Complete Genome Sequence of a Sulfur-Oxidizing Bacterium, Alcaligenes faecalis Strain NLF5-7, Isolated from Livestock Wastewater.

The complete genome sequence of Alcaligenes faecalis strain NLF5-7, which was isolated from livestock wastewater, is reported. The genome of strain NLF5-7 contains genes for assimilatory sulfate reduction, dissimilatory sulfate reduction and oxidation, and an SOX system, based on its functional genetic characteristics.

Draft Genome Sequence of a Sulfur-Oxidizing Bacterium, Aquamicrobium lusatiense NLF2-7, Isolated from Livestock Wastewater.

Here, we report the draft genome sequence of Aquamicrobium lusatiense NLF2-7, a Gram-negative, aerobic, non-flagellum-forming, rod-shaped bacterium that was isolated from livestock wastewater in South Korea. The assembled genome sequence is 5,201,486 bp, with 4,972 protein-coding sequences in 12 contigs, and possess the genes for the sulfur oxidation pathway.

Microvirga terrae sp. nov., Isolated from Soil.

A Gram-stain-negative and strictly aerobic bacterium, strain R24T, was isolated from soil in South Korea. Cells were non-motile short rods showing catalase- and oxidase-positive activities. Growth was observed at 15-40 °C (optimum, 25-30 °C) and pH 6.0-10.0 (optimum, 8.0-9.0), and in the presence of 0-3.0% NaCl (optimum, 0%). Strain R24T contained ubiquinone-10 as the sole respiratory quinone, C16:0, C18:0, and summed feature 8 (comprising C18:1 ω7c and/or C18:1 ω6c) as the major fatty acids, and phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylcholine as the major polar lipids. The DNA G+C content calculated from the whole genome sequence was 64.4%. Strain R24T was most closely related to Microvirga aerilata 5420S-16T with a 98.6% 16S rRNA gene sequence similarity. Average nucleotide identity and digital DNA-DNA hybridization values between strain R24T and all Microvirga species were less than 82.5 and 23.8%, respectively. Phylogenetic analyses based on the 16S rRNA gene and whole genome sequences revealed that strain R24T formed a phyletic lineage within the genus Microvirga. Based on its phenotypic, chemotaxonomic, and molecular characteristics, strain R24T represents a novel species of the genus Microvirga, for which the name Microvirga terrae sp. nov. is proposed. The type strain is R24T (= KACC 21784T = JCM 34259T).

Draft Genome Sequence of Stenotrophomonas daejeonensis Strain NLF4-10 Isolated from Livestock Wastewater.

Here, we report the draft genome sequence of Stenotrophomonas daejeonensis strain NLF4-10, isolated from a livestock wastewater treatment plant in Nonsan, Republic of Korea. The whole-genome sequence of S. daejeonensis strain NLF4-10 was analyzed using the Pacific Biosciences Sequel and Illumina NovaSeq sequencing platforms. The genome comprises a 3,655,148 bp chromosome with a GC content of 68%, 3,274 coding DNA sequences (CDSs), 59 transfer RNAs (tRNAs), and 4 noncoding RNAs (ncRNAs).

The Self-Bleaching Process of Microcystis aeruginosa is Delayed by a Symbiotic Bacterium Pseudomonas sp. MAE1-K and Promoted by Methionine Deficiency.

