Metabolomics Reveals Lysinibacillus capsici TT41-Induced Metabolic Shifts Enhancing Drought Stress Tolerance in Kimchi Cabbage (Brassica rapa L. subsp. pekinensis).

Climate change has increased variable weather patterns that affect plants. To address these issues, we developed a microbial biocontrol agent against drought stress in kimchi cabbage (Brassica rapa L. subsp. pekinensis). We selected three bacterial strains (Leifsonia sp. CS9, Bacillus toyonensis TSJ7, and Lysinibacillus capsici TT41) because they showed a survival rate of up to 50% and good growth rate when treated with 30% PEG 6000. The three strains were treated with kimchi cabbage to confirm their enhanced drought stress resistance under non-watering conditions. Among the three strains, the TT41 treated group showed a significant increase in various plant parameters compared with the negative control on the 7th day. We performed extensive profiling of primary and secondary metabolites from kimchi cabbage and the TT41 strain. Multivariate and pathway analyses revealed that only the TT41 group clustered with the well-watered group and showed almost the same metabolome on the 7th day. When treated with TT41, lactic acid was identified as an indicator metabolite that significantly improved drought stress tolerance. Furthermore, lactic acid treatment effectively induced drought stress tolerance in kimchi cabbage, similar to that achieved with the TT41 strain.

Identification and characterization of Brevibacillus halotolerans B-4359: a potential antagonistic bacterium against red pepper anthracnose in Korea.

Our study aimed to identify potential biocontrol agents (BCAs) against major phytopathogens under in vitro conditions by screening the Freshwater Bioresources Culture Collection (FBCC), Korea. Of the identified 856 strains, only 65 exhibited antagonistic activity, among which only one representative isolation, Brevibacillus halotolerans B-4359 was selected based on its in vitro antagonistic activity and enzyme production. Cell-free culture filtrate (CF) and volatile organic compounds (VOCs) of B-4359 were shown to be effective against the mycelial growth of Colletotrichum acutatum. Notably, B-4359 was found to promote spore germination in C. acutatum instead of exhibiting a suppressive effect when the bacterial suspension was mixed with the spore suspension of C. acutatum. However, B-4359 showed an excellent biological control effect on the anthracnose of red pepper fruits. Compared to other treatments and untreated control, B-4359 played a more effective role in controlling anthracnose disease under field conditions. The strain was identified as B. halotolerans using BIOLOG and 16S rDNA sequencing analyses. The genetic mechanism underlying the biocontrol traits of B-4359 was characterized using the whole-genome sequence of B-4359, which was closely compared with related strains. The whole-genome sequence of B-4359 consisted of 5,761,776 bp with a GC content of 41.0%, including 5,118 coding sequences, 117 tRNA, and 36 rRNA genes. The genomic analysis identified 23 putative secondary metabolite biosynthetic gene clusters. Our results provide a deep understanding of B-4359 as an effective biocontrol agent against red pepper anthracnose for sustainable agriculture.

Microbacterium elymi sp. nov., Isolated from the Rhizospheric Soil of Elymus tsukushiensis, a Plant Native to the Dokdo Islands, Republic of Korea.

Microbacterium elymi KUDC0405T was isolated from the rhizosphere of Elymus tsukushiensis from the Dokdo Islands. The KUDC0405T strain was Gram-stain-positive, non-spore forming, non-motile, and facultatively anaerobic bacteria. Strain KUDC0405T was a rod-shaped bacterium with size dimensions of 0.3-0.4 × 0.7-0.8 µm. Based on 16S rRNA gene sequences, KUDC0405T was most closely related to Microbacterium bovistercoris NEAU-LLET (97.8%) and Microbacterium pseudoresistens CC-5209T (97.6%). The dDDH (digital DNA-DNA hybridization) values between KUDC0405T and M. bovistercoris NEAU-LLET and M. pseudoresistens CC-5209T were below 17.3% and 17.5%, respectively. The ANI (average nucleotide identity) values among strains KUDC0405T, M. bovistercoris NEAU-LLET, and M. pseudoresistens CC-5209T were 86.6% and 80.7%, respectively. The AAI (average amino acid identity) values were 64.66% and 64.97%, respectively, between KUDC0405T and its closest related type strains. The genome contained 3,596 CDCs, three rRNAs, 46 tRNAs, and three non-coding RNAs (ncRNAs). The genomic DNA GC content was 70.4%. The polar lipids included diphosphatydilglycerol, glycolipid, phosphatydilglycerol, and unknown phospholipid, and the major fatty acids were anteiso-C17:0 and iso-C16:0. Strain KUDC0405T contained MK-12 as the major menaquinone. Based on genotypic, phylogenetic, and phenotypic properties, strain KUDC0405T should be considered a novel species within the genus Microbacterium, for which we propose the name M. elymi sp. nov., and the type strain as KUDC0405T (=KCTC 49411T, =CGMCC1.18472T).

