Chemically Cross-Linked Hammerhead Ribozyme as an Efficient RNA Interference Tool.

RNA-cleaving ribozymes are promising candidates as general tools of RNA interference (RNAi) in gene manipulation. However, compared with other RNA systems, such as siRNA and CRISPR technologies, the ribozyme tools are still far from broad applications on RNAi due to their poor performance in the cellular context. In this work, we report an efficient RNAi tool based on chemically modified hammerhead ribozyme (HHR). By the introduction of an intramolecular linkage into the minimal HHR to reconstruct the distal interaction within the tertiary ribozyme structure, this cross-linked HHR exhibits efficient RNA substrate cleavage activities with almost no sequence constraint. Cellular experiments suggest that both exogenous and endogenous RNA expression can be dramatically knocked down by this HHR tool with levels comparable to those of siRNA. Unlike the widely applied protein-recruiting RNA systems (siRNA and CRISPR), this ribozyme tool functions solely on RNA itself with great simplicity, which may provide a new approach for gene manipulation in both fundamental and translational studies.

Characterizing the pathogenicity and mycotoxin production capacity of Fusarium spp. causing root rot of Angelica sinensis in China.

Root rot is a very destructive soil-borne disease, which severely affects the quality and yield of Angelica sinensis in major planting areas of Gansu Province, China. Twelve Fusarium strains were identified from root rot tissue and infected soil in the field, by comparing each isolate strain internal transcriptional spacer, translation elongation factor 1-α sequence and RNA polymerase second largest subunit gene (RPB2) with the sequences of known fungal species in the NCBI database. Of these isolates, four were F. acuminatum, followed by three F. solani, two F. oxysporum, and one each of F. equiseti, F. redolens, and F. avenaceum. Under greenhouse conditions, pathogenicity testing experiment was carried out using five strains: two F. acuminatum, one F. solani, one F. oxysporum, and one F. equiseti. Among them, the incidence of F. acuminatum-induced root rot on A. sinensis was 100%; hence, it was the most aggressive. Liquid chromatography was used to show that F. acuminatum was capable of producing neosolaniol (NEO), deoxynivalenol (DON), and T-2 toxins. Of these, the level of NEO produced by F. acuminatum was high, compared with the other two toxins. By isolating Fusarium spp. and characterizing their toxin-producing capacity, this work provides a new information for effectively preventing and controlling A. sinensis root rot in the field, as well as improving the quality of its medicinal materials. Keywords: Angelica sinensis, Fusarium spp., mycotoxins, pathogenicity tests, root rot disease.

Mutation of CsARC6 affects fruit color and increases fruit nutrition in cucumber.

KEY MESSAGE: A mutation of CsARC6 not only causes white fruit color in cucumber, but also affects plant growth and fruit quality. Fruit color of cucumber is a very important agronomic trait, but most of the genes affecting cucumber white fruit color are still unknow, and no further studies were reported on the effect of cucumber fruit quality caused by white fruit color genes. Here, we obtained a white fruit mutant em41 in cucumber by EMS mutagenesis. The mutant gene was mapped to a 548 kb region of chromosome 2. Through mutation site analysis, it was found to be a null allele of CsARC6 (CsaV3_2G029290). The Csarc6 mutant has a typical phenotype of arc6 mutant that mesophyll cells contained only one or two giant chloroplasts. ARC6 protein was not detected in em41, and the level of FtsZ1 and FtsZ2 was also reduced. In addition, FtsZ2 could not form FtsZ ring-like structures in em41. Although these are typical arc6 mutant phenotypes, some special phenotypes occur in Csarc6 mutant, such as dwarfness with shortened internodes, enlarged fruit epidermal cells, decreased carotenoid contents, smaller fruits, and increased fruit nutrient contents. This study discovered a new gene, CsARC6, which not only controls the white fruit color, but also affects plant growth and fruit quality in cucumber.

Antifungal activity and mechanism of palmarosa essential oil against pathogen Botrytis cinerea in the postharvest onions.

