Glaciecola mesophila sp. nov., a novel marine agar-digesting bacterium

Alteromonas-like strains KMM 241(T) and KMM 642, isolated from marine invertebrate specimens, were investigated to clarify their taxonomic position. The novel isolates were aerobic, Gram-negative, motile, slightly halophilic and heterotrophic and hydrolysed polysaccharides. They did not hydrolyse urea, gelatin or casein and produced acid weakly from carbohydrates. The DNA G + C content ranged between 44.6 and 44.8 mol%. DNA-DNA similarity between the two strains was 71%. Comparison of the 16S rRNA gene sequence of strain KMM 241(T) revealed 94.5-94.8% similarity to Glaciecola species. The novel strains shared several phenotypic and physiological properties with members of Glaciecola, but they differed in their lack of pigment production, their minimal and maximal growth temperatures and their ability to hydrolyse agar and carrageenan and in the utilization of organic compounds. On the basis of phenotypic and physiological characteristics as well as phylogenetic analysis, the isolates should be assigned to a novel species, Glaciecola mesophila sp. nov. The type strain is strain KMM 241(T) (=DSM 15026(T)).