Search Results (286)

Latex-producing plants harbor unique microbial communities that may play important roles in host defense; however, their diversity and biocontrol potential remain largely unexplored. Characterizing these communities provides opportunities to identify novel microbial-derived antifungal agents for sustainable crop protection. Bacterial strains were isolated from the latex of Alstonia scholaris (L.) R. Br. and identified using 16S rRNA gene sequencing. Antifungal activity was evaluated against four phytopathogens: Fusarium graminearum, Colletotrichum musae, Colletotrichum gloeosporioides, and Glomerella cingulata. Bioassay-guided fractionation, size-exclusion chromatography, SDS-PAGE, and LC-MS/MS were used to characterize antifungal proteins. Nine bacterial strains were isolated, including eight Bacillus spp. and one Enterococcus faecalis. Among them, Bacillus sp. AsL-2 exhibited the strongest broad-spectrum antifungal activity, inhibiting fungal growth by up to 80%. The antifungal activity of its crude extract remained stable over a wide temperature range. Further characterization identified a novel endo-β-1,3-1,4-glucanase enzyme (~23 kDa) as the major antifungal protein. This study reveals A. scholaris latex as an underexplored microbial niche and identifies Bacillus sp. AsL-2, affiliated with the B. velezensis–B. amyloliquefaciens species complex, as a promising biocontrol candidate. The identified antifungal enzyme represents a potential natural alternative to synthetic fungicides for sustainable agricultural disease management. Full article

The growing demand for sustainable protein sources has increased interest in algae and aquatic plants as alternatives to animal-derived proteins. These resources are rich in protein, amino acids, and umami compounds but require suitable extraction methods to maximize yield and quality. This study compared three green extraction techniques—maceration (MAE, 80 °C, 2 h), ultrasound-assisted extraction (UAE, 750 W, 20 kHz, 50% amplitude, 35 °C, pH 12, 1 h), and enzyme-assisted extraction (EAE, 5% β-glucanase/flavourzyme, 55 °C, pH 6.5, 1 h)—on five raw materials: wakame (commercial seaweed), hair seaweed, sea lettuce, water silk algae, and Wolffia. The result revealed that both raw materials and extraction methods significantly (p < 0.05) affected protein yield, amino acid, physicochemical properties, and taste detection with e-tongue. Wolffia extracted by MAE yielded the highest protein overall, followed by UAE and EAE methods, when compared with commercial seaweed. The relationship between amino acid profiles and taste detection was investigated by principal component analysis (PCA) and hierarchical cluster analysis (HCA); the samples with higher glutamic and aspartic acids were linked with umami taste, while histidine contributed to bitter taste. Overall, the findings highlighted that extraction efficiency was influenced more by the extraction method–material compatibility than the raw material alone. Full article

Straw returning, a core practice in conservation tillage, promotes sustainable intensification; however, it faces challenges such as inefficient decomposition, nutrient competition, and pathogen accumulation. To address these limitations, this study aimed to develop a multifunctional microbial consortium specifically designed for straw-incorporating cropping systems. The consortium comprises four Bacillus strains with complementary enzymatic systems, isolated from diverse ecological niches. It exhibited robust lignocellulolytic enzyme production, with manganese peroxidase (7709.33 U/L), laccase (450.65 U/L), endo-β-1,4-glucanase (154.67 U/mL), and filter paper activity (309.18 U/L). The consortium significantly enhanced rice straw degradation by 37.18% and increased nitrogen (N) release by 16.13% compared to the control. Moreover, the consortium exhibited a 67.56% inhibition rate against Magnaporthe oryzae and reduced both the incidence rate and disease index of leaf blast and panicle blast. Field trials revealed increases in the rice grain yield of 9.63% and 6.94% when applied alone and 6.75% and 5.18% when co-applied with straw residues. These findings highlight the multifunctional agricultural potential of the consortium and provide a sustainable strategy to overcome the limitations of straw-incorporating farming systems. Full article