AIMS: Botrytis cinerea is a pathogenic fungus that infests multiple crops, which causes a severe decrease in yield and generates substantial losses in the economy. Palmarosa essential oil (PEO) is a primary aromatic compound extracted from palmarosa that is commonly used for scent, medicine, and flavoring foods due to its diverse bioactive properties. In this study, we explored the antifungal activity and the main mechanism of action of PEO against B. cinerea. In addition, the components and control effects of PEO were also studied. METHODS AND RESULTS: The antifungal assay was tested using the mycelial growth rate method and colony morphology. The constituents of PEO were identified according to gas chromatography/mass spectrometry (GC-MS). The main mechanism of action of PEO was evaluated by measuring representative indicators, which consist of cell contents leakage, excess reactive oxygen species (ROS), and other related indicators. The results indicated that at a concentration of 0.60 ml l-1, PEO exhibits strong antifungal activity against B. cinerea. The PEO mainly included 13 compounds, of which citronellol (44.67%), benzyl benzoate (14.66%), and acetyl cedrene (9.63%) might be the main antifungal ingredients. The study elucidated the main mechanism of action of PEO against B. cinerea, which involved the disruption of cell membrane structure, resulting in altered the cell membrane permeability, leakage of cell contents, and accumulation of excess ROS. CONCLUSIONS: PEO is a satisfactory biological control agent that inhibits B. cinerea in postharvest onions. PEO (0.60 ml l-1) exhibited strong antifungal activity by disrupting the cell membrane structure, altering cell membrane permeability, leading to the cell contents leakage, accumulation of excess ROS and increased level of Malondialdehyde (MDA) compared to the control group.

Leucobacter edaphi sp. nov., a highly chromate-tolerant bacterium isolated from chromium containing chemical plant soil.

A Gram-positive, aerobic, rod-shaped non-motile, non-sporulating bacterium, designated CSA2T, was isolated from chromium-containing soils collected from a chemical plant. The 16S rRNA gene sequence of strain CSA2T showed the highest homology with Leucobacter chromiireducens subsp. solipictus (97.85%), Leucobacter chromiireducens subsp. chromiireducens (97.85%). The digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI) and the amino acid identity (AAI) values among strains CSA2T and the selected Leucobacter species were 20.6-23.4% (dDDH), 72.67-78.03% (ANI) and 66.39-76.16% (AAI), falling below the recommended thresholds for species delimitation. The principal fatty acids were anteiso-C15:0, iso-C16:0 and anteiso-C17:0. The polar lipids were phosphatidylglycerol, diphosphatidylglycerol and an unknown glycolipid. The major menaquinones detected were MK-10 and MK-11. The cell-wall amino acids included 2,4-diaminobutyric acid, threonine, glutamic acid, alanine and glycine. Based on molecular feature, phenotypic and chemotaxonomic, strain CSA2T was considered to be a novel species of the genus Leucobacter., and the name Leucobacter edaphi sp. nov. is proposed. The type strain is CSA2T (= JCM 34360T = CGMCC 1.18747T).

Ochrobactrum chromiisoli sp. nov., Isolated from Chromium-Contaminated Soil.

A Gram-stain-negative, non-spore-forming, flagellated, motile, aerobic, rod-shaped bacteria strain, designated YY2XT, was isolated from chromium-contaminated soil. Phylogenetic analysis based on 16S rRNA gene, recA gene, and whole genome indicated that the strain represented a new member of the genus Ochrobactrum, family Brucellaceae, class Alphaproteobacteria. The phylogenetic trees based on 16 s rRNA gene, revealed that Falsochrobactrum ovis DSM26720T (96.7%), Ochrobactrum gallinifaecis DSM15295T (96.2%), and Pseudochrobactrum asaccharolyticum DSM25619T (96.2%) are the most closely related phylogenetic neighbors of strain YY2XT. The draft genome of YY2XT was approximately 4,650,646 bp in size with a G + C content of 53.0 mol%. Average nucleotide identity and digital DNA-DNA hybridization values among strain YY2XT and the selected Brucellaceae species were 71.4-83.1% and 13.5-42.7%, which are below the recommended cut-off values for species delineation. Growth of strain YY2XT occurred within pH 5-10 (optimum, pH 7-8), 4 â„ƒ-42 °C (optimum, 30 °C), and NaCl concentrations of 0.0-6.0% (optimum, 1.0%). Major quinone system was ubiquinone 10, the major fatty acids were C16:0, C18:1ω7c, and C16:1ω7c and the major polyamines were spermidine and putrescine. Major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, and four undefined lipids. On the basis of the phenotypic, genotypic and chemotaxonomic traits, strain YY2XT was considered to represent a novel species of the genus Ochrobactrum, for which the name Ochrobactrum chromiisoli sp. nov. is proposed. The type strain is YY2XT (= CCTCC AB 2023035T = JCM 36000T).