Proof-of-Concept of a Sensor-Based Evaluation Method for Better Sensitivity of Upper-Extremity Motor Function Assessment.

In rehabilitation, the Fugl-Meyer assessment (FMA) is a typical clinical instrument to assess upper-extremity motor function of stroke patients, but it cannot measure fine changes of motor function (both in recovery and deterioration) due to its limited sensitivity. This paper introduces a sensor-based automated FMA system that addresses this limitation with a continuous rating algorithm. The system consists of a depth sensor (Kinect V2) and an algorithm to rate the continuous FM scale based on fuzzy inference. Using a binary logic based classification method developed from a linguistic scoring guideline of FMA, we designed fuzzy input/output variables, fuzzy rules, membership functions, and a defuzzification method for several representative FMA tests. A pilot trial with nine stroke patients was performed to test the feasibility of the proposed approach. The continuous FM scale from the proposed algorithm exhibited a high correlation with the clinician rated scores and the results showed the possibility of more sensitive upper-extremity motor function assessment.

Metabacillus elymi sp. nov., isolated from the Rhizosphere of Elymus tsukushiensis, a plant native to the Dokdo Islands, Republic of Korea.

Dokdo islands in Republic of Korea, is not suited to survive plant because strong wind, low organic content and high salinity. Nevertheless, 64 taxa of plants have a symbiotic relationship with microbe. The Metabacillus elymi KUDC1714T was isolated from the rhizosphere of Elymus tsukushiensis collected from Dokdo Islands. This bacterial strain was Gram-stain positive, non-motile, non-spore forming, aerobic and rod-shape bacteria with 0.4-0.5 × 2.5-3.0 µm in size. Colonies were smooth, yellowish-white circular and 2.0-3.0 mm in diameter. KUDC1714T was capable of growing at 10-45 °C (optimum, 30 °C), pH 7-11 (optimum, pH 8) and 0-8.0% (w/v) NaCl (optimum, 1.0-2.0%). Flagella were not observed by transmission electron microscopy. Phylogenetic analyses, based on 16S rRNA gene sequences, showed that KUDC1714T belonged to the genus Metabacillus formed a phyletic lineage within the genus Metabacillus of the family Bacillaceae. The strain KUDC1714T was most closely related to Metabacillus sediminilitoris DSL-17 T (98.2%), Metabacillus litoralis SW-211 T (98.2%) and Metabacillus halosaccharovorans E33T (97.7%) based on 16S rRNA gene sequence. In silico DNA-DNA hybridization using genome-to-genome distance calculator were analysed at 25.8% and 23.5% in strain KUDC1714T and Metabacillus sediminilitoris DSL-17 T, and strain KUDC1714T and Metabacillus litoralis SW-211 T, respectively. Strain KUDC1714T and its closet type strain were all below cut-off point of the average nucleotide identity and average amino acid identity values. The genome contains 5197 CDSs, 3 rRNAs, 118 tRNAs, 5 ncRNAs. The genomic DNA G + C content was 34.8 mol%. Its polar lipids were diphosphatidylglycerol, phosphatidylglycerol and its major fatty acids were anteiso-C15:0 and iso-C15:0. The strain KUDC1714T contained menaquinone-7 as major isoprenoid quinone. Based on its genetic data, physiological and biochemical characteristics, strain KUDC1714T should be considered a novel species of the genus Metabacillus, for which we propose the name Metabacillus elymi sp. nov. the type strain is KUDC1714T (= KCTC 33222 T, = DSM 27608 T).

