Two Gram-positive, non-endospore-forming rods, strains C5T and T8T
, were isolated from the phyllospheres of Cerastium holosteoides and Trifolium repens, respectively, and were studied in detail for their taxonomic position. 16S rRNA gene sequence analysis allocated both isolates clearly to the genus
Rhodococcus
. Isolate C5T was most closely related to
Rhodococcus fascians
and
Rhodococcus yunnanensis
, showing 99.2 % gene sequence similarity to both species. Strain T8T revealed the highest 16S rRNA gene sequence similarity to
Rhodococcus corynebacterioides
(98.8 %) and
Rhodococcus kroppenstedtii
(98.6 %). The quinone system of both strains was composed of dihydrogenated menaquinones with eight (major amount) as well as nine, seven and six isoprenoid units (MK-8H2, MK-9H2 MK-7H2 MK-6H2).The polar lipid profiles of strains C5T and T8T consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and one unknown phospholipid. Additionally, strain C5T contained one unknown glycolipid, and strain T8T three unknown aminolipids. The fatty acid profiles contained major amounts of C16 : 0, C18 : 1ω9c and 10-methyl C18 : 0, which supported the grouping of the two isolates in the genus
Rhodococcus
. Physiological/biochemical characterization and DNA–DNA hybridizations with the type strains of the most closely related species allowed a clear phenotypic and genotypic differentiation of both strains. For this reason, we propose strain C5T ( = LMG 26203T = CCM 7906T) as the type strain of a novel species with the name Rhodococcus cerastii sp. nov., and strain T8T ( = LMG 26204T = CCM 7905T) as the type strain of a second novel species with the name Rhodococcus trifolii sp. nov.
A Gram-positive-staining, non-endospore-forming actinobacterium, designated C7T , was isolated from the leaf surface of Trifolium repens. On the basis of 16S rRNA gene sequence analysis, strain C7 T was shown to belong to the genus Williamsia and was most closely related toWilliamsia maris SJS0289/JS1 T (98.0 % 16S rRNA gene sequence similarity), Williamsia deligens IMMIB RIV-956 T (96.4 %) and Williamsia serinedens IMMIB SR-4 T (95.7 %). The quinone system consisted predominantly of the menaquinones MK-9(H 2 ), MK-8(H 2 ) and MK-7(H 2 ). The major components in the polar lipid profile were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol. Mycolic acids were present. These chemotaxonomic traits and the major fatty acids, which were C 16 : 1 v7c, Strain C7 T was isolated from the leaf surface of Trifolium repens, which was collected from a meadow in the HainichDün region of Germany (Fischer et al., 2010). The strain was isolated after growth on M125 medium (http://www. dsmz.de/) at 25 u C for 14 days and maintained on nutrient agar (Oxoid) at 30 u C for 48 h. On M125 medium, the colony type exhibited by the isolate was present only occasionally, while other colony morphologies dominated.The strain was preserved in nutrient broth (Oxoid) with 20 % (v/v) glycerol at 280 u C or by lyophilization.Cell morphology was determined by phase-contrast microscopy as described by Kämpfer & Kroppenstedt (2004). Gram-staining was performed as described by Gerhardt et al. (1994).The 16S rRNA gene sequence of strain C7 T (1372 bp) was determined and analysed as described previously (Kämpfer & Kroppenstedt, 2004) , 2007). Genetic distances were calculated on the basis of pairwise comparisons and cluster analyses were performed with neighbour joining as well as maximum likelihood with fastDNAml (Olsen et al., 1994) using ARB. Tree reconstruction using the maximum-likelihood method was performed with a 30 % conservation filter (only alignment columns in which the frequency of the most abundant nucleotide is ¢30 % were included) as well as without filters. A maximum-parsimony tree was calculated with MEGA4. No significant differences could be observed between these trees. A neighbour-joining tree (without filters) is shown in Fig. 1. All of the nodes were also recovered in the maximum-likelihood and maximum-parsimony trees. Sequence similarity calculations on the basis of pairwise comparison indicated that the closest relatives of strain C7 T Abbreviations: NA, nitroanilide; NP, nitrophenyl.The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain C7T is FR691321. For analysis of mycolic acids, quinones and polar lipids, cells were grown in nutrient broth for 48 h at 28 u C in shake flasks at 180 r.p.m. The occurrence of mycolic acids was determined by TLC as described by Minnikin et al. (1975). Menaquinones were extracted and analysed as described by Collins et al. (1979) and Groth et al. (1996). Polar lipids were extracted by the method of Minnikin et al. (1979)...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.