Flavisolibacter galbus sp. nov., isolated from soil in Jeju Island Abstract A Gram-stain negative, non-motile, and yellow-coloured bacterium, designated 17J28-26T, was isolated from soil in Jeju Island, Korea. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain 17J28-26T formed a distinct lineage within the family Chitinophagaceae (order Chitinophagales, class Chitinophagia), and is closely related to Flavisolibacter ginsenosidimutans (96.8% 16S rRNA gene sequence similarity), and Flavisolibacter ginsengisoli (96.6%). Growth was observed at 18–37 °C (optimum 30 °C) in R2A medium at pH 7.0. The major cellular fatty acids of strain 17J28-26T were summed feature 3 (C16:1 ω6c and/or C16:1 ω7c), and iso-C15:0. The predominant respiratory quinone was MK-7. The major polar lipid was identified as phosphatidylethanolamine. Based on biochemical, chemotaxonomic and phylogenetic characteristics, strain 17J28-26T represents a novel bacterial species within the family Chitinophagaceae, for which the name Flavisolibacter galbus sp. nov. is proposed. The type strain of Flavisolibacter galbus is 17J28-26T (= KCTC 62222T = JCM 33203T).

Spirosoma sordidisoli sp. nov., a propanil-degrading bacterium isolated from a herbicide-contaminated soil Abstract A novel Gram-stain negative, aerobic, rod-shaped, asporogenous, propanil-degrading bacterial strain, TY50T, was isolated from a herbicide-contaminated soil in Nanjing, China. Strain TY50T was found to grow optimally at pH 9.0, 30 °C and in the absence of NaCl. The G + C content of the total DNA was determined to be 55.5 mol%. The 16S rRNA gene sequence of strain TY50T shows high identity to that of Spirosoma lacussanchae CPCC 100624T (99.3%), Spirosoma metallicum PR1014kT (94.8%) and Spirosoma soli MIMBbqt12T (94.6%). DNA–DNA hybridization indicated that the isolate had relatively low levels of DNA–DNA relatedness with S. lacussanchae CPCC 100624T (48.3%). Average nucleotide identity and the digital DNA–DNA hybridizations for draft genomes between strain TY50T and S. lacussanchae CPCC 100624T were 93.2% and 51.0%, respectively. The major cellular fatty acids of strain TY50T were identified as C16:1ω5c (24.5%) and summed feature 3 (C16:1ω6c/C16:1ω7c, 40.7%). MK-7 was found to be the predominant respiratory quinone. The major polar lipid profile includes phosphatidylethanolamine, an unidentified lipid and an unidentified aminolipid. These chemotaxonomic data support the affiliation of strain TY50T with the members of the genus Spirosoma. Strain TY50T can be distinguished from its close phylogenetic neighbours based on its phenotypic, genotypic, and chemotaxonomic features. Therefore, strain TY50T represents a novel member of the genus Spirosoma, for which the name Spirosoma sordidisoli sp. nov. is proposed. The type strain is TY50T (= KCTC 62494T = CCTCC AB 2018041T).

Algoriphagus litoralis sp. nov., isolated from the junction between the ocean and a freshwater lake Abstract A Gram-stain negative, non-motile and short rod shaped bacterium, designated strain DSL-12T, was isolated from seawater of the East China Sea and characterised phylogenetically and phenotypically. Optimal growth was found to occur at 28 °C (range 4–40 °C), pH 7 (range 6–12) and with 3% (w/v) NaCl (range 0–8%). Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain DSL-12T is related to members of the genus Algoriphagus and shares high sequence similarities with Algoriphagus boritolerans DSM 17298T (97.6%) and Algoriphagus alkaliphilus DSM 22703T (97.6%). The 16S rRNA gene sequence identities between strain DSL-12T and other current members of the genus Algoriphagus were below 96.4%. The digital DNA–DNA hybridization values between strain DSL-12T and the type strains A. boritolerans DSM 17298T and A. alkaliphilus DSM 22703T were found to be 21.2 ± 2.4% and 20.2 ± 2.4%, respectively. The average nucleotide identity (ANI) values between strain DSL-12T and A. boritolerans DSM 17298T and A. alkaliphilus DSM 22703T were found to be 83.2% and 82.8%, respectively. The sole respiratory quinone was identified as MK-7. The major polar lipids were identified as phosphatidylethanolamine, diphosphatidylglycerol, one unidentified phospholipid and two unidentified lipids. The major fatty acids identified as were iso-C15:0, summed feature 8 (C18:1ω7c and/or C18:1ω6c), C16:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and iso-C17:0. The G+C content of the genomic DNA was determined to be 43.3 mol%. The combined genotypic and phenotypic data indicate that strain DSL-12T represents a novel species of the genus Algoriphagus, for which the name Algoriphagus litoralis sp. nov. is proposed, with the type strain DSL-12T (= KCTC 62647T = MCCC 1K03536T).

