Antonie van Leeuwenhoek.Journal of Microbiology.Fundamental and applied aspects of microbiology. Topics of particular interest include: structure & development; biochemistry & molecular biology; taxonomy, physiology & metabolic studies; genetics; ecological studies; especially molecular ecology; marine microbiology; medical microbiology; molecular biological aspects of microbial pathogenesis and bioinformatics.

Cohnella candidum sp. nov., radiation-resistant bacterium from soil Abstract A Gram-stain positive, endospore-forming, circular, convex, cream colored, designated strain 18JY8-7T, was isolated from soil collected in Jeju Island, South Korea. Phylogenetic analysis using 16S rRNA gene sequences showed that strain 18JY8-7T formed a distinct lineage within the family Paenibacillaceae (order Bacillales, class Bacilli), and is closely related to Cohnella rhizosphaerae (96.1%, sequence similarity) and Cohnella xylanilytica (96.0%). Optimal growth occurred at 30 °C, pH 6.5 and in the absence of NaCl. The predominant cellular fatty acids were anteiso-C15:0 and iso-C16:0. The major respiratory quinone was MK-7. The polar lipids profile comprised of diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. The DNA G + C content was 57.0 mol %. The genotypic and phenotypic analyses revealed the differentiation of strain 18JY8-7T from all recognized Cohenella species. The strain 18JY8-7T, therefore represents a novel bacterial species within the family Paenibacillaceae, for which the name Cohnella candidum sp. nov. is proposed. The type strain is 18JY8-7T (= KCTC 33969T = JCM 33199T).

Tellurirhabdus rosea gen. nov., sp. nov., a new member of the family Cytophagaceae isolated from soil in South Korea Abstract Strain U15T, rod-shaped, catalase and oxidase positive, non-motile, hot pink pigmented, Gram-negative bacterium, was isolated from soil of Udo port, Udo Island, South Korea. Growth was observed at 10–48 °C, pH 6–11, and 0% (w/v) NaCl. Optimum growth conditions are 30–40 °C, pH 7–10, and 0% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA sequences showed that strain U15T forms a distinct clade with type strains of the family Cytophagaceae, with similarities below 89%. The major polar lipids are phosphatidylethanolamine and phosphatidylserine. Strain U15T was found to contain MK-7 as the only menaquinone, and iso-C15:0, C16:1ω5c, iso-C17:0 3-OH and summed feature 3 (comprising C16:1ω7c and/or C16:1ω6c) as the major fatty acids (> 10%). The DNA G + C content of strain U15T was determined to be 54.3 mol%. Based on the phylogenetic, phenotypic characteristics and chemotaxonomic analysis data, strain U15T (= KCTC 62116T = JCM 32361T) should be classified as representing a novel species of a novel genus within the family Cytophagaceae for which the name Tellurirhabdus rosea gen. nov., sp. nov., is proposed.

Detection and virulence potential of a phospholipase D-negative Corynebacterium ulcerans from a concurrent diphtheria and infectious mononucleosis case Abstract Diphtheria by Corynebacterium ulcerans is increasingly occurring in children, adolescents and adults. In addition to diphtheria toxin (DT), phospholipase D (PLD) is considered a virulence factor of C. ulcerans. In the present study, a first case of concurrent diphtheria by a PLD-negative C. ulcerans and infectious mononucleosis (IM) was verified. Clinical and microbiological profiles and binding properties to human Fibrinogen (Fbg), Fibronectin (Fn) and type I collagen (col I) biotinylated proteins and virulence to Caenorhabditis elegans were investigated for C. ulcerans strain 2590 (clinical isolate) and two control strains, including PLD-positive BR-AD22 wild type and PLD-negative ELHA-1 PLD mutant strains. MALDI-TOF assays and a multiplex PCR of genes coding for potentially toxigenic corynebacteria identified strain 2590 as non-DT producing. Interestingly, strain 2590 did not express PLD activity in the CAMP test although the presence of the pld gene was verified. PLD-negative 2590 and a PLD-positive 210932 strains showed similar affinity to Fbg, Fn and type I collagen. C. elegans were able to escape from C. ulcerans strains, independent of PLD and DT production. Higher mortality of nematodes was verified for PLD-negative strains. Additional studies concerning multifactorial virulence potential of C. ulcerans, including environmental conditions remain necessary.