Various interactions between marine cyanobacteria and heterotrophic bacteria have been known, but the symbiotic relationships between Microcystis and heterotrophic bacteria remain unclear. An axenic M. aeruginosa culture (NIES-298) was quickly bleached after exponential growth, whereas a xenic M. aeruginosa culture (KW) showed a normal growth curve, suggesting that some symbiotic bacteria may delay this bleaching. The bleaching process of M. aeruginosa was distinguished from the phenomena of previously proposed chlorosis and programmed cell death in various characteristics. Bleached cultures of NIES-298 quickly bleached actively growing M. aeruginosa cultures, suggesting that M. aeruginosa itself produces bleach-causing compounds. Pseudomonas sp. MAE1-K delaying the bleaching of NIES-298 cultures was isolated from the KW culture. Bleached cultures of NIES-298 treated with strain MAE1-K lost their bleaching ability, suggesting that strain MAE1-K rescues M. aeruginosa from bleaching via inactivation of bleaching compounds. From Tn5 transposon mutant screening, a metZ mutant of strain MAE1-K (F-D3) unable to synthesize methionine, promoting the bleaching of NIES-298 cultures but capable of inactivating bleaching compounds, was obtained. The bleaching process of NIES-298 cultures was promoted with the coculture of mutant F-D3 and delayed by methionine supplementation, suggesting that the bleaching process of M. aeruginosa is promoted by methionine deficiency. IMPORTANCE Cyanobacterial blooms in freshwaters represent serious global concerns for the ecosystem and human health. In this study, we found that one of the major species in cyanobacterial blooms, Microcystis aeruginosa, was quickly collapsed after exponential growth by producing self-bleaching compounds and that a symbiotic bacterium, Pseudomonas sp. MAE1-K delayed the bleaching process via the inactivation of bleaching compounds. In addition, we found that a metZ mutant of strain MAE1-K (F-D3) causing methionine deficiency promoted the bleaching process of M. aeruginosa, suggesting that methionine deficiency may induce the production of bleaching compounds. These results will provide insights into the symbiotic relationships between M. aeruginosa and heterotrophic bacteria that will contribute to developing novel strategies to control cyanobacterial blooms.

Rhodococcus oxybenzonivorans sp. nov., a benzophenone-3-degrading bacterium, isolated from stream sediment.

A Gram-stain-positive, facultative aerobic, oxidase-negative, catalase-positive, non-sporulating, and non-motile bacterium, which degraded benzophenone-3, was isolated from stream sediment collected in the Republic of Korea and designated as strain S2-17T. Cells of this strain were rod-shaped during the early growth phase but became coccoid after the late exponential growth phase. Bacterial growth was observed at 15-37 °C (optimum, 25-30 °C) and pH 6.0-9.5 (optimum, pH 7.5-8.5) and in the presence of 0-9.0 % (w/v) NaCl (optimum, 0-1.0 %). Menaquinone-8 (H2) was the sole isoprenoid quinone, and C16 : 0, C17 : 1 ω8c, summed feature 3 (comprising C16 : 1 ω7c/C16 : 1 ω6c) and C18 : 1 ω9c were the major fatty acids. The cell wall of strain S2-17T contained meso-diaminopimelic acid, and arabinose, galactose and mycolic acid were found in whole-cell hydrolysates, suggesting a chemotype IV cell wall. The G+C content of the genome was 65.6 mol%. Phylogenetic analyses revealed that strain S2-17T formed a phyletic lineage within the genus Rhodococcus and was most closely related to Rhodococcus jostii DSM 44719T (99.2 % 16S rRNA gene sequence similarity). Average nucleotide identity and digital DNA-DNA hybridization values between strain S2-17T and R. jostii DSM 44719T were 82.6 and 26.5 %, respectively, indicating differences between the species. Based on its phenotypic, chemotaxonomic and molecular features, strain S2-17T represents a novel species of the genus Rhodococcus, for which the name Rhodococcus oxybenzonivorans sp. nov. is proposed. The type strain is S2-17T (=KACC 19281T=JCM 32046T).

Linear Six-Carbon Sugar Alcohols Induce Lysis of Microcystis aeruginosa NIES-298 Cells.

