[Choice and selection of a Staphylococcus saprophyticus strain--a urease producer]

A new strain of Staphylococcus saprophyticus was isolated from natural sources. The strain has a higher activity of urease comparing to other cultures producing the enzyme. The strain is referred to as S. saprophyticus L-1. The natural variability of the strain was studied and the population was shown to have only one morphological type of colonies. The homogeneous population reversed to R and S forms after storage under vaseline oil. Although S forms had a lower viability, they produced more urease under the conditions of submerged cultivation than R forms. As the result of selection among S form colonies, three variants which retained the ability to synthesize urease at a high rate upon many passages were isolated.