Planococcus maritimu ML1206 Strain Enhances Stress Resistance and Extends the Lifespan in Caenorhabditis elegans via FOXO/DAF-16.

The antioxidant effect of probiotics has been widely recognized across the world, which is of great significance in food, medicine, and aquaculture. There are abundant marine microbial resources in the ocean, which provide a new space for humans to explore new probiotics. Previously, we reported on the anti-infective effects of Planococcus maritimu ML1206, a potential marine probiotic. The antioxidant activity of ML1206 in C. elegans was studied in this paper. The study showed that ML1206 could improve the ability of nematodes to resist oxidative stress and effectively prolong their lifespan. The results confirmed that ML1206 could significantly increase the activities of CAT and GSH-PX, and reduce the accumulation of reactive oxygen species (ROS) in nematodes under oxidative stress conditions. In addition, ML1206 promoted DAF-16 transfer to the nucleus and upregulated the expression of sod-3, hsp-16.2, and ctl-2, which are downstream antioxidant-related genes of DAF-16. Furthermore, the expression of the SOD-3::GFP and HSP-16.2::GFP was significantly higher in the transgenic strains fed with ML1206 than that in the control group fed with OP50, with or without stress. In summary, these findings suggest that ML1206 is a novel marine probiotic with an antioxidant function that stimulates nematodes to improve their defense abilities against oxidative stress and prolong the lifespan by regulating the translocation of FOXO/DAF-16. Therefore, ML1206 may be explored as a potential dietary supplement in aquaculture and for anti-aging and antioxidant purposes.

Echinicola salinicaeni sp. nov., a novel bacterium isolated from saltern mud.

A novel gram-negative, aerobic, pink, motile, gliding, rod-shaped bacterium, designated P51T, was isolated from saline silt samples in Yantai, China. It was able to grow at 4-42 °C (optimum 33 °C), pH 4.0-9.0 (optimum 7.0), and in 0-11.0% NaCl (optimum 4.0%, w/v). It grew at 4 °C, which was lower than the minimum temperature for related strains. The genome consisted of 4111 genes with a total length of 5 139 782 bp. The 16S rRNA gene sequence analysis indicated that strain P51T was a member of the genus Echinicola and most closely related to 'Echinicola shivajiensis'. A genome analysis identified genes encoding proteins associated with carbon source utilisation, and the carotenoid biosynthesis and ß-lactam resistance pathways. Strain P51T shared an average nucleotide identity value below 84.7%, an average amino acid identity value between 70.8 and 89.3%, and a digital DNA-DNA hybridisation identity of between 17.9-28.2% with closely related type strains within the genus Echinicola. The sole menaquinone was MK-7, and the major fatty acids were iso-C15:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c), summed feature 4 (anteiso-C17:1 B and/or iso-C17:1 I), and summed feature 9 (iso-C17:1ω9c and/or 10-methyl C16:0). The polar lipids included one phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified phospholipid, three unidentified aminolipids, and one unknown lipid. The phenotypic, chemotaxonomic, and phylogenetic analyses suggest that strain P51T is a novel species of the genus Echinicola, for which the name Echinicola salinicaeni sp. nov. is proposed. The type strain was P51T (KCTC 82513T = MCCC 1K04413T).

Planococcus maritimus ML1206 Isolated from Wild Oysters Enhances the Survival of Caenorhabditis elegans against Vibrio anguillarum.

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.

Oceaniglobus ichthyenteri sp. nov., isolated from the gut microflora of sea bass (Dicentrarchus labrax L.) and emended description of the genus Oceaniglobus.