Serratia rhizosphaerae sp. nov., a novel plant resistance inducer against soft rot disease in tobacco.

A novel Gram-negative, facultatively anaerobic, non-spore-forming and rod-shaped bacterial strain (KUDC3025T) was isolated from rhizospheric soil of Artemisia japonica subsp. littoricola collected from the Dokdo Islands, Republic of Korea and bacterial strain MYb239 was isolated from compost from Kiel, Germany. Phylogenetic analysis based on 16S rRNA gene sequences, multilocus genes (atpD, gyrB, infB and rpoB), and whole-genome sequences indicated that both strains belonged to the genus Serratia and were most closely related to Serratia rubidaea KCTC 2927T. The average nucleotide identity values based on blast and MUMmer, tetranucleotide usage pattern and genome-based digital DNA-DNA hybridization values were all below the 95.0 %/95.0 %/0.998/70 % cutoff points. The genome G+C content was 58.0 mol%. The cellular quinone content contained ubiquinone-8 and the major components in the fatty acid profile were C16 : 0, C17 : 0 cyclo and C14 : 0. The polar lipid profile included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unknown amino lipids, two unknown phospholipids and an unknown lipid. Based on phenotypic, chemotaxonomic and genotypic data, strain KUDC3025T (DSM 106578T=CGMCC 1.18473T) and MYb239 represents a novel species, for which the name Serratia rhizosphaerae sp. nov. is proposed. Furthermore, strain KUDC3025T was able to suppress disease symptoms by priming the plant defence system components, including the salicylic acid and ethylene pathways, furthering our understanding of Serratia as potential plant growth promoting bacteria.

Adhaeribacter radiodurans sp. nov., isolated from the rhizospheric soil of Elymus tsukushiensis, a plant native to the Dokdo Islands, Republic of Korea.

KUDC8001T was isolated from the rhizosperic soil of Elymus tsukushiensis in the Dokdo Islands, Republic of Korea. Strain KUDC8001T was Gram-stain-negative, non-motile and rod-shaped. KUDC8001T was catalase- and oxidase-positive. This strain is capable of growing at 4-37 °C and pH 7.0-8.0 and exhibited optimal growth at 25 °C and pH 7.0. It could be grown in R2A, nutrient agar and ISP2 agar plates. The cell width ranged from 0.7 to 1.0 µm, and length ranged from 2.5 to 5.5 µm. The genomic G+C content was 40.8 mol%. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that the strain KUDC8001T belongs to the genus Adhaeribacter, which is most closely related to the strain A. pallidiroseus HMF7616T (97.5%). The DNA relatedness of KUDC8001T with the type strains of A. pallidiroseus HMF7616T, A. swui 17 mud1-7T and A. arboris HMF7605T was ≤80.3 % based on average nucleotide identity calculations and ≤86.9 % based on average amino acid identity calculations. In silico DNA-DNA hybridization values of the strain KUDC8001T with the most closely related strains were 22.1, 24.0 and 24.4 %. Based on its phenotypic, phylogenetic, genetic and chemotaxonomic features, the strain KUDC8001T should be considered as a novel species in the genus Adhaeribacter, for which we have proposed the name Adhaeribacter radiodurans sp. nov. The type strain is KUDC8001T (=KCTC 82078T=CGMCC 1.18475T).

Divergent Strategies for the π-Extension of Heteroaryl Halides Using Norbornadiene as an Acetylene Synthon.

Pd-catalyzed multicomponent coupling reactions of five-membered heteroaryl halides and norbornadiene (NBD) were developed. Either direct addition of (benzo)azoles or 2:1 annulation was achieved depending on the propensity of the intermediate complex to undergo palladacycle formation, determined by the nature and substitution pattern of the heteroarene. The obtained exo- and cis-diheteroaryl norbornenes underwent epimerization and retro-Diels-Alder reactions to afford the corresponding trans-isomers and π-extended heteroaromatic systems, respectively, demonstrating the versatility of NBD as an acetylene synthon.

