Sphingomicrobium sediminis sp. nov., isolated from marine sediment in the Republic of Korea.

A Gram-stain-negative, rod-shaped, bright-orange coloured bacterium without flagellum, designated as strain GRR-S6-50T, was isolated from a tidal flat of Garorim bay, Taean-gun, Chungcheongbuk-do, Republic of Korea. Cells grew aerobically at 20-37 °C (optimum, 30 °C), pH 7.0-10.0 (optimum, pH 7.0) and with 1-5 % (w/v) NaCl (optimum, 3 %). The 16S rRNA gene sequence analysis demonstrated that strain GRR-S6-50T was closely related to Sphingomicrobium aestuariivivum AH-M8T with a sequence similarity of 97.80 % followed by Sphingomicrobium astaxanthinifaciens CC-AMO-30BT (97.44 %), Sphingomicrobium marinum CC- AMZ-30MT (97.16 %), Sphingomicrobium arenosum CAU 1457T (96.37 %), Sphingomicrobium flavum CC-AMZ-30NT (95.31 %) and Sphingomicrobium lutaoense CC-TBT-3T (95.23 %). The average nucleotide identity and digital DNA-DNA hybridization values with related strains ranged from 74.5 to 77.3% and 21.1 to 35.0 %, respectively. The G+C content of strain GRR-S6-50T was 63.30 mol%. The strain has ubiquinone-10 as the predominant respiratory quinone and the major fatty acids were C18 : 3 ω6c (54.57 %) and C17 : 1 ω6c (10.58 %). The polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, three unidentified lipids and one glycolipid. On the basis of the results of phylogenetic, phenotypic and chemotaxonomic studies, strain GRR-S6-50T is regarded to represent a novel species within the genus Sphingomicrobium, for which the name Sphingomicrobium sediminis sp. nov. (KACC 22562T=KCTC 92123T=JCM 35084T) is proposed.

Tenacibaculum tangerinum sp. nov., isolated from a tidal flat sediment.

An orange-coloured bacterium, designated as strain GRR-S3-23T, was isolated from a tidal flat sediment collected from Garorim Bay, Chuncheongbuk-do, Republic of Korea. Cells of GRR-S3-23T were aerobic, Gram-stain-negative, rod-shaped and motile. GRR-S3-23T grew at 18-40 °C (optimum, 30 °C), pH 7.0-9.0 (optimum, pH 7.0) and with 2-4 % NaCl (optimum, 2-3 % w/v). Results of 16S rRNA gene sequence analysis indicated that GRR-S3-23T was closely related to Tenacibaculum aiptasiae a4T (97.6 %), followed by Tenacibaculum aestuarii SMK-4T (97.5 %), Tenacibaculum mesophilum MBIC 1140T (97.4 %), Tenacibaculum singaporense TLL-A2T (97.3 %), Tenacibaculum crassostreae JO-1T (97.2 %),and Tenacibaculum sediminilitoris YKTF-3T (97.1 %). The average amino acid identity values between GRR-S3-23T and the related strains were 86.8-72.8 %, the average nucleotide identity values were 83.3-74.1 %, and the digital DNA-DNA hybridization values were 27.0-19.6 %. GRR-S3-23T possessed menaquinone-6 (MK-6) as major respiratory quinone and had summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c, 20.6 %) and iso-C15 : 1G (10.8 %) as major fatty acids (>10.0 %). The polar lipid profiles of GRR-S3-23T contained phosphatidylethanolamine, one unidentified aminolipid, one unidentified aminophospholipid, three unidentified lipids, one unidentified glycolipid and four unidentified phospholipids. The DNA G+C content of GRR-S3-23T was 33.7%. On the basis of the results of the polyphasic analysis involving phylogenetic, phylogenomic, physiological and chemotaxonomic analyses described in this study, GRR-S3-23T is considered to represent a novel species within the genus Tenacibaculum, for which the name Tenacibaculum tangerinum is proposed. The type strain is GRR-S3-23T (=KCTC 102029T=KACC 23271T=JCM 36353T).

Evolutionary innovations through gain and loss of genes in the ectomycorrhizal Boletales.

