In our preceeding papers, it was reported that almost all of the bacterial strains isolated from fresh, frozen and spoiled sea-fish could be placed in the 6 groups,
Pseudomonas I, II, III/IV-NH, III/IV-H,
Vibrio, and
Moraxella. In the present study, a number of biological properties of 314 isolates, including 33 of
Pseudomonas I, 36 of
Pseudomonas II, 75 of
Pseudomonas III/IV-NH, 77 of
Pseudomonas III/IV-H, 60 of
Vibrio and 43 of
Moraxella, were investigated in the hope of finding differentiating features among these groups. The results obtained are summarized below.
Although
Pseudomonas I had been differentiated from
Pseudomonas II basing on the fluorescent pigmentation, in the present work it was shown that there was a great similarity between the general biological properties of
Pseudomonas I and II organisms. Accordingly, it was proposed that the two groups should be classified as an identical one,
Pseudomonas I/II. The
Pseudomonas I/II organisms grew in NaCl absent nutrient agar, but failed to grow in 7% NaCl. The
Pseudomonas I/II was characterized with acid production from glucose in only aerobic condition, inability of H
2S production and of casein hydrolysis, resistance to 5μg/ml malachite green and 100μg/ml leucomycin.
Pseudomonas III/IV-NH also grew in NaCl absent medium and did not in 7% NaCl. This group was distinguished from
Pseudomonas III/IV-H with H
2S production, nitrate reduction and resistance to 50μg/ml methylene blue. Basing on the several features of
Pseudomonas III/IV-NH found in this work it was suggested that the group is identical with
Pseudomonas putrefaciens. Pseudomonas III/IV-H was clearly distinguished from
Pseudomonas I/II and III/IV-NH with growth response at 0 and 7% NaCl and the other several properties mentioned above. The most important feature, which distinguished
Vibrio from the other groups was ability of acid production from glucose in both aerobic and anaerobic conditions. Failure to grow both at 0 and 7% NaCl, ability of nitrate reduction, and sensitivity to 5μg/ml malachite green were also found to be useful for the identification of the
Vibrio group.
Moraxella was characterized with the stout or coccoid form of the cells, growth ability in both 0 and 7% NaCl media, failure of acid productian from the carbohydrates, sensitivity to 3 I.U. /ml penicillin and 0.1μg/ml ampicillin.
View full abstract