Bacterial valorization of lignin for the sustainable production of value-added bioproducts.

As the most abundant aromatic biopolymer in the biosphere, lignin represents a promising alternative feedstock for the industrial production of various value-added bioproducts with enhanced economical value. However, the large-scale implementation of lignin valorization remains challenging because of the heterogeneity and irregular structure of lignin. General fragmentation and depolymerization processes often yield various products, but these approaches necessitate tedious purification steps to isolate target products. Moreover, microbial biocatalytic processes, especially bacterial-based systems with high metabolic activity, can depolymerize and further utilize lignin in an eco-friendly way. Considering that wild bacterial strains have evolved several metabolic pathways and enzymatic systems for lignin degradation, substantial efforts have been made to exploit their potential for lignin valorization. This review summarizes recent advances in lignin valorization for the production of value-added bioproducts based on bacterial systems. Additionally, the remaining challenges and available strategies for lignin biodegradation processes and future trends of bacterial lignin valorization are discussed.

Protective role of native root-associated bacterial consortium against root-knot nematode infection in susceptible plants.

Root-knot nematodes (RKNs) are a global menace to agricultural crop production. The role of root-associated microbes (RAMs) in plant protection against RKN infection remains unclear. Here we observe that cucumber (highly susceptible to Meloidogyne incognita) exhibits a consistently lower susceptibility to M. incognita in the presence of native RAMs in three distinct soils. Nematode infection alters the assembly of bacterial RAMs along the life cycle of M. incognita. Particularly, the loss of bacterial diversity of RAMs exacerbates plant susceptibility to M. incognita. A diverse range of native bacterial strains isolated from M. incognita-infected roots has nematode-antagonistic activity. Increasing the number of native bacterial strains causes decreasing nematode infection, which is lowest when six or more bacterial strains are present. Multiple simplified synthetic communities consisting of six bacterial strains show pronounced inhibitory effects on M. incognita infection in plants. These inhibitory effects are underpinned via multiple mechanisms including direct inhibition of infection, secretion of anti-nematode substances, and regulation of plant defense responses. This study highlights the role of native bacterial RAMs in plant resistance against RKNs and provides a useful insight into the development of a sustainable way to protect susceptible plants.

Novel Carboxymethyl Cellulose/Gelatin-Based Film Incorporated with Zein-Stabilized Lemon Essential Oil Pickering Emulsion for the Preservation of Cherries.

In this study, a zein-stabilized lemon essential oil Pickering emulsion (ZLPE) was incorporated into a carboxymethyl cellulose/gelatin (CMC/GL) composite film to develop a bio-based packaging material with bioactive properties. The average droplet size of the ZLPE was measured at 3.62 ± 0.08 µm, with a zeta potential of -31.33 ± 0.32 mV, highlighting its excellent stability. The image results of confocal laser microscopy and scanning electron microscopy validated the uniform distribution of ZLPE in the film. The incorporation of ZLPE reduced the water solubility of films by 45.90% and decreased its water vapor permeability by 22.61%, thereby enhancing its hydrophobicity. Additionally, the ZLPE-loaded film improved mechanical properties, enhanced UV-blocking capabilities, and increased thermal stability. The introduction of ZLPE led to the antioxidant activity of the CMC/GL film increasing by six times the original level and endowed it with outstanding antibacterial properties. As a result, cherries packaged with the ZLPE film demonstrated superior preservation performance and extended shelf life in the preservation experiment, exhibiting the film's potential as a food packaging material.

Biocontrol Mechanisms of Three Plant Essential Oils Against Phytophthora infestans Causing Potato Late Blight.

Late blight, caused by the notorious pathogen Phytophthora infestans, poses a significant threat to potato (Solanum tuberosum) crops worldwide, impacting their quality as well as yield. Here, we aimed to investigate the potential use of cinnamaldehyde, carvacrol, and eugenol as control agents against P. infestans and to elucidate their underlying mechanisms of action. To determine the pathogen-inhibiting concentrations of these three plant essential oils (PEOs), a comprehensive evaluation of their effects using gradient dilution, mycelial growth rate, and spore germination methods was carried out. Cinnamaldehyde, carvacrol, and eugenol were capable of significantly inhibiting P. infestans by hindering its mycelial radial growth, zoospore release, and sporangium germination; the median effective inhibitory concentration of the three PEOs was 23.87, 8.66, and 89.65 µl/liter, respectively. Scanning electron microscopy revealed that PEOs caused the irreversible deformation of P. infestans, resulting in hyphal shrinkage, distortion, and breakage. Moreover, propidium iodide staining and extracellular conductivity measurements demonstrated that all three PEOs significantly impaired the integrity and permeability of the pathogen's cell membrane in a time- and dose-dependent manner. In vivo experiments confirmed the dose-dependent efficacy of PEOs in reducing the lesion diameter of potato late blight. Altogether, these findings provide valuable insight into the antifungal mechanisms of PEOs vis-à-vis late blight-causing P. infestans. By utilizing the inherent capabilities of these natural compounds, we could effectively limit the harmful impacts of late blight on potato crops, thereby enhancing agricultural practices and ensuring the resilience of global potato food production.