We aimed to identify genomic traits of transitions to ectomycorrhizal ecology within the Boletales by comparing the genomes of 21 symbiotrophic species with their saprotrophic brown-rot relatives. Gene duplication rate is constant along the backbone of Boletales phylogeny with large loss events in several lineages, while gene family expansion sharply increased in the late Miocene, mostly in the Boletaceae. Ectomycorrhizal Boletales have a reduced set of plant cell-wall-degrading enzymes (PCWDEs) compared with their brown-rot relatives. However, the various lineages retain distinct sets of PCWDEs, suggesting that, over their evolutionary history, symbiotic Boletales have become functionally diverse. A smaller PCWDE repertoire was found in Sclerodermatineae. The gene repertoire of several lignocellulose oxidoreductases (e.g. laccases) is similar in brown-rot and ectomycorrhizal species, suggesting that symbiotic Boletales are capable of mild lignocellulose decomposition. Transposable element (TE) proliferation contributed to the higher evolutionary rate of genes encoding effector-like small secreted proteins, proteases, and lipases. On the other hand, we showed that the loss of secreted CAZymes was not related to TE activity but to DNA decay. This study provides novel insights on our understanding of the mechanisms influencing the evolutionary diversification of symbiotic boletes.

Halomonas getboli sp. nov., a halotolerant bacteria isolated from a salt flat.

A novel Gram-stain-negative, rod-shaped, cream-coloured, motile, halotolerant bacterium, designated as YJPS3-2T, was isolated from saltern sediment of the Yellow sea in Yongyu-do, Republic of Korea. Strain YJPS3-2T grew at pH 5.0-10.0 (optimum, pH 7.0), 4-40 °C (optimum, 30 °C) and with 1-15% (w/v) NaCl (optimum 3 %). The 16S rRNA gene sequence analysis indicated that strain YJPS3-2T was closely related to those of Halomonas halophila F5-7T (98.75 %), Halomonas salina F8-11T (98.74 %), Halomonas smyrnensis AAD6T (98.66 %), Halomonas organivorans G-16.1T (98.34 %), Halomonas koreensis SS20T (97.98 %) and Halomonas beimenensis NTU-107T (96.93 %). The average nucleotide identity and digital DNA-DNA hybridization values between YJPS3-2T and related type strains were 86.9-91.6 % and 32.0-44.8 %. Strain YJPS3-2T was characterized as having Q-9 as the predominant respiratory quinone and the principal fatty acids (>10 %) were C16 : 0 (31.4 %), C19 : 0 ω8c cyclo (16.3 %), C17 : 0 cyclo (11.9 %) and C12 : 0 3-OH (10.4 %). The polar lipids consisted of phosphatidylcholine, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of strain YJPS3-2T is 68.1mol %. Based on the polyphasic taxonomic evidence presented in this study, YJPS3-2T should be classified as representing a novel species within the genus Halmonas, for which name Halomonas getboli is proposed, with the type strain YJPS3-2T (= KCTC 92124T=KACC 22561T=JCM 35085T).

Aurantiacibacter sediminis sp. nov., a marine bacterium isolated from a tidal flat.

A yellow-coloured bacterium, designated as strain JGD-13T, was isolated from a tidal flat in the Republic of Korea. Cells were Gram-stain-negative, aerobic, non-flagellated and rod-shaped. Growth was observed at 4-42 °C (optimum, 30 °C), at pH 6.0-12.0 (pH 7.0-8.0) and at 1-7 % (w/v) NaCl concentration (3 %). The 16S rRNA gene sequence analysis indicated that strain JGD-13T was closely related to Aurantiacibacter gangjinensis K7-2T with a sequence similarity of 98.2 %, followed by Aurantiacibacter aquimixticola JSSK-14T (98.1 %), Aurantiacibacter atlanticus s21-N3T (97.6 %), Aurantiacibacter zhengii V18T (97.6 %) and Aurantiacibacter luteus KA37T (97.5 %). The average nucleotide identity and digital DNA-DNA hybridization values with related strains were 70.3-76.2 % and 18.5-20.3 %. The genomic DNA G+C content was 60.2 mol%. Phylogenetic analysis using the maximum-likelihood method showed that strain JGD-13T formed a clade with A. aquimixticola JSSK-14T and A. gangjinensis K7-2T. The major fatty acids were summed feature 8 (39.7 %) and C17 : 1 ω6c (14.4 %). The predominant respiratory quinone was ubiquinone-10. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one sphingoglycolipid and three unidentified lipids. On the basis of phylogenetic, phenotypic and chemotaxonomic characteristics, strain JGD-13T represents a novel species within the genus Aurantiacibacter, for which the name Aurantiacibacter sediminis JGD-13Tsp. nov. is proposed. The type strain is JGD-13T (=KCTC 72892T=KACC 21676T=JCM 33995T).