First Report of Powdery Mildew Caused by Erysiphe cruciferarum on Orychophragmus violaceus in China.

Orychophragmus violaceus is an annual or perennial herb in the Brassicaceae family. It is widely planted in China and used as an ornamental and green manure plant (Luo et al. 2022). In September 2022, a survey conducted in a 600 m2 garden in Lanzhou (36°06'N, 103°43'E) found that over 70% of O. violaceus plants were infected with powdery mildew, with 80% of the leaf area on the upper surface of infected leaves was infected. The white colonies on the upper surface of the leaves gradually expanded, thickened, and spread to cover the stem surface. In severe cases, entire foliage withered and the plants died. Fungal structures were taken from the leaves with adhesive tape and placed in sterile water for microscopic observation. The conidiophores were upright, cylindrical, composed of 3 to 4 cells, and measured 92.3 ± 12.9 × 9.2 ± 0.6 µm (n=30). Conidial pedicels had 21.6 ± 3.4 µm (n=50) long cylindrical podocytes. Monoconidia were cylindrical or oval in shape, 32.9 ± 6.1 µm long and 15.1 ± 2.1 µm wide (n=80). Conidia lacked an obvious cellulose body. The bud tubes formed from the end of conidia, and papillary appressoria developed on the epiphytic mycelia. Based on these morphological characteristics, the pathogen was initially identified as Erysiphe cruciferarum (Braun et al. 2012). To validate the identity, the internal transcribed spacer (ITS) region of an isolate EYL was amplified by PCR and sequenced using both ITS1/ITS4 and ITS5/PM6 primers (Takamatsu et al. 2001). The resulting sequences were deposited at GenBank (accession nos: OR437967 and OR437969). The ITS sequence of the isolate EYL (OR437967) is 99% (451/453) identical to E. cruciferarum (KP730001) on Brassica napus in China and that of the isolate EYL (OR437969) is 100% (509/509) identical to E. cruciferarum (KM260718) on B. juncea in Vietnam. Pathogenicity experiments were performed on six-week-old plants with an average of 10 ± 0.8 leaves. In the inoculated group, five healthy plants were inoculated by gently pressing the upper surface of diseased leaves against the upper surface of leaves of healthy plants for about 5 to 10 seconds. In the control group, the leaves of five healthy plants were treated with asymptomatic using the same method as described above. The plants were maintained in a greenhouse set at 25℃, 14-h photoperiod, and ≥ 70% humidity. After 13 days, all inoculated plants showed symptoms of powdery mildew, while the plants in the control group had no symptoms. The fungus on the inoculated plant was re-isolated and identified as E. cruciferarum based on its morphological characteristics and ITS sequence. Powdery mildew caused by E. cruciferarum has been reported on Cleome hassleriana in Italy and B. juncea in Australia (Garibaldi et al. 2009; Kaur et al. 2008). To our knowledge, this is the first time that powdery mildew caused by E. cruciferarum have been reported on O. violaceus in China. This disease poses a potential threat to the quality and yield of O. violaceus plants, which may warrant the development of preventative and management strategies in the future.

First Report of Powdery Mildew Caused by Erysiphe cruciferarum on Centella asiatica in China.