Cyanobacterial blooms are a global concern due to their adverse effects on water quality and human health. Therefore, we examined the effects of various compounds on Microcystis aeruginosa growth. We found that Microcystis aeruginosa NIES-298 cells were lysed rapidly by linear six-carbon sugar alcohols including mannitol, galactitol, iditol, fucitol, and sorbitol, but not by other sugar alcohols. Microscopic observations revealed that mannitol treatment induced crumpled inner membrane, an increase in periplasmic space, uneven cell surface with outer membrane vesicles, disruption of membrane structures, release of intracellular matter including chlorophylls, and eventual cell lysis in strain NIES-298, which differed from the previously proposed cell death modes. Mannitol metabolism, antioxidant-mediated protection of mannitol-induced cell lysis by, and caspase-3 induction in strain NIES-298 were not observed, suggesting that mannitol may not cause organic matter accumulation, oxidative stress, and programmed cell death in M. aeruginosa. No significant transcriptional expression was induced in strain NIES-298 by mannitol treatment, indicating that cell lysis is not induced through transcriptional responses. Mannitol-induced cell lysis may be specific to strain NIES-298 and target a specific component of strain NIES-298. This study will provide a basis for controlling M. aeruginosa growth specifically by non-toxic substances.

Elucidating the biodegradation pathway and catabolic genes of benzophenone-3 in Rhodococcus sp. S2-17.

A new bacterium, Rhodococcus sp. S2-17, which could completely degrade an emerging organic pollutant, benzophenone-3 (BP-3), was isolated from contaminated sediment through an enrichment procedure, and its BP-3 catabolic pathway and genes were identified through metabolic intermediate and transcriptomic analyses and biochemical and genetic studies. Metabolic intermediate analysis suggested that strain S2-17 may degrade BP-3 using a catabolic pathway progressing via the intermediates BP-1, 2,4,5-trihydroxy-benzophenone, 3-hydroxy-4-benzoyl-2,4-hexadienedioic acid, 4-benzoyl-3-oxoadipic acid, 3-oxoadipic acid, and benzoic acid. A putative BP-3 catabolic gene cluster including cytochrome P450, flavin-dependent oxidoreductase, hydroxyquinol 1,2-dioxygenase, maleylacetate reductase, and α/ß hydrolase genes was identified through genomic and transcriptomic analyses. Genes encoding the cytochrome P450 complex that demethylates BP-3 to BP-1 were functionally verified through protein expression, and the functions of the other genes were also verified through knockout mutant construction and intermediate analysis. This study suggested that strain S2-17 might have acquired the ability to catabolize BP-3 by recruiting the cytochrome P450 complex and α/ß hydrolase, which hydrolyzes 4-benzoyl-3-oxoadipic acid to benzoic acid and 3-oxoadipic acid, genes, providing insights into the recruitment of genes of for the catabolism of emerging organic pollutants.

Flavobacterium microcysteis sp. nov., isolated from a culture of Microcystis aeruginosa.

A Gram-stain-negative, yellow-pigmented, strictly aerobic bacterium, designated strain MaA-Y11T, was isolated from a culture of Microcystis aeruginosa in the Republic of Korea. Cells were non-motile rods showing catalase- and oxidase-positive reactions. Growth of strain MaA-Y11T was observed at 25-37 °C (optimum, 30 °C) and pH 6.0-9.0 (optimum, 7.0) and in the presence of 0-1.0 % (w/v) NaCl (optimum, 0 %). Strain MaA-Y11T did not produce flexirubin-type pigments. Strain MaA-Y11T contained iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as major cellular fatty acids and menaquinone-6 as the sole isoprenoid quinone. Phosphatidylethanolamine, three unidentified aminolipids and four unidentified lipids were detected as the major polar lipids. The G+C content of the genomic DNA was 37.0 mol%. Phylogenetic analysis, based on 16S rRNA gene sequences, showed that strain MaA-Y11T formed a phyletic lineage with Flavobacterium lindanitolerans IP-10T within the genus Flavobacterium. Strain MaA-Y11T was most closely related to Flavobacterium lindanitolerans IP-10T, with a 98.85 % 16S rRNA gene sequence similarity, and shared less than 93.87 % sequence similarities with other type strains. Average nucleotide identity and in silico DNA-DNA hybridization values between strain MaA-Y11T and the type strain of F. lindanitolerans were 87.0 and 32.3 %, respectively. Here, we conclude that strain MaA-Y11T represents a new species of the genus Flavobacterium, for which the name Flavobacterium microcysteis sp. nov. is proposed. The type strain is MaA-Y11T (=KACC 21225T=JCM 33501T).

