Exopolysaccharide production of Lactobacillus pentosus KS27 and optimization of production conditions

In this study, it was aimed to determine the exopolysaccharide (EPS) production of Lactobacillus pentosus KS27 depending on the temperature, incubation time and medium composition and to determine the optimum conditions of these conditions. The characterization of the exopolysaccharide produced under optimum conditions was carried out. In the study 3 different time conditions (25oC-25oC-45oC) were determined for the temperature, glycerol and sucrose were used as the medium and 3 different periods (24-36-48 hours) were determined. According to the determined variables, 27 different EPS production trials were determined with the Box-Behnken experiment matrix. In these experiments, the highest yield was obtained as a result of 36 hours incubation at 25oC. %7,5 sucrose concentration and %7,5 glycerol concentration were used as carbon sources and 1913,75 mg/L EPS was obtained. The amount of EPS obtained in this trial was 213,75 mg/L. According to the obtained data, the optimum point was tried to be determined and the production of 2158 mg/L EPS was estimated when production was carried out with the condition that the sucrose concentration was %5,31, the glycerol concentration was %10,92, the temperature was 25oC and the incubation period was 46,14 hours for the highest yield from 100 conditions with an expectation degree of 1. When production was carried out under the specified conditions, 2178 mg/L EPS production was achieved. It was determined that the solubility of EPS produced under optimal conditions was achieved with the highest water content (%98 ± 0,01), while the water binding capacity was also found to be as high as %1970 ± 0,01 and showed compliance with common EPS characteristics. The Differential Scanning Calorimeter analysis showed a gradual deterioration of to 250oC and a slow deterioration of up to 400oC. With the FTIR analysis peak values between 3289 and 517 cm-1 were deciphered and functional groups were determined. When the NMR spectrum was examined, the heterogeneous structure suitable for the structure of EPS was analyzed by defining the peak entities with three separate regions.