This study investigated the impact of two yeast strains (SP665 and CGC62) and glucanase enzyme treatments (A-D) on the secondary fermentation kinetics and aroma profile of sparkling Prosecco wines. The strains exhibited markedly different fermentation behaviors: SP665 induced rapid refermentation, reaching 8.5 bar in 46 days, while CGC62 showed a slower fermentation rate, reaching 6.5 bar in 64 days. Despite these kinetic differences, basic enological parameters after refermentation and following three months of lees aging were similar for both strains. A total of 66 volatile compounds across various chemical families were identified and quantified. Principal component analysis (PCA) revealed that aging time (T1 vs. T2) was the main driver of variability (50.74% of total variance), with SP665 and CGC62 wines showing distinct profiles. At T1, SP665 wines had higher levels of acetate esters and norisoprenoids, while CGC62 wines were richer in volatile sulfur compounds (VSCs) and monoterpenoids. At T2, SP665 wines showed increased levels of carbon disulfide, higher alcohols, and ethyl butanoate, whereas CGC62 wines retained higher concentrations of varietal compounds and certain esters. The effect of glucanase enzymes varied depending on yeast strain and aging stage. Enzyme treatments, especially C (β-glucanase) and D, influenced the concentration of several aroma compounds, particularly in CGC62 wines, enhancing varietal aromas and esters. However, the impact on SP665 wines was more limited and emerged primarily after aging. Although differences in aroma composition were statistically significant, most changes were below olfactory perception thresholds. Overall, glucanase enzymes and yeast selection influenced aroma development, though their effects may have limited sensory relevance. Full article

Fusarium oxysporum-induced soft rot severely threatens postharvest pitaya quality and storage life, and while vanillin shows promise in the disease management, its mechanisms for controlling pitaya decay remain incompletely understood. In this study, we systematically investigated the molecular mechanism by which vanillin inhibits soft rot in postharvest pitaya, employing physiological and biochemical characterization, bioinformatics analysis, and molecular biology techniques. Compared with control fruit on 10 d, vanillin treatment significantly reduced disease index and lesion area by 27.12% and 67.43%, respectively. Meanwhile, vanillin treatment delayed the degradation of total soluble solids (TSSs) and titratable acidity (TA) and promoted the accumulation of total phenolics and flavonoids. Additionally, vanillin enhanced the activities of defense-related enzymes, such as catalase (CAT), superoxide dismutase (SOD), phenylalanine ammonia-lyase (PAL), β-1,3-glucanase (GLU), chitinase (CHI), peroxidase (POD) and polyphenol oxidase (PPO), and increased antioxidant capacity, as evidenced by increased DPPH radical scavenging capacity and ascorbic acid content. This resulted in reduced oxidative damage, as indicated by decreased levels of malondialdehyde (MDA), H₂O₂ and O₂^•−. Yeast one-hybrid (Y1H), dual-luciferase reporter (DLR) and subcellular localization revealed that HuTGA1, a nuclear-localized transcriptional activator, specifically bound to the as-1 cis-acting element and activated expression of HuNPR1 and HuNPR5-1. Transient overexpression of HuTGA1 reduced reactive oxygen species (ROS) accumulation and upregulated related genes. These findings suggest that vanillin treatment might enhance pitaya resistance by activating the HuTGA1-HuNPR signaling module, providing insights into the molecular mechanisms underlying vanillin-induced resistance. Full article

This research study investigated the potential biotechnological applications of yeast species obtained from cocoa fermentation performed in Côte d’Ivoire. A total of 279 yeast isolates were molecularly identified and then screened for their antifungal ability against various Aspergillus species and for the production of aromatic compounds and extracellular enzymes. Thirty-one yeast species belonging to nineteen genera, dominated by Pichia, Candida, Hanseniaspora, and Rhodotorula, were isolated from fermented cocoa beans. All extracellular enzymes screened were produced by most yeast species, except β-glucanase and esterase activity, whereas the most common enzyme was β-glucosidase. Yeasts of the Pichia, Saccharomyces, Candida, Clavispora, and Hanseniaspora genera produced various enzymes, including xylanase, β-glucosidase, polygalacturonase, invertase, pectinase, and chitinase. The 88 aromatic compounds produced were grouped into five main chemical families, including esters, alcohols, acids, aldehydes, and ketones. Wickerhamomyces anomalus was the highest producer of major desirable aromatic compounds, including alcohols, ketones, and esters. All yeast species showed a specific antagonistic effect against the growth of various Aspergillus species, but Candida incommunis, Saccharomyces cerevisiae, and Torulaspora delbrueckii recorded the greatest antifungal ability. These yeast species could be used to develop promising starter cultures to improve the organoleptic quality of various fermented foods and beverages. Full article

