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1.
Mar Drugs ; 19(3)2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33809116

RESUMO

With the widespread occurrence of aquaculture diseases and the broad application of antibiotics, drug-resistant pathogens have increasingly affected aquatic animals' health. Marine probiotics, which live under high pressure in a saltwater environment, show high potential as a substitute for antibiotics in the field of aquatic disease control. In this study, twenty strains of non-hemolytic bacteria were isolated from the intestine of wild oysters and perch, and a model of Caenorhabditis elegans infected by Vibrio anguillarum was established. Based on the model, ML1206, which showed a 99% similarity of 16S rRNA sequence to Planococcus maritimus, was selected as a potential marine probiotic, with strong antibacterial capabilities and great acid and bile salt tolerance, to protect Caenorhabditis elegans from being damaged by Vibrio anguillarum. Combined with plate counting and transmission electron microscopy, it was found that strain ML1206 could significantly inhibit Vibrio anguillarum colonization in the intestinal tract of Caenorhabditis elegans. Acute oral toxicity tests in mice showed that ML1206 was safe and non-toxic. The real-time qPCR results showed a higher expression level of genes related to the antibacterial peptide (ilys-3) and detoxification (ugt-22, cyp-35A3, and cyp-14A3) in the group of Caenorhabditis elegans protected by ML1206 compared to the control group. It is speculated that ML1206, as a potential probiotic, may inhibit the infection caused by Vibrio anguillarum through stimulating Caenorhabditis elegans to secrete antibacterial effectors and detoxification proteins. This paper provides a new direction for screening marine probiotics and an experimental basis to support the potential application of ML1206 as a marine probiotic in aquaculture.

3.
Curr Microbiol ; 78(5): 2151-2159, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33792761

RESUMO

A Gram-stain-negative, aerobic, non-motile, white-pigmented, short rod-shaped, and alginate-degrading bacterium, designated B1Z28T, was isolated from the gut of the abalone Haliotis rubra obtained at Weihai, China. Strain B1Z28T was found to grow at 4-35 °C, pH 6.5-9.0, and in the presence of 0.5-8.0% (w/v) NaCl. Cells were positive for oxidase and catalase activity. The 16S rRNA-based phylogenetic analysis revealed that the nearest phylogenetic neighbors of strain B1Z28T were Tritonibacter scottomollicae MCCC 1A06440T (98.1%), Ruegeria faecimaris KCTC 23044T (98.0%), and Ruegeria meonggei KCTC 32450T (97.8%). Based on phylogenomic analysis, the average nucleotide identity (ANI) values between strain B1Z28T and the neighbor strains were 71.6, 77.2, and 78.1%, respectively; the digital DNA-DNA hybridization (dDDH) values based on the draft genomes between strain B1Z28T and its closest neighbors were 20.5, 20.8, and 21.6%, respectively. Ubiquinone-10 (Q-10) was detected as the predominant respiratory quinone. The dominant cellular fatty acids were Summed feature 8 (contained C18:1 ω7c and/or C18:1 ω6c). The polar lipids included phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phospholipid (PL), aminolipid (AL), and three unidentified lipids. Based on the phylogenetic and phenotypic characteristics, strain B1Z28T is considered to represent a novel species of the genus Ruegeria, for which the name Ruegeria haliotis sp. nov. is proposed. The type strain is B1Z28T (= KCTC 72686T = MCCC 1H00393T).

4.
Curr Microbiol ; 78(5): 2160-2164, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33813642

RESUMO

A Gram-stain-negative, yellow-pigmented, rod-shaped, strictly aerobic, non-motile bacterium, designated BDHS18T, was isolated from the sediment of the Hasuhai Lake, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that this strain belongs to the genus Moheibacter in the family Flavobacteriaceae and its closest relative was Moheibacter sediminis JCM 19634T (96.0%), followed by Moheibacter stercoris DSM 29388T (95.3%). Cells of strain BDHS18T were catalase-positive and oxidase-negative. Strain BDHS18T was found to grow optimally at 28-33 â„ƒ, pH 7.5-8.0, and in the presence of approximately 1.0% (w/v) NaCl. Major cellular fatty acids were iso-C15:0, iso-C17:0 3-OH, Summed feature 4 and Summed feature 9. The predominant respiratory quinone was MK-6. The predominant polar lipids in strain BDHS18T were phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G + C content was 36.9 mol%. According to the phylogenetic analysis, physiological and phenotypic characteristics, strain BDHS18T represents a novel species of the genus Moheibacter, for which the name Moheibacter lacus sp. nov. is proposed. The type strain is BDHS18T (= KCTC 72160T = MCCC 1H00369T).