A Gram-stain-negative, non-flagellated, catalase-positive, oxidase-positive bacterial strain, designated YLY08T, was isolated from the gut microflora of sea bass (Dicentrarchus labrax L.) collected from the coast of Yuanyao Wharf, Weihai, PR China, and subjected to a polyphasic taxonomic study. Strain YLY08T grew optimally at 28-30 °C, at pH 7.0-7.5 and in the presence of 2.0-3.0 % (w/v) NaCl. Poly-ß-hydroxybutyrate granules were produced. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain YLY08T clustered with the type strain of Oceaniglobus indicus, with which it exhibited 95.3 % sequence similarity, while the similarity to other genera was below 95.0 %. Genomic analyses, including average nucleotide identity and the digital DNA-DNA hybridization, clearly separated YLY08T from O. indicus MCCC 1A11863T with values below the thresholds for species delineation. The major cellular fatty acid was summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The sole respiratory quinone detected was Q-10. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidyldimethylethanolamine, diphosphatidylglycerol, one unidentified aminolipid and one unidentified phospholipid. The genome of strain YLY08T, with 38 assembled contigs, was 3.9 Mb long with a G+C content of 59.0 mol%. The results of the phenotypical, phylogenetic and biochemical analyses between the strain YLY08T and the related type strain indicated that this strain represents a novel species in genus Oceaniglobus within the family Rhodobacteraceae, for which the name Oceaniglobus ichthyenteri sp. nov. is proposed. The type strain is YLY08T (=MCCC 1H00318T=KCTC 62182T).

Cohaesibacter celericrescens sp. nov., isolated from sea catfish.

A novel Gram-stain-negative, rod-shaped, ivory-white, facultatively anaerobic and catalase-positive bacterium, designated H1304T, was isolated from the gut of sea catfish from Coast of Weihai, China. Optimal growth occurred at 30-33 °C (range, 4-37 °C) and pH 7.0-7.5 (range, pH 6.5-9.0) with 2.0-3.0 % (w/v) NaCl (range, 0.5-4.0 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that H1304T belonged to the genus Cohaesibacter and was most closely related to Cohaesibactermarisflavi CGMCC 1.9157T (96.7 % 16S rRNA gene sequence similarity), Cohaesibactergelatinilyticus MCCC 1A02698T (96.3 %) and Cohaesibacterhaloalkalitolerans KCTC 32038T (96.0 %). The sole isoprenoid quinone was Q-10, the polar lipid profile consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylcholine, glycolipid, an unidentified phospholipid and an unidentified aminolipid. The major fatty acids (>10 %) were C18 : 1ω7c and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c). The DNA G+C content of strain H1304T is 50.8 mol%. Based on the combination of phylogenetic analysis, phenotypic data and chemotaxonomic data, strain H1304T is considered to represent a novel species within the genus Cohaesibacter in the family Cohaesibacteraceae, for which the name Cohaesibacter celericrescens sp. nov. is proposed. The type strain of the new species is H1304T (=KCTC 62075T=MCCC 1H00241T).

Transition-metal-free multinitrogenation of amides by C-C bond cleavage: a new approach to tetrazoles.

A metal-free brand-new one-pot multinitrogenation of amides for the chemo- and regioselective synthesis of 1,5-disubstituted tetrazoles has been developed. By means of electrophilic amide activation, and further C-C bond cleavage and rearrangement, a diverse set of functionalized 1,5-DST derivatives were selectively constructed under mild conditions. As showcased in the mechanisms, the chemoselectivity is easily switched by the selection of the starting materials in the reaction.

Primorskyibacter marinus sp. nov., isolated from coastal sediment.

