A NEW RING-FORMING BACTERIUM ARCOCELLA-AQUATICA GEN ET SP-NOV

A new genus of ring-forming bacteria Arcocella is described. The bacte ria assigned to the new genus are freshwater isolates. Cells are vibri oids, stretched spirals, or S-shaped. Morphological similarity with re presentatives of Flectobacillus was noted. The bacteria are strict aer obes. The optimal temperature is 28 - 30 degrees C, and the optimal pH is 6.8 - 7.2. No growth occurs on rich media. Carbohydrates, but not amino acids or organic acids, support growth. Nitrate and ammonium can be used as nitrogen sources. The GC content in the DNA is 34.5 mole % . The genome size is 2.9 x 10(9) Da. The DNA homology with reference s trains of Flectobacillus major and Spirosoma linguale was 15% and zero , respectively.