[Use of Pseudomonas bacteria strains for determining water-assimilable carbon]

The ability of 12 Pseudomonas putida and Pseudomonas fluorescens strains for growth in the tap water has been studied. All of them grew well in pasteurized Kyiv tap water at 500 colony-forming units--CFU/ml inoculum reaching the maximal titre 1.7 x 10(4)-4.6 x 10(6) CFU/ml after 240 hours of incubation. The most intensive growth was observed in strain P. putida UCM B-143, capable to assimilation of 84 different sources of carbon nutrition. The linear dependence between strain 143 growth and acetate carbon concentration in the interval of 10 to 60 microg/l has been demonstrated in deionized water with addition of necessary mineral salts; its yield was 4.5 x 10(6) CFU/microg of assimilable acetate carbon (AOC). Determination of AOC of water using standard methods, standard strain P. fluorescens UCM B-385 (P17, ATCC 49642) and selected strain P. putida B-143 gave the similar values of AOC quantities in the Kyiv tap water (536 and 600 microg of AOC in 11, accordingly). Viability of strain 143 grown in the artesian water decreased more quickly than that of the standard strain which is possibly connected with origin of both cultures: strain 143 was isolated from wheat rhizosphere while strain P17--from the drinking water.