Microlunatus elymi sp. nov., a novel actinobacterium isolated from rhizospheric soil of the wild plant Elymus tsukushiensis.

An actinobacterial strain, designated KUDC0627T, was isolated from rhizospheric soil that contained Elymus tsukushiensis on the Dokdo Islands, Republic of Korea. Cells were Gram-stain-positive, facultative anaerobic, non-motile and non-endospore-forming cocci. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that strain KUDC0627T belongs to the genus Microlunatus and is most closely related to Microlunatus soli DSM 21800T (98.5 %), Microlunatus endophyticus DSM 100019T (97.7 %) and Microlunatus ginsengisoli Gsoil 633T (96.5 %). The average nucleotide identity scores and average amino acid identity values were all below the 95.0 % cut-off point. In silico DNA-DNA hybridization, using the Genome-to-Genome Distance Calculator, estimated that there is 22.3 % DNA relatedness between KUDC0627T and M. soli DSM 21800T. The genomic DNA G+C content was 66.9 mol%. The major menaquinone was MK-9(H4) and the major diagnostic diamino acid in the cell-wall peptidoglycan was ll-diaminopimelic acid. The polar lipid profile included diphosphatidylglycerol, phosphatidylglycerol, unidentified phospholipids, unidentified glycolipids and unidentified lipids. The major cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0 and iso-C16 : 0. Based on phenotypic, chemotaxonomic, and phylogenetic data, strain KUDC0627T (=KCTC 39853T=JCM 32702T) represents a novel species, for which the name Microlunatus elymi sp. nov. is proposed.

Nocardioides sambongensis sp. nov., isolated from Dokdo Islands soil.

Strain KUDC5002T was isolated from soil sampled on the Dokdo Islands, Republic of Korea. This bacterial strain was Gram stain-positive, non-motile, rod-shaped, capable of growing at 25-37°C and pH 5.0-12.0, and showed optimal growth at 30 °C and pH 7.0-8.0. Strain KUDC5002T could be grown in tryptic soy broth containing less than 7.0 % NaCl (w/v). The cell width ranged from 0.5 to 0.6 µm and length ranged from 0.8 to 1.0 µm. Strain KUDC5002T was catalase- and oxidase-positive. Its genomic G+C content was 72.2 mol%. Its major fatty acids were C18 : 1 ω9c (17.3 %), iso-C16 : 0 (16.0 %) and iso-C17 : 0 (11.4 %). Phylogenetic analysis, based on 16S rRNA gene sequences, showed that strain KUDC5002T belongs to the genus Nocardioides and is most closely related to strain Nocardioides humi DCY24T (97.0 %). Based on its phenotypic, phylogenetic, genetic and chemotaxonomic features, strain KUDC5002T should be considered a novel species in the genus Nocardioides, for which we have proposed the name Nocardioides sambongensis sp. nov. The type strain is KUDC5002T (=KCTC 39855T=DSM 106604T).

Bacillus salidurans sp. nov., isolated from salt-accumulated pepper rhizospheric soil.

A Gram-stain-positive, facultatively anaerobic, motile and rod-shaped bacterium, designated KNUC7312T, was isolated from salt-accumulated rhizospheric soil in a pepper greenhouse in Miryang city, Republic of Korea. Cell growth of strain KNUC7312T occurred at 10-45 °C (optimum, 30 °C) and pH 7-12 (optimum, pH 7). In addition, this strain was able to tolerate 0-12 % NaCl (w/v) concentration (optimum, 0-1 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain KNUC7312T clustered together with other species of the genus Bacillus and was most closely related to Bacillus humi DSM 16318T (98.0 %). The predominant respiratory quinone was menaquinone-7 (MK-7). The major cellular fatty acids were anteiso C15 : 0, iso-C15 : 0 and iso-C14 : 0. The polar lipid profile contained the major components diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unidentified aminolipids. The cell-wall peptidoglycan contained meso-diaminopimelic acid as the major diagnostic diamino acid. Strain KNUC7312T showed a low DNA-DNA relatedness value (47.36 %) with B. humi DSM 16318T, which supported that this strain represents a novel Bacillusspecies. On the basis of phenotypic, chemotaxonomic and phylogenetic evidence, strain KNUC7312T represents a novel species within the genera Bacillus. The name Bacillus salildurans sp. nov. is proposed. The type strain is KNUC7312T (KCTC 33852T=CGMCC 1.13629T).

