Search

A Gram-stain-negative, aerobic, oxidase-positive, weakly catalase-positive, motile by means of a single polar flagellum, rod-shaped bacterium designated as strain S2-9 T was isolated from sediment sampled in Wiyang pond, Republic of Korea. Growth of this strain was observed at 10-40 °C (optimum, 35 °C) and pH 5.5-9.5 (optimum, pH 7.0-8.0) and in the presence of 0-0.5 % NaCl in Reasoner's 2A broth. The major fatty acids (>10 %) of strain S2-9 T were C 16 : 0 and summed feature 3 (comprising a mixture of C 16 : 1  ω 7 c and/or C 16 : 1  ω 6 c ). Ubiquinone-8 was detected as the respiratory quinone. The major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. Strain S2-9 T showed the highest 16S rRNA gene sequence similarity to Paucibacter oligotrophus ' CR182 (98.4 %), all type strains of T (98.7 %), followed by ' Paucibacter aquatile ' CR182 (98.4 %), all type strains of Pelomonas species (98.1-98.3 %), Mitsuaria chitosanitabida NBRC 102408 T (97.9 %), Kinneretia asaccharophila KIN192 T (97.8 %), Mitsuaria chitinivorans HWN-4 T (97.4 %), and Paucibacter toxinivorans 2C20 T (97.4 %). Phylogenetic trees based on the 16S rRNA gene and whole-genome sequences showed that strain S2-9 T formed a tight phylogenetic lineage with Paucibacter species (CHU3 T , CR182, and 2C20 T strains were 76.6-79.3% and 19.5-21.5 %, respectively. The genomic DNA G+C content of strain S2-9 T was 68.3 mol%. Notably, genes responsible for both sulphur oxidation and reduction and denitrification were found in the genome of strain S2-9 Paucibacter strains were 76.6-79.3% and 19.5-21.5 %, respectively. The genomic DNA G+C content of strain S2-9 T was 68.3 mol%. Notably, genes responsible for both sulphur oxidation and reduction and denitrification were found in the genome of strain S2-9 T represents a novel species of the genus T is involved in the nitrogen and sulphur cycles in pond ecosystems. Based on the polyphasic taxonomic results, strain S2-9 T represents a novel species of the genus Paucibacter , for which the name Paucibacter sediminis sp. nov. is proposed. The type strain is S2-9 T (= KACC 22267 T = JCM 34541 T ).

A Gram-stain-negative and facultative aerobic bacterium, strain 16-MA T , was isolated from seawater of Yellow Sea in South Korea. Cells were catalase- and oxidase-positive and non-motile rods. Growth occurred at 4-37 °C (optimum, 30 °C) and pH 6.0-11.0 (optimum, 8.0), and in the presence of 0-7.0% NaCl (optimum, 3 %). Strain 16-MA T contained ubiquinone-8 as the sole isoprenoid quinone, C 16 : 0 and summed feature three as the major fatty acids (>10 %), and phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid, an unidentified aminophospholipid, and an unidentified polar lipid as the major polar lipids. The genome size and DNA G+C content of strain 16-MA T were 3.69 Mb and 46.0 mol%, respectively. Strain 16-MA T was most closely related to Alishewanella alkalitolerans LNK-7.1 T with a 97.9 % 16S rRNA gene sequence similarity. A phylogenomic tree based on whole genome sequences showed that strain 16-MA T formed a phylogenetic lineage within the genus Alishewanella . Based on the phenotypic, chemotaxonomic, and molecular analyses, strain 16-MA T represents a novel species of the genus Alishewanella , for which the name Alishewanella maricola is proposed. The type strain is 16-MA T (=KACC 22238 T =JCM 34596 T ).

Two Gram-stain-negative, facultative aerobic, catalase- and oxidase-positive, and non-motile rod bacteria, strains BL T and W38 T , that were isolated from soil and freshwater, respectively, were taxonomically characterized. Both strains optimally grew at 30 °C and pH 7.0 in Reasoner's 2A medium and contained ubiquinone-8 as the sole respiratory quinone. As major fatty acids (>10 %), strain BL T contained iso-C 15 : 0 and summed features 3 and 9 (comprising iso-C 15 : 0 2-OH and/or C 16 : 1  ω 7 c /ω6 c and iso-C 17 : 1  ω 9 c and/or C 16 : 0 10-methyl, respectively), whereas strain W38 T and summed feature 9. Diphosphatidylglycerol and phosphatidylmonomethylethanolamine as major polar lipids and phosphatidylethanolamine and phosphatidylglycerol as minor polar lipids were detected in both strains. The DNA G+C contents of strains BL 15 : 0 , iso-C 16 : 0 and summed feature 9. Diphosphatidylglycerol and phosphatidylmonomethylethanolamine as major polar lipids and phosphatidylethanolamine and phosphatidylglycerol as minor polar lipids were detected in both strains. The DNA G+C contents of strains BL T and W38 T were 68.3 and 65.3 %, respectively. Phylogenetic analyses based on 16S rRNA gene and genome sequences revealed that strains BL T and W38 T formed a tight phylogenetic lineage with Tahibacter species, and they shared 98.8 % 16S rRNA gene sequence similarity and 75.5 % average nucleotide identity (ANI) and 16.6 % digital DNA-DNA hybridization (dDDH) values, indicating that they are different species. Strains BL T and W38 T were most closely related to Tahibacter caeni BUT-6 T and Tahibacter aquaticus PYM5-11 T with 97.7 and 98.0 % 16S rRNA gene sequence similarities, respectively. ANI and dDDH values between strain BL T and T. caeni BUT-6 T and between strain W38 T and T. aquaticus DSM 21667 T represent two different novel species of the genus T and W38 T represent two different novel species of the genus Tahibacter sp. nov. are proposed. The type strains of Tahibacter soli sp. nov. and Tahibacter amnicola sp. nov. are proposed. The type strains of T. soli and T. amnicola are BL T (=KACC 22831 T =JCM 35402 T ) and W38 T (=KACC 22832 T =JCM 35749 T ), respectively.