Geomonas soli gen. nov., sp. nov., a New Member of the Family Comamonadaceae, Isolated from Soil.

A Gram-stain negative, facultative aerobic bacterial strain, designated strain S-16T, was isolated from soil in South Korea. Colonies were white-milkish and cells were non-motile rods with oxidase- and catalase-positive activities. The growth of strain S-16T was observed at 20-40 °C (optimum, 25-30 °C) and pH 5.5-7.0 (optimum, pH 6.5). Ubiquinone-8 was identified as the sole respiratory quinone and C12:0, C16:0, C18:0, C15:1ω5c and summed feature 3 (comprising C16:1ω7c and/or C16:1ω6c) were identified as the major fatty acids (>5%). The major polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid, two unidentified phospholipids and an unidentified polar lipid. The G + C content of the genomic DNA calculated from the whole genome sequence was 66.8 mol%. Strain S-16T was most closely related to Piscinibacter aquaticus IMCC1728T, Rhizobacter gummiphilus NS21T and Rhizobacter dauci H6T with 16S rRNA gene sequence similarities of 97.93%, 97.93% and 97.44%, respectively. Phylogenetic analyses based on 16S rRNA gene and whole genome sequences suggested that strain S-16T could form a distinct phyletic lineage as a new genus within the family Comamonadaceae. Based on the phenotypic, chemotaxonomic and molecular features, strain S-16T represents the type strain of a novel species of a novel genus within the family Comamonadaceae, for which the name Geomonas soli gen. nov., sp. nov. is proposed. The type strain is S-16T (= KACC 19792T = JCM 32971T).

Amentoflavone, a novel cyanobacterial killing agent from Selaginella tamariscina.

Harmful cyanobacterial bloom (HCB) by Microcystis aeruginosa is increasingly becoming a serious concern to the environment and human health alike. Currently, many physical, chemical, and biological controls are underway to eliminate HCB, but natural chemicals are rarely used. To find a control agent with low environmental toxicity and high potential for practical use, 60 plant extracts were screened. Only Selaginella tamariscina extract killed all four Microcystis aeruginosa strains, but not the other tested bacteria. Chloroform fraction of S. tamariscina extract (CSE) showed the highest killing activity. The effects of CSE on M. aeruginosa were monitored using differential interference contrast microscopy and flow-cytometry analysis, scanning electron microscopy, and transmission electron microscopy. The images showed that CSE-treated cells were abnormally altered, with damaged cell membranes, peptidoglycan layers, and cytoplasm. Quadrupole time-of-flight liquid chromatography-mass spectrometry was used to identify amentoflavone as a major active compound. Pure amentoflavone, even at low concentrations showed a powerful killing effect on M. aeruginosa, but not on other non-cyanobacteria. Overall, in this study, we have highlighted the potentials of S. tamariscina extracts and amentoflavone as selective HCB control agents.

The effect of salt concentrations on the fermentation of doenjang, a traditional Korean fermented soybean paste.