Paenibacillus elymi sp. nov., isolated from the rhizosphere of Elymus tsukushiensis, a plant native to the Dokdo Islands, Republic of Korea.

Strain KUDC6143T was isolated from the rhizosphere of Elymus tsukushiensis, a plant native to the Dokdo Islands, Republic of Korea. Cells of this bacterial strain were Gram-positive, endospore-forming, motile and rod-shaped. The strain was capable of growth at a temperature of 25-45 °C and at a pH of 6.0-12.0; it showed an optimal growth at a temperature of 30 °C and at a pH of 7.0. In addition, it grew on a tryptic soy agar and in a tryptic soy broth containing less than 4.0 % NaCl (w/v). The cell length ranged from 2.0 to 2.7 µm. KUDC6143T was catalase-negative and oxidase-positive, and it hydrolysed starch but not casein. Its genomic G+C content was 50.3 mol%. Its major fatty acids were anteiso-C15 : 0, C16 : 0, and iso-C16 : 0. Phylogenetic analysis, based on the 16S rRNA gene sequences, showed that KUDC6143T belonged to the genus Paenibacillus, with the most closely related type strain being Paenibacillus pinihumi S23T (97.8 %). Based on its phenotypic characteristics, phylogenetic data and genetic data, strain KUDC6143T should be considered as representing a novel species of the genus Paenibacillus, for which we propose the name Paenibacillus elymi sp. nov. The type strain is KUDC6143T (=KCTC 33853T=DSM 106581T).

Regioselective C-H alkenylation of imidazoles and its application to the synthesis of unsymmetrically substituted benzimidazoles.

A palladium-catalyzed C-H alkenylation of imidazoles has been developed. High C5 selectivity was achieved for C2-unsubstituted and C2-substituted imidazoles using oxygen and copper(ii) acetate, respectively, as oxidants. The obtained products were applied to benzannulation through a sequence involving transposition of N-alkyl groups to give C4-alkenyl imidazoles, alkenylation, thermal 6π-electrocyclization, and oxidation, affording unsymmetrically substituted benzimidazoles.

Alleviation of Salt Stress in Pepper (Capsicum annum L.) Plants by Plant Growth-Promoting Rhizobacteria.

In the present study, we demonstrate that the growth of salt-stressed pepper plants is improved by inoculation with plant growth-promoting rhizobacteria (PGPR). Three PGPR strains (Microbacterium oleivorans KNUC7074, Brevibacterium iodinum KNUC7183, and Rhizobium massiliae KNUC7586) were isolated from the rhizosphere of pepper plants growing in saline soil, and pepper plants inoculated with these PGPR strains exhibited significantly greater plant height, fresh weight, dry weight, and total chlorophyll content than non-inoculated plants. In addition, salt-stressed pepper plants that were inoculated with B. iodinum KNUC7183 and R. massiliae KNUC7586 possessed significantly different total soluble sugar and proline contents from non-inoculated controls, and the activity of several antioxidant enzymes (ascorbate peroxidase, guaiacol peroxidase, and catalase) was also elevated in PGPR-treated plants under salt stress. Overall, these results suggest that the inoculation of pepper plants with M. oleivorans KNUC7074, B. iodinum KNUC7183, and R. massiliae KNUC7586 can alleviate the harmful effects of salt stress on plant growth.

Paenibacillus aceris sp. nov., isolated from the rhizosphere of Acer okamotoanum, a plant native to Ulleungdo Island, Republic of Korea.

