Publications

4381

AbstractA previously unknown haplotype of the plant pathogen ‘CandidatusLiberibacter solanacearum’ (Lso) was found in cultivated carrots and parsnips in eastern Finland. That same haplotype was found in western Finland, over 300 km away, in the family Polygonaceae, the speciesFallopia convolvulus(wild buckwheat) andPersicaria lapathifolia(pale persicaria) growing as weeds within carrot and parsnip fields. The infected plants, both apiaceous and polygonaceous, showed symptoms of foliar discolouration. This is the first report of Lso bacteria in plants of the family Polygonaceae. The finding that the polygonaceous plants infected with a previously unknown haplotype of Lso were growing among the apiaceous plants infected with Lso haplotype C suggests that these two haplotypes might be transmitted by different vectors. Phylogenetic analyses showed that the new haplotype, called haplotype H, is distinct from the previously characterized haplotypes and appears to have diverged early from their common ancestor. Multi-locus sequence analysis revealed four different sequence types (strains) within the haplotype H. These findings suggest that the haplotype H is likely to be endemic in northern Europe and that the genetic diversity within the Lso species is higher than previously assumed.

A novel aerobic moderately thermophilic bacterium, strain 3753OT, was isolated from a Chukotka hot spring (Arctic, Russia) using the newly developed technology of laser engineering of microbial systems. Сells were regular short rods, 0.4×0.8–2.0 µm in size, with a monoderm-type envelope and a single flagellum. The temperature and pH ranges for growth were 42–60 °C and pH 6.5–8.5, the optima being 50–54 °C and pH 7.3. Strain 3753OT grew chemoorganoheterotrophically on a number of carbohydrates or peptidic substrates and volatile fatty acids, and chemolithoautotrophically with siderite (FeCO3) as the electron donor. The major cellular fatty acid was branched C19 : 0. Phosphatidylethanolamine, phosphatidylglycerol and two unidentified phospholipids as well as two yellow carotenoid-type pigments were detected in the polar lipid extract. Strain 3753OT was inhibited by chloramphenicol, polymyxin B, vancomycin, streptomycin, neomycin and kanamycin, but resistant to the action of novobiocin and ampicillin. The DNA G+C content was 69.9 mol%. The 16S rRNA gene as well as 51 conservative protein sequence-based phylogenetic analyses placed strain 3753OT within the previously uncultivated lineage OLB14 in the phylum Chloroflexi . Taking into account the phylogenetic position as well as phenotypic properties of the novel isolate, the novel genus and species Tepidiforma bonchosmolovskayae gen. nov., sp. nov., within the Tepidiformaceae fam. nov., the Tepidiformales ord. nov. and the Tepidiformia classis nov. are proposed. The type strain of Tepidiforma bonchosmolovskayae is 3753OT (=VKM B-3389T=KTCT 72284T).

Chain elongation by medium-chain fatty acid (MCFA)-producing microbiomes offers an opportunity to produce valuable chemicals from organic streams that would otherwise be considered waste. However, the physiology and energetics of chain elongation are only beginning to be studied, and many of these organisms remain uncultured. We analyzed MCFA production by two uncultured organisms that were identified as the main MCFA producers in a microbial community enriched from an anaerobic digester; this characterization, which is based on meta-multi-omic analysis, complements the knowledge that has been acquired from pure-culture studies. The analysis revealed previously unreported features of the metabolism of MCFA-producing organisms.

AbstractHolospora-like bacteria are obligate intracellularAlphaproteobacteria, inhabiting nuclei ofParameciumciliates and other protists.Alphaproteobacteriahave drawn significant attention, as both closest existing relatives of bacteria that gave rise to mitochondria, as well as a class of intracellular bacteria with numerous important pathogens.HLB clade includes two genera –Holospora(Hafkine 1980) andcandidatusGortzia (Boscaro 2013). These bacteria have a peculiar life cycle with two morphological forms, a strict specificity to the host species and the type of nucleus they inhabit.Here we describe a new species of HLB –candidatusGortzia yakutica sp. nov., a symbiont from macronucleus ofParamecium putrinum, the first known HLB for thisParameciumspecies. The new symbiont shows morphological similarities with other HLB. The phylogenetic analysis of SSU rDNA gene places it intocandidatusGortzia clade.

Abstract Background: Candidatus Phytoplasma ulmi is the causative agent of elm yellows and has been categorised in the European Union as a quarantine pathogen in the past. For central and northern European countries, information on the occurrence and distribution of the pathogen and its impact on elms is scarce, so a survey of native elm trees has been conducted in Germany. Results: About 6,500 samples in total, from Ulmus minor , Ulmus laevis and Ulmus glabra , were collected nationwide. Phytoplasma detection was performed by applying a universal 16Sr DNA-based real-time PCR assay and a novel Ca . P. ulmi species-specific real-time PCR assay targeting the 16S-23S spacer region. Both assays revealed that 28% of the samples were infected by Ca . P. ulmi, but infection rates of the elm species and regional incidences differed. The infection of trees is not correlated to disease-specific symptoms. The survey identified a regional disparity of infection which was high in east, south and central Germany, whereas only a few infected sites were found in the western and northern parts of the country. No correlation was apparent between altitude level and the prevalence of infection. First insights into the monitoring of the seasonal titre of Ca . P. ulmi in an infected tree by real-time PCR revealed high colonisation in all parts of the tree throughout the year. Conclusions: Ca . P. ulmi-infection is widely present in elms in Germany. The rare occurrence of symptoms indicates either a high degree of tolerance in elm populations or a low virulence of pathogen strains enabling high infection rates in a long-living host.