[Decrease of phosphate concentration in the medium by Brevibacterium casei cells]

Brevibacteria able to decrease phosphate concentration in the medium are of interest for the study of the role of bacteria in the phosphorus cycle and for development of biotechnology of phosphate removal from waste. Brevibacterium casei, Brevibacterium linens, and Brevibacterium epidermidis grown in media with initial phosphorus concentrations of 1-11 mM were shown to decrease its concentration by 90%. The composition of the incubation medium required for B. casei to carry out this process was established. This process occurs in the absence of glucose but requires the presence of Mg2+, NH4+, and alpha-ketoglutarate. The latter two components may be replaced by amino acids metabolized to NH4+ and alpha-ketoglutarate: histidine, arginine, glutamine, proline, or glutamic acid. No formation of insoluble phosphate salts was observed when the media were incubated under the same conditions with heat-inactivated cells or without cells at pH 7-8.5.