5.
Arch Microbiol ; 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33655407

RESUMO

A novel Gram-stain-negative, aerobic, non-flagellated, non-motile, oval-rod-shaped and light pink to light tawny-pigmented bacterial strain (designated 1151T) were isolated from marine green algae obtained from the coastal seawater of Weihai, China. Strain 1151T was found to grow at 15-37 °C (optimum, 33 °C), pH 7.0-9.5 (optimum, 7.5-8.5) and in the presence of 1-6% (w/v) NaCl (optimum, 3%). Cells were oxidase-positive and catalase-positive. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 1151T was a member of the genus Sulfitobacter and exhibited the hightest sequence similarity to Sulfitobacter indolifex DSM 14862T (96.6%), followed by the sequence similarity to Sulfitobacter aestuarii hydD52T (96.5%) and Sulfitobacter profundi SAORIC-263T (96.5%). The average nucleotide identity and digital DDH values between strain 1151T and Sulfitobacter indolifex DSM 14862T were 69.9% and 20.9%, respectively. The average amino acid identity between strain 1151T and Sulfitobacter pontiacus DSM 10014T (type strain of the type species) was 62.3%. Q-10 was detected as the sole respiratory quinone. The dominant cellular fatty acids were sum feature 8 (C18: 1ω7c; 44.1%), C20: 1ω7c (29.7%) and C18: 0 (11.7%). The DNA G + C content of strain 1151T was 51.8 mol%. The polar lipids included phosphatidylglycerol (PG), phosphatidylethanolamine (PE), phosphatidylcholine (PC), and three unidentified lipids (L1, L2 and L3). Based on the phylogenetic and phenotypic characteristics, strain 1151T is considered to represent a novel species of the genus Sulfitobacter, for which the name Sulfitobacter algicola sp. nov. is proposed. The type strain is 1151T (= KCTC 72513T = MCCC 1H00384T).

6.
Arch Microbiol ; 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33656587

RESUMO

A Gram-stain-negative, aerobic, non-motile, yellow-pigmented rod-shaped and alginate-degrading bacterium, designated B1N29T, was isolated from the gut of the abalone Haliotis rubra obtained in Weihai, China. Strain B1N29T was found to grow at 4-35 ℃ (optimum, 25 ℃), at pH 6.5-9.0 (optimum, 7.0-7.5) and in the presence of 0.5-9% (w/v) NaCl (optimum, 2%). Cells were positive for oxidase and catalase activity. The 16S rRNA-based phylogenetic analysis revealed that the nearest phylogenetic neighbors of strain B1N29T were Tamlana carrageenivorans KCTC 62451T (98.2%) and Tamlana agarivorans KCTC 22176T (97.7%). Based on the phylogenomic analysis, the average nucleotide identity (ANI) values between strain B1N29T and the neighbor strains were 79.2 and 79.0%, respectively; the digital DNA-DNA hybridization (dDDH) values between strain B1N29T and its two closest neighbors were 22.8 and 23.0%, respectively. Menaquinone-6 (MK-6) was detected as the sole respiratory quinone. The dominant cellular fatty acids were iso-C15:0, iso-C17:0 3-OH, anteiso-C15:0 and iso-C15:1 G. The polar lipids included phosphatidylethanolamine, one aminophospholipid, seven aminolipids and five unidentified lipids. Based on the phylogenetic and phenotypic characteristics, strain B1N29T is considered to represent a novel species of the genus Tamlana, for which the name Tamlana haliotis sp. nov. is proposed. The type strain is B1N29T (= KCTC 72683T = MCCC 1H00394T).

