EXOPOLYSACCHARIDE SYNTHESIS PRODUCTIVITY BY BACILLUS MUCILAGINOSUS DEPENDING ON THE NITROGEN SOURCE AND ORIGIN OF INOCULUM

I M Malinovska

doi:10.35868/1997-3004.21.12-17

Abstract

It was established that Bacillus mucilaginosus C-3 requires introduction of nitrogen sourceinto the culture medium in form of nitrate as themost optimal for maximal accumulation of bacterial biomass and sporulation process. Introduction of the ammonium form was less efficient. It was shown that the intensity of nitrogensource use by B. mucilaginosus is highly depended on the physiological state of the inoculum cells. At sowing of spore inoculum theoptimal concentration of potassium nitrate was2.5 g/l resulting in 1010 cells/ml, while under theuse of vegetative cells the optimal concentrationof potassium nitrate was 1.0 g/l leading to theaccumulation of 109 cells/ml.Use of spore inoculum had ensured themaximum productivity of extracellular polysaccharide synthesis. With the higher number ofB. mucilaginosus subcultures in a vegetativestate the efficiency of the exopolysaccharidesynthesis has decreased: after the second passage — by 20.0 %, after the fourth — by 56.5 %,after the sixth — at 127.8 %. After eighth passage the culture loses its ability to synthesizepolysaccharide, especially on the medium withthe N : C ratio 1 : 3 and resume this ability onlyafter sporulation and the significant increase ofthe N : C ratio.

Highlights

The extracellular polysaccharide Bacillus mucilaginosus has broad prospects for the use in practice: in medicine (immune-stimulating, immunomodulatory, antiviral, antitumor activity) and animal husbandry (food additive in the diet of farm animals, preserving forage), in oil and mining industry, in the production of ceramics and lubricants, substitutes of known technical oils, antiwear additive in brake and cooling solutions [1-3]
The extracellular polysaccharide Bacillus mucilaginosus has broad prospects for the use in practice: in medicine and animal husbandry, in oil and mining industry, in the production of ceramics and lubricants, substitutes of known technical oils, antiwear additive in brake and cooling solutions [1-3]
Most scientists advocate the need for nitrogen administration to the culture medium composition [4; 7]

Summary

Introduction

The extracellular polysaccharide Bacillus mucilaginosus has broad prospects for the use in practice: in medicine (immune-stimulating, immunomodulatory, antiviral, antitumor activity) and animal husbandry (food additive in the diet of farm animals, preserving forage), in oil and mining industry, in the production of ceramics and lubricants, substitutes of known technical oils, antiwear additive in brake and cooling solutions [1-3]. The works, devoted to the study of principles of growth and synthesis of extracellular polysaccharide B. mucilaginosus, are controversial [4-7]. S. Podhorskyi et al [5; 6], the potential growth of culture on nitrogen-free environments is possible. Most scientists advocate the need for nitrogen administration to the culture medium composition [4; 7].

Results

Conclusion