus subtilis bacteria with the addition of yeast extract 5%, wheat bran and molasses 5%, the synthesis of cellulases was 0.541±0.0017 units/ml and 0.534±0.002 units/ml, respectively. In this case, the pH of the medium is 5.5. Cultivation time is 48 hours at 37 oC. Thus, optimizing the bacterial cultivation environment in order to increase the synthesis of cellulases makes it possible to activate cellulolytic bacteria, which makes it possible to increase the number of endogluconases. Research to optimize the conditions for cultivating cellulolytic bacteria is ongoing.