7.
Curr Microbiol ; 78(4): 1656-1661, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33651188

RESUMO

A novel Gram-strain-negative, rod-shaped, non-flagellated, non-gliding, beige-pigmented and aerobic bacterium, designated strain UJN715T, was isolated from rhizosphere soil of Alhagi sparsifolia obtained from Alear city, located in Xinjiang province, PR China. Growth optimally occurred at 37 °C, pH 6.5-7.5, and 0-3% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain UJN715T belonged to the genus Chelativorans, with the highest sequence similarity to Chelativorans multitrophicus DSM 9103 T (97.7%). Genome sequencing revealed a genome size of 5 702 301 bp and a G + C content of 64.1 mol%. The ANI, POCP and the dDDH between strain UJN715T and C. multitrophicus DSM 9103 T were 76.2%, 49.3%, and 20.5%, respectively. The prediction result of secondary metabolites based on genome showed that the strain UJN715T contained one cluster of ectoine production, one cluster of non-ribosomal peptide synthetase (NRPS), one cluster of type I polyketide synthases (TIPKS), one cluster of bacteriocin, one cluster of TfuA-related, one cluster of N-acetylglutaminylglutamine amide (NAGGN) production, one cluster of terpene production, two clusters of homoserine lactone (Hserlactone) production. The major respiratory quinone was Q-10. The major fatty acids were iso-C17:0, C18:0 and C19:0 cyclo ω8c and its polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phospholipids, unknown lipids, diphosphatidylglycerol, aminoglycolipid, unidentified aminophospholipids. On the basis of these data, strain UJN715T is considered to represent a novel species of the genus Chelativorans, for which the name Chelativorans alearense sp. nov. is proposed. The type strain is UJN715T (= KCTC 72856T = CCTCC AB2019378T).

8.
Artigo em Inglês | MEDLINE | ID: mdl-33751321

RESUMO

A facultatively anaerobic bacterium, strain W62T, was isolated from the marine solar saltern in Weihai, China. Cells of the novel strain were Gram-stain negative, non-flagellated, non-gliding, rod-shaped and around 0.3-0.5 × 2.5-3.9 µm in size. Optimum growth occurred at 33-37 °C, with 3-5% (w/v) NaCl and at pH 7.0-7.5. On the basis of phylogenetic analysis of the 16S rRNA gene sequence, strain W62T had close relationship with Marinobacter vulgaris F01T (98.6%), Marinobacter confluentis KCTC 42705T (98.4%) and Marinobacter halotolerans NBRC 110910T (97.7%). Genome sequencing revealed a genome size of 4,050,555 bp, a G+C content of 57.3% and a complete sox system related to thiosulfate oxidization. Strain W62T had ubiquinone-9 as the sole respiratory quinone and possessed Summed Features 3 (C16:1 ω7c/C16:1 ω6c), C16:0 and C18:1 ω9c as the major fatty acids. The major polar lipids of strain W62T were identified as aminophospholipid, phosphatidylglycerol and phosphatidylethanolamine. According to the results of the phenotypic, chemotaxonomic characterization, phylogenetic properties and genome analysis, strain W62T should represent a novel specie of the genus Marinobacter, for which the name Marinobacter orientalis sp. nov. is proposed. The type strain is W62T (= MCCC 1H00317T = KCTC 62593T).

