Rhodococcus psychrotolerans sp. nov., isolated from rhizosphere of Deschampsia antarctica

• Published in: Antonie van Leeuwenhoek 2018-04, Vol.111 (4), p.629-636
• Main Authors: Silva, Leonardo Jose, Souza, Danilo Tosta, Genuario, Diego Bonaldo, Hoyos, Harold Alexander Vargas, Santos, Suikinai Nobre, Rosa, Luiz Henrique, Zucchi, Tiago Domingues, Melo, Itamar Soares
• Format: Article
• Language: English
• Subjects: Arabinose; Bacteria; Biomedical and Life Sciences; Carbon sources; Cardiolipin; Cell culture; Colonies; Cream; Culture media; Deoxyribonucleic acid; Deschampsia; DNA; Fatty acids; Galactose; Gene sequencing; Hydrolysates; Life Sciences; Lipids; Medical Microbiology; Microbiology; New species; Original Paper; pH effects; Phosphatidylethanolamine; Phosphatidylglycerol; Phosphatidylinositol; Phylogenetics; Phylogeny; Plant Sciences; Rhizosphere; Rhodococcus; Ribonucleic acid; RNA; rRNA 16S; Soil Science & Conservation
• ISSN: 0003-6072; 1572-9699
• DOI: 10.1007/s10482-017-0983-7

A novel actinobacterium, designated strain CMAA 1533 T , was isolated from the rhizosphere of Deschampsia antarctica collected at King George Island, Antarctic Peninsula. Strain CMAA 1533 T was found to grow over a wide range of temperatures (4–28 °C) and pH (4–10). Macroscopically, the colonies were observed to be circular shaped, smooth, brittle and opaque-cream on most of the culture media tested. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CMAA 1533 T belongs to the family Nocardiaceae and forms a distinct phyletic line within the genus Rhodococcus . Sequence similarity calculations indicated that the novel strain is closely related to Rhodococcus degradans CCM 4446 T , Rhodococcus erythropolis NBRC 15567 T and Rhodococcus triatomae DSM 44892 T (≤ 96.9%). The organism was found to contain meso -diaminopimelic acid, galactose and arabinose in whole cell hydrolysates. Its predominant isoprenologue was identified as MK-8(H 2 ) and the polar lipids as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. The major fatty acids were identified as Summed feature (C 16:1 ω6c and/or C 16:1 ω7c), C 16:0 , C 18:1 ω9c and 10-methyl C 18:0 . The G+C content of genomic DNA was determined to be 65.5 mol%. Unlike the closely related type strains, CMAA 1533 T can grow at 4 °C but not at 37 °C and was able to utilise adonitol and galactose as sole carbon sources. Based on phylogenetic, chemotaxonomic and physiological data, it is concluded that strain CMAA 1533 T (= NRRL B-65465 T  = DSM 104532 T ) represents a new species of the genus Rhodococcus , for which the name Rhodococcus psychrotolerans sp. nov. is proposed.