Serratia microhaemolytica sp. nov., isolated from an artificial lake in Southern China Abstract A Gram-stain negative, facultatively anaerobic, rod-shaped, non-motile and non-spore forming bacterium, designated ZS-11T, was isolated from an artificial freshwater lake in Guangzhou city, Guangdong province, China. Growth of strain ZS-11T was observed at the temperature 18–42 °C (optimum 32–37 °C), pH 6.0–8.0 (optimum 7.0) and 0.5–3.0% (w/v) NaCl (optimum 0.5%, w/v), and also found to be enhanced in the presence of CO2. Pairwise comparison of 16S rRNA gene sequences showed that the strain shared high similarities with Serratia entomophila DSM 12358T (96.1%), Serratia ficaria DSM 4569T (96.0%), Serratia plymuthica DSM 4540T (96.0%), Rahnella victoriana FRB 225T (95.9%) and Rouxiella badensis DSM 100043T (95.8%). The phylogenomic dendrograms showed that strain ZS-11T formed a distinct cluster within the clade of the genus Serratia. The major fatty acids (> 20%) present in the cells were C16:0, C16:1ω7c/C16:1ω6c and C18:1ω7c/C18:1ω6c, which were consistent with those of S. entomophila CCUG 55496T and Serratia liquefaciens CCUG 9285T. The DNA G + C content for the genome was 49.3%. Based on these phenotypic and genotypic data, strain ZS-11T is considered to represent a new species of the genus Serratia, for which the name Serratia microhaemolytica sp. nov. is proposed. The type strain is ZS-11T (= CCTCC AB 2018040T = KCTC 62413T).

Candida spp. and phagocytosis: multiple evasion mechanisms Abstract Invasive fungal infections are a global health problem, mainly in hospitals, where year by year hundreds of patients die because of these infections. Commensal yeasts may become pathogenic to human beings, affecting mainly immunocompromised patients. During infectious processes, the immune system uses phagocytes to eliminate invader microorganisms. In order to prevent or neutralize phagocyte attacks, pathogenic yeasts can use virulence factors to survive, as well as to colonize and infect the host. In this review, we describe how Candida spp., mainly Candida albicans, interact with phagocytes and use several factors that contribute to immune evasion. Polymorphism, biofilm formation, gene expression and enzyme production mediate distinct functions such as adhesion, invasion, oxidative stress response, proteolysis and escape from phagocytes. Fungal and human cells have similar structures and mechanisms that decrease the number of potential targets for antifungal drugs. Therefore, research on host–pathogen interaction may aid in the discovery of new targets and in the development of new drugs or treatments for these diseases and thus to save lives.