A novel Gram-stain-negative, whitish-yellow, rod-shaped, non-pigmented, aerobic, oxidase-positive and catalase-positive bacterium, designated PX7T, was isolated from coastal sediment of Xiaoshi Island, Weihai, China (37° 31' 36″ N, 122° 00' 58″ E). Strain PX7T grew optimally at 30 °C, at pH 7.0-7.5 and in the presence of 3.0 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain PX7T formed a robust clade with members of the genus Primorskyibacter and was closely related to Primorskyibacter sedentarius, Primorskyibacter aestuariivivens and Primorskyibacter insulae with 96.5, 96.2 and 95.1 % sequence similarities, respectively. The sole respiratory quinone of strain PX7T was ubiquinone-10, and the dominant fatty acid was C18 : 1ω7c (80.2 %). The major polar lipids were phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, one unidentified aminolipid, one unidentified phospholipid and one unidentified lipid. The DNA G+C content of strain PX7T was 60.2 mol%. Based on the combination of phylogenetic analyses, phenotypic and chemotaxonomic data, strain PX7T is considered to represent a novel species within the genus Primorskyibacter in the family Rhodobacteraceae, for which the name Primorskyibacter marinus sp. nov. is proposed. The type strain of the new species is PX7T (=KCTC 42952T=MCCC 1H00196T).

Aquimarina sediminis sp. nov., isolated from coastal sediment.

A strictly aerobic, Gram-stain negative, long rod-shaped, motile by gliding and yellow pigmented bacterium, designated strain w01T, was isolated from marine sediment. The strain was characterised to determine its taxonomic position by using a polyphasic approach. Strain w01T was observed to grow optimally in the presence of 3.0% (w/v) NaCl, at 30 °C and to hydrolyse Tweens 20, 40 and 80, starch, casein and alginate. Carotenoid pigments were found to be produced but not flexirubin-type pigments. On the basis of 16S rRNA gene sequence similarities, strain w01T is phylogenetically affiliated with the genus Aquimarina and is closely related to Aquimarina macrocephali JCM 15542T (97.4% sequence similarity) and Aquimarina muelleri KCTC 12285T (97.0%). Lower sequence similarities (< 97.0%) were found with the other currently recognised members of the genus Aquimarina. The predominant fatty acids were identified as iso-C15:0 (33.7%), C18:0 3-OH (16.8%) and C17:1ω7c (10.6%). The polar lipid profile was found to contain phosphatidylethanolamine, an unidentified aminolipid and two unidentified polar lipids. MK-6 was identified as the sole respiratory quinone. The G + C content of the genomic DNA was determined to be 33.3 mol%. Strain w01T can be differentiated genotypically and phenotypically from recognised species of the genus Aquimarina. The isolate is therefore concluded to represent a novel species, for which the name Aquimarina sediminis sp. nov. is proposed, with the type strain w01T (= KCTC 62350T = MCCC 1H00287T).

Roseovarius salinarum sp. nov., isolated from a marine solar saltern.

A Gram-stain-negative, rod-shaped, non-motile and halophilic bacterium, designated N53T, was isolated from a marine solar saltern in Wendeng, China. Cells of strain N53T were 0.3-0.4 µm wide and 2.0-5.5 µm long, catalase-positive and oxidase-positive. The bacterium grew optimally at 33 °C, at pH 7.0-8.0 and in the presence of 6.0 % (w/v) NaCl. Bacteriochlorophyll a was not found. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain N53T formed a phylogenetic lineage with members of the genus Roseovarius. Strain N53T exhibited the highest levels of similarity to Roseovarius pacificus (94.6 %) and Roseovarius confluentis (94.6 %), with a lower level to Roseovarius tolerans was 94.0 %. The percentage of conserved proteins and average nucleotide identity values between N53T and the type strain of the type species, Roseovarius tolerans, were 66.1 and 76.4 %, respectively. The genomic DNA G+C content was 68.1 mol%. The sole respiratory quinone was ubiquinone-10. The predominant cellular fatty acids (>10 %) were C18 : 1ω7c (54.0 %) and C16 : 0 (17.9 %). The polar lipids of strain N53T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, an unidentified aminolipid, two unidentified phospholipids and two unidentified glycolipids. The differential phenotypic properties, together with the chemotaxonomic and genomic distinctiveness, revealed that strain N53T was separate from other recognized species of the genus Roseovarius. On the basis of the data presented here, strain N53T represents a novel species of the genus Roseovarius, for which the name Roseovariussalinarum sp. nov. is proposed. The type strain is N53T (=MCCC 1H00200T=KCTC 52886T).

