- Volume 68, Issue 4, 2018

A Gram-stain-negative, non-motile and ovoid or rod-shaped bacterial strain, DBTF-13T, which was isolated from a tidal flat sediment of the Yellow Sea in South Korea, was characterized taxonomically. Strain DBTF-13T grew optimally at 25–30 °C and pH 7.0–8.0, and in the presence of 2.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences revealed that strain DBTF-13T formed an evolutionary lineage independent of other genera, including the genera Pseudooctadecabacter and Octadecabacter . Strain DBTF-13T exhibited 16S rRNA gene sequence similarity values of 96.9 % to the type strain of Pseudooctadecabacter jejudonensis , and of 95.8–96.5 % to the type strains of Octadecabacter species. Strain DBTF-13T contained Q-10 as the predominant ubiquinone and C18 : 1 ω7c and C16 : 0 as the major fatty acids. The major polar lipids of strain DBTF-13T were phosphatidylcholine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain DBTF-13T was 61.6 mol%. The chemotaxonomic data and other differential phenotypic properties made it reasonable to differentiate strain DBTF-13T from the genera Pseudooctadecabacter and Octadecabacter . On the basis of the data presented, strain DBTF-13T constitutes a new genus and species within the class Alphaproteobacteria , for which the name Aestuariibius insulae gen. nov., sp. nov. is proposed. The type strain is DBTF-13T (=KACC 19432T=NBRC 113038T).

Previously, experimental DNA–DNA hybridization (DDH) between Shewanella haliotis JCM 14758T and Shewanella algae JCM 21037T had suggested that the two strains could be considered different species, despite minimal phenotypic differences. The recent isolation of Shewanella sp. MN-01, with 99 % 16S rRNA gene identity to S. algae and S. haliotis , revealed a potential taxonomic problem between these two species. In this study, we reassessed the nomenclature of S. haliotis and S. algae using available whole-genome sequences. The whole-genome sequence of S. haliotis JCM 14758T and ten S. algae strains showed ≥97.7 % average nucleotide identity and >78.9 % digital DDH, clearly above the recommended species thresholds. According to the rules of priority and in view of the results obtained, S. haliotis is to be considered a later heterotypic synonym of S. algae . Because the whole-genome sequence of Shewanella sp. strain MN-01 shares >99 % ANI with S. algae JCM 14758T, it can be confidently identified as S. algae .

Two strains of Gram-stain-negative, facultatively anaerobic short-rod bacteria were recovered from two different food samples in Ma’anshan city, Anhui province, China in 2008. The bacteria were characterized in a polyphasic taxonomic study that included phenotypic, phylogenetic and genotypic methodologies. Phylogenetic analysis of the 16S rRNA gene demonstrated that the two strains belonged to the genus Proteus and were most similar to Proteus vulgaris ATCC 29905T with a score of 99.7 %. Phylogenetic analysis of the rpoB gene placed the two strains into a cluster with a distinctly interspecies phylogenetic branch that was clearly separated from six type strains of the genus Proteus , with the most closely related species being Proteus mirabilis ATCC 29906T. In silico genomic comparisons, including in silico DNA–DNA hybridization (isDDH) and average nucleotide identity (ANI) analysis showed that the representative strain, 08MAS0041T, and all six Proteus species share less than 70 % isDDH and have a 95 % ANI cutoff level, supporting the designation of the two strains as a novel species of the genus Proteus . The predominant cellular fatty acids of strain 08MAS0041T were C16 : 0 (24.8 %), C16 : 1ω7c/16 : 1ω6c (16.5 %), C18 : 1ω6c/C18 : 1 ω7c (14.5 %), C17 : 0 cyclo (12.6 %) and C16 : 1iso I/C14 : 0 3-OH (10.6 %). The analysis of biochemical, phylogenetic and genomic data confirmed that the two strains were clearly different from all recognized species of the genus Proteus and represent a novel Proteus species, for which the name Proteus alimentorum sp. nov. is proposed. The type strain is 08MAS0041T (=DSM 104685T=CGMCC 1.15939T).