9.
Arch Microbiol ; 2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-33774710

RESUMO

A gram-stain-negative, non-motile and rod-shaped strain, designated wg1T, was isolated from activated sludge obtained from wastewater treatment plant in Binzhou (Shandong province, PR China). Growth of strain wg1T occurred at 25-45 °C (optimum, 37 °C), at pH 7.0-9.0 (optimum growth at pH 8.0) and at a salinity range of 0-4% (optimum, 1%). The chemotaxonomic, phenotypic and genomic traits were investigated. The 16S rRNA gene sequence analysis showed that strain wg1T belonged to the genus Paracoccus. The species with highest similarity to strain wg1T was Paracoccus communis VKM B-2787T (98.27%), followed by Paracoccus kondratievae VKM B-2222T (98.25%). The isoprenoid quinone was Q-10. Major cellular fatty acids were summed feature 8, C16:0 and C18:0. The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), aminoglycolipid (AGL), phosphatidylglycerol (PG), phosphatidylcholine (PC), aminolipid (AL), one unidentified lipid (L) and one unidentified phospholipid (PL). The genome size was 4,834,448 bp with a G+C content of 67.67 mol%. The prediction result of secondary metabolites based on genome has shown that the strain wg1T contained 12 clusters, and the gene involved in primary metabolism showed differences in the comparison between wg1T and reference strains. The dDDH values of strain wg1T with P. communis VKM B-2787T, P. kondratievae VKM B-2222T and P. denitrificans DSM 413T were 45.30, 30.60 and 39.50%, respectively. Based on its physiological properties, chemotaxonomic characteristics and low ANI and dDDH results, strain wg1T is considered to represent a novel species for which the name Paracoccus binzhouensis sp. nov., is proposed. The type strain is wg1T (= KCTC 72861T = CCTCC AB 2019400T).

10.
Artigo em Inglês | MEDLINE | ID: mdl-33774759

RESUMO

A facultatively anaerobic bacterium, strain M1531T, was isolated from a red alga (Porphyra) at coastal water in Weihai, China. Cells of the novel strain were Gram-stain-negative, rod-shaped, motile by means of a single polar flagellum and around 0.6-0.8 × 2.0-3.0 µm in size. Optimum growth occurred at 30 °C, with 2% (w/v) NaCl and at pH 6.5-7.0. On the basis of the result of phylogenetic analysis of the 16S rRNA gene sequence, stain M1531T had close relative with Thalassotalea euphylliae KCTC 42743T (96.9%). Genome sequencing revealed a genome size of 4,061,950 bp, a G + C content of 39.1 mol% and four protein-coding genes related to the degradation of alginate. According to the data obtained, strain M1531T shared ANI value below 95-96%, dDDH value below 23.8% with the closely related type species. Strain M1531T had Q-8 as the predominant isoprenoid quinone and possessed Summed Features 3 (C16:1 ω7c/C16:1 ω6c), C16:0 and Summed Features 8 (C18:1 ω7c/C18:1 ω6c) as the major fatty acids. The polar lipids of strain M1531T were identified as phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminolipid and four unidentified lipids. According to the results of the phenotypic, chemotaxonomic characterization, phylogenetic properties and genome analysis, strain M1531T represents a novel specie of the genus Thalassotalea, for which the name Thalassotalea algicola sp. nov. is proposed. The type strain is M1531T (= MCCC 1H00400T = KCTC 72865T).

11.
Arch Microbiol ; 2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33665709

RESUMO

A Gram-stain-negative, non-motile, aerobic, rod-shaped and reddish-pigmented bacterium, designated 8A47T, was isolated from a marine solar saltern located in Wendeng, PR China. The novel strain 8A47T grows at 20-42 °C, pH 7.0-9.0, and in the presence of 2.0-14.0% (w/v) NaCl. Optimal growth was observed at 37-40 °C, pH 7.5-8.0, and with 4.0-6.0% (w/v) NaCl. The phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 8A47T formed an evolutionary lineage with members of the genus Rhodohalobacter. Strain 8A47T exhibited high level of similarity to Rhodohalobacter barlenses MCCC 1K03442T (94.7%) and Rhodohalobacter halophilus JZ3C29T (93.5%). The major fatty acids were summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C16:0 and iso-C15:0. The sole respiratory quinone was MK-7. The polar lipids of the new isolate consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified lipid, two unidentified phospholipids and three unidentified glycolipids and. The genomic DNA G + C content of the strain 8A47T was 47.7 mol%. Based on its phenotypic, chemotaxonomic, genotypic and genomic characteristics presented in this study, strain 8A47T is considered to represent a novel species of the genus Rhodohalobacter, for which the name Rhodohalobacter mucosus sp. nov. is proposed. The type strain is 8A47T (= KCTC 62603T = MCCC 1H00329T).

