[Auxotrophy and utilization of oxidized and reduced mineral sulfur forms by Brevundimonas diminuta strains]

Connection between auxotrophy of Brevundimonas diminuta strains for sulphur-containing amino acids and presence of oxidized or reduced sulphur forms in the medium has been shown. When grown in synthetic medium supplied with sulphate or sulphite B. diminuta strains required cystine, biotin, pantothenate and vitamin B12 for growth and utilized very limited spectrum--from 8 to 12--carbon sources. In the presence of 5 g/l of thiosulphate in the medium instead of mentioned sulphur-containing salts strains of this species did not require cystine and assimilated the ammonium nitrogen. The intensity of their growth in these conditions was lower and carbon nutrition spectra more limited than in custine-containing medium. Tetrathionate, elemental sulphur, sulphide were less efficient than thiosulphate, but they also provided growth of B. diminuta strains in the media supplied with ammonium salts, necessary vitamins and such universal C-sources as aspartate, glutamate, proline. Neither oxidized nor reduced mineral sulphur forms were able to substitute sulphur-containing amino acids for Comamonas terrigena strain requiring methionine.