Aspergillus candidus is a species frequently isolated from stored grain, food, indoor environments, soil and occasionally also from clinical material. Recent bioprospecting studies highlighted the potential of using A. candidus and its relatives in various industrial sectors as a result of their significant production of enzymes and bioactive compounds. A high genetic variability was observed among A. candidus isolates originating from various European countries and the USA, that were mostly isolated from indoor environments, caves and clinical material. The A. candidus sensu lato isolates were characterized by DNA sequencing of four genetic loci, and agreement between molecular species delimitation results, morphological characters and exometabolite spectra were studied. Classical phylogenetic methods (maximum likelihood, Bayesian inference) and species delimitation methods based on the multispecies coalescent model supported recognition of up to three species in A. candidus sensu lato. After evaluation of phenotypic data, a broader species concept was adopted, and only one new species, Aspergillus dobrogensis, was proposed. This species is represented by 22 strains originating from seven countries (ex-type strain CCF 4651T=NRRL 62821T=IBT 32697T=CBS 143370T) and its differentiation from A. candidus is relevant for bioprospecting studies because these species have different exometabolite profiles. Evaluation of the antifungal susceptibility of section Candidi members to six antifungals using the reference EUCAST method showed that all species have low minimum inhibitory concentrations for all tested antifungals. These results suggest applicability of a wide spectrum of antifungal agents for treatment of infections caused by species from section Candidi.

Two strains (DMKU-PPS4-5T and DMKU-EPS3-4) representing a single novel anamorphic yeast species were isolated from two peat samples collected in Kan Tulee peat swamp forest, Surat Thani Province, Thailand. The strains differed by two nucleotide substitutions in the sequences of the D1/D2 region of the large subunit (LSU) rRNA gene and only one nucleotide substitution in the internal transcribed spacer (ITS) region. Phylogenetic analysis based on the D1/D2 regions showed that the two strains represented a single species in the genus Saturnispora and were clearly distinct from other related species. Saturnispora sekii was the most closely related species, but with 1.7–2.1 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 3.1–3.3 % nucleotide substitutions in the ITS region. They therefore represent a novel species of the genus Saturnispora, although the formation of ascospores was not observed. The name Saturnispora kantuleensis f.a., sp. nov. is proposed. The type strain is DMKU-PPS4-5T (=CBS 15217T=TBRC 7762T).

Six novel yeast species, Starmerella camargoi f.a., sp. nov., Starmerella ilheusensis f.a., sp. nov., Starmerella litoralis f.a., Starmerella opuntiae f.a., sp. nov., sp. nov., Starmerella roubikii f.a., sp. nov. and Starmerella vitae f.a, sp. nov. are proposed to accommodate 19 isolates recovered from ephemeral flowers or bees in Brazil, Costa Rica and Belize. Sequence analysis of the ITS-5.8S region (when available) and the D1/D2 domains of the large subunit of the rRNA gene showed that the six novel yeasts are phylogenetically related to several species of the Starmerella clade. The type strains are Starmerella camargoi f.a., sp. nov. UFMG-CM-Y595T (=CBS 14130T; Mycobank number MB 822640), Starmerella ilheusensis f.a., sp. nov. UFMG-CM-Y596T (=CBS CBS14131T; MB 822641), Starmerella litoralis f.a., sp. nov. UFMG-CM-Y603T (=CBS14104T; MB 822642), Starmerella opuntiae f.a., sp. nov. UFMG-CM-Y286T (=CBS 13466T; MB 822643), Starmerella roubikii f.a., sp. nov. UWOPS 01–191.1 (=CBS 15148; MB 822645) and Starmerella vitae f.a., sp. nov. UWOPS 00–107.2 (=CBS 15147T; MB 822646). In addition, 25 species currently assigned to the genus Candida are reassigned formally to the genus Starmerella.