Publications

4474

Although species of the order Nostocales have morphological similarities to each other, some Nostoc species have been considered cryptic and are classified in the families Nostocaceae, Nodulariaceae and Aphanizomenaceae. Since then, the phylogenetic and morphological evaluation of Nostoc-like organisms has led to the taxonomic revision of some genera in different families. In the present work a cyanobacterium morphologically identified as Nostoc was isolated from an extreme cold lotic environment, in a high mountain of the Transmexican Volcanic Belt, and was taxonomically and phylogenetically characterized based on a polyphasic approach. Analysis of the 16S rRNA gene sequence references: Reofilinostoc matlalcueyense gen. et sp. nov. Thus, establishing a new genus of the family Nodulariaceae. The morphology of Reofilinostoc in the wild is reminiscent of a mouse ear, it is of 0.4-1.2 cm in length and has a firm cartilaginous texture; colonies can be pale green, brown or dark green in colour. Through a microscopic inspection, the filaments resemble to Komarekiella atlantica, Desikacharya nostocoides and Minunostoc cylindricum. While, the phylogenetic approach yielded similar results and consistently showed that Reofilinostoc matlalcueyense F02 (OR724089) is closely related to D. nostocoides and M. cylindricum in the core clade of Nodulariaceae. This research revealed that some comparisons between genera of Nodulariaceae exhibited similarity values higher than 97%, such as Atlanticothrix vs. Goleter and Cyanocohniella vs. Anabaenopsis. Nevertheless, in comparison to these phylogenetically closer genera, a substantial difference in the length and structure of D1-D1’, Box-B and V3 helix was demostrated; where Reofilinostoc, Desikacharya, and Minunostoc are part of the Nodulariaceae family; leading to the establishment of Reofilinostoc gen. nov., with Reofilinostoc matlalcueyense sp. nov. as the type species.

A genome-based polyphasic approach was used to determine the taxonomic status of two novel bacterial strains, SCSIO 12594T and SCSIO 12813T, isolated from tissues of a coral. Both strains were Gram-stain-negative and facultatively anaerobic. The genome sizes of strains SCSIO 12594T and SCSIO 12813T were 3.9 Mb and 4.1 Mb, respectively, and they possessed DNA G+C contents of 55.1 and 46.2 mol%, respectively . Both strains were found to be catalase- and oxidase-positive, while SCSIO 12594T also could hydrolyse starch. SCSIO 12594T was observed to grow at between 20 and 37 °C (optimally at 25 °C) and at a pH range from 6 to 7 and in the presence of 3–7 % (w/v) NaCl. The growth of SCSIO 12813T required seawater and occurred at 20–30 °C (optimum, 25 °C), pH 5–8 (optimum, pH 6–7) and in the presence of 3–3.7 % (w/v) NaCl. The results of 16S rRNA gene-based phylogenetic analysis indicated that SCSIO 12594T shared 92.97 % or less sequence similarity with its closest relatives Rhodobium gokarnense JA173T and other members of the order Hyphomicrobiales. The results of 16S rRNA sequences-based phylogenetic analysis of SCSIO 12813T indicated that Croceimicrobium hydrocarbonivorans A20-9T (89.34 %) was the most closely related species. SCSIO 12594T and SCSIO 12813T can be readily separated from their closest relatives, as indicated by the results of phylogenomic analysis, low average nucleotide indexes, average amino acid identity, digital DNA–DNA hybridisation (dDDH) similarities and associated phenotypic and chemical data. Consequently, the two coral isolates are considered to represent two novel genera and species for which the names Coralliovum pocilloporae gen. nov., sp. nov. and Sanyastnella coralliicola gen. nov., sp. nov. are proposed, the type strains are SCSIO 12594T (= JCM 35320T = GDMCC 1.3060T) and SCSIO 12813T (= JCM 35373T = GDMCC 1.3063T), respectively. In addition, two novel families, Coralliovaceae fam. nov. and Sanyastnellaceae fam. nov are proposed to accommodate Coralliovum pocilloporae gen. nov., sp. nov. and Sanyastnella coralliicola gen. nov., sp. nov., respectively.