Bioactive composite films with improved antioxidant and barrier properties prepared from sodium alginate and deep eutectic solvent treated distillers' grains.

In this work, a straightforward approach utilizing distillers' grains (DG) waste and sodium alginate (SA) was developed to prepare functional and bioactive packaging films. Deep eutectic solvents (DESs) were initially synthesized from choline chloride (CO), betaine (BO), glycerol (GO), and oxalic acid. Composite films were then prepared from DES-treated DG slurry and SA at different ratios. Characterization and analysis revealed that adding 75 % CO-treated DG slurry reduced the water vapor permeability (WVP) by over 66 % compared to that of the SA film. Composite films containing CO/BO-treated DG slurry had an ultraviolet light barrier rate exceeding 99 %, while those with 75 % DES-treated DG slurry demonstrated excellent antioxidant activity, with a 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging rate of 80.14 %-88.35 %, representing a 322.45 %-365.73 % increase compared to that of the pure SA film. These composite films also exhibited favorable mechanical properties (31.58 MPa, 5.53 % EB), thermal stability, and biodegradability, extending the shelf life of grapes by 1.8 times. In conclusion, bioactive composite films derived from DES-treated DG are expected to replace petroleum-based plastics, enhancing sustainable biomass use and environmental responsibility.

Identification of microbial diversity in buried ivory soil at the Sanxingdui site in Guanghan City, China, using high-throughput sequencing.

Introduction: The Sanxingdui Site in Guanghan City, Sichuan Province, China, is one of the precious heritage sites of the ancient Chinese civilization. Archaeological work at Sanxingdui is of great significance in clarifying the origins and main contents of the ancient Shu culture and the Yangtze River civilization. Since the 1920s, archaeologists have conducted extensive excavations and research at the site, with particular attention given to the large number of ivory artifacts unearthed. However, the buried ivory is influenced by soil pH, temperature, humidity, and other physical and chemical factors, along with the potential impact of microbial activities that may lead to the corrosion and decomposition of ivory. By understanding the types and activities of microorganisms, appropriate measures can be taken to protect and preserve cultural relics. Methods: Multi-point sampling of soil samples around the ivory of the three sacrificial pits at the Sanxingdui site was carried out, and strict aseptic operation was carried out during the sampling process. Subsequently, the microbial community structure and diversity in the buried ivory soil of Sanxingdui site were identified and analyzed by Illumina high-throughput sequencing technology. Results: 16S rRNA and internal transcribed spacer sequence analysis revealed significant differences in the soil microbial community structure among different sacrificial pits. The dominant bacterial phyla were the Proteobacteria, GAL15, Actinobacteriota, Bacteroidota, and Methylomirabilota. The dominant fungal phyla were Ascomycota, Mortierellomhcota, and Basidiomycota. Most dominant bacterial and fungal communities play an indispensable role in the ivory corrosion mechanism, promoting the decay and decomposition process through various means such as decomposing organic matter and producing acidic substances. Discussion: It is particularly important to take a series of measures to control microbial activity to effectively protect ivory. Our preliminary study of the mechanism of action of microorganisms on ivory in a buried environment provides a scientific basis to prevent and protect against microbial degradation in ancient ivory unearthed in Sanxingdui. Following the research results, suitable antibacterial agents tailored to the preservation environment and microbial characteristics of ancient ivory can be prepared. Ensure that the selected antibacterial agents meet safety and effectiveness requirements to maximize protection against microbial degradation of ancient ivory.

Effects of biodegradable (PBAT/PLA) and conventional (LDPE) mulch film residues on bacterial communities and metabolic functions in different agricultural soils.

Soil health is a crucial aspect of sustainable agriculture and food production, necessitating attention to the ecological risks associated with substantial amounts of mulch film residues. Biodegradable mulch films (BDMs) carry the same risk of mulch film residues formation as low-density polyethylene (LDPE) mulch films during actual use. More information is needed to elucidate the specific impacts of mulch film residues on the soil environment. Integrated 16S rRNA gene sequencing and non-targeted metabolomics, this study revealed the response patterns of bacterial communities, metabolites, and metabolic functions in the soil from three different agricultural regions to the presence of mulch film residues. LDPE mulch film residues negatively impacted the bacterial communities in the soils of Heilongjiang (HLJ) and Yunnan (YN) and had a lesser impact on the metabolic spectrum in the soils of HLJ, YN, and Xinjiang (XJ). BDM residues had a greater negative impact on all three soils in terms of both the bacterial communities and metabolites. The impact of BDM treatment on the soils of HLJ, YN, and XJ increased sequentially in that order. It is recommended that, when promoting the use of biodegradable mulch films, a fuller assessment should be made, accounting for local soil properties.