Four sets of doenjang (traditional Korean fermented soybean paste) with 9%, 12%, 15%, and 18% solar salt concentrations were prepared and their pH, microbial abundances and communities, metabolites, and volatile compounds were analyzed periodically during the entire fermentation. The speeds of decrease in pH and increase in microbial abundances, representing microbial activity, were higher during early fermentation in lower (9% and 12%) salt doenjang. Microbial abundances in 15% and 18% salt doenjang were significantly lower than in the 9% and 12% salt doenjang, indicating low microbial activity. Community analysis revealed that Bacillus, Staphylococcus, and Clostridium and Aspergillus, Scopulariopsis, Fusarium, Mucor, and Penicillium, which might be derived from doenjang-meju used for preparing doenjang, were identified as major bacterial and fungal genera, respectively, in all doenjang samples. Weissella, Tetragenococcus, Oceanobacillus, and Debaryomyces, not dominant in doenjang-meju, were also identified as major groups in low salt doenjang. Metabolite analysis showed that amino acid profiles were relatively similar independent of salt concentrations and microbial growth, indicating important roles of indigenous proteases present in doenjang-meju, not microbial activity during doenjang fermentation, in amino acid production. The metabolism of free sugars to organic acids and biogenic amine production were greater in lower salt doenjang, which might be associated with the growth of microbes, particularly lactic acid bacteria. A higher level of and more diverse volatile compounds were identified in lower salt doenjang, indicating close association with microbial growth. This study provides a deeper understanding of doenjang fermentation and insight into the development of low salt doenjang.

Maribacter algicola sp. nov., isolated from a marine red alga, Porphyridium marinum, and transfer of Maripseudobacter aurantiacus Chen et al. 2017 to the genus Maribacter as Maribacter aurantiacus comb. nov.

A Gram-stain-negative, strictly aerobic and moderately halophilic bacterial strain, designated strain PoM-212T, was isolated from a marine alga, Porphyridium marinum, in the Republic of Korea. Cells were catalase- and oxidase-positive rods with gliding motility without flagellum. Growth was observed at 20-40 °C (optimum, 30 °C) and pH 5.0-8.5 (pH 5.0-5.5) and in the presence of 0.5-5 % (w/v) NaCl (2-3 %). Strain PoM-212T contained iso-C15 : 1, iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) as major fatty acids and menaquinone-6 as the sole isoprenoid quinone. Phosphatidylethanolamine, three unidentified aminolipids and two unidentified polar lipids were detected as major polar lipids. The G+C content of the genomic DNA was 41.0 mol%. Strain PoM-212T was most closely related to Maribacter lutimaris KJ4T, Maripseudobacter aurantiacus CDA4T and Maribacter flavus C3T with 97.2, 97.2 and 97.0 % 16S rRNA gene sequence similarities, respectively, and it formed a distinct phylogenetic lineage from them within the genus Maribacter. Maripseudobacter aurantiacus formed a close phylogenetic lineage with Maribacter flavus with 99.7 % 16S rRNA gene sequence similarity, but their digital DNA-DNA hybridization value was 67.4 %. On the basis of its phenotypic, chemotaxonomic and molecular properties, strain PoM-212T represents a novel species of the genus Maribacter, for which the name Maribacter algicola sp. nov. is proposed. The type strain is PoM-212T (=KACC 19789T=JCM 32941T). The transfer of Maripseudobacter aurantiacus to the genus Maribacter as Maribacter aurantiacus comb. nov. is also proposed (type strain CDA4T=KCTC 52409T=MCCC 1K03210T).

Hwanghaeella grinnelliae gen. nov., sp. nov., isolated from a marine red alga.

A Gram-stain-negative, strictly aerobic and moderately halophilic bacterium, designated strain Gri0909T, was isolated from a red marine alga, Grinnellia species, in the Yellow Sea of the Republic of Korea. Cells were motile by a single polar flagellum and short-rods showing oxidase and catalase activities. Growth was observed at 10-37 °C (optimum, 30 °C) and pH 6.0-9.0 (optimum, pH 8.0) and in the presence of 0-12.0 % (w/v) NaCl (optimum, 2.0-3.0 %). Strain Gri0909T contained C16 : 0, C18 : 1 2-OH, anteiso-C15 : 0 and summed feature 8 (comprising C18 : 1 ω7c and/or C18 : 1 ω6c) as major fatty acids. Ubiquinone-10 was identified as the sole isoprenoid quinone. Major polar lipids consisted of phosphatidylethanolamine, an identified phospholipid, four unidentified aminolipids and five unidentified lipids. The G+C content of the genomic DNA calculated from the whole-genome sequence was 59.1 mol%. Strain Gri0909T was most closely related to Marivibriohalodurans ZC80T with 91.4 % 16S rRNA gene sequence similarity. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Gri0909T formed a phyletic lineage within the family Rhodospirillaceae. The very low 16S rRNA gene sequence similarities, together with distinct phenotypic and chemotaxonomic properties, served to differentiate strain Gri0909T from phylogenetically closely related genera. Here it is proposed that strain Gri0909T represents a new species of a novel genus of the family Rhodospirillaceae, for which the name Hwanghaeella grinnelliae gen. nov., sp. nov. is proposed. The type strain is Gri0909T (=KACC 19793T=JCM 32943T).

