Biochemical characteristics of 117 Pseudomonas cultures isolated from water bodies and washings off the hospital environment objects were under study, including the strains from patients' wound surfaces. Analysis of the strains' characteristics permitted referring 83.8 +/- 3.7% of them to typical ones as regards their biochemistry. 45.9 +/- 7.5% of these were P. putida, 21.4 +/- 4.8% were P. aeruginosa, 10.2 +/- 1.01% P. fluorescens strains, and the shares of P. cepacia and P. stutzeri strains were 11.2% each. 16.2% of the strains were found atypical because of lysine decarboxylase and growth at 42 degrees C; they were conditionally referred to P. putida. One third of these cultures were isolated in hospital. The detected differences may be helpful in identification of Pseudomonas.