Photothermal hydrogels for infection control and tissue regeneration.

In this review, we report investigating photothermal hydrogels, innovative biomedical materials designed for infection control and tissue regeneration. These hydrogels exhibit responsiveness to near-infrared (NIR) stimulation, altering their structure and properties, which is pivotal for medical applications. Photothermal hydrogels have emerged as a significant advancement in medical materials, harnessing photothermal agents (PTAs) to respond to NIR light. This responsiveness is crucial for controlling infections and promoting tissue healing. We discuss three construction methods for preparing photothermal hydrogels, emphasizing their design and synthesis, which incorporate PTAs to achieve the desired photothermal effects. The application of these hydrogels demonstrates enhanced infection control and tissue regeneration, supported by their unique photothermal properties. Although research progress in photothermal hydrogels is promising, challenges remain. We address these issues and explore future directions to enhance their therapeutic potential.

The impact of arbuscular mycorrhizal fungi and endophytic bacteria on peanuts under the combined pollution of cadmium and microplastics.

It remains unclear how symbiotic microbes impact the growth of peanuts when they are exposed to the pollutants cadmium (Cd) and microplastics (MPs) simultaneously. This study aimed to investigate the effects of endophytic bacteria Bacillus velezens SC60 and arbuscular mycorrhizal fungus Rhizophagus irregularis on peanut growth and rhizosphere microbial communities in the presence of Cd at 40 (Cd40) or 80 (Cd80) mg kg-1 combined without MP or the presence of low-density polyethylene (LDPE) and poly butyleneadipate-co-terephthalate (PBAT). This study assessed soil indicators, plant parameters, and Cd accumulation indicators. Results showed that the application of R. irregularis and B. velezens significantly enhanced soil organic carbon and increased Cd content under the conditions of Cd80 and MPs co-pollution. R. irregularis and B. velezens treatment increased peanut absorption and the enrichment coefficient for Cd, with predominate concentrations localized in the peanut roots, especially under combined pollution by Cd and MPs. Under treatments with Cd40 and Cd80 combined with PBAT pollution, soil microbes Proteobacteria exhibited a higher relative abundance, while Actinobacteria showed a higher relative abundance under treatments with Cd40 and Cd80 combined with LDPE pollution. In conclusion, under the combined pollution conditions of MPs and Cd, the co-treatment of R. irregularis and B. velezens effectively immobilized Cd in peanut roots, impeding its translocation to the shoot.

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 transcribed spacer, translation elongation factor 1-α sequence and RNA polymerase second largest subunit gene 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 could produce neosolaniol (NEO), deoxynivalenol, 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 new information for effectively preventing and controlling A. sinensis root rot in the field as well as improving the quality of its medicinal materials.

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.

Biodegradation and Decolorization of Crystal Violet Dye by Cocultivation with Fungi and Bacteria.

Microbial degradation of dyes is vital to understanding the fate of dyes in the environment. In this study, a fungal strain A-3 and a bacterial strain L-6, which were identified as Aspergillus fumigatus and Pseudomonas fluorescens, respectively, had been proven to efficiently degrade crystal violet (CV) dye. The decolorization of CV dye by fungal and bacterial cocultivation was investigated. The results showed that the decolorization rate of cocultures was better than monoculture (P. fluorescens in L-6 (PF), and that of A. fumigatus A-3 (AF)). Furthermore, enzymatic analysis further revealed that Lac, MnP, Lip, and NADH-DCIP reductases were involved in the biodegradation of CV dyes. UV-visible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS) were used to examine the degradation products. GC-MS analysis showed the presence of 4-(dimethylamino) benzophenone, 3-dimethylaminophenol, benzyl alcohol, and benzaldehyde, indicating that CV was degraded into simpler compounds. The phytotoxicity tests revealed that CV degradation products were less toxic than the parent compounds, indicating that the cocultures detoxified CV dyes. As a result, the cocultures are likely to have a wide range of applications in the bioremediation of CV dyes.

Metabolic variations in root tissues and rhizosphere soils of weak host plants potently lead to distinct host status and chemotaxis regulation of Meloidogyne incognita in intercropping.