Investigating the role of anodic potential in the biodegradation of carbamazepine in bioelectrochemical systems.

Anode potential is a critical factor in the biodegradation of organics in bioelectrochemical systems (BESs), but research on these systems with complex recalcitrant co-substrates at set anode potentials is scarce. In this study, carbamazepine (CBZ) biodegradation in a BES was examined over a wide range of set anode potentials (-200 to +600 mV vs Ag/AgCl). Current generation and current densities were improved with the increase in positive anode potentials. However, at a negative potential (-200 mV), current generation was higher as compared to that for +000 and +200 mV. The highest CBZ degradation (84%) and TOC removal efficiency (70%) were achieved at +400 mV. At +600 mV, a decrease in CBZ degradation was observed, which can be attributed to a low number of active bacteria and a poor ability to adapt to high voltage. This study signified that BESs operated at optimum anode potentials could be used for enhancing the biodegradation of complex and recalcitrant contaminants in the environment.

Genomic and metabolic features of Tetragenococcus halophilus as revealed by pan-genome and transcriptome analyses.

The genomic and metabolic diversity and features of Tetragenococcus halophilus, a moderately halophilic lactic acid bacterium, were investigated by pan-genome, transcriptome, and metabolite analyses. Phylogenetic analyses based on the 16S rRNA gene and genome sequences of 15 T. halophilus strains revealed their phylogenetic distinctness from other Tetragenococcus species. Pan-genome analysis of the T. halophilus strains showed that their carbohydrate metabolic capabilities were diverse and strain dependent. Aside from one histidine decarboxylase gene in one strain, no decarboxylase gene associated with biogenic amine production was identified from the genomes. However, T. halophilus DSM 20339T produced tyramine without a biogenic amine-producing decarboxylase gene, suggesting the presence of an unidentified tyramine-producing gene. Our reconstruction of the metabolic pathways of these strains showed that T. halophilus harbors a facultative lactic acid fermentation pathway to produce l-lactate, ethanol, acetate, and CO2 from various carbohydrates. The transcriptomic analysis of strain DSM 20339T suggested that T. halophilus may produce more acetate via the heterolactic pathway (including d-ribose metabolism) at high salt conditions. Although genes associated with the metabolism of glycine betaine, proline, glutamate, glutamine, choline, and citrulline were identified from the T. halophilus genomes, the transcriptome and metabolite analyses suggested that glycine betaine was the main compatible solute responding to high salt concentration and that citrulline may play an important role in the coping mechanism against high salinity-induced osmotic stresses. Our results will provide a better understanding of the genome and metabolic features of T. halophilus, which has implications for the food fermentation industry.

Oceaniradius stylonematis gen. nov., sp. nov., isolated from a red alga, Stylonema cornu-cervi.