Centella asiatica belongs to the Umbelliferae family of perennial herbaceous plants, which are grown worldwide for use as health supplements, edible vegetables and traditional herbs, and are of vital medicinal and edible value in China. (Biswas et al. 2021). In October 2022, the investigation in the 800 m2 garden of Lanzhou (36°06' N,103°43' E) found that more than 80% of C. asiatica plants were infected by powdery mildew, and the leaf infection rate was 90%. The disease severely affects the actual value of C. asiatica. At the beginning of the disease, thin, radial, irregular white colonies appear on the leaves and gradually spread to the stems. The white colony then expands and thickens, covering the upper surface of the whole leaf, and gradually spreading to the lower parts of the stem and leaf. In severe cases, the leaves wither and die. A small portion of fungal spores was glued from the leaf surface with adhesive tape and placed in sterile water for microscopic examination (Zhang et al. 2022). The conidiophore is upright, cylindrical, composed of 3-4 cells, and its size is 72 to 110 × 8 to 10 µm. Conidial pedicels have 16 to 26 µm long cylindrical podocytes. Monoconidia are cylindrical or oval in shape, 16 to 37 µm long, width 11 to 18 µm (n=80). Conidia lack an obvious cellulose body. The bud tube is formed from the end of conidia, and papillary appressorium develops on the epiphytic mycelia. Based on these morphological characteristics, the pathogen was initially identified as Erysiphe cruciferarum (Braun et al. 2012). To validate the identity, the internal transcribed spacer (ITS) of the pathogen (JXC) rDNA was amplified by PCR and sequenced with PM6/ITS5 and PM5/ITS4 primers (Takamatsu et al. 2001). The resulting sequences were registered to GenBank (GenBank Accession OP935627 and OQ253404). At the same time, the ITS sequence size was 535 bp and 521 bp respectively. The ITS sequence of the JXC was 99% (527/534) identical to E.cruciferarum (KT588635) on Eschscholzia californica in Slovakia and 99% (527/534) identical to E.cruciferarum (KC878683) on Chinese Cabbage in China. The ITS sequences from GenBank were subjected to conduct maximum likelihood phylogenetic analysis by MEGA 7.0. The data indicate that strain JXC and E. cruciferarum are clustered on the same branch. The pathogenicity test was performed according to Koch's postulate. By gently pressing the infected leaves on five healthy potted C. asiatica. Meanwhile, five uninoculated plants were used as controls (Zhang et al. 2022). The plants were put into a greenhouse culture (25℃, 14 h light, 10 h dark, humidity ≥ 70%). After 12 days, the inoculated plants showed symptoms of powdery mildew, while the control group had no symptoms. The fungus on the inoculated plant was re-isolated, and identified as E. cruciferarum based on morphological observations and molecular identification. The powdery mildew caused by E.cruciferarum has been reported on Indian mustard in Korea and Chinese cabbage in China, respectively (Kim et al. 2009; Zhao et al. 2014). To our knowledge, this is the first report of C. asiatica powdery mildew caused by E.cruciferarum in China. This finding poses a potential threat to the quality and yield of C. asiatica plants, while providing a preventive basis for the cultivation of C. asiatica.

Biological activities and applications of exopolysaccharides produced by lactic acid bacteria: a mini-review.

Exopolysaccharides (EPSs) are naturally occurring high-molecular-weight carbohydrates that have been widely studied for their biological activities, including antioxidant, immunomodulatory, anticancer and gut microbiota regulation activities. Polysaccharides are abundant in nature and can be derived from animals, plants, algae, and microorganisms, but among polysaccharides with potential uses, EPSs from microorganisms have the advantages of a short production cycle, high yield, and independence of production from season and climate and thus have broad prospects. While the safety of the producing microorganism can represent a problem in application of microbial EPSs, lactic acid bacteria (LAB) have been used by humans for thousands of years, and they and their products are generally recognized as safe. This makes LAB excellent sources for exopolysaccharides. EPS-producing LAB are readily found in nature. Through screening of strains, optimization of culture conditions, and improvement of the growth medium, the yield of EPSs from LAB can be increased and the scope of application broadened. This review summarizes EPSs from LAB in terms of structure, function and applications, as well as yield optimization, and introduces recent research on the biological activities and practical applications of LAB EPSs, aiming to provide references for researchers in related areas.

The major component of cinnamon oil as a natural substitute against Fusarium solani on Astragalus membranaceus.

AIMS: Root rot caused by Fusarium solani is an important disease seriously affecting the yield and quality of Astragalus membranaceus. Therefore, this study was performed to elucidate the antifungal activities and mechanisms of cinnamaldehyde treatment against F. solani and its control effect for A. membranaceus root rot. METHODS AND RESULTS: Cinnamaldehyde significantly inhibited mycelial growth and spore germination of F. solani in dose-dependent, and the median effective concentration was 178.68 µl l-1 . Furthermore, scanning electron microscopy, propidium iodide staining, cell leakage experiments and ergosterol quantitation illuminated that cinnamaldehyde could alter the mycelial morphology, damage the plasma membrane and hinder the biosynthesis of ergosterol. Besides, cinnamaldehyde induced the generation of reactive oxygen species by synergistically upregulating the genes encoded subunits for NADPH oxidase. The disease suppression efficacy of 600 µl l-1 cinnamaldehyde against A. membranaceus root rot was 92.98 ± 6.08% (p < 0.05) under greenhouse conditions. CONCLUSIONS: This study proved that cinnamaldehyde could markedly inhibit the growth of F. solani in vitro and effectively suppress the occurrence of A. membranaceus root rot, perhaps by inducing oxidative damage, which results in the distortion of F. solani, and the destruction of cell membrane integrity and permeability. SIGNIFICANCE AND IMPACT OF THE STUDY: This study first explores the antifungal mechanisms of cinnamaldehyde against F. solani in vivo and vitro, thereby providing a promising candidate for disease biocontrol.