Aquimarina celericrescens sp. nov., isolated from seawater.

An orange-coloured, slender rod-shaped, gliding bacterium, designated NS08T, was isolated from coastal water of Xiaoshi Island, Weihai, China (37° 31' 36'' N 122° 00' 58'' E). Cells were Gram-stain-negative, non-spore-forming, non-flagellated, aerobic, catalase-positive and oxidase-negative. Growth occurred at 10-37 °C (optimum 30 °C), in the presence of 1.0-5.0 % (w/v) NaCl (optimum 2.0-3.0 %) and at pH 6.5-9.0 (optimum pH 7.0-7.5). Carotenoid pigments were produced but flexirubin-type pigments were not. The major fatty acids (>10 %) were iso-C15 : 0 and iso-C17 : 0 3-OH. The sole isoprenoid quinone of strain NS08T was menaquinone MK-6 and the DNA G+C content was 39.4 mol%. The polar lipid compositions of strain NS08T and the type strain of the type species of the genus Aquimarina, Aquimarina muelleri KCTC 12285T, were very similar with phosphatidylethanolamine, an unidentified aminolipid and two unknown polar lipids as the major components. A phylogenetic tree based on 16S rRNA gene sequences showed that strain NS08T formed an evolutionary lineage within the genus Aquimarina and shared the highest level of similarity to A. versatilis JCM 19528T (96.0 %) while level to A. muelleri KCTC 12285T was 95.0 %. Phenotypic characteristics distinguished strain NS08T from described members of the genus Aquimarina. On the basis of the evidence presented in this study, strain NS08T represents a novel species of the genus Aquimarina, for which the name Aquimarina celericrescens sp. nov. is proposed. The type strain is NS08T (=KCTC 52897T=MCCC 1H00191T).

Electrophilic Cyclization and Intermolecular Acetalation of 2-(4-Hydroxybut-1-yn-1-yl)benzaldehydes: Synthesis of Diiodinated Diepoxydibenzo[c,k][1,9]dioxacyclohexadecines.

An expedient strategy for the preparation of diiodinated diepoxydibenzo[c,k][1,9]dioxacyclohexadecines from readily available 2-(4-hydroxybut-1-yn-1-yl)benzaldehydes through electrophile-triggered tandem cyclization/intermolecular acetalation sequence has been presented. The electrophilic macrocyclization can be performed under mild conditions and in up to gram quantities. Moreover, palladium-catalyzed coupling and reduction reactions of the resulting iodides could efficiently afford oxa-macrocycles.

Cloning and functional analysis of the SiRLK35 gene in Setaria italic L.

Receptor like protein kinases (RLKs) play vital roles in both plant development and stress conditions. Using drought-treated "Yugu 1" as materials, a drought-responsive RLK gene, SiRLK35, was isolated through iTRAQ analysis. In this study, the further analyses of the gene functions were carried out. First, full-length SiRLK35 was amplified by PCR using the cDNA of foxtail millet seedlings as a template. The expression patterns of SiRLK35 under NaCl, PEG, ABA, GA and MeJA treatment were analyzed by quantitative real-time PCR (qRT-PCR), and we found that the expression of SiRLK35 could be induced under different treatments, especially under NaCl treatment. Second, the prokaryotic expression plasmid of SiRLK35 was constructed, and the salt resistance of SiRLK35 was detected by the bacterial plaque growth method. And we uncovered that the growth and tolerance of SiRLK35-containing Escherichia coli strains were in better conditions than control under the NaCl stress. Lastly, pCambia1301P-SiRLK35 was constructed and transformed into rice to obtain transgenic plants. The tolerance of transgenic rice plants to salt stress was higher than that of controls through physiological analysis. We propose that SiRLK35 may participate in salt and stress resistance processes, which could provide potential theoretical foundation for the stress resistance varieties cultivation and breeding of foxtail millet.