Numerous bacteria in the human gut microbiome remain unknown and/or have yet to be cultured. While collections of human gut bacteria have been published, few strains have been made publicly available. A major hurdle in making strains publicly available is their deposition to public culture collections. We propose a framework for the bulk-deposition of strains to culture collections, which removes many of the barriers previously identified (www.dsmz.de/bulk-deposit). Using this bulk-deposition system we have created a publicly available collection of human gut isolates. The Human intestinal Bacteria Collection (HiBC) (www.hibc.rwth-aachen.de) contains 340 strains representing 198 species within 29 families and 7 phyla, of which 29 previously unknown species are taxonomically described and named. These included two butyrate-producing species of Faecalibacterium and new dominant species associated with health and inflammatory bowel disease, Ruminococcoides intestinale and Blautia intestinihominis, respectively. Plasmids were prolific within the HiBC isolates, with almost half (46%) of strains containing plasmids, with a maximum of six within a strain. This included a broadly occurring plasmid (pBAC) that exists in three diverse forms across Bacteroidales species. Megaplasmids were identified within two strains, the pMMCAT megaplasmid is globally present within multiple Bacteroidales species. This collection of easily searchable and publicly available gut bacterial isolates will facilitate functional studies of the gut microbiome.

Terrestrial cyanobacteria are extremely diverse. In urban areas, they can be found as black stains on the surface of building walls, stone monuments, or man-made structures. Many of the terrestrial cyanobacteria are still understudied. To expand knowledge of terrestrial cyanobacterial diversity, a polyphasic characterization was performed to identify 12 strains isolated from campus of University of the Ryukyus, Okinawa, Japan. Multigene phylogenetic analyses based on 16S rRNA gene and 16S-23S rRNA internal transcribed spacer (ITS) region showed that the isolated strains formed two independent subclades within Nodosilinea, and were distantly related to all described Nodosilinea species. The 16S-23S rRNA ITS secondary structures showed variations for D1-D1′ and Box B domain, while V3 domain was almost identical among entire species of Nodosilinea, including the studied strains. In addition, a unique morphological character, i.e. forming nodule or spiral shape, was also observed in certain studied strains. According to polyphasic characterization, Nodosilinea coculeatus sp. nov. and Nodosilinea terrestrialis sp. nov., were proposed as two new species of terrestrial cyanobacteria from Okinawa.

Metcalfa pruinosa (Say, 1830) - новий інвазивний шкідник Humulus lupulus L., який заселяє 130 видів рослин у Києві. Крім того, він є переносником Candidatus Phytoplasma asteris, який інфікує H. lupulus. З огляду на це, ми проаналізували та порівняли літературні дані щодо хазяїв M. pruinosa у Києві та Ca. P. asteris загалом. В результаті ми виявили 13 їхніх спільних рослин-хазяїв: Acer negundo L., Citrus limon (L.) Osbeck, Corylus avellana L., Fraxinus excelsior L., H. lupulus, Musa acuminata Colla, Prunus cerasus L., Prunus domestica L., Rosa canina L., Sonchus oleraceus L., Tilia cordata Mill., Trifolium pratense L., Vitis vinifera L. У подальших дослідженнях слід оцінити інфікованість цих хазяїв Ca. P. asteris.

Abstract Diaphorina citri serves as the primary vector for ‘Candidatus Liberibacter asiaticus’ (CLas), the bacterium associated with the severe Asian form of huanglongbing. CLas-positive D. citri are more fecund than their CLas-negative counterparts and require extra energy expenditure. Therefore, understanding the molecular mechanisms linking metabolism and reproduction is of particular importance. In this study, we found adipokinetic hormone (DcAKH) and its receptor (DcAKHR) were essential for increasing lipid metabolism and fecundity in response to CLas infection in D. citri. Knockdown of DcAKH and DcAKHR not only resulted in the accumulation of triacylglycerol and a decline of glycogen, but also significantly decreased fecundity and CLas titer in ovaries. Combined in vivo and in vitro experiments showed that miR-34 suppresses DcAKHR expression by binding to its 3’ untranslated region, whilst overexpression of miR-34 resulted in a decline of DcAKHR expression and CLas titer in ovaries and caused defects that mimicked DcAKHR knockdown phenotypes. Additionally, knockdown of DcAKH and DcAKHR significantly reduced juvenile hormone (JH) titer and JH signaling pathway genes in fat bodies and ovaries, including the JH receptor, methoprene-tolerant (DcMet), and the transcription factor, Krüppel homolog 1 (DcKr-h1), that acts downstream of it, as well as the egg development related genes vitellogenin 1-like (DcVg-1-like), vitellogenin A1-like (DcVg-A1-like) and the vitellogenin receptor (DcVgR). As a result, CLas hijacks AKH/AKHR-miR-34-JH signaling to improve D. citri lipid metabolism and fecundity, while simultaneously increasing the replication of CLas, suggesting a mutualistic interaction between CLas and D. citri ovaries.