Combining multiple Bacillus spp. with fish protein hydrolysates mitigates root rot (Fusarium solani) and improves cucumber seedlings growth and substrate nutrients.

AIMS: The effect of Bacillus strains combined with fish protein hydrolysates (FPHs) on cucumber root rot disease, seedlings growth and substrate nutrients was investigated. METHODS AND RESULTS: We isolated three strains capable of mitigating cucumber root rot disease, XY-1 and XY-13 strains were identified as B. amyloliquefaciens, and XY-53 strain as B. subtilis. In the absence of bacteria, The 200×dilution (5 ml L-1 ) of FPHs was the optimum concentration for improving cucumber seedlings growth. In vivo antibiosis tests showed that combined bacteria alongside FPHs inhibited the pathogen growth by 85%~90%, higher than individual bacteria. The FPHs combined either with XY-1 and XY-53 strains or with XY-13 and XY-53 strains promoted seedlings growth under infection, whereas FPHs combined with a mixture of XY-1, XY-13 and XY-53 strains showed the highest total phosphorus and organic matter content in substrate. Moreover, FPHs combined with XY-53 strain increased urease activity, while combined either with XY-13 and XY-53 strains or with XY-1, XY-13 and XY-53 strains increased sucrase activity under infection. CONCLUSIONS: FPHs combined with B. amyloliquefaciens and B. subtilis had great potential to suppress growth of root rot and promote cucumber seedlings and increase substrate nutrient content. SIGNIFICANCE AND IMPACT OF THE STUDY: Co-inoculation of B. amyloliquefaciens and B. subtilis with addition of FPHs is a good strategy for maintaining healthy crops.

First Report of Powdery Mildew Caused by Erysiphe polygoni on Trifolium repens in China.

White clover (Trifolium repens L.) belongs to the Fabaceae family legume and is cultivated in China for its medicinal properties and ornamental value. White clover is grown around the world for forage, turf , green manure and soil conservation purposes (Zhang el al. 2016). In October 2021, an investigation of a 1,000 m2 plant nursery in Lanzhou, China (36°06'N, 103°83'E) found that 80% of White clover plants were infected, and powdery mildew covered 95% of the leaf area. The disease had seriously destroyed the forage quality and reduced the ornamental value. Initially, thin, radial, irregular white colonies appeared on leaves and gradually spread to stems. The white colonies then expanded and thickened to cover upper surface of the leaf, and microscopic hyphae appeared on the bottom of the leaf. In severe cases, the infection resulted in dieback of the leaf. A small area of sporulating fungus was stripped off from the leaf surface with tape and mounted in sterile water for microscopic examination (Mukhtar et al. 2017). Conidiophores were cylindrical, consisting of a foot cell followed by three to four short cells, measuring 75 to 160 × 7 to 10 µm. Conidiophores had straight, cylindric foot cells ranging from 25 to 40 µm long. Singly produced conidia were hyaline and ranged in shape from oblong to cylindrical. Conidia lacked distinct fibrotic bodies and measured 30 to 45 × 15 to 25 µm in length. Long, unbranched germ tubes formed from the ends of the conidia and nipple-shaped appressoria developed on epiphytic mycelia. Based on these morphological characteristics, the pathogen was initially identified morphologically as Erysiphe polygoni (Braun and Cook 2012). To validate the identity, the internal transcribed spacer (ITS) region of the pathogen (SY77) rDNA was amplified by PCR and sequenced using the ITS1/ITS4 primers (White et al. 1990). The resulting sequences were registered to GenBank (GenBank Accession No.OM280998). The ITS sequence of the SY77 was 100% (640/640) identical to E. polygoni (LC009892) on Polygonum aviculare in the United Kingdom and 99% (638/640) identical to E. polygoni (MK685172) on Antigonon leptopus in Taiwan. MEGA 7.0 was used to conduct the neighbor-joining phylogenetic analysis using the ITS sequences from GenBank. The data indicated that the strain SY77 and E. polygoni clustered together on the same branch. Pathogenicity tests were conducted by gently pressing the infected leaves onto five healthy potted White clover plants, while five non-inoculated plants were used as controls (Michael et al. 2021). The plants were maintained in a growth chamber (25 ℃, 14 h light, and 10 h dark period, RH > 80%). After 10 days, the inoculated plants developed powdery mildew symptoms, whereas the control plants remained symptom-free. The fungus on the inoculated plants was re-isolated, re-identified, and confirmed as E. polygoni based on morphological observations and molecular identification. There is no previous report on E. polygoni causing powdery mildew on White clover in China. The powdery mildew caused by E. polygoni on Red clover has been reported in China and Bulgaria, respectively (Yuan el al.1991; Galina el al. 2017). To our knowledge, this is the first report of powdery mildew caused by E. polygoni on White clover in China. References: 1. Zheng, L., et al. 2018. Plant Dis. 102:628. 2. Mukhtar, G., et al. 2017. Plant Dis.101:1, 246. 3. Braun, U., and Cook, R. T. A. 2012. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No.11. CBS, Utrecht. 4. Michael, R. F., et al. 2021.Plant Dis. First look.( doi.org/ 10.1094/PDIS-09-21-2060-PDN). 5. Yuan, Q. H., el al.1991. Pratacult Sci.05:59 (in Chinese). 6. Galina, N., et al, 2017. BIOTECHNOL Anim Husb.33.127.