A Novel Auxiliary Agarolytic Pathway Expands Metabolic Versatility in the Agar-Degrading Marine Bacterium Colwellia echini A3T.

Marine microorganisms encode a complex repertoire of carbohydrate-active enzymes (CAZymes) for the catabolism of algal cell wall polysaccharides. While the core enzyme cascade for degrading agar is conserved across agarolytic marine bacteria, gain of novel metabolic functions can lead to the evolutionary expansion of the gene repertoire. Here, we describe how two less-abundant GH96 α-agarases harbored in the agar-specific polysaccharide utilization locus (PUL) of Colwellia echini strain A3T facilitate the versatility of the agarolytic pathway. The cellular and molecular functions of the α-agarases examined by genomic, transcriptomic, and biochemical analyses revealed that α-agarases of C. echini A3T create a novel auxiliary pathway. α-Agarases convert even-numbered neoagarooligosaccharides to odd-numbered agaro- and neoagarooligosaccharides, providing an alternative route for the depolymerization process in the agarolytic pathway. Comparative genomic analysis of agarolytic bacteria implied that the agarolytic gene repertoire in marine bacteria has been diversified during evolution, while the essential core agarolytic gene set has been conserved. The expansion of the agarolytic gene repertoire and novel hydrolytic functions, including the elucidated molecular functionality of α-agarase, promote metabolic versatility by channeling agar metabolism through different routes. IMPORTANCEColwellia echini A3T is an example of how the gain of gene(s) can lead to the evolutionary expansion of agar-specific polysaccharide utilization loci (PUL). C. echini A3T encodes two α-agarases in addition to the core ß-agarolytic enzymes in its agarolytic PUL. Among the agar-degrading CAZymes identified so far, only a few α-agarases have been biochemically characterized. The molecular and biological functions of two α-agarases revealed that their unique hydrolytic pattern leads to the emergence of auxiliary agarolytic pathways. Through the combination of transcriptomic, genomic, and biochemical evidence, we elucidate the complete α-agarolytic pathway in C. echini A3T. The addition of α-agarases to the agarolytic enzyme repertoire might allow marine agarolytic bacteria to increase competitive abilities through metabolic versatility.

Altererythrobacter lutimaris sp. nov., a marine bacterium isolated from a tidal flat and reclassification of Altererythrobacter deserti, Altererythrobacter estronivorus and Altererythrobacter muriae as Tsuneonella deserti comb. nov., Croceicoccus estronivorus comb. nov. and Alteripontixanthobacter muriae comb. nov.

A yellow-coloured bacterium, designated strain JGD-16T, was isolated from a tidal flat in Janggu-do, Garorim Bay, Taean-gun, Chungcheongbuk-do, Republic of Korea. Cells were Gram-stain-negative, aerobic, non-flagellated and short ovoid to coccoid-shaped. Growth was observed at 10-37 °C (optimum, 30 °C), pH 6.0-9.0 (pH 8.0) and with 1-5% (w/v) NaCl (2%). Results of 16S rRNA gene sequence analysis indicated that strain JGD-16T was closely related to Altererythrobacter xiamenensis LY02T (97.1 %), Altererythrobacter aurantiacus O30T (96.3 %), Altererythrobacter ishigakiensis JPCCMB0017T (95.8 %), Altererythrobacter epoxidivorans JCS350T (95.7 %) and Altererythrobacter insulae BPTF-M16T (95.3%). Phylogenomic analysis using the maximum-likelihood algorithm showed that strain JGD-16T formed a clade with the genus Altererythrobacter. The genomic DNA G+C content was 57.8 mol%. The predominant respiratory quinone was ubiquinone-10. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, a sphingoglycolipid, an unidentified glycolipid and an unidentified lipid. The major fatty acids were C18:1 ω7c (31.5 %) and C18:3 ω6c (19.6 %). On the basis of its phylogenomic, physiological and chemotaxonomical characteristics, strain JGD-16T represents a novel species within the genus Altererythrobacter, for which the name Altererythrobacter lutimaris JGD-16Tsp. nov. is proposed. The type strain is JGD-16T (=KCTC 72632T=KACC 21405T=JCM 33750T). We also propose the reclassification of Altererythrobacter deserti as Tsuneonella deserti comb. nov., Altererythrobacter estronivorus as Croceicoccus estronivorus comb. nov. and Altererythrobacter muriae as Alteripontixanthobacter muriae comb. nov.