A Gram-stain-negative, strictly aerobic bacterium, designated StC1T, was isolated from a marine alga, Stylonema cornu-cervi, in the Republic of Korea. Cells were oxidase- and catalase-positive rods that were motile by a single lateral flagellum. Growth of strain StC1T was observed at 30-45 °C(optimum, 37 °C), pH 6.0-11.0 (pH 7.0) and in the presence of 1.0-8.0 % (w/v) NaCl (2 %). Strain StC1T contained summed feature 8 (comprising C18 : 1ω7c/C18 : 1 ω6c) and 11-methyl-C18 : 1ω7c as the major fatty acids. Sulfoquinovosyl diacylglycerol, phosphatidylethanolamine and phosphatidylglycerol and ubiquinone-10 were identified as the major polar lipids and the sole isoprenoid quinone, respectively. The G+C content of the genomic DNA was 64.7 mol%. Strain StC1T was most closely related to Oricola cellulosilytica CC-AMH-OT, Nitratireductor basaltis J3T, Aquamicrobiumahrensii 905/1T and Mesorhizobium tamadayense Ala-3T with 97.3 , 96.9 , 96.8  and 96.6 % 16S rRNA gene sequence similarities, respectively, but it formed a distinct phylogenic lineage within the family Phyllobacteriaceae. On the basis of phenotypic, chemotaxonomic and molecular properties, strain StC1T represents a novel genus of the family Phyllobacteriaceae, for which the name Oceaniradius stylonematis gen. nov., sp. nov. is proposed. The type strain is StC1T (=KACC 19231T=JCM 32050T).

Tetragenococcus halophilus MJ4 as a starter culture for repressing biogenic amine (cadaverine) formation during saeu-jeot (salted shrimp) fermentation.

Biogenic amines (BAs) are frequently present in traditionally fermented salted foods. In this study, a Tetragenococcus halophilus strain (MJ4) with no BA-producing ability was isolated from a fish (anchovy) sauce. Strain MJ4 did not produce BAs from supplied precursors and no BA-producing genes were identified in its genome. Bacterial community analysis showed that in non-inoculated saeu-jeot (shrimp sauce) fermentation, Tetragenococcus predominated after 82 days, while in strain MJ4-inoculated saeu-jeot, Tetragenococcus predominated during the entire fermentation. Strain MJ4 repressed the growth of T. muriaticus, a known BA producer, during fermentation, but metabolite analysis demonstrated that metabolite profiles, including amino acids, were similar regardless of MJ4 inoculation. The metabolite analysis also showed that strain MJ4 clearly repressed the formation of cadaverine during fermentation. This study suggests that the use of strain MJ4 as a starter culture in salted fish fermentation may be a good strategy for the reduction of BA formation.

Rhodophyticola porphyridii gen. nov., sp. nov., isolated from a red alga, Porphyridium marinum.

A Gram-stain-negative, strictly aerobic and moderately halophilic bacterium, designated strain MA-7-27T, was isolated from a marine red alga, Porphyridium marinum, in the Republic of Korea. The cells of strain MA-7-27T were non-motile rods showing oxidase- and catalase-positive activities. Growth of strain MA-7-27T was observed at 15-45 °C (optimum, 30 °C), pH 5.0-9.0 (pH 7.0) and in the presence of 0.0-5.0 % (w/v) NaCl (2.0 %). Strain MA-7-27T contained C10 : 0, summed feature 1 (comprising iso-C15 : 1 h and/or C13 : 1 3-OH) and summed feature 8 (comprising C18 : 1 ω7c and/or C18 : 1 ω6c) as the major fatty acids. The only isoprenoid quinone detected was ubiquinone-10. The major polar lipids of strain MA-7-27T were phosphatidylglycerol, two unidentified phospholipids and two unidentified aminolipids. The G+C content of the genomic DNA was approximately 63.6 mol%. Strain MA-7-27T was most closely related to the type strains of Boseongicola aestuarii BS-W15T and Nioella nitratireducens SSW136T with 96.98 % and 96.12 % 16S rRNA gene sequence similarities, respectively, but phylogenetic analyses showed that strain MA-7-27T formed a clearly distinct phylogenic lineage from the closely related strains. The phenotypic, chemotaxonomic and molecular properties support that strain MA-7-27T represents a novel genus of the family Rhodobacteraceae, for which the name Rhodophyticola porphyridii gen. nov., sp. nov. is proposed. The type strain is MA-7-27T (=KACC 18805T=JCM 31537T).