Optimization of fermentation conditions, purification and rheological properties of poly (γ-glutamic acid) produced by Bacillus subtilis 1006-3.

This study aimed to investigate the optimal fermentation condition, purification and rheological properties of extracellular polymers produced by Bacillus subtilis 1006-3. An optimum temperature of 30.2 °C, inoculation amount of 6.1%, and pH of 8.2 were determined via Response Surface Methodology. The result of amino acid analysis and gel electrophoresis indicated that the obtained polymer contained only glutamic acid, with a wide molecular weight range. This polymer was finally determined as γ-PGA by infrared spectroscopy. The γ-PGA solution displayed a behavior of pseudoplastic non-Newtonian fluid with shear thinning properties, which can be described by the Ostward-de Waele power law model. The apparent viscosity of γ-PGA solution increased with the increase in its concentration from 1% to 10%. The deviation in pH from neutral value, and the addition of NaCl or MgCl2 can reduce the apparent viscosity of γ-PGA solution, and it was more sensitive to Mg2+ than to Na+ addition. At the concentration of 4, 6, and 8%, γ-PGA solution showed predominantly viscous response in the range of 0.1-100 rad/s angular frequency (G″>G'). These results indicated the potential application of the γ-PGA as a thickening agent.

Leucobacter chromiisoli sp. nov., isolated from chromium-containing chemical plant soil.

A Gram-stain-positive, rod-shaped, aerobic, non-motile, non-sporulating bacterial strain, designated CSA1T, was isolated from chromium-containing soil sampled at a chemical plant. Growth of strain CSA1T occurred at pH 6-10 (optimum, pH 7), 15-45 °C (optimum, 30 °C) and in the presence of 0.5-6.5 % (w/v) NaCl (optimum, 2 %). The 16S rRNA gene sequence of strain CSA1T revealed the highest similarity to Leucobacter ruminantium A2T (97.5 %), Leucobacter tardus K 70/01T (97.3 %), Leucobacter humi Re6T (96.6 %), Leucobacter kyeonggiensis F3-P9T (96.2 %), Leucobacter zeae CC-MF41T (96.1 %) and Leucobacter weissii S27T (96.0 %). The draft genome of CSA1T was approximately 3 350 931 bp in size with a G+C content of 70.6 mol%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values among strain CSA1T and the selected Leucobacter species were 74.0-79.2 % (ANIb), 84.3-87.1 % (ANIm) and 21.5-25.4 % (dDDH), which are below the recommended cutoff values for species delineation. The major fatty acids were anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unknown glycolipid. The predominant menaquinones were MK-11, MK-8 and MK-6. The cell-wall amino acids were 2,4-diaminobutyric acid, alanine, glycine, glutamic acid and threonine. From the phenotypic, chemotaxonomic and molecular features, strain CSA1T was considered to represent a novel species of the genus Leucobacter, for which the name Leucobacter chromiisoli sp. nov. is proposed. The type strain is CSA1T (=JCM 34359T=CGMCC 1.18746T).

