Ways for increasing the efficiency of technologies for the synthesis of microbial exopolysaccharides. Part 1. Establishing optimal conditions for biosynthesis

Conducting experiments in which only one factor is varied is the easiest way to establish the optimal conditions of producer cultivation. Usually, in such studies, a consistent determination of the nature and concentration of the carbon and nitrogen source, pH, temperature, duration of cultivation, as well as the method of inoculum preparation is carried out. Such single-factor studies remain an effective tool for the initial determination of the most critical factors which cause the greatest impact on the biosynthesis process and require additional optimization. Further optimization of producer cultivation conditions using multivariate studies involves the use of various methods of mathematical planning of experiments, one of which is the Plackett-Burman design, which allows determining the level of influence on the process of a large number of variables while conducting a smaller number of experiments. For the combined analysis of factors which have the greatest influence on the process of exopolysaccharides biosynthesis, other more complex mathematical models are usually used, in particular, the Box-Wilson method, the central composite design, or the Box-Behnken design. A significant advantage of the Box-Behnken design is that it does not contain combinations for which all factors are at the highest or lowest levels at the same time. The analyzed literature data of recent years regarding ways to increase the efficiency of microbial exopolysaccharides technologies proved the need to use an integrated approach to solve this problem. So, at the first stage, it is necessary to establish the optimal composition of the nutrient medium. At the same time, the most modern approach is to conduct multifactorial studies using complex mathematical models, which take into account the interrelationship of various studied factors and make it pos sible to more accurately establish the optimal conditions of the cultivation process, which ensure increasing the concentration of microbial exopolysaccharides by 2—10 times compared to that before optimization.