Genome mining for ribosomally synthesised and post-translationally modified peptides (RiPPs) reveals undiscovered bioactive potentials of actinobacteria Abstract One of the most diverse groups of bioactive bacterial metabolites is the ribosomally synthesised and post-translationally modified peptides (RiPPs) with different bioactivities. The process of genome mining has made it possible to predict the presence of such clusters among the huge genomic data available today. Despite the great potential of actinobacteria in producing natural products and the myriad of completely sequenced genomes available, a comprehensive genome mining of these bacteria for RiPPs is lacking. Here, a collection of 629 complete actinobacterial genomes were analysed to explore their RiPP biosynthesis potential. Using BAGEL3 genome mining tool, the presence of 477 RiPP biosynthesis gene clusters (BGCs) was shown, including all known classes of bacterial RiPPs. RiPP-encoding potential was shown to be widespread among different members of actinobacteria especially within the plant and soil-inhabiting strains. The notable presence of LAP BGCs in plant-associating actinobacteria was also illustrated. Streptomyces, Amycolatopsis, Kitasatospora and Frankia showed greater potential in RiPP biosynthesis while lanthipeptides and lasso peptides were the most distributed RiPPs. Three cyanobactin BGCs were also detected. Generally evidence of promising ability of actinobacteria to synthesise diverse classes of RiPPs as well as information needed to rationally select appropriate taxa for rational screening of specific RiPPs are presented.

Hymenobacter oligotrophus sp. nov., isolated from a contaminated agar plate Abstract A taxonomic study of a Gram-stain negative, rod-shaped, motile, asporogenous, catalase- and oxidase-positive bacterium, sh-6T, forming pink-red colonies, isolated from a contaminated R2A plate in the laboratory was performed. Its optimum growth temperature was determined to be 28 °C in the absence of NaCl on R2A plates. On the basis of 16S rRNA gene sequence analysis, strain sh-6T belongs to the genus Hymenobacter and is closely related to Hymenobacter deserti ZLB-3T (95.05%), Hymenobacter paludis KBP-30T (94.96%), Hymenobacter coalescens WW84T (94.04%), Hymenobacter gummosus ANT-18T (93.38%), Hymenobacter ocellatus Myx2105T (93.70%), Hymenobacter jeollabukensis 1-3-3-8T (93.48%) and Hymenobacter koreensis GYR3077T (93.21%). Comparison of the genome of strain sh-6T and that of H. gummosus ANT-18T gave digital DNA–DNA hybridization and Average Nucleotide Identity values of 20.6% and 78.4%, respectively. The respiratory isoprenoid quinone and polyamine component were identified as MK-7 and sym-homospermidine, respectively. The major cellular fatty acids identified as iso-C15:0, summed feature 4 (iso-C17:1 I/anteiso B), iso-C16:0, iso-C17:0 3-OH and iso-C17:0. The major polar lipid of strain sh-6T determined to be phosphatidylethanolamine. The DNA G+C content was determined to be 60.5 mol%. On the basis of the evidence presented in this study, a novel species of the genus Hymenobacter, Hymenobacter oligotrophus sp. nov., is proposed, with the type strain sh-6T (= CCTCC AB 2016064T = KCTC 62345T).

Jiella endophytica sp. nov., a novel endophytic bacterium isolated from root of Ficus microcarpa Linn. f. Abstract A Gram-negative, aerobic, short rodshaped, asporogenous bacterium, designated CBS5Q-3T, was isolated from a surface-sterilised root of Ficus microcarpa Linn. f. collected from Guangxi, China and investigated by a polyphasic approach to determine its taxonomic position. Strain CBS5Q-3T was found to grow optimally with 2% (w/v) NaCl at 30 °C, pH 7.0–8.0. Substrate mycelia and aerial mycelia were not formed, and no diffusible pigments were observed on the media tested. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain CBS5Q-3T is closely related to species of genus Jiella and shares high 16S rRNA gene sequence similarity of 98.1% with Jiella aquimaris JCM 30119T. The average nucleotide identity and in silico DNA–DNA hybridization values between strain CBS5Q-3T and J. aquimaris JCM 30119T were 82.8% and 26.0%, respectively. The DNA G + C content of strain CBS5Q-3T was determined to be 66.5 mol %. The cell wall peptidoglycan was found to contain meso-diaminopimelic acid and ubiquinone Q-10 identified as the respiratory lipoquinone. The polar lipids were found to be comprised of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylmonomethylethanolamine, phosphatidylethanolamine and three unidentified aminolipids, while the major fatty acids were identified as C18:1ω7c and cyclo-C19:0ω8c. On the basis of phylogenetic, chemotaxonomic and phenotypic data, strain CBS5Q-3T can be concluded to represent a novel species of the genus Jiella, for which the name Jiella endophytica sp. nov. is proposed. The type strain is CBS5Q-3T (= JCM 33167T = CGMCC 1.13863T).