Hymenobacter persicinus sp. nov., a novel member of the family Hymenobacteraceae Abstract A bacterial strain, 1-3-3-3T, was isolated from a soil sample collected in Jeollabuk-do province, South Korea. Cells were observed to be Gram-stain negative, short rod-shaped and colonies to be red-pink in colour. Analysis of 16S rRNA gene sequences identified this strain as a member of the genus Hymenobacter in the family Hymenobacteraceae, with high levels of 16S rRNA sequence similarity with Hymenobacter algoricola VUG-A23aT(98.0%), Hymenobacter knuensis 16F7C-2 (97.9%), Hymenobacter fastidiosus VUG-A124T (97.1%), Hymenobacter elongatus VUG-A112T (97.0%), Hymenobacter chitinivorans Txc1T (97.0%) and Hymenobacter aquaticus16F3PT (96.7%). Growth of strain 1-3-3-3T was observed at 10–30 °C, pH 6–8 and in the presence of 0–1.0% NaCl. The genomic G + C content was determined to be 61.6 mol %. The predominant respiratory quinone of the isolate was found to be MK-7; the major fatty acids were identified as iso-C15:0 (19.9%), summed feature 3 (C16:1ω7c/C16:1ω6c, 19.7%), summed feature 4 (iso-C17:1 I/anteiso-C17:1 B, 17.8%), C16:1ω5c (12.5%) and anteiso-C15:0 (11.2%), and the major polar lipid was found to be phosphatidylethanolamine. The phenotypic and chemotaxonomic data support the affiliation of strain 1-3-3-3T with the genus Hymenobacter. However, the DNA-DNA relatedness between the isolate and its closest phylogenetic neighbours was lower than 34%. The DNA–DNA hybridization result and the differentiating phenotypic properties clearly indicate that strain 1-3-3-3Trepresents a novel species in the genus Hymenobacter, for which the name Hymenobacter persicinus sp. nov. is proposed. The type strain is 1-3-3-3T (= KCTC 52742T = JCM 32191T).

Transcription factor CgAzf1 regulates melanin production, conidial development and infection in Colletotrichum gloeosporioides Abstract Rubber anthracnose caused by Colletotrichum gloeosporioides leads to huge economic loss in the natural rubber industry every year. Conidia of C. gloeosporioides are a major infection source but little is known about molecular mechanisms underlying conidial development and infection. In this study, the C. gloeosporioide C2H2 zinc-finger protein transcription factor gene CgAzf1 is shown to be involved in melanin production, conidial development and infection. Deletion of CgAzf1 resulted in decreased melanin production and hydrophilicity of aerial mycelium was increased. The mutants also showed reduced conidiation, low germination rate, and the formation of appressorium lagged too. Virulence assays showed that the CgAzf1 deletion strain could not infect intact rubber tree leaves and had an attenuated virulence on the wounded leaves. Quantitative RT-PCR showed that CgAzf1 regulates expression of genes involved in the MAPK, cAMP-PKA and melanin biosynthesis pathways.

Production of a novel killer toxin from Saccharomyces eubayanus using agro-industrial waste and its application against wine spoilage yeasts Abstract The juicing industry generates large amounts of waste that mostly lack commercial value and, in the absence of waste treatment policies, produces environmental pollution. Also, microbiological spoilage is a major concern in the wine industry and control tools are limited. Taking these challenges into account, agro-industrial waste coming from ultrafiltrated apple and pear juice were used to grow Saccharomyces eubayanus and to produce its killer toxin (SeKT). A Plackett–Burman screening was performed in order to optimize SeKT production in ultrafiltrated apple and pear juice. The optimized medium was characterized: 75% v/v WUJ, 0.5% m/v KH2PO4, 0.5% m/v MgSO4, 0.5% m/v (NH4)SO4, 0.5% g/L urea, 10% v/v glycerol and 0.1% v/v Triton X-100. SeKT produced in WUJ optimised medium was used to perform killer assays against wine spoilage yeasts and showed antagonistic activity against Brettanomyces bruxellensis, Pichia guilliermondii, Pichia manshurica and Pichia membranifaciens. Different inhibition percentages against spoilage species in a wine environment (49–69%) were detected and preserved for at least 48 h. For the first time, this work reports the ability of S. eubayanus to produce a killer toxin with potential use as a biocontrol tool in winemaking. Producing SeKT using agro-industrial waste as an alternative medium to cultivate S. eubayanus would have industrial, economic and ecological benefits.

Neisseria chenwenguii sp. nov. isolated from the rectal contents of a plateau pika ( Ochotona curzoniae ) Abstract Two Gram-stain negative, catalase positive, coccus shaped bacteria, designated 10023T and 10010, were isolated from the rectal contents of a plateau pika (Ochotona curzoniae) in Qinghai–Tibet Plateau, China. Based on 16S rRNA gene sequence analysis, phylogenetic trees showed that these two isolates (10023T, 10010) group with members of the genus Neisseria. Additionally, these two isolates exhibited high 16S rRNA gene sequence similarity with Neisseria zalophi CSL 7565T (96.98%), Neisseria wadsworthii WC 05-9715T (96.92%) and Neisseria canis ATCC 14687T (96.79%). Further phylogenetic analysis based on the rplF gene showed that these two novel strains can be easily discriminated from phylogenetically closely related species. Optimal growth was found to occur on BHI agar with 5% defibrinated sheep blood at 37 °C and growth was also observed on nutrient agar, Columbia blood agar and chocolate agar plates; however, growth was not observed on MacConkey agar after 7 days. The major cellular fatty acids of these strains were identified as C16:0 and C16:1ω7c/C16:1ω6c. The complete genome size of the type strain 10023T is 2,496,444 bp, with DNA G+C content of 54.0 mol %. The average nucleotide identity values were 73.5–79.3% between isolate 10023T and reference Neisseria spp. Based on polyphasic analysis, these isolates (10023T and 10010) are considered to represent a novel species in the genus Neisseria, for which the name Neisseria chenwenguii sp. nov. is proposed. The type strain is 10023T (= DSM 103440T = CGMCC 1.15736T).

