Rhodococcus cerastii sp. nov. and Rhodococcus trifolii sp. nov., two novel species isolated from leaf surfaces

Abstract

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.

The detection and phylogenetic analysis of the alkane 1-monooxygenase gene of members of the genus Rhodococcus

“…This might indicate the presence of a sub-clade in the genus Rhodococcus containing mainly plant-associated rhodococci. Moreover, it is striking that R. trifolii, a close relative of R. corynebacterioides [18], loosely clustered with R. fascians and its closest relatives in the alkB gene-based tree (Fig. 1).…”

“…The applicability of the investigated alkB gene as a phylogenetic marker can be best investigated and shown in the case of these clusters. As noted above, R. cerastii and R. cercidiphylli have been described recently as plantassociated rhodococci [18,20]. Type strains of these species share considerably high 16S rRNA gene similarity with each other, and with R. fascians and R. yunnanensis (Fig.…”

Rhodococcus antrifimi sp. nov., isolated from dried bat dung of a cave

“…The genus Rhodococcus , which was first proposed by Zopf (1891), is a member of the family Nocardiaceae (order Corynebacteriales ), which also consists of the genera Nocardia as the type genus, Gordonia , Millisia , Skermania , Smaragdicoccus and Williamsia (Zhi et al , 2009; Adachi et al , 2007). At the time of writing, this genus contains 39 species with validly published names and most of the members have been isolated from a variety of environmental sources, such as soils, air, bioreactor sludge, industrial wastewater, animal dung, the gut of insects, limestone, marine sediments, cold deserts and animals and plants (Jones & Goodfellow, 2012; Li et al , 2012; Nimaichand et al , 2013; Kämpfer et al , 2013, 2014). During a study on bacterial diversity from a cave on Jeju Island, Republic of Korea, many novel strains have been isolated from soils and bat dung inside natural caves (Lee, 2006a, b, c, 2013).…”

Rhodococcus lactis sp. nov., an actinobacterium isolated from sludge of a dairy waste treatment plant

“…On the basis of 16S rRNA gene sequence phylogenetic analysis, the genus was divided into nine subclades by Gürtler et al (2004). Species of the genus have been isolated from diverse ecological niches such as a limestone deposition site (Nimaichand et al , 2013), leaf surface (Kämpfer et al , 2013) and blood sucking bug (Yassin, 2005), and have been frequently isolated from industrial waste treatment plants (Apajalahti et al , 1986; Yoon et al , 2000; Wang et al , 2010; Kämpfer et al , 2014; Peng et al , 2014). There has been a significant increase in the number of species characterized within this genus in the last decade (http://www.bacterio.cict.fr/qr/rhodococcus.html) suggesting its importance in the environment.…”