Electrophilic Cyclization of Aryl Propargylic Alcohols: Synthesis of Dihalogenated 6,9-Dihydropyrido[1,2-a]indoles via a Cascade Iodocyclization.

A strategy for the synthesis of 6,9-dihydropyrido[1,2-a]indoles through a cascade iodocyclization of 4-(3-methyl-1H-indol-1-yl)-1,1-diphenylbut-2-yn-1-ol derivatives is presented. This reaction was conducted under very mild conditions and in a short time. The reactions are metal-free, are environmentally friendly and give up to 94% yield. Moreover, the obtained halides allow functional group diversification by palladium-catalyzed coupling reactions, which could act as potential intermediates for the synthesis of valuable compounds.

BF3·OEt2-AgSCF3 Mediated Trifluoromethylthiolation/Cascade Cyclization of Propynols: Synthesis of 4-((Trifluoromethyl)thio)-2H-chromene and 4-((Trifluoromethyl)thio)-1,2-dihydroquinoline Derivatives.

A BF3·OEt2-AgSCF3 mediated direct trifluoromethylthiolation/cascade cyclization of propynols involving the SCF3 anion nucleophilic pathway is developed. This protocol also provides an opportunity to construct valuable trifluoromethylthio-substituted 2H-chromene and 1,2-dihydroquinoline systems with high efficiency under mild conditions. Additionally, the developed BF3·OEt2-AgSCF3 reaction system could be scaled up to gram quantities in a satisfactory yield without inert gas protection.

AgSCF3-Mediated Trifluoromethylthiolation/Radical Cascade Cyclization of 1,6-Enynes.

A AgSCF3-mediated radical cascade cyclization/trifluoromethylthiolation of 1,6-enynes triggered by a C-C triple bond is developed. This protocol also provides another opportunity to construct a valuable trifluoromethylthio-substituted polycyclic fluorene system through the formations of one C-SCF3 bond and two C-C bonds in a single step.

Facile Synthesis of Carbazoles via a Tandem Iodocyclization with 1,2-Alkyl Migration and Aromatization.

A strategy for the synthesis of iodocarbazoles through a tandem iodocyclization with migration and aromatization is presented. This sequential cascade process is concisely conducted at room temperature and in a short time. Moreover, the obtained halides can be further applied to palladium-catalyzed coupling reactions, which act as the important intermediates for building other valuable compounds.

Copper-catalyzed difunctionalization of activated alkynes by radical oxidation-tandem cyclization/dearomatization to synthesize 3-trifluoromethyl spiro[4.5]trienones.

A copper-catalyzed difunctionalizing trifluoromethylation of activated alkynes with the cheap reagent sodium trifluoromethanesulfinate (NaSO2CF3 or Langlois' reagent) has been developed incorporating a tandem cyclization/dearomatization process. This strategy affords a straightforward route to synthesis of 3-(trifluoromethyl)-spiro[4.5]trienones, and presents an example of difunctionalization of alkynes for simultaneous formation of two carbon-carbon single bonds and one carbon-oxygen double bond.

Direct oxidative nitration of aromatic sulfonamides under mild conditions.

A direct nitration of aromatic sulfonamides using sodium nitrite as the nitrating agent has been developed. The reaction shows typically mono-substitution selectivity and can be enlarged to the gram scale with good yield.

Facile synthesis of halogenated spiroketals via a tandem iodocyclization.

A strategy for the synthesis of spiroketal compounds through a tandem iodocyclization of 1-(2-ethynylphenyl)-4-hydroxybut-2-yn-1-one derivatives is presented. This reaction could proceed under very mild conditions in a short time and avoid the use of expensive and toxic metal catalysts. Moreover, the resulting halides can be further exploited by subsequent palladium-catalyzed coupling reactions, which act as the important intermediates for building other valuable compounds.