Microbiology

Three strictly anaerobic, methanogenic strains JH1T, JH4 and JH8 were isolated from rumen of the Korean native cattle (HanWoo; Bos taurus coreanae) in South Korea. The colonies were circular, opaque, and slightly yellowish. Phylogenetic analyses of 16S rRNA gene and mcrA (encoding α subunit of methyl-coenzyme M reductase) sequences confirmed the affiliation of the novel strains with the Methanobacteriales , and Methanobrevibacter wolinii SHT was the most closely related species. The 16S rRNA gene and mcrA sequence similarities between strains JH1T, JH4 and JH8 and M. wolinii SHT were 96.2 and 89.0 % respectively, and DNA–DNA hybridization of the isolates and M. wolinii DSM 11976T showed a 20 % reassociation. Strain JH1T exhibited 92 % DNA–DNA relatedness with strains JH4 and JH8, and their 16S rRNA gene and mcrA sequences were identical. Cells stained Gram-positive and were non-motile rods, 1.5–1.8 µm long and 0.6 µm wide. The strains were able to use H2/CO2 and formate. The optimum temperature and pH ranges for growth were 37–40 °C and pH 6.5–7.0. The DNA G+C content of strain JH1T was 28 mol%. Based on data from this study using a polyphasic approach, the three strains represent a novel species of genus Methanobrevibacter , for which the name Methanobrevibacter boviskoreani sp. nov. is proposed. The type strain is JH1T ( = KCTC 4102T = JCM 18376T).

A novel halotolerant actinomycete, designated strain BNT52T, was isolated from soil collected from Cihanbeyli Salt Mine in the central Anatolia region of Turkey, and examined using a polyphasic taxonomic approach. The isolate was found to have chemical and morphological properties typical of the genus Amycolatopsis and formed a distinct phyletic line in the 16S rRNA gene tree. Strain BNT52T was most closely related to Amycolatopsis nigrescens CSC17Ta-90T (96.7 %), Amycolatopsis magusensis KT2025T (96.6 %), Amycolatopsis sulphurea DSM 46092T (96.6 %), Amycolatopsis dongchuanensis YIM 75904T (96.5 %), Amycolatopsis ultiminotia RP-AC36T (96.4 %) and Amycolatopsis sacchari DSM 44468T (96.4 %). Sequence similarities with other strains of species of the genus Amycolatopsis were lower than 96.2 %. The isolate grew at 20–37 °C, pH 6–12 and in the presence of 0–10 % (w/v) NaCl. The cell wall of the novel strain contained meso-diaminopimelic acid and arabinose and galactose as the diagnostic sugars. Major fatty acids were iso-C16 : 0 2-OH and iso-C16 : 0. The predominant menaquinone was MK-9(H4). The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylmethylethanolamine. The genomic DNA G+C content was 68.8 mol%. On the basis of the data from this polyphasic taxonomic study, strain BNT52T represents a novel species within the genus Amycolatopsis for which the name Amycolatopsis cihanbeyliensis sp. nov. is proposed (type strain BNT52T = KCTC 29065T = NRRL B-24886T = DSM 45679T).

Phytoplasmas classified in group 16SrXII infect a wide range of plants and are transmitted by polyphagous planthoppers of the family Cixiidae. Based on 16S rRNA gene sequence identity and biological properties, group 16SrXII encompasses several species, including ‘Candidatus Phytoplasma australiense ’, ‘Candidatus Phytoplasma japonicum ’ and ‘Candidatus Phytoplasma fragariae ’. Other group 16SrXII phytoplasma strains are associated with stolbur disease in wild and cultivated herbaceous and woody plants and with bois noir disease in grapevines (Vitis vinifera L.). Such latter strains have been informally proposed to represent a separate species, ‘Candidatus Phytoplasma solani’, but a formal description of this taxon has not previously been published. In the present work, stolbur disease strain STOL11 (STOL) was distinguished from reference strains of previously described species of the ‘Candidatus Phytoplasma ’ genus based on 16S rRNA gene sequence similarity and a unique signature sequence in the 16S rRNA gene. Other stolbur- and bois noir-associated (‘Ca. Phytoplasma solani’) strains shared >99 % 16S rRNA gene sequence similarity with strain STOL11 and contained the signature sequence. ‘Ca. Phytoplasma solani’ is the only phytoplasma known to be transmitted by Hyalesthes obsoletus. Insect vectorship and molecular characteristics are consistent with the concept that diverse ‘Ca. Phytoplasma solani’ strains share common properties and represent an ecologically distinct gene pool. Phylogenetic analyses of 16S rRNA, tuf, secY and rplV–rpsC gene sequences supported this view and yielded congruent trees in which ‘Ca. Phytoplasma solani’ strains formed, within the group 16SrXII clade, a monophyletic subclade that was most closely related to, but distinct from, that of ‘Ca. Phytoplasma australiense ’-related strains. Based on distinct molecular and biological properties, stolbur- and bois noir-associated strains are proposed to represent a novel species level taxon, ‘Ca. Phytoplasma solani’; STOL11 is designated the reference strain.