A Gram-stain-negative, strictly aerobic, oxidase-positive, catalase-negative, motile by gliding, creamy white-pigmented bacterium, designated strain S2-8 T , isolated from a sediment sample from a Wiyang pond in the Republic of Korea, was subjected to polyphasic taxonomic analysis. Growth was observed at 10-40 °C (optimum: 30 °C), pH 7-8 and 0-0.5% NaCl. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain S2-8 T belonged to the family Sphingobacteriaceae in the phylum Bacteroidota and was closely related to Solitalea longa HR-AV T , Solitalea canadensis DSM 3403 T and Solitalea koreensis R2A36-4 T with 97.2, 96.7 and 93.7 % 16S rRNA gene sequence similarities, respectively. Average nucleotide identity and digital DNA-DNA hybridization values for these type strains were 72.0-75.2% and 21.2-21.9 %, respectively. The major respiratory quinone is menaquinone-7. The major fatty acids were iso-C 15 : 0 , iso-C 17 : 0 3-OH and summed feature 3 (comprising C 16 : 1  ω 7 c and/or C 16 : 1 ). The major polar lipids were phosphatidylethanolamine, two unidentified amino acids and four unidentified lipids. The G+C content of genomic DNA was 37.9 mol%. Based on polyphasic taxonomic analysis, it was observed that strain S2-8  ω 6 c ). The major polar lipids were phosphatidylethanolamine, two unidentified amino acids and four unidentified lipids. The G+C content of genomic DNA was 37.9 mol%. Based on polyphasic taxonomic analysis, it was observed that strain S2-8 T is a novel species belonging to the genus Solitalea , for which the name Solitalea lacus sp. nov. is proposed. The type strain is S2-8 T (= KACC 22266 T = JCM 34533 T ).

A novel Gram-stain-negative, yellow-pigmented, non-motile and rod-shaped bacterial strain designated MMS21-Er5 T was isolated and subjected to polyphasic taxonomic characterization. MMS21- Er5 T could grow at 4-34 °C (optimum, 30 °C), at pH 6-8 (optimum, pH 7) and in the presence of 0-2% NaCl (optimum, 1 %). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that MMS21- Er5 T showed low levels of sequence similarities with other species, as the highest similarity of 97.83 % was observed with Flavobacterium tyrosinilyticum THG DN8.8 T , then 97.68 % with ' Flavobacterium ginsengiterrae ' DCY 55 and 97.63 % with Flavobacterium banpakuense 15F3 T , which were well below the suggested cutoff for species distinction. The whole genome sequence of MMS21-Er5 T consisted of a single contig of 5.63 Mbp, and the DNA G+C content was 34.06 mol%. The in-silico DNA-DNA hybridization and orthologous average nucleotide identity values were highest with Flavobacterium tyrosinilyticum KCTC 42726 T (45.7 and 91.92% respectively). The predominant respiratory quinone for the strain was menaquinone-6 (MK-6), the major cellular fatty acid was iso-C 15 : 0 , and the diagnostic polar lipids were phosphatidylethanolamine and phosphatidyldiethanolamine. The combination of physiological and biochemical tests clearly distinguished the strain from related species of the genus Flavobacterium . On the basis of these results, strain MMS21-Er5 T evidently represents a novel species of the genus Flavobacterium, for which the name Flavobacterium humidisoli sp. nov. is proposed (type strain=MMS21-Er5 T =KCTC 92256 T =LMG 32524 T ).

A Gram-stain-negative and strictly aerobic bacterium, strain R24 T , 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 R24 T contained ubiquinone-10 as the sole respiratory quinone, C 16:0 , C 18:0 , and summed feature 8 (comprising C 18:1 ω7c and/or C 18:1 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 R24 T was most closely related to Microvirga aerilata 5420S-16 T with a 98.6% 16S rRNA gene sequence similarity. Average nucleotide identity and digital DNA-DNA hybridization values between strain R24 T 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 R24 T formed a phyletic lineage within the genus Microvirga. Based on its phenotypic, chemotaxonomic, and molecular characteristics, strain R24 T represents a novel species of the genus Microvirga, for which the name Microvirga terrae sp. nov. is proposed. The type strain is R24 T (= KACC 21784 T  = JCM 34259 T )., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Lipids in microalgae are energy-rich compounds and considered as an attractive feedstock for biodiesel production. To redirect carbon flux from competing pathways to the fatty acid synthesis pathway of Tetraselmis sp., we used three types of chemical inhibitors that can block the starch synthesis pathway or photorespiration, under nitrogen-sufficient and nitrogen-deficient conditions. The starch synthesis pathway in chloroplasts and the cytosol can be inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea and 1,2-cyclohexane diamine tetraacetic acid (CDTA), respectively. Degradation of glycine into ammonia during photorespiration was blocked by aminooxyacetate (AOA) to maintain biomass concentration. Inhibition of starch synthesis pathways in the cytosol by CDTA increased fatty acid productivity by 27% under nitrogen deficiency, whereas the blocking of photorespiration in mitochondria by AOA was increased by 35% under nitrogen-sufficient conditions. The results of this study indicate that blocking starch or photorespiration pathways may redirect the carbon flux to fatty acid synthesis.