Ulvibacterium marinum gen. nov., sp. nov., a novel marine bacterium of the family Flavobacteriaceae , isolated from a culture of the green alga Ulva prolifera Abstract A Gram-stain negative, aerobic, rod-shaped, and non-motile bacterium, designated strain CCMM003T, was isolated from a culture of the green alga Ulva prolifera. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain CCMM003T belongs to the family Flavobacteriaceae and exhibits a close relationship to Pseudozobellia thermophila DSM 19858T (92.5%). Optimal growth occurred in the presence of 4% (w/v) NaCl, at pH 7.0 and 30 °C. The polar lipids of strain CCMM003T consisted of phosphatidylethanolamine and six unidentified lipids. The predominant isoprenoid quinone was MK-6. The major fatty acids were iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH and summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH). The DNA G + C content of strain CCMM003T calculated on the basis of the genome sequence was 41.2 mol% and the genome size was 5.9 Mbp. On the basis of data from this polyphasic study, strain CCMM003T is considered to represent a novel genus and species of the family Flavobacteriaceae, for which the name Ulvibacterium marinum gen. nov., sp. nov. is proposed. The type strain is CCMM003T (= MCCC 1K03244T =KCTC 52639T).

Halalkalicoccus subterraneus sp. nov., an extremely halophilic archaeon isolated from a subterranean halite deposit Abstract An extremely halophilic archaeon, designated strain GSM28T, was isolated from a subterranean halite deposit in a Yunnan salt mine, China. Cells of the strain were observed to be cocci, non-motile and Gram-variable, and to require at least 15% (w/v) NaCl for growth (optimum 20%). Growth was found to occur in the ranges of 20–45 °C (optimum 42 °C) and pH 6.0–8.5 (optimum 7.5). Cells did not lyse in distilled water. Phylogenetic analysis based on 16S rRNA gene sequences indicated that this strain belongs to the genus Halalkalicoccus and shows 99.1% similarities with its close phylogenetic relative Halalkalicoccus paucihalophilus DSM 24557T. Genomic ANI analysis showed that the DNA–DNA relatedness between strain GSM28T and the closely related species Hac. paucihalophilus DSM 24557T and Halalkalicoccus jeotgali B3T was 83.7% and 83.1%, respectively. The major polar lipids were determined to be phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, sulfated mannosyl-glucosyl-glycerol diether-1 and two unidentified glycolipids. The DNA G + C content was determined to be 61.8 mol %. On the basis of physiological, biochemical tests and phylogenetic differentiations, strain GSM28T is concluded to represent a novel species in the genus Halalkalicoccus, for which the name Halalkalicoccus subterraneus sp. nov. is proposed. The type strain is GSM28T (= CGMCC 1.16344T = NBRC 113432T).

Cultivation and characterization of the bacterial assemblage of epsomic Basque Lake, BC Abstract Athalassohaline waters that are rich in divalent ions are good analogues for the chemical environments of Mars and the ocean worlds. Sulfate salts, along with chlorides, are important in Mars regolith with Ca, Fe, Mg, and Na counterions. Certain lakes in the Pacific Northwest are saturated with MgSO4 as epsomite. Here we report on the microbial community of Basque Lake, BC, a group of playas that is saturated with MgSO4. More than 60 bacterial isolates were obtained from Basque Lake soils by enrichment culture and repetitive streak-plating using media containing 10% (~ 1.7 M) NaCl or 50% (~ 2 M) MgSO4. Most of the isolates (~ 75%) were Gram-positive, motile, and produced endospores. Isolates related to Marinococcus halophilus and Virgibacillus marismortui dominated the collection. Halomonas and Salinivibrio were Gram-negative genera found at Basque Lake. Nearly all of the Basque Lake isolates grew at 50% MgSO4, with 65% growing at 60% MgSO4. Several isolates could grow in saturated (67%) MgSO4 (aw = 0.90). All of the isolates grew at 10% NaCl with 70% growing at 20% salinity (~ 3.5 M NaCl; aw = 0.82). Basque Lake isolates grew better at basic pH than acidic pH, with 80% growing at pH 9 and 30% growing at pH 10. Only 20% of the isolates grew at pH 5. Numerical taxonomy dendrograms based on 44 phenetic characteristics showed a strong correspondence to phylogenetic trees constructed from 16S rRNA gene sequences. Pyrosequencing of 16S rRNA gene sequences from direct DNA extracts of Basque Lake soils recovered predominantly Proteobacteria (60%), Firmicutes (11%), and unclassified bacteria (27%). Microbes capable of growth under the extreme chemical conditions of Mars are a particular concern for forward planetary protection should they contaminate a spacecraft.

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
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6948891480

alsfakia@gmail.com