Genomic insights into the salt tolerance and cold adaptation of Planococcus halotolerans SCU63T.

Planococcus halotolerans, recently described as a novel species with SCU63T as the type strain, is capable of thriving in up to 15% NaCl and temperatures as low as 0 °C. To better understand its adaptation strategies at the genomic level, strain SCU63T was subjected to whole-genome sequencing and data mining. The high-quality assembly yielded 17 scaffolds with a genome size of 3,622,698 bp. Its genome harbors 3683 protein-coding sequences and 127 RNA genes, as well as three biosynthetic gene clusters and 25 genomic islands. The phylogenomic tree provided compelling insights into the evolutionary relationships of Planococcus. Comparative genomic analysis revealed key similarities and differences in the functional gene categories among Planococcus species. Strain SCU63T was shown to have diverse stress response systems for high salt and cold habitats. Further comparison with three related species showed the presence of numerous unique gene clusters in the SCU63T genome. The strain might serve as a good model for using extremozymes in various biotechnological processes.

Ornithinibacillus caprae sp. nov., a moderate halophile isolated from the hides of a white goat.

A novel Gram-stain-positive, motile, moderate halophile, strain L9T, was isolated from hides of white goat in China. The isolate grew optimally at 30 °C, at pH 7 and with 5-10% (w/v) NaCl. The predominant menaquinone was MK-7, and the major cellular fatty acids were identified as iso-C15:0 and anteiso-C15:0. The peptidoglycan amino acid type was determined to be A4ß, containing L-ornithine and D-aspartic as diagnostic amino acids. The phospholipids were dominated by diphosphatidylglycerol, phosphatidylglycerol, one unidentified aminophospholipid and two unidentified phospholipids. Genome sequencing resulted in a genome size of 4.0 Mbp and a DNA G + C content of 35.9 mol%. Phylogenetic trees based on the 16S rRNA gene sequences showed the isolate to be closely related to Oceanobacillus limi H9BT (98.2% similarity) and Ornithinibacillus halophilus G8BT (97.5% similarity). The ANI and dDDH values between strain L9T and the closely related species were 69.8-76.1% and 13.0-20.5%, respectively. On the basis of the data presented, strain L9T represents a novel species of the genus Ornithinibacillus, for which the name Ornithinibacillus caprae sp. nov. is proposed. The type strain is L9T (= KCTC 43176T = CGMCC 1.17659T).

Ochrobactrum teleogrylli sp. nov., a pesticide-degrading bacterium isolated from the insect Teleogryllus occipitalis living in deserted cropland.

A Gram-stain-negative, non-spore-forming, motile, aerobic, rod-shaped bacteria strain, designated LCB8T, was isolated from the insect Teleogryllus occipitalis captured from a deserted cropland in Shuangliu district, Chengdu, PR China. Phylogenetic analysis on the basis of 16S rRNA gene sequence indicated that the strain represented a member of the genus Ochrobactrum, family Brucellaceae, class Alphaproteobacteria. Ochrobactrum pecoris CCUG 60088T (97.9 %) and Ochrobactrum haematophilum CCUG 38531T (98.8 %) were identified as the most closely related phylogenetic neighbours of strain LCB8T. The novel strain was able to grow at salt concentrations of 0-4.5 % (w/v), pH 5-9 and temperatures of 20-42 °C. The major quinone system was ubiquinone Q-10, the major fatty acids were C18 : 1ω7c, C16 : 0 and C18 : 0. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylmonomethylethanolamine, diphosphatidylglycerol and four undefined aminolipids. The major polyamines were putrescine and spermidine. Genome sequencing revealed a genome size of 4.76 Mbp and a DNA G+C content of 57.1 mol%. These phenotypic, genotypic and chemotaxonomic traits excellently supported the affiliation of LCB8T to the genus Ochrobactrum. Pairwise determined whole-genome average nucleotide identity (ANI) values indicated that strain LCB8T represents a novel species, for which we propose the name Ochrobactrum teleogrylli sp. nov. with the type strain LCB8T (=KCTC 72031T=CGMCC 1.13984T).

Halomonas pellis sp. nov., a moderately halophilic bacterium isolated from wetsalted hides.