Novosphingobium aureum sp. nov., a marine bacterium isolated from salt flat sediment.

A Gram-stain-negative, aerobic, pale yellow-coloured, rod-shaped marine bacterium designated strain YJ-S2-02T was isolated from salt flat sediment sampled in Yongyu-do, Republic of Korea. Strain YJ-S2-02T grew at pH 6.0-9.0 (optimum, pH 7.0), 10-40 °C (optimum, 30 °C) and with optimum 1 % (w/v) NaCl. The 16S rRNA gene sequence analysis indicated that strain YJ-S2-02T was closely related to Novosphingobium naphthalenivorans NBRC 102051T (97.8 %) followed by Novosphingobium mathurense SM117T (97.5 %), Novosphingobium indicum H25T (97.3 %), Novosphingobium pentaromativorans US6-1T (96.8 %), Novosphingobium fontis STM-14T (96.6 %), Novosphingobium endophyticum EGI60015T (96.5 %), Novosphingobium naphthae D39T (96.5 %) and Novosphingobium malaysiense MUSC 273T (95.9 %). The average nucleotide identity and estimated DNA-DNA hybridization values between YJ-S2-02T and related type strains were 77.0-77.9 % and 19.1-24.0 %. Strain YJ-S2-02T was characterized as having Q-10 as the predominant respiratory quinone and the principal fatty acids (>10 %) were summed feature 8 (C18 : 1 ω6c/ω7c, 20.7 %), C18 : 3 ω6c (16.3 %) and C17 : 1 ω6c (11.8 %). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, sphingolipids and two unidentified lipids. The DNA G+C content of strain YJ-S2-02T was 65.6 mol%. On the basis of the polyphasic taxonomic evidence presented in this study, YJ-S2-02T should be classified as representing a novel species within the genus Novosphingobium, for which name Novosphingobium aureum is proposed, with the type strain YJ-S2-02T (=KACC 21677T =KCTC 72891T=JCM 33996T).

Novel Monomeric Fungal Subtilisin Inhibitor from a Plant-Pathogenic Fungus, Choanephora cucurbitarum: Isolation and Molecular Characterization.

The bacterial protease inhibitor domains known as Streptomyces subtilisin inhibitors (SSI) are rarely found in fungi. Genome analysis of a fungal pathogen, Choanephora cucurbitarum KUS-F28377, revealed 11 SSI-like domains that are horizontally transferred and sequentially diverged during evolution. We investigated the molecular function of fungal SSI-like domains of C. cucurbitarum, designated "choanepins." Among the proteins tested, only choanepin9 showed inhibitory activity against subtilisin as the target protease, accounting for 47% of the inhibitory activity of bacterial SSI. However, the binding affinity (expressed as the dissociation constant [Kd ]) of choanepin9 measured via microscale thermophoresis was 21 nM, whereas that for bacterial SSI is 34 nM. The trend of binding and inhibitory activity suggests that the two inhibitors exhibit different inhibitory mechanisms for subtilisin protease. Interestingly, choanepin9 was identified as a monomer in studies in vitro, whereas bacterial SSI is a homodimer. Based on these observations, we constructed a monomeric bacterial SSI protein with decreased binding affinity to abrogate its inhibitory activity. By altering the reactive sites of choanepin9 deduced from the P1 and P4 sites of bacterial SSI, we reestablished that these residues in choanepins are also crucial for modulating inhibitory activity. These findings suggest that the fungal SSI evolved to target specific cognate proteases by altering the residues involved in inhibitory reactivity (reactive sites) and binding affinity (structural integrity). The function of fungal SSI proteins identified in this study provides not only a clue to fungal pathogenesis via protease inhibition but also a template for the design of novel serine protease inhibitors.IMPORTANCE Until recently, Streptomyces subtilisin inhibitors (SSI) were reported and characterized only in bacteria. We found SSI-like domains in a plant-pathogenic fungus, Choanephora cucurbitarum KUS-F28377, which contains 11 sequentially diverged SSI-like domains. None of these fungal SSI-like domains were functionally characterized before. The active form of fungal SSI-like protein is a monomer, in contrast to the homodimeric bacterial SSI. We constructed a synthetic monomer of bacterial SSI to demonstrate the modulation of its activity based on structural integrity and not reactive sites. Our results suggest the duplication and divergence of SSI-like domains of C. cucurbitarum within the genome to inhibit various cognate proteases during evolution by modulating both binding and reactivity. The molecular functional characterization of fungal SSI-like domains will be useful in understanding their biological role and future biotechnological applications.

