Pelagihabitans pacificus gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from a deep-sea seamount

Effect of different strains on quality characteristics of soy yogurt: Physicochemical, nutritional, safety features, sensory, and formation mechanism

The purpose of the study was to explore effect of four different strains on quality characteristics of soy yogurt. The results showed that four strains were all related to the genus Lactobacillus and N1 was Lacticaseibacillus rhamnosus, N2 was Lacticaseibacillus paracasei, N3 was Lacticaseibacillus plantarum, and N4 was Lacticaseibacillus acidophilus. The result analysis of biochemical, sensory, nutritional, functional and safety properties of fermentation process and end products showed that the soy yogurt fermented with L. rhamnosus N1 had the highest isoflavone content and the lowest phytic acid content; the soy yogurt fermented with L. paracasei N2 had the highest content of free amino acids and oligosaccharides, the lowest content of trypsin inhibitors; the soy yogurt fermented with L. plantarum N3 had the lowest oil content; the soy yogurt fermented with L. acidophilus N4 had optimal functional properties. In summary, N4 was suitable as a fermentation strain for soymilk.

Marixanthotalea marina gen. nov., sp. nov., a bacterium in the family Flavobacteriaceae isolated from seawater

A Gram-stain-negative, yellow-pigmented, non-motile, rod-shaped, catalase-positive, strictly aerobic marine bacterium, designated XHP0103T, was isolated from seawater collected from the southern Yellow Sea, PR China (34° 45' 53″ N 119° 25' 30″ E). Strain XHP0103T grew optimally at 28 °C, pH 7.5 and in 1.0-3.0 % (w/v) sea salt. MK-6 was the major respiratory quinone. The major cellular fatty acids (>10%) were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The polar lipid profile contained phosphatidylethanolamine, an unidentified aminolipid, an unidentified glycolipid and an unidentified lipid. Results of 16S rRNA gene sequence analysis indicated that strain XHP0103T displayed highest sequence similarity to Aestuariibaculum marinum IP7T (94.1 %). However, the phylogenetic trees based on 16S rRNA gene sequences suggested that strain XHP0103T clustered with Tamlana crocina HST1-43T (93.4 % sequence similarity) and Aestuariivivens insulae AH-MY3T (93.5 %). Genome sequencing revealed that strain XHP0103T comprised 3 134 388 bp with 2770 protein-coding genes, and the DNA G+C content was 35.5 %. The average nucleotide identity and digital DNA-DNA hybridization values between strain XHP0103T and T. crocina HST1-43T were 73.6 and 17.3 %, respectively. Based on phylogenetic, phenotypic, genomic and chemotaxonomic evidence, strain XHP0103T represents a novel genus in the family Flavobacteriaceae, for which the name Marixanthotalea marina gen. nov., sp. nov. is proposed. The type strain is XHP0103T (=MCCC 1K06060T=JCM 34682T).

Marinigracilibium pacificum gen. nov., sp. nov., a starch-degrading bacterium isolated from tropical western Pacific

The Gram-stain-negative, golden-yellow-colored, non-spore-forming, strictly aerobic, slender rod-shaped bacterial strain, designated KN852^T, was isolated from a seamount in the tropical western Pacific. The predominant respiratory quinone was MK-7 and the polar lipid profiles contained phosphatidylethanolamine, one unidentified phospholipid and six unidentified polar lipids. The predominant cellular fatty acids were iso-C_15:0, summed feature 3(C_16:1ω7c and/or iso-C_15:0 2OH), iso-C_17:0 3OH and iso-C_15:1 G. Phylogenetic analyses of 16S rRNA gene sequence revealed that strain KN852^T was affiliated with the family Flammeovirgaceae of the phylum Bacteroidota and formed a distinct lineage. The genomic DNA G + C content of strain KN852^T was 34.8%. Collectively, based on phenotypic, chemotaxonomic, phylogenetic and genomic evidence presented, strain KN852^T represents a novel species of a novel genus of the family Flammeovirgaceae, for which the name Marinigracilibium pacificum gen. nov., sp. nov. is proposed. The type strain is KN852^T (= CGMCC 1.17119^T = KCTC 72433^T).