A Gram-stain-negative, moderately halophilic strain, designated strain L5T, was isolated from wetsalted hides collected from Chengdu, south-west PR China. The cells were motile, facultative aerobic, short rod-shaped and non-endospore-forming. Growth of strain L5T occurred at pH 6-10 (optimum, pH 8), 10-45 °C (optimum, 30 °C) and in the presence of 1-17 % (w/v) NaCl (optimum, 10 %). Results of phylogenetic analyses based on 16S rRNA, gyrB and rpoD gene sequences and its genome revealed that strain L5T belonged to the genus Halomonas. Strain L5T was found to be most closely related to the type strains of Halomonas saliphila, Halomonas lactosivorans, Halomonas kenyensis, Halomonas daqingensis and Halomonas desiderata (98.8, 98.6, 98.3, 97.9 and 97.4 % 16S rRNA gene sequence similarity, respectively). The draft genome was approximately 4.2 Mb in size with a G+C content of 63.5 mol%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization values among strain L5T and the selected Halomonas species were 83.3-88.9 % (ANIm), 71.1-87.3 % (ANIb) and 20.2-34.6 %, which are below the recommended cutoff values. Major fatty acids were C16 : 0, C16 : 1 ω7c, C18 : 1 ω7c and C19 : 0 cyclo ω8c and the predominant ubiquinone was Q-9, with minor ubiquinone Q-8 also present. The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, four unidentified aminophospholipids and three unidentified phospholipids. Based on the mentioned polyphasic taxonomic evidence, strain L5T represents a novel species within the genus Halomonas, for which Halomonas pellis sp. nov. is proposed. The type strain is L5T (=CGMCC 1.17335T=KCTC 72573T).

Gracilibacillus salitolerans sp. nov., a moderate halophile isolated from saline soil in Northwest China.

A moderately halophilic strain, designated SCU50T, was recovered from a saline soil sample and characterized by a polyphasic approach. The 16S rRNA gene sequence analysis showed that strain SCU50T belonged to the genus Gracilibacillus and was most closely related to Gracilibacillus thailandensis TP2-8T (98.1 % similarity) and Gracilibacillus orientalis XH-63T (97.7 %). Genomic average nucleotide identity and digital DNA-DNA hybridization analyses confirmed the separate species status of the new isolate relative to other recognized Gracilibacillus species. The genome size was about 5.09 Mbp and the DNA G+C content was 36.7 mol%. The strain grew optimally at 10-15 % (w/v) NaCl, pH 6.5-7.5 and 25-30 °C. It contained anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0 as the dominant fatty acids and menaquinone-7 as the major respiratory quinone. The polar lipid profile was examined and found to comprise diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid and one unidentified lipid. The cell-wall peptidoglycan type was A1γ based on meso-diaminopimelic acid. Combining the data from phenotypic, chemotaxonomic, genomic and phylogenetic characterization, it was concluded that strain SCU50T should be assigned as representing a novel species within the genus Gracilibacillus. Thus, a novel taxon named Gracilibacillus salitolerans sp. nov. was first established, with SCU50T (=CGMCC 1.17336T=KCTC 43107T) as the type strain.

Description of Salinicola corii sp. nov., a Halotolerant Bacterium Isolated from Wetsalted Hides.

A novel Gram-stain-negative, moderately halotolerant, rod-shaped bacterium, designated strain L3T, was isolated from a wetsalted hide in Chengdu, China. The organism grew optimally at 30 °C, at pH 8 and with 5-10% (w/v) NaCl. The major cellular fatty acids were C16:0, C16:1ω7c, C18:1ω7c and C19:0 cyclo ω8c; the predominant respiratory quinone was Q-9; the phospholipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and three unidentified phospholipids. Phylogenetic trees based on the 16S rRNA, gyrB and rpoD genes' sequences, obtained using three different algorithms, clearly revealed the isolate belonged to the genus Salinicola, and was found to be closely related to Salinicola acroporae JCM 30412T, Salinicola socius CGMCC 1.12383T and Salinicola lusitanus CR50T. The draft genome was approximately 4.5 Mb in size with 4486 predicted coding sequences, and the G+C content was 62.6 mol%. The maximum values of ANI and dDDH between strain L3T and the three above-mentioned type species were 89.2% and 63.8%, respectively. Differential phenotypic properties, together with the genome analysis, support the view that strain L3T represents a novel species, Salinicola corii sp. nov., with the type strain L3T (=CGMCC 1.17272T=KCTC 72572T).