Root-knot nematodes (RKNs) inflict extensive damage to global agricultural production. Intercropping has been identified as a viable agricultural tool for combating RKNs, but the mechanisms by which intercropped plants modulate RKN parasitism are still not well understood. Here, we focus on the cucumber-amaranth intercropping system. We used a range of approaches, including the attraction assay, in vitro RNA interference (RNAi), untargeted metabolomics, and hairy root transformation, to unveil the mechanisms by which weak host plants regulate Meloidogyne incognita chemotaxis towards host plants and control infection. Amaranth roots showed a direct repellence to M. incognita through disrupting its chemotaxis. The in vitro RNAi assay demonstrated that the Mi-flp-1 and Mi-flp-18 genes (encoding FMRFamide-like peptides) regulated M. incognita chemotaxis towards cucumber and controlled infection. Moreover, M. incognita infection stimulated cucumber and amaranth to accumulate distinct metabolites in both root tissues and rhizosphere soils. In particular, naringenin and salicin, enriched specifically in amaranth rhizosphere soils, inhibited the expression of Mi-flp-1 and Mi-flp-18. In addition, overexpression of genes involved in the biosynthesis of pantothenic acid and phloretin, both of which were enriched specifically in amaranth root tissues, delayed M. incognita development in cucumber hairy roots. Together, our results reveal that both the distinct host status and disruption of chemotaxis contribute to M. incognita inhibition in intercropping.

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.

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.

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).

Effect of in situ vermicomposting combined with biochar application on soil properties and crop yields in the tomato monoculture system.

Vermicompost and biochar have been widely used to improve soil conditions. However, little information is available regarding the efficiency and effectiveness of in situ vermicomposting with biochar (IVB) in monoculture soils. In this study, we estimated the effects of IVB on soil physiochemical and microbial properties, crop yields, and fruit quality under the tomato monoculture system. The soil treatments considered were (i) untreated monoculture soil (MS, control), (ii) MS plus 1.5 t/ha biochar applied to soil surface (MS+1.5BCS), (iii) MS plus 3 t/ha biochar applied to soil surface (MS+3BCS), (iv) MS mixed with 1.5 t/ha biochar (MS+1.5BCM), (v) MS mixed with 3 t/ha biochar (MS+3BCM), (vi) in situ vermicomposting (VC), (vii) VC plus 1.5 t/ha biochar applied to VC surface (VC+1.5BCS), (viii) VC plus 3 t/ha biochar applied to VC surface (VC+3BCS), (ix) VC mixed with 1.5 t/ha biochar (VC+1.5BCM), and (x) VC mixed with 3 t/ha biochar (VC+3BCM). In general, soil pH varied from 7.68 to 7.96 under VC-related treatments. The microbial diversity was much higher in bacterial communities (OTU: 2284-3194, Shannon index: 8.81-9.91) than in fungal communities (OTU: 392-782, Shannon index: 4.63-5.71) in VC-related treatments. Specifically, Proteobacteria was the dominant bacterial phylum, followed by Bacteroidota, Chloroflexi, Patescibacteria, Acidobacteriota, Firmicutes, and Myxococcota. It is worth noting that IVB-related treatments could increase the relative abundance of Acidobacteria and reduced the relative abundance of Bacteroidetes. In addition, the VC+1.5BCM treatment exhibited the greatest yield (9377.6 kg/667m2) and simultaneously showed higher fruit quality (vitamin C, 28.94 mg/100g; soluble sugar, 20.15%) as compared to other treatments. Our results suggested that in situ vermicomposting with biochar can improve soil properties and enhance both crop yields and fruit quality under the tomato monoculture system.

Comprehensive analyses of microtubule-associated protein MAP65 family genes in Cucurbitaceae and CsaMAP65s expression profiles in cucumber.

MAP65 is a microtubule-binding protein family in plants and plays crucial roles in regulating cell growth and development, intercellular communication, and plant responses to various environmental stresses. However, MAP65s in Cucurbitaceae are still less understood. In this study, a total of 40 MAP65s were identified from six Cucurbitaceae species (Cucumis sativus L., Citrullus lanatus, Cucumis melo L., Cucurbita moschata, Lagenaria siceraria, and Benincasa hispida) and classified into five groups by phylogenetic analysis according to gene structures and conserved domains. A conserved domain (MAP65_ASE1) was found in all MAP65 proteins. In cucumber, we isolated six CsaMAP65s with different expression patterns in tissues including root, stem, leaf, female flower, male flower, and fruit. Subcellular localizations of CsaMAP65s verified that all CsaMAP65s were localized in microtubule and microfilament. Analyses of the promoter regions of CsaMAP65s have screened different cis-acting regulatory elements involved in growth and development and responses to hormone and stresses. In addition, CsaMAP65-5 in leaves was significantly upregulated by salt stress, and this promotion effect was higher in cucumber cultivars with salt tolerant than that without salt tolerant. CsaMAP65-1 in leaves was significantly upregulated by cold stress, and this promotion was higher in cold-tolerant cultivar than intolerant cultivar. With the genome-wide characterization and phylogenetic analysis of Cucurbitaceae MAP65s, and the expression profile of CsaMAP65s in cucumber, this study laid a foundation for further study on MAP65 functions in developmental processes and responses to abiotic stress in Cucurbitaceae species.