Muricauda ochracea sp. nov., isolated from a tidal flat in the Republic of Korea.

A yellowish-brown-coloured bacterium, designated strain JGD-17T, was isolated from a tidal flat of Janggu-do, Garorim bay, Taean-gun, Chungcheongbuk-do, Republic of Korea. Cells were Gram-stain-negative, aerobic, non-flagellated and long-rod-shaped. Growth was observed at 20-45 °C (optimum, 25-30 °C), at pH 6.0-10.0 (9.0) and with 1-5 % (w/v) NaCl (1-3 %). Results of 16S rRNA gene sequence analysis indicated that strain JGD-17T was closely related to Muricauda nanhaiensis SM1704T (96.1 %), Muricauda olearia CL-SS4T (95.0 %), Muricauda beolgyonensis BB-My12T (94.9 %), Muricauda marina H19-56T (94.7 %) and Muricauda indica 3PC125-7T (94.5 %). The ranges of values for the average nucleotide identity and digital DNA-DNA hybridization analyses with related strains were 71.3-74.1 % and 16.9-18.2 %. The genomic DNA G+C content was 41.1 mol%. Phylogenetic analysis using the neighbour-joining method showed that strain JGD-17T formed a clade with Muricauda nanhaiensis SM1704T, Muricauda lutaonensis CC-HSB-11T, Muricauda lutea CSW06T and Muricauda pacifica SM027T. The major fatty acids were iso-C15 : 0 (26.9 %), iso-C15 : 1 G (19.5 %) and iso-C17 : 0 3-OH (12.7 %). The predominant respiratory quinone was menaquinone-6. The polar lipids were phosphatidylethanolamine, an unidentified aminolipid, an unidentified phospholipid and two unidentified lipids. On the basis of phylogenetic, phenotypic and chemotaxonomic characteristics, strain JGD-17T represents a novel species within the genus Muricauda, for which the name Muricauda ochracea sp. nov. is proposed. The type strain is JGD-17T (=KCTC 72732T=KACC 21486T=JCM 33817T).

Marinobacter halodurans sp. nov., a halophilic bacterium isolated from sediment of a salt flat.

A Gram-staining-negative, aerobic, cream-coloured, marine bacterium, with rod-shaped cells, designated strain YJ-S3-2T, was isolated from salt flat sediment of Yongyu-do, Republic of Korea. YJ-S3-2T grew at pH 5.0-9.0 (optimum pH 7.0), 4-45 °C (optimum 30 °C) and with 1-18 % (w/v) NaCl (optimum 6 %). The results of 16S rRNA gene sequence analysis indicated that YJ-S3-2T was closely related to Marinobacter segnicrescens SS011B1-4T (97.0 %) followed by, 'Marinobacter nanhaiticus' D15-8W (96.7 %), Marinobacter bryozoorum 50-11T (96.7 %), Marinobacter koreensis DSMZ 179240T T (96.5 %) and Marinobacter bohaiensis T17T (96.5 %). The average nucleotide identity (ANI) and the genome to genome distance calculator (GGDC) estimate values between YJ-S3-2T and related type strains were 73.7-79.8 and 19.9-22.5 %, and also 73.5 and 20.7 % with Marinobacter hydrocarbonoclasticus. YJ-S3-2T was characterized as having Q-9 as the predominant respiratory quinone and the principal fatty acids (>10 %) were C16 : 0 (22.3 %), summed feature 9 (C17 : 1iso ω9c/C16 : 0 10-methyl, 13.8 %) and 3 (C16 : 1ω7c/C16 : 1ω6c, 11.9 %). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids and two unidentified phospholipids. The DNA G+C content of YJ-S3-2T is 60.9 mol%. On the basis of the polyphasic taxonomic evidence presented in this study, YJ-S3-2T should be classified as representing a novel species within the genus Marinobacter, for which name Marinobacter halodurans sp. nov. is proposed, with the type strain YJ-S3-2T (=KACC 19883T=KCTC 62937T=JCM 33109T).

Genomic and transcriptomic perspectives on mycoremediation of polycyclic aromatic hydrocarbons.