Aggregatimonas sangjinii gen. nov., sp. nov., a novel silver nanoparticle synthesizing bacterium belonging to the family Flavobacteriaceae

Microbially synthesized nanoparticles has received increasing attentions owing to the broad applications in biology and medicine. In this study, we report a novel bacterium that biologically generates silver nanoparticles (AgNPs). This bacterium, designated strain F202Z8^T, was isolated from a rusty iron plate found in the intertidal region of Taean, South Korea. The morphological, biochemical and molecular characteristics predicted that strain F202Z8^T belongs to the family Flavobacteriaceae. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain F202Z8^T forms a distinct lineage with closely related genera Maribacter, Pelagihabitans, Pseudozobellia, Zobellia, Pricia, and Costertonia and showed the highest similarity to Maribacter aestuarii GY20^T (94.5%). The digital DNA-DNA hybridization and average nucleotide identity values calculated from the whole genome-sequence comparison between strain F202Z8^T and other members of the family Flavobacteriaceae were in the ranges of 12.7%-16.9% and 70.3%-74.4%, respectively, suggesting that strain F202Z8^T represented a novel genus. The complete genome sequence of strain F202Z8^T is 4,723,614 bp, with 43.26% G + C content. Based on the COG, GO, KEGG, NR, and Swiss-Prot databases, the genomic analysis of F202Z8^T revealed the presence of 17 putative genes responsible for the synthesis of AgNPs. Our polyphasic taxonomic results suggested that this strain represents a novel species of a novel genus in the family Flavobacteriaceae, for which the name Aggregatimonas sangjinii gen. nov., sp. nov. is proposed. The type strain of Aggregatimonas sangjinii is F202Z8^T (= KCCM 43411^T = LMG 31494^T). Overall, our data provide fundamental information to potentially utilize this novel bacterium for synthesis of nanoparticles.

Snuella sedimenti sp. nov., isolated from marine sediment

A Gram stain-negative, aerobic, motile by gliding, rod-shaped bacterial strain CAU 1569^T was isolated from marine sediment on Shido Island in Incheon. It grew at 20-37 °C (optimum, 30 °C), pH 6.0-9.0 (optimum, 7.0), 2-6% NaCl (w/v) (optimum, 2%). Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain CAU 1569^T formed a distinct lineage with only the type strain of Snuella. Strain CAU 1569^T showed high similarity to S. lapsa KACC 14152^T (95.8%), Mariniflexile gromovii KMM KCTC 12570^T, Aestuariibaculum marinum KCTC 52521^T (95.4%), A. suncheonense KACC 16186^T (94.6%) and Yeosuana aromativorans KCCM 42019^T (94.4%). The genome contained 57 contigs, 3,437 protein-coding gene, 3 rRNAs (5, 16, and 23S), 43 tRNAs, and with a 35.7 mol% G + C content. The DDH value between strain CAU 1569^T and S. lapsa KACC 14152^T was 39.4 ± 0.6%. The only isoprenoid quinone was menaquinone 6 (MK-6). The major fatty acids were iso-C_15:0, C_15:1-iso G, and C_17:0 iso 3-OH. Strain CAU 1569^T contained diphosphatidylglycerol, aminoglycolipid, unidentified aminolipid, and three unidentified lipids. Based on phylogenetic, genomic, physiologic, and chemotaxonomic characterizations, strain CAU 1569^T represents a novel Snuella species, which the name Snuella sedimenti sp. nov. is proposed. The type of strain is CAU 1569^T (= KCTC 82409^T = MCCC 1K05670^T).

Pacificispira spongiicola gen. nov., sp. nov., a nitrate-reducing bacterium isolated from tropical western Pacific

The Gram-stain-negative, strictly aerobic, curved-to-spiral rod-shaped bacterial strain, designated KN72^T, was isolated from the Caroline Seamounts in the Pacific Ocean. Phylogenetic analysis of 16S rRNA gene sequences revealed that strain KN72^T was a member of the family Rhodospirillaceae and formed a distinct lineage. Strain KN72^T contained ubiquinone-10 as the major respiratory quinone. The polar lipid profiles contained phosphatidylethanolamine, phosphatidylglycerol, one aminolipid and three phospholipids. The predominant cellular fatty acids were C_16:0 and summed feature 8 (comprising C_18:1ω7c/C_18:1ω6c). The strain KN72^T displayed highest 16S rRNA gene sequence similarities with Hwanghaeella grinnelliae Gri0909^T (92.3%), Marivibrio halodurans ZB80^T (91.0%) and Aestuariispira insulae AH-MY2^T (90.1%). The DNA G+C content of strain KN72^T was 61.1%. Collectively, based on phenotypic, chemotaxonomic, phylogenetic and genomic evidence presented, strain KN72^T represents a novel species of a novel genus of the family Rhodospirillaceae, for which the name Pacificispira spongiicola gen. nov., sp. nov. is proposed. The type strain is KN72^T (= CGMCC 1.17142^T = KCTC 72429^T).