12.
Artigo em Inglês | MEDLINE | ID: mdl-33565957

RESUMO

A Gram-stain-negative, aerobic, yellow, non-motile, rod-shaped and alginate-degrading bacterium, designated Dm15T, was isolated from marine alga collected in Weihai, PR China. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Dm15T represents a distinct line of the family Flavobacteriaceae. Strain Dm15T had the highest 16S rRNA gene sequence similarity to its closest phylogenetic neighbour Arcticiflavibacter luteus (96.7 %) and 93.7-96.4 % sequence similarity to other phylogenetic neighbours (Bizionia paragorgiae, Winogradskyella thalassocola, Ichthyenterobacterium magnum, Psychroserpens burtonensis and Arcticiflavibacter luteus) in the family Flavobacteriaceae. The novel isolate was able to grow at 10-40 °C (optimum, 30-33 °C), pH 7.0-9.0 (optimum, pH 7.0-7.5) and with 0.5-6.0 % NaCl (optimum 2.0-3.0 %, w/v). It could grow at 40 °C, and degrade alginate and cellulose, which were different from the neighbour genera. The draft genome consisted of 3395 genes with a total length of 3 798 431 bp and 34.1mol% G+C content. Especially, there were some specific genes coding for cellulase and alginate lyase, which provided a basis for the above phenotypic characteristics. The strain's genome sequence showed 71.1-80.2 % average amino acid identity values and 71.8-77.7 % average nucleotide identity values compared to the type strains of related genera within the family Flavobacteriaceae. It shared digital DNA-DNA hybridization identity of 19.8 and 20.9 % with I. magnum and A. luteus, respectively. The sole menaquinone was MK-6. The major fatty acids were iso-C15 : 0 and iso-C15 : 1 G. The polar lipids included six unidentified polar lipids, four unidentified aminolipids and phosphatidylethanolamine. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain Dm15T represents a novel species of a new genus in the family Flavobacteriaceae, phylum Bacteroidetes, for which the name Flavihalobacter algicola gen. nov., sp. nov. is proposed. The type strain is Dm15T (KCTC 42256T=CICC 23815T).

13.
Arch Microbiol ; 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33629140

RESUMO

A novel bright yellow pigmented, Gram-stain-negative, gliding, aerobic and rod-shaped marine bacterium, designated strain S7007T, was isolated from a marine sediment sample taken from Jingzi Wharf, Weihai, China. The bacterium was able to grow at 4-33 °C (optimum 28 °C), at pH 6.5-9.0 (optimum 7.0) and with 2.0-4.0% (w/v) NaCl (optimum 3.0%). According to the phylogenetic analysis based on the 16S rRNA gene sequences, strain S7007T was associated with the genus Tenacibaculum and showed highest similarity to Tenacibaculum adriaticum JCM 14633T (98.0%). The average nucleotide identity (ANI) scores of strain S7007T with T. adriaticum JCM 14633T and T. maritimum NBRC 110778T were 78.3% and 77.1%, respectively and the Genome-to-Genome Distance Calculator (dDDH) scores were 20.5% and 19.9%, respectively. The sole isoprenoid quinone was MK-6 and the major cellular fatty acids (> 10.0%) were iso-C15:0, iso-C15:0 3-OH, iso-C15: 1 G and summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c). The major polar lipids of strain S7007T were phosphatidylethanolamine, phosphatidyldimethylethanolamine, one unidentified lipid and two unidentified aminolipids. The genomic DNA G + C content was 30.9 mol %. The combined phenotypic data and phylogenetic inference that strain S7007T should be classified as a novel species in the genus Tenacibaculum, for which the name Tenacibaculum pelagium sp. nov. is proposed. The type strain is S7007T (= MCCC 1H00428T = KCTC 72941T).