Heavy metal resistance genes and plasmid-mediated quinolone resistance genes in Arthrobacter sp. isolated from Brazilian soils Abstract Arthrobacter sp. are Gram-positive bacilli commonly obtained from soil and in the hospital environment. These species have been reported to cause several types of infection. Heavy metals are a threat to the ecological system due to their high-levels of toxicity and the fluoroquinolones are antimicrobials widely used for the treatment of different bacterial infections. The aim of this study was to investigate the resistance to fluoroquinolone and heavy metals, the presence of plasmid-mediated resistance (PMQR) genes and heavy metals resistance (HMR) genes and the presence of plasmids in Arthrobacter sp. obtained from Brazilian soils. Bacterial isolation was performed using soil samples from different Brazilian regions. The bacterial identification was performed by 16S rRNA gene sequencing. The resistance profile for fluoroquinolones and heavy metals was determined by MIC. Several PMQR and HMR genes and plasmid families were investigated by PCR. Eight isolates were obtained from soil samples from different cultivations and regions of Brazil. All isolates were resistant to all fluoroquinolones, cadmium, cobalt and zinc and the majority to copper. Among the PMQR genes, the qepA (4) was the most prevalent, followed by qnrS (3), qnrB (3), oqxB (2) and oqxA (1). Among the HMR genes, the copA was detected in all isolates and the czcA in two isolates. The replication origin of the ColE-like plasmid was detected in all isolates; however, no plasmid was detected by extraction. The association of resistance to heavy metals and antimicrobials is a threat to the environmental balance and to human health. There are no studies reporting the association of PMQR and HMR genes in bacteria belonging to the genus Arthrobacter. To the best of our knowledge, this is the first report of qnrB, qepA, oqxA and oqxB in Arthrobacter species.

Biocontrol capability of local Metschnikowia sp. isolates Abstract This study set out to isolate and identify epiphytic yeasts producing pulcherrimin, and to evaluate their potential as biological control agents (BCAs). We isolated Metschnikowia sp. strains from flowers and fruits collected in Poland. The plant material had been collected between April to September 2017 from two small orchards where traditional organic management is employed. We identified the essential phenotypic features of the yeast, including assimilation and enzymatic profiles, stress resistance, adhesion properties, and antimicrobial activity against various fungi involved in crop and/or food spoilage. Yeast screening was performed using YPD agar supplemented with chloramphenicol and Fe(III) ions. Taxonomic classification was determined by sequence analysis of the D1/D2 domains of the large subunit rRNA gene. The isolates were identified as Metschnikowia andauensis and Metschnikowia sinensis. The yeast isolates were further characterized based on their enzymatic and assimilation profiles, as well as their growth under various stress conditions. In addition, the hydrophobicity and adhesive abilities of the Metschnikowia isolates were determined using a MATH test and luminometry. Their antagonistic action against molds representing typical crop spoiling microflora was also evaluated. The assimilation profiles of the wild isolates were similar to those displayed by collection strains of M. pulcherrima. However, some of the isolates displayed more beneficial phenotypic properties, especially good growth under stress conditions. Several of the epiphytes grew well over a wider range of temperatures (8–30 °C) and pH levels (3–9), and additionally showed elevated tolerance to ethanol (8%), glucose (30%), and peroxides (50 mM). The hydrophobicity and adhesion of the yeast cells were strain- and surface-dependent. The tested yeasts showed potential for use as BCAs, with some exhibiting strong antagonism against molds belonging to the genera Alternaria, Botrytis, Fusarium, Rhizopus, and Verticillium, as well as against yeasts isolated as food spoilage microbiota.