Exiguobacterium algae sp. nov. and Exiguobacterium qingdaonense sp. nov., two novel moderately halotolerant bacteria isolated from the coastal algae

Two Gram-stain-positive, facultatively anaerobic, rod-shaped bacterial strains, S126^T and S82^T, were isolated from coastal algae of China. Strains S126^T and S82^T are halotolerant and could grow in the presence of 0-13% NaCl and 0-14% NaCl, respectively. The two strains shared 98.9% 16S rRNA gene sequence similarity with each other and 93.4-99.8% similarity with type strains of Exiguobacterium species. The major fatty acids (> 10%) of strains S126^T and S82^T were iso-C_17:0, iso-C_13:0, anteiso-C_13:0 and iso-C_15:0. The predominant quinones of strains S126^T and S82^T were MK-7 and MK-8. The polar lipid profiles of strain S126^T and S82^T contained diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The cell-wall peptidoglycans of both strains S126^T and S82^T were of the A3α L-Lys-Gly type. The average nucleotide identity (ANI) and average nucleotide index (AAI) between strains S126^T and S82^T and type strains of Exiguobacterium species were all below the thresholds to discriminate bacterial species, indicating that they constitute two novel species in the genus Exiguobacterium. Based on polyphasic taxonomy characterization and genomic aspects, the names Exiguobacterium algae sp. nov. and Exiguobacterium qingdaonense sp. nov. are proposed for the two novel species, with type strains being S126^T (= CGMCC 1.17116^T = KCTC 43079 ^T) and S82^T (= CGMCC 1.17115^T = KCTC 43078^T), respectively.

Marinisubtilis pacificus gen. nov., sp. nov., a Member of the Family Microbacteriaceae Isolated From a Deep-Sea Seamount

A Gram-stain-positive, yellow, aerobic, slender rod-shaped bacterial strain, designated KN1116^T, was isolated from a deep-sea seamount. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain KN1116^T was related to the genus Chryseoglobus and had highest 16S rRNA gene sequence identity with Chryseoglobus frigidaquae CW1^T (98.5%). The predominant cellular fatty acids were anteiso-C_15:0 and iso-C_16:0. The quinone system for strain KN1116^T comprised menaquinone MK-12, MK-11, MK-10 and MK-13. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, six unknown glycolipids, two unidentified phospholipids and one unknown polar lipid. The cell-wall peptidoglycan of strain KN1116^T was of the type B1β, containing 2,4-diaminobutyric acid as the diamino acid. Genome sequencing revealed the strain KN1116^T has a genome size of 2.7 Mbp and a G+C content of 69.4 mol%. Based on phenotypic, chemotaxonomic, phylogenetic and genomic data, strain KN1116^T represents a novel species of a novel genus of the family Microbacteriaceae, for which the name Marinisubtilis pacificus gen. nov., sp. nov. is proposed. The type strain of Marinisubtilis pacificus is KN1116^T (=CGMCC 1.17143^T =KCTC 49299^T).

Oceanomicrobium pacificus gen. nov., sp. nov., a member of the family Rhodobacteraceae isolated from seawater of tropical western Pacific

The Gram-stain-negative, aerobic, ovoid or rod-shaped bacterial strain, designated KN286^T, was isolated from seawater of tropical western Pacific. Growth occurred between 15 and 40 °C (optimally at 30-35 °C), pH 6-9 (optimally at 7.0) and in the presence of 0.5-5.0% (w/v) NaCl (optimally between 2.0 and 3.0%). Strain KN286^T contained Q-10 as the major respiratory quinone. The polar lipid profile contained phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, three phospholipids, three glycolipids, and three unidentified polar lipids. The predominant cellular fatty acid was summed feature 8 (composed of C_18:1ω7c and/or C_18:1ω6c). Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain KN286^T was a member of the family Rhodobacteraceae and formed a distinct lineage. Strain KN286^T has a genome size of 3.25 Mbp and a G + C content of 65.0 mol%. It encoded with some genes for carbohydrate-active enzymes, such as GH20 (Glycoside Hydrolase Family 20) and PL1 (Polysaccharide Lyase Family 1) and did not encode with a set of genes for reduction of nitrate to nitrite (nitrate reductase gamma subunit, respiratory nitrate reductase alpha N-terminal and respiratory nitrate reductase beta C-terminal). Based on phylogenetic analyses with single-copy orthologous clusters, low isDDH value (19.6%), low ANI (72.4%) and low AAI (65.7%) results, differential chemotaxonomic and physiological properties, strain KN286^T represents a novel species of a novel genus of the family Rhodobacteraceae, for which the name Oceanomicrobium pacificus gen. nov., sp. nov. is proposed. The type strain of Oceanomicrobium pacificus is KN286^T (=CGMCC 1.17118^T = KCTC 72430^T).