Strain KUDC4121T was isolated from the rhizosphere of Acer okamotoanum, a plant native to the Korean island of Ulleungdo. The strain was a Gram-stain-positive, non-spore-forming, non-motile, rod-shaped bacterium that can grow at 18-37 °C and pH 6.0-7.5, with optimum growth at 30 °C and pH 7.0. It grew on tryptic soy agar containing less than 0.5 % (w/v) NaCl and in R2A broth. Cell length ranged from 2.0 to 2.5 µm. Strain KUDC4121T was oxidase- and catalase-positive and did not hydrolyse starch or casein. The genomic G+C content was 48.8 mol%. The major fatty acids were anteiso-C15 : 0 and iso-C16 : 0. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KUDC4121T belongs to the genus Paenibacillus. The closest type strain was Paenibacillus chondroitinus DSM 5051T, with 97.8 % similarity, followed by Paenibacillus alginolyticus DSM 5050T (97.6 %), Paenibacillus ferrarius CY1T (97.5 %), Paenibacillus pocheonensis Gsoil 1138T (97.5 %), Paenibacillus frigoriresistens YIM 016T (97.5 %), Paenibacillus pectinilyticus RCB-08T (97.2 %) and Paenibacillus aestuarii CJ25T (96.9 %). Based on its phenotypic properties and phylogenetic and genetic data, strain KUDC4121T should be considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus aceris sp. nov. is proposed. The type strain is KUDC4121T (=KCTC 13870T=DSM 24950T).

Bowmanella dokdonensis sp. nov., a novel exoelectrogenic bacterium isolated from the seawater of Dokdo, Korea.

A Gram-negative, motile, and rod-shaped bacterial strain, UDC354(T), was isolated from the seawater of Dokdo, Korea. The strain UDC354(T) displayed optimal growth at 30-37 °C in the presence of 0-2 % (w/v) NaCl at pH 8. Strain UDC354(T) was found to contain Q-8 and 9 as isoprenoid ubiquinones; C16:0 (22.9 %), summed feature 3 (iso-C15:0 2-OH and C16:1 ω7c) (21.4 %) and C18:1 ω7c (12.2 %) as the major fatty acids; and diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine as the major polar lipids. The DNA G+C content was found to be 54.1 mol %. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain UDC354(T) belongs to the genus Bowmanella, of the family Alteromonadaceae, and is closely related to Bowmanella pacifica W3-3A(T) (95.2 %) and Bowmanella denitrificans BD1(T) (95.0 %). It was found that strain UDC354(T) is exoelectrogenic and is capable of generating 6.6 µW/cm(3) in marine broth in the microbial fuel cells. Based on the analysis of the phenotypic, chemotypic and phylogenetic characteristics, a new species, Bowmanella dokdonensis sp. nov. is proposed. The type strain is UDC354(T) (=KCTC 42147(T)=JCM 30855(T)).

Biological control and plant growth promoting capacity of rhizobacteria on pepper under greenhouse and field conditions.

Plant growth promoting rhizobacteria Ochrobactrum lupini KUDC1013 and Novosphingobium pentaromativorans KUDC1065 isolated from Dokdo Island, S. Korea are capable of eliciting induced systemic resistance (ISR) in pepper against bacterial spot disease. The present study aimed to determine whether plant growth-promoting rhizobacteria (PGPR) strains including strain KUDC1013, strain KUDC1065, and Paenibacillus polymyxa E681 either singly or in combinations were evaluated to have the capacity for potential biological control and plant growth promotion effect in the field trials. Under greenhouse conditions, the induced systemic resistance (ISR) effect of treatment with strains KUDC1013 and KUDC1065 differed according to pepper growth stages. Drenching of 3-week-old pepper seedlings with the KUDC-1013 strain significantly reduced the disease symptoms. In contrast, treatment with the KUDC1065 strain significantly protected 5-week-old pepper seedlings. Under field conditions, peppers treated with PGPR mixtures containing E681 and KUDC1013, either in a two-way combination, were showed greater effect on plant growth than those treated with an individual treatment. Collectively, the application of mixtures of PGPR strains on pepper might be considered as a potential biological control under greenhouse and field conditions.