Bacteria in Stomach of Marine Little Toothed Whales

The isolation of bacteria was made in order to ascertain their role in producing free isovaleric and other lower fatty acids which were detected previously in the stomachs of porpoises. The 14 strains were isolated aerobically from the stomachs of whales by using a modified ZOBELL 2216 medium and 2.5% NaCI glucose broth medium. Eleven strains of Vibrio and one strain each of Corynebacterium and Staphylococcus were obtained from adult Neomeris phocaenoides, Prodelphinus sp., and Stenella attenuata and the one strain of Staphylococcus from a nursling of Delphinus delphis. The bacteria were identified by the system of BERGEY's manual or SHEWAN et al.. The viable bacterial counts were about 105/ml in each stomach of S. attenuate caught alive, the greater proportion consisting of Vibrio. All Vibrio strains grew well at 30 to 35•Ž, and also were able to grow at pH 4.85, though the optimum pH for growth was pH 6 to 7. Halophilic Vibrio strains grew abundantly in 2 to 4% NaCl containing nutrient broth. The isolated bacteria may originate from the intestinal flora of fishes ingested by whales, because their features resemble those of gut Vibrio of fishes.