Estimation of the Ability to Decompose Sodium Benzoate by a Bacterium Isolated from Biohumus Eicenia Fetida

Abstract

The study presents growth kinetics of a BG28 bacterial strain isolated from vermicompost (generated with the use of Eisenia fetida worms). The strain was given a codename BG28. It was revealed that the isolate is capable of using high concentrations of sodium benzoate (up to 15 g/l) as a substrate. At the same time, the rate and division constants of a culture that grows at 5 g/l, 10 g/l, and 15 g/l do not differ. However, the mean and specific increment of BG28 at the end of the logarithmic growth phase is significantly higher in the variant with 5 g/l. It was testified, that with the shortest duration of the logarithmic growth phase on a medium with 5 g/l, the substrate loss constant is higher than in other variants. The difference in the kinetic parameters of the culture at 5 g/l and 10 g/l sodium benzoate is insignificant. With an increase of the substrate concentration to 15 g/l, the duration of the logarithmic growth phase increased significantly, but the sodium benzoate decrease constant was found to be the lowest. During the study of the individual properties of BG28, it was revealed that the strain is capable of growing on benzoic acid. On this basis, it can be assumed that the culture contributes to the degradation of plant residues during vermicomposting. Besides, the isolate grows on a mineral nutrient medium with polyethylene glycol 6000 and liquid paraffin. In the process of the individual properties estimation, it was revealed that the strain is capable of local suppression of the Alternaria brassicicola VKM F-1864 mold growth when co-cultivated on agar nutrient medium.