Mycoremediation holds great potential in remedying toxic environments contaminated with polyaromatic organic pollutants. To harness the natural process for practical applications, understanding the genetic and molecular basis of the remediation process is prerequisite. Compared to known bacterial degradation pathways of aromatic pollutants, however, the fungal degradation system is less studied and understanding of the genetic basis for biochemical activity is still incomplete. In this review, we surveyed recent findings from genomic and transcriptomic approaches to mycoremediation of aromatic pollutants, in company with the genomic basis of polycyclic aromatic hydrocarbon (PAH) degradation by basidiomycete fungi, Dentipellis sp. KUC8613. Unique features in the fungal degradation of PAHs were outlined by multiple cellular processes: (i) the initial oxidation of recalcitrant contaminants by various oxidoreductases including mono- and dioxygenases, (ii) the following detoxification, and (iii) the mineralization of activated pollutants that are common metabolism in many fungi. Along with the genomic data, the transcriptomic analysis not only posits a full repertoire of inducible genes that are common or specific to metabolize different PAHs but also leads to the discovery of uncharacterized genes with potential functions for bioremediation processes. In addition, the metagenomic study accesses community level of mycoremediation process to seek for the potential species or a microbial consortium in the natural environments. The comprehensive understanding of fungal degradation in multiple levels will accelerate practical application of mycoremediation. Key points • Mycoremediation of polyaromatic pollutants exploits a potent fungal degrader. • Fungal genomics provides a full repository of potential genes and enzymes. • Mycoremediation is a concerted cellular process involved with many novel genes. • Multi-omics approach enables the genome-scale reconstruction of remedying pathways.

Chryseobacterium phosphatilyticum sp. nov., a phosphate-solubilizing endophyte isolated from cucumber (Cucumis sativus L.) root.

A bacterial strain, designated as ISE14T, with Gram-stain-negative and non-motile rod-shaped cells, was isolated from the root of a cucumber plant collected in a field in Iksan, Republic of Korea and was characterized using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ISE14T represented a member of the genus Chryseobacterium and was closely related to Chryseobacterium viscerum 687B-08T (16S rRNA gene sequence similarity of 98.50 %), Chryseobacterium lactis NCTC 11390T (98.49 %), Chryseobacterium ureilyticum F-Fue-04IIIaaaaT (98.49 %) and Chryseobacterium oncorhynchi 701B-08T (98.04 %). Average nucleotide identity values between genome sequences of strain ISE14T and the closely related species ranged from 81.44 to 83.15 %, which were lower than the threshold of 95 % (corresponding to a DNA-DNA hybridization value of 70 %). The DNA G+C content of strain ISE14T was 36.3 mol%. The dominant fatty acids were iso-C15 : 0, summed feature 9 (iso-C17 : 1ω9c and/or C16 : 0 10-methyl), summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c) and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, three unidentified aminolipids and eight unidentified lipids; the predominant respiratory quinone was MK-6. On the basis of the evidence presented in this study, strain ISE14T can be distinguished from closely related species belonging to the genus Chryseobacterium. Thus, strain ISE14T is a novel species of the genus Chryseobacterium, for which the name Chryseobacteriumphosphatilyticum sp. nov. is proposed. The type strain is ISE14T (=KACC 19820T=JCM 32876T).

Gemmobacter lutimaris sp. nov., a marine bacterium isolated from a tidal flat.

A novel cream-pigmented marine bacterium, designated strain YJ-T1-11T, was isolated from a tidal flat at Yeongjong-do, Republic of Korea. Cells were rod-shaped, non-motile, aerobic, Gram-reaction-negative, oxidase-positive and catalase-positive. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain YJ-T1-11T clustered with Gemmobacter fontiphilus JS43T (98.3 %) within the genus Gemmobacter and its closest neighbours were G.emmobacter aquatilis DSM 3857T (98.5 %), Gemmobacter aquaticus A1-9T (98.4 %), Gemmobacterlanyuensis Orc-4T (98.4 %), Gemmobacterfontiphilus JS43T (98.3 %), Gemmobactercaeni DCA-1T (98.2 %), Gemmobacternanjingensis Y12T (97.5 %) and Gemmobactertilapiae Ruye-53T (97.2 %). Average nucleotide identity values between the genome sequences of strain YJ-T1-11T and the related type strains ranged from 77.08 to 90.48 %. The predominant fatty acid of strain YJ-T1-11T was summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c). The major isoprenoid quinone was Q-10 and the DNA G+C content was 65.6 mol%. The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol and three unidentified lipids. The DNA-DNA relatedness values between strain YJ-T1-11T and the type strains of the 12 phylogenetically related species of the genus Gemmobacter were 23.6-53.7 %. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain YJ-T1-11T is considered to represent a novel species of the genus Gemmobacter, for which the name Gemmobacter lutimaris sp. nov. is proposed. The type strain is YJ-T1-11T (=KCTC 62715T=JCM 32828T).

