Two strictly anaerobic bacterial strains, designated IP3-3T and SBP-1, were isolated from groundwater contaminated by chlorinated alkanes and alkenes at a Superfund Site located near Baton Rouge, Louisiana (USA). Both strains reductively dehalogenate a variety of polychlorinated aliphatic alkanes, including 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2,2-tetrachloroethane, 1,1,2-trichloroethane and 1,2,3-trichloropropane, when provided with hydrogen as the electron donor. To clarify their taxonomic position, strains IP3-3T and SBP-1 were characterized using a polyphasic approach. Both IP3-3T and SBP-1 are mesophilic, non-spore-forming, non-motile and Gram-stain-negative. Cells of both strains are irregular cocci with diameters of 0.4–1.1 µm. Both are resistant to ampicillin and vancomycin. The genomic DNA G+C contents of strains IP3-3T and SBP-1 are 55.5±0.4 and 56.2±0.2 mol% (HPLC), respectively. Major cellular fatty acids include C18 : 1ω9c, C16 : 0, C14 : 0 and C16 : 1ω9c. 16S rRNA gene sequence based phylogenetic analyses indicated that the strains cluster within the phylum Chloroflexi most closely related to but distinct from the species Dehalogenimonas lykanthroporepellens (96.2 % pairwise similarity) and Dehalococcoides mccartyi (90.6 % pairwise similarity). Physiological and chemotaxonomic traits as well as phylogenetic analysis support the conclusion that these strains represent a novel species within the genus Dehalogenimonas for which the name Dehalogenimonas alkenigignens sp. nov. is proposed. The type strain is IP3-3T ( = JCM 17062T = NRRL B-59545T).
Two Gram-stain-negative, non-motile, non-pigmented cocci, designated IMCC11369T and IMCC11389, were isolated from surface seawater of the East Sea of Korea by high-throughput cultivation based on dilution to extinction. Strains IMCC11369T and IMCC11389 shared 99.9 % 16S rRNA gene sequence similarity and >86.3 % DNA–DNA relatedness, which suggested that they belong to the same genomic species. The isolates were most closely related to Lentisphaera araneosa HTCC2155T (99.0 % 16S rRNA gene sequence similarity). Phylogenetic analysis revealed that the isolates formed a robust cluster with L. araneosa HTCC2155T. DNA–DNA relatedness values, however, showed that the isolates were distantly related to L. araneosa HTCC2155T (2.0–18.6 %), which suggested that they represent a separate genomic species in the genus Lentisphaera . The two isolates were phenotypically differentiated from their closest relative by several characteristics, including degradation of macromolecules and carbon source utilization. The DNA G+C content was 44.5–45.2 mol% and the predominant cellular fatty acids were C14 : 0, C16 : 1ω9c and C16 : 0. Strain IMCC11369T contained MK-7 as the respiratory quinone and phosphatidylethanolamine and an unknown lipid as the major polar lipids. On the basis of data obtained in this study, a novel species is proposed to accommodate the isolates, Lentisphaera marina sp. nov. The type strain is IMCC11369T ( = KCTC 23780T = NBRC 108776T).
Yellow leaf disease (YLD) with phytoplasmal aetiology is a serious disease of arecanut palm in India. The present study was undertaken to characterize the 16S rRNA and secA gene sequences of the Indian arecanut YLD phytoplasma for ‘Candidatus Phytoplasma ’ species assignment and 16Sr group/subgroup classification. Phytoplasma 16S rRNA genes were amplified using three sets of semi-nested/nested primers, 1F7/7R3–1F7/7R2, 4Fwd/3Rev–4Fwd/5Rev and P1/P7–R16F2n/R16R2, producing amplicons of 491, 1150 and 1250 bp, respectively, from diseased samples. The amplicons were cloned and sequenced. A blast search showed that the sequences had 99 % similarity with sugar cane white leaf phytoplasma (16SrXI) and Napier grass stunt phytoplasma (16SrXI). Phylogenetic analysis based on the 16S rRNA gene revealed the clustering of YLD phytoplasma with the rice yellow dwarf and Bermuda grass white leaf groups. The YLD phytoplasma F2nR2 sequence shared 97.5 % identity with that of ‘Candidatus Phytoplasma oryzae ’ and 97.8 % identity with that of ‘Candidatus Phytoplasma cynodontis ’. Hence, for finer differentiation, we examined the secA gene-based phylogeny, where the YLD phytoplasma clustered with Napier grass stunt and sugar cane grassy shoot phytoplasmas, both belonging to the rice yellow dwarf group. Hence, we are assigning the Indian arecanut YLD phytoplasma as a ‘Candidatus Phytoplasma oryzae ’-related strain. Virtual RFLP analysis of a 1.2 kb fragment of the 16S rRNA gene (F2nR2 region) identified the Indian arecanut YLD phytoplasma as a member of 16SrXI-B subgroup. We name the phytoplasma Indian yellow leaf disease phytoplasma, to differentiate it from the Hainan YLD phytoplasma, which belongs to group 16SrI.