14.
Artigo em Inglês | MEDLINE | ID: mdl-33502295

RESUMO

A facultatively anaerobic bacterium, strain S0837T, was isolated from the marine sediment of Jingzi Wharf, Weihai, China. Cells of the novel strain were Gram-stain-negative, non-flagellated, non-gliding, non-pigmented and rod-shaped. Cells were around 0.3-0.5×1.0-1.4 µm in size and often appeared singly. Optimum growth occurred at 33 °C, with 2 % (w/v) NaCl and at pH 7.0-7.5. On the basis of the results of 16S rRNA gene sequences, stain S0837T had the closest relative with Sulfitobacter delicatus KCTC 32183T (98.0 %). Genome sequencing revealed a genome size of 3 785 026 bp, a G+C content of 59.8 mol% and several genes related with sulphur oxidation. The strain shared 98.0 % 16S rRNA sequence similarities with closely related type species and shared ANI value below 95-96 %, dDDH value of showed relatedness of 27.4, 25.2 and 25.2 % respectively with the closely related type species. Strain S0837T had ubiquinone-10 as the sole respiratory quinone, and possessed summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c) as the major fatty acid. The major polar lipids were phosphatidylglycerol, phosphatidylcholine and phosphatidylethanolamine. According to the results of the phenotypic, chemotaxonomic characterization, phylogenetic properties and genome analysis, strain S0837T should represent a novel species of the genus Sulfitobacter, for which the name Sulfitobacter maritimus sp. nov. is proposed. The type strain is S0837T (=MCCC 1K04635T=KCTC 72860T).


Assuntos
Sedimentos Geológicos/microbiologia , Filogenia , Rhodobacteraceae/classificação , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Rhodobacteraceae/isolamento & purificação , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/química
15.
Antonie Van Leeuwenhoek ; 114(3): 225-233, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33400070

RESUMO

A Gram-stain-negative, non-spore-forming, non-motile, short-rod-shaped, and aerobic bacterial strain (designated L72T) was isolated from propylene oxide saponification wastewater activated sludge obtained from a wastewater treatment facility in Binzhou (Shandong Province, PR China). Strain L72T grew between 25 and 40 °C (optimum growth at 30 °C). The pH range for growth was between 6.0 and 8.0 (optimum growth at pH 7.0). The range of NaCl concentrations for the growth of strain L72T was 0-3.0 % (w/v), with optimum growth at 1.0-2.0 % (w/v). The major cellular fatty acids of strain L72T were C19:0cyclo ω8c, C18:1ω7c, iso-C15:0, and anteiso-C15:0. Strain L72T contained Q-10 as the predominant respiratory quinone. The polar lipid profile was composed of Phosphatidylcholine, Glycolipid, Aminophospholipid, Phosphatidylethanolamine, Phosphatidylserine, Phosphatidyldimethylethanolamine, one unknown lipid (L) and two unidentified Phospholipids (PL). Genome sequencing revealed a genome size of 4,703,686 bp and a G + C content of 69.0 mol%. The 16S rRNA gene sequence similarities of strain L72T with other species were less than 94%. Phylogenetic analyses based on 16S rRNA gene sequences and genome data, revealed that strain L72T formed a distinct phylogenetic lineage within the order Hyphomicrobiales, separating them from members of all families. Strain L72T showed 70.7% average nucleotide identity and 18.6% digital DNA-DNA hybridization identity with the closely related species Rhodoligotrophos defluvii. Based on the phenotypic, phylogenetic and chemotaxonomic data, a new family Propylenellaceae fam. nov. comprising the genus Propylenella gen. nov. and species Propylenella binzhouense sp. nov. is proposed. The type strain is L72T (=  CCTCC AB 2019081T  =  KCTC 72254T).

