The effect of carbohydrates on the pigmentation of strain <i>Arthrobacter agilis </i>wb28
The article presents the results of a study on the influence of carbon sources, such as carbohydrates and sugar alcohols, on the growth and pigmentation of the Arthrobacter agilis wb28 strain isolated from wheat bran. Nutrient media were seeded with A. agilis wb28 cells by pricking. The cultivation of the strain was carried out at a temperature of 28 ± 1°C for 7 days. The presence of growth was determined by the turbidity of the medium, film and gas formation. It was shown that A. agilis wb28 cells are able to consume agar-agar components as the sole carbon source and synthesize metabolites that shift the pH of the medium to the alkaline region on Hiss medium, which is designed to assess the saccharolytic ability of microorganisms. It was found that the alkalinization of the medium during the growth of the A. agilis wb28 strain is characteristic in the presence of mainly oligosaccharides, polysaccharide, and sugar alcohol, with the exception of fructose monosaccharide. Media containing monosaccharides, such as glucose, arabinose, xylose, and galactose are not effective for the development of the A. agilis wb28 strain and pigment formation. As a result of the cultivation of the A. agilis wb28 strain on media with rhamnose and mannitol, acidification occurs, with it being more pronounced on the medium with mannitol. Pigmentation is also more pronounced on the medium with mannitol. The studied strain of A. agilis wb28 develops in the presence of glucose and fructose in comparison with the known strains of the genus Arthrobacter - pigment-formers, and to a greater extent forms a pigment on a medium with fructose. Gas formation during cultivation of the studied strain on all media used was not detected. More preferred carbohydrate sources for pigment formation by A. agilis wb28 are the disaccharides sucrose, lactose, maltose, fructose monosaccharide, and raffinose trisaccharide.