Comprehensive genomic and transcriptomic analysis of polycyclic aromatic hydrocarbon degradation by a mycoremediation fungus, Dentipellis sp. KUC8613.

The environmental accumulation of polycyclic aromatic hydrocarbons (PAHs) is of great concern due to potential carcinogenic and mutagenic risks, as well as their resistance to remediation. While many fungi have been reported to break down PAHs in environments, the details of gene-based metabolic pathways are not yet comprehensively understood. Specifically, the genome-scale transcriptional responses of fungal PAH degradation have rarely been reported. In this study, we report the genomic and transcriptomic basis of PAH bioremediation by a potent fungal degrader, Dentipellis sp. KUC8613. The genome size of this fungus was 36.71 Mbp long encoding 14,320 putative protein-coding genes. The strain efficiently removed more than 90% of 100 mg/l concentration of PAHs within 10 days. The genomic and transcriptomic analysis of this white rot fungus highlights that the strain primarily utilized non-ligninolytic enzymes to remove various PAHs, rather than typical ligninolytic enzymes known for playing important roles in PAH degradation. PAH removal by non-ligninolytic enzymes was initiated by both different PAH-specific and common upregulation of P450s, followed by downstream PAH-transforming enzymes such as epoxide hydrolases, dehydrogenases, FAD-dependent monooxygenases, dioxygenases, and glycosyl- or glutathione transferases. Among the various PAHs, phenanthrene induced a more dynamic transcriptomic response possibly due to its greater cytotoxicity, leading to highly upregulated genes involved in the translocation of PAHs, a defense system against reactive oxygen species, and ATP synthesis. Our genomic and transcriptomic data provide a foundation of understanding regarding the mycoremediation of PAHs and the application of this strain for polluted environments.

Genomic discovery of the hypsin gene and biosynthetic pathways for terpenoids in Hypsizygus marmoreus.

BACKGROUND: Hypsizygus marmoreus (Beech mushroom) is a popular ingredient in Asian cuisine. The medicinal effects of its bioactive compounds such as hypsin and hypsiziprenol have been reported, but the genetic basis or biosynthesis of these components is unknown. RESULTS: In this study, we sequenced a reference strain of H. marmoreus (Haemi 51,987-8). We evaluated various assembly strategies, and as a result the Allpaths and PBJelly produced the best assembly. The resulting genome was 42.7 Mbp in length and annotated with 16,627 gene models. A putative gene (Hypma_04324) encoding the antifungal and antiproliferative hypsin protein with 75% sequence identity with the previously known N-terminal sequence was identified. Carbohydrate active enzyme analysis displayed the typical feature of white-rot fungi where auxiliary activity and carbohydrate-binding modules were enriched. The genome annotation revealed four terpene synthase genes responsible for terpenoid biosynthesis. From the gene tree analysis, we identified that terpene synthase genes can be classified into six clades. Four terpene synthase genes of H. marmoreus belonged to four different groups that implies they may be involved in the synthesis of different structures of terpenes. A terpene synthase gene cluster was well-conserved in Agaricomycetes genomes, which contained known biosynthesis and regulatory genes. CONCLUSIONS: Genome sequence analysis of this mushroom led to the discovery of the hypsin gene. Comparative genome analysis revealed the conserved gene cluster for terpenoid biosynthesis in the genome. These discoveries will further our understanding of the biosynthesis of medicinal bioactive molecules in this edible mushroom.

FunGAP: Fungal Genome Annotation Pipeline using evidence-based gene model evaluation.

MOTIVATION: Successful genome analysis depends on the quality of gene prediction. Although fungal genome sequencing and assembly have become trivial, its annotation procedure has not been standardized yet. RESULTS: FunGAP predicts protein-coding genes in a fungal genome assembly. To attain high-quality gene models, this program runs multiple gene predictors, evaluates all predicted genes, and assembles gene models that are highly supported by homology to known sequences. To do this, we built a scoring function to estimate the congruency of each gene model based on known protein or domain homology. AVAILABILITY AND IMPLEMENTATION: FunGAP is written in Python script and is available in GitHub ( https://github.com/CompSynBioLab-KoreaUniv/FunGAP ). This software is freely available only for noncommercial users. CONTACT: igchoi@korea.ac.kr. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

The obligate alkalophilic soda-lake fungus Sodiomyces alkalinus has shifted to a protein diet.