16.
Artigo em Inglês | MEDLINE | ID: mdl-33332262

RESUMO

A novel Gram-stain-negative, strictly aerobic, coccoid and agar-hydrolysing bacterium, designated RQJ05T, was isolated from the marine red algae Gelidium amansii collected from the coastal area of Rizhao, PR China. Cells of strain RQJ05T were approximately 0.8-1.0×1.3-3.0 µm in size and motile by means of a polar flagellum. Growth occurred at 4-33 °C (optimum, 25-30 °C), pH 7.0-8.5 (optimum, pH 7.5-8.0) and in the presence of 1.0-7.0 % (w/v) NaCl (optimum, 2.0-3.0 %). Strain RQJ05T showed oxidase-positive and catalase-negative activities. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain RQJ05T formed a phylogenetic lineage with members of the family Alteromonadaceae and exhibited 16S rRNA gene sequence similarities of 92.6, 91.3, 90.2 and 90.1 % to Catenovulum maritimum Q1T, Catenovulum agarivorans YM01T, Paraphotobacterium marinum NSCS20N07DT and Algicola sagamiensis B-10-31T, respectively. The major cellular fatty acids of strain RQJ05T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 0 and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The major polar lipids of strain RQJ05T were phosphatidylethanolamine, phosphatidylglycerol and two aminophospholipids. Strain RQJ05T contained Q-8 as the major respiratory quinone. The genomic DNA G+C content was 39.0 mol%. On the basis of genotypic, phenotypic and phylogenetic evidence, strain RQJ05T is presented as a representative of a novel species in a new genus, for which the name Algibacillus agarilyticus gen. nov., sp. nov. is proposed. The type strain is RQJ05T (=KCTC 62846T=MCCC 1H00352T).


Assuntos
Alteromonadaceae/classificação , Filogenia , Rodófitas/microbiologia , Alteromonadaceae/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
17.
Artigo em Inglês | MEDLINE | ID: mdl-33141654

RESUMO

A novel Gram-stain-negative, aerobic, yellow-pigmented bacterium was isolated from seawater of Aoshan Bay, and designated as strain ASW18T. Strain ASW18T was a long-rod-shaped bacterium without flagellum and lacked gliding ability. Based on 16S rRNA gene phylogeny, strain ASW18T showed the closest relationship to Croceivirga radicis MCCC 1A06690T, with a sequence similarity of 97.0 %. Strain ASW18T was able to grow at 25-40 °C, at pH 5.5-9.5 and with 0.5-9 % (w/v) NaCl. The genomic DNA G+C content of strain ASW18T was 37.3 %. The predominant cellular fatty acids of strain ASW18T were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G. The major polar lipids were phosphatidylethanolamine, phosphatidyldimethylethanolamine, an aminolipid and three unidentified lipids. The respiratory quinone of strain ASW18T was menaquinone with six isoprene units (MK-6). Based on the present polyphasic analysis, strain ASW18T represents a novel species of the genus Croceivirga, for which the name Croceivirga litoralis sp. nov. is proposed; the type strain is ASW18T (=MCCC 1K04203T=KCTC 72852T). In addition, it is also proposed that Muricauda lutea should be reclassified as Croceivirga lutea comb. nov.; the type strain is CSW06T (=CGMCC 1.15761T=JCM 31455T=KCTC 52375T=MCCC 1K03195T).

18.
Arch Microbiol ; 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-33037888

RESUMO

A novel Gram-strain-negative, beige-pigmented, aerobic, rod-shaped, non-flagellated and non-gliding bacterium, designated strain lm93T, was isolated from rhizosphere soil of Alhagi sparsifolia obtained from Alar city, located in Xinjiang province, China. Growth optimally occurred at 30 °C, pH 6.5-7.5, and 0-2% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain lm93T belonged to the genus Chelativorans, with highest sequence similarity to Chelativorans multitrophicus DSM 9103T (96.9%). Genome sequencing revealed a genome size of 5 689 708 bp and a G + C content of 64.3 mol%. The ANI, POCP and the dDDH between strain lm93T and C. multitrophicus DSM 9103T were 76.4%, 54.8% and 0.8%, respectively. The prediction result of secondary metabolites based on genome showed that the strain lm93T contained one cluster of bacteriocin, one cluster of terpene production, two clusters of ectoine production, one cluster of non-ribosomal peptide synthetase, one cluster of type I polyketide synthases, three clusters of homoserine lactone production, one cluster of N-acetylglutaminylglutamine amide production and one cluster of phosphonate production. The major respiratory quinone was Q-10. The major fatty acids were C19:0 cyclo ω8c, iso-C17:0 and summed feature 8 (C18:1 ω6c and/or C18:1 ω7c) and its polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, two unidentified aminophospholipids, aminoglycolipid, three unknown lipids and diphosphatidylglycerol. On the basis of these data, strain lm93T is considered to represent a novel species of the genus Chelativorans, for which the name Chelativorans xinjiangense sp. nov. is proposed. The type strain is lm93T (= KCTC 72857T = CCTCC AB2019376T).

