Deinobacterium chartae gen. nov., sp. nov., an extremely radiation-resistant, biofilm-forming bacterium isolated from a Finnish paper mill

Abstract

A rod-shaped, non-spore-forming, non-motile, aerobic, oxidase and catalase-positive and radiation-resistant bacterium (designated strain K4.1T) was isolated from biofilm collected from a Finnish paper mill. The bacterium grew as pale pink colonies on oligotrophic medium at 12 to 50 °C (optimum 37 to 45 °C) and at pH 6 to 10.3. The DNA G+C content of the strain was 66.8 mol%. According to 16S rRNA gene sequence analysis, strain K4.1T was distantly related to the genus Deinococcus, sharing highest similarity with Deinococcus pimensis (90.0 %). In the phylogenetic tree, strain K4.1T formed a separate branch in the vicinity of the genus Deinococcus. The peptidoglycan type was A3β with l-Orn–Gly–Gly and the quinone system was determined to be MK-8. The polar lipid profile of strain K4.1T differed markedly from that of the genus Deinococcus. The predominant lipid of strain K4.1T was an unknown aminophospholipid and it did not contain the unknown phosphoglycolipid predominant in the polar lipid profiles of deinococci analysed to date. Two of the predominant fatty acids of the strain, 15 : 0 anteiso and 17 : 0 anteiso, were lacking or present in small amounts in species of the genus Deinococcus. Phylogenetic distinctness and significant differences in the polar lipid and fatty acid profiles suggest classification of strain K4.1T as a novel genus and species in the family Deinococcaceae, for which we propose the name Deinobacterium chartae gen. nov., sp. nov. The type strain is K4.1T (=DSM 21458T =HAMBI 2721T).