Sodiomyces alkalinus is one of the very few alkalophilic fungi, adapted to grow optimally at high pH. It is widely distributed at the plant-deprived edges of extremely alkaline lakes and locally abundant. We sequenced the genome of S. alkalinus and reconstructed evolution of catabolic enzymes, using a phylogenomic comparison. We found that the genome of S. alkalinus is larger, but its predicted proteome is smaller and heavily depleted of both plant-degrading enzymes and proteinases, when compared to its closest plant-pathogenic relatives. Interestingly, despite overall losses, S. alkalinus has retained many proteinases families and acquired bacterial cell wall-degrading enzymes, some of them via horizontal gene transfer from bacteria. This fungus has very potent proteolytic activity at high pH values, but slowly induced low activity of cellulases and hemicellulases. Our experimental and in silico data suggest that plant biomass, a common food source for most fungi, is not a preferred substrate for S. alkalinus in its natural environment. We conclude that the fungus has abandoned the ancestral plant-based diet and has become specialized in a more protein-rich food, abundantly available in soda lakes in the form of prokaryotes and small crustaceans.

Maribacter litoralis sp. nov. a marine bacterium isolated from seashore.

A novel Gram-stain-negative, moderately halophilic and aerobic bacterium, designated strain SDRB-Phe2T, was isolated from coastal sediment of the yellow sea in Sindu-ri, Republic of Korea. Cells were oxidase-positive, catalase-positive, rod-shaped and surrounded by a capsule with gliding motility. Colonies were yellow-coloured, circular, pulvinate with entire margins. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SDRB-Phe2T formed a distinct lineage within the genus Maribacter of the family Flavobacteriaceae. Stain SDRB-Phe2T exhibited 16S rRNA gene sequence similarity values of 97.1-98.9 % to the type strains of Maribacterstanieri, Maribacterspongiicola, Maribacter forsetii, Maribacter dokdonensis, Maribacter aquivivus, Maribactercaenipelagi, Maribacterlitorisediminis, Maribactersedimenticola, Maribacterulvicola, Maribacter confluentis and Maribacter orientalis, and of 94.8-96.7 % to the type strains of the other species of the genus Maribacter. Strain SDRB-Phe2T contained MK-6 as the predominant respiratory quinone and iso-C15 : 1 G, iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the major fatty acids. The polar lipids of strain SDRB-Phe2T were phosphatidylethanolamine, one unidentified amino lipid and two unidentified lipids. The DNA G+C content was 36.2 mol%. DNA-DNA relatedness values of strain SDRB-Phe2T to the type strains of the 11 phylogenetically related species of the genus Maribacter were 21.9-38.6 %. On the basis of the phenotypic features, phylogenetic and DNA-DNA hybridization analyses presented here, strain SDRB-Phe2T (=JCM 32373T=KCTC 62273T=DSM 106042T) represents a novel species of the genus Maribacter, for which the name Maribacterlitoralis sp. nov. is proposed.

Zobellella maritima sp. nov., a polycyclic aromatic hydrocarbon-degrading bacterium, isolated from beach sediment.

A novel Gram-stain-negative, motile, rod-shaped bacterium, designated strain 102-Py4T, was isolated from Sinduri beach sediment in Taean, Republic of Korea. Cells were aerobic, oxidase-positive and catalase-positive. The isolate grew optimally with 1-3 % (w/v) NaCl, but NaCl is not an absolute requirement for growth. 16S rRNA gene sequence analysis revealed that strain 102-Py4T clustered together with Zobellella aerophila and fell within the clade formed by recognized species of the genus Zobellella. Its closest phylogenetic neighbours were Z. aerophila JC2671T (98.1 % 16S rRNA gene sequence similarity), Zobellella denitrificans ZD1T (96.4 %) and Zobellella taiwanensis ZT1T (96.0 %). The major fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C12 : 0, summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol and two unidentified amino lipids. The DNA G+C content was 62.1 mol%. The DNA-DNA relatedness value between strain 102-Py4T and Z. aerophila JC2671T was 12.4±1.3 %. The phenotypic properties of 102-Py4T demonstrated that this strain could be distinguished from other Zobellella species. On the basis of the data presented, strain 102-Py4T (=KCTC 62272T=JCM 32359T=DSM 106043T) is considered to represent a novel species of the genus Zobellella, for which the name Zobellella maritima sp. nov. is proposed.