Paraconexibacter algicola gen. nov., sp. nov., a novel actinobacterium isolated from a eutrophic lake during the end of cyanobacterial harmful algal blooms, and proposal of Paraconexibacteraceae fam. nov. in the order Solirubrobacterales

摘要

A novel bacterium, strain Seoho-28(T), was isolated from a shallow eutrophic lake during the end of cyanobacterial harmful algal blooms and was characterized taxonomically and phylogenetically. Strain Seoho-28(T) was a Gram-stain-negative, aerobic, rod-shaped and non-motile bacterium. The strain grew optimally with 0% NaCl and at 25-30 degrees C on Reasoner's 2A medium. The phylogenetic analysis based on 165 rRNA gene sequences positioned the novel strain among the order Solirubrobacterales, but sequence similarities to known species were less than 94.7%. The genomic DNA G+C content of the strain Seoho-28(T) was 74.2 mol%. Genomic comparisons of strain Seoho-28T with families in the order Solirubrobacterales were made using the Genome-to-Genome Distance Calculator, average nucleotide identity and average amino acid identity analyses (values indicated <= 14.9, <= 73.5 and <= 57.8%, respectively). Strain Seoho-28(T) contained C-16:10-iSO, C-18:1 omega 9c and C-16.0 as major fatty acids and MK-7 (H-4) as the major quinone. Strain Seoho-28(T) contained diphosphatidylglycerol. phosphatidylinositol and an unidentified phospholipid as major polar lipids. Meso- and LL-diaminopimelic acids were the diagnostic diamino acids in the cell-wall peptidoglycan. Based on the genotypic, chemotaxonomic and phenotypic results, strain Seoho-28(T) represents a novel genus and species, Paraconexibacter algicola gen. nov., sp. nov., which belongs to a new family Paraconexibacteraceae in the order Solirubrobacterales and the class Thermoleophilia. The type strain is Seoho-28(T) (=KCTC 39791(T)=JCM 31881(T)).