19.
Appl Microbiol Biotechnol ; 104(24): 10541-10553, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33104843

RESUMO

Agar-degrading bacteria are crucial drivers for the carbon cycle in the marine environments due to their ability that use algae as a carbon source. Although numerous agar-degrading bacteria and agarases have been reported, little is known about expression levels of agar-degrading genes in wild strains. Here, the genome of an agar-hydrolyzing marine bacterium, Catenovulum maritimus Q1T, was sequenced and annotated with 11 agarase and 2 neoagarooligosaccharide hydrolase genes. Quantitative PCR revealed that all the annotated agar-degrading genes were expressed consistently that initially upregulated and then gradually downregulated under agarose induction. Moreover, the presence of glucose inhibited the agar-degrading ability, in terms of both gene expression and enzymatic activity. These facts indicated the agar-degrading ability of wild bacteria was mainly induced by agarose and repressed by the available carbon source. Additionally, a ß-agarase, AgaQ1, belonging to the GH16 family, with high expression in strain Q1T, was cloned and characterized. Biochemical analysis showed that the recombinant AgaQ1 was substrate-specific, yielding neoagarotetraose and neoagarohexaose as the main products. It exhibited optimal activity at 40 °C, pH 8.0, and an agarose concentration of 1.6% (w/v). Besides, AgaQ1 showed a high-specific activity (757.7 U/mg) and stable enzymatic activity under different ion or agent treatments; thus, AgaQ1 has great potential in industrial applications. KEY POINTS: • The genome of C. maritimus Q1T was sequenced and annotated with 11 agarases and 2 Nabh genes. • The expression of agar-degrading genes in the strain C. maritimus Q1T was induced by agarose. • Glucose was the carbon source utilized prior to agarose for bacterial growth. • A ß-agarase, AgaQ1, with high expression and activity was identified.

20.
Microbiome ; 8(1): 126, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32867860

RESUMO

BACKGROUND: Bacterial predation is an important selective force in microbial community structure and dynamics. However, only a limited number of predatory bacteria have been reported, and their predatory strategies and evolutionary adaptations remain elusive. We recently isolated a novel group of bacterial predators, Bradymonabacteria, representative of the novel order Bradymonadales in δ-Proteobacteria. Compared with those of other bacterial predators (e.g., Myxococcales and Bdellovibrionales), the predatory and living strategies of Bradymonadales are still largely unknown. RESULTS: Based on individual coculture of Bradymonabacteria with 281 prey bacteria, Bradymonabacteria preyed on diverse bacteria but had a high preference for Bacteroidetes. Genomic analysis of 13 recently sequenced Bradymonabacteria indicated that these bacteria had conspicuous metabolic deficiencies, but they could synthesize many polymers, such as polyphosphate and polyhydroxyalkanoates. Dual transcriptome analysis of cocultures of Bradymonabacteria and prey suggested a potential contact-dependent predation mechanism. Comparative genomic analysis with 24 other bacterial predators indicated that Bradymonabacteria had different predatory and living strategies. Furthermore, we identified Bradymonadales from 1552 publicly available 16S rRNA amplicon sequencing samples, indicating that Bradymonadales was widely distributed and highly abundant in saline environments. Phylogenetic analysis showed that there may be six subgroups in this order; each subgroup occupied a different habitat. CONCLUSIONS: Bradymonabacteria have unique living strategies that are transitional between the "obligate" and the so-called facultative predators. Thus, we propose a framework to categorize the current bacterial predators into 3 groups: (i) obligate predators (completely prey-dependent), (ii) facultative predators (facultatively prey-dependent), and (iii) opportunistic predators (prey-independent). Our findings provide an ecological and evolutionary framework for Bradymonadales and highlight their potential ecological roles in saline environments. Video abstract.

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