Seed physical dormancy, also known as hard-seededness, is a characteristic commonly found in higher plants, which functions to prevent water and oxygen from passing through the impermeable seed coat. Background: Notably, seed dormancy has emerged as a critical factor in the domestication of leguminous plants. Alfalfa (Medicago sativa L.) is a globally cultivated high-quality legume forage crop, while the seeds from different varieties maintain varying degrees of hard-seededness. However, the molecular mechanisms underlying physical dormancy in alfalfa seeds remain poorly understood. In particular, the regulatory mechanisms at the transcriptomic level remain unclear, which has hindered the breeding process of varieties with low hard-seededness. Methods: In this study, we performed global transcriptome analysis to discover the genes specifically expressed in the alfalfa seed coat and provide insights into alfalfa seeds’ physical dormancy domestication traits. RNA sequencing was performed on various alfalfa tissues, including roots, stems, leaves, flowers, and seed coats. Results: This analysis led to the identification of 4740 seed coat-specific expressed genes, including key genes such as KNOX4 (a class II KNOTTED-like homeobox gene), qHs1 (encoding endo-1,4-β-glucanase), GmHs1-1 (encoding a calcineurin-like metallophosphoesterase), and KCS12 (β-ketoacyl-CoA synthase). In addition, several seed coat-specific transcription factor families were identified, including ERF, B3, and NAC, among others. Furthermore, a comparison of gene expression profiles between seeds with and without physical dormancy revealed 60 upregulated and 197 downregulated genes associated with physical dormancy. Crucially, functional enrichment analysis demonstrated that these genes are predominantly associated with lipid metabolism pathways, particularly those involved in the formation of “monolayer-surrounding lipid storage bodies.” Conclusions: This key finding suggests that the establishment of physical dormancy is closely linked to the biosynthesis and deposition of specialized lipid-based layers in the seed coat, which likely constitute the primary barrier to water penetration. Our study thus provides fundamental insights and a valuable genetic resource for future functional studies aimed at deciphering and manipulating physical dormancy in alfalfa. Full article

An increasing trend toward alternative methods in grapevine protection is evident, diverging from conventional chemical approaches. Biostimulants, such as chitosan hydrochloride, are compounds able to elicit the synthesis of plants’ metabolites, leading to an increase in their natural defence mechanism. Some of these metabolites could potentially impact wine sensory properties such as colour, mouthfeel, and aroma. This study investigates the effect of chitosan hydrochloride treatment on Sauvignon blanc vines, isolating impacts on plant, grape, and wine levels. Using a randomized block design with 74 potted plants grown in a glasshouse, the study found that foliar chitosan application did not affect plant growth or phenolic compound accumulation in the leaves. Conversely, it significantly decreased polyphenol oxidase (PPO) activity and increased antioxidant activity and polyphenolic content in grape berries. Treated berries exhibited doubled protein content, less thaumatin-like proteins, and more β-glucanases and chitinases than control grapes. Microvinifications revealed that wines from treated grapes had higher total polyphenols, polysaccharides, Abs 320 nm values, and total proteins than control wines. These preliminary results suggest that chitosan application affects key grape metabolites with potential implications for wine quality, warranting further investigation. Full article

Biological control using beneficial microbes offers a sustainable alternative to chemical fungicides for managing postharvest diseases. This study reports the isolation and characterization of Bacillus amyloliquefaciens AsL-1 from the latex of Alstonia scholaris (L.) R. Br., unconventional ecological niche. The cell-free supernatant (CFS) of AsL-1 showed strong antifungal activity, inhibiting the growth of Colletotrichum musae (48.89 ± 0.57%), Glomerella cingulata (52.22 ± 0.00%), Fusarium graminearum (47.78 ± 0.57%), and Colletotrichum gloeosporioides (47.78 ± 0.00%) in vitro. Microscopy revealed that the CFS disrupted fungal development by blocking conidial germination and appressorium formation, and in C. gloeosporioides caused melanization defects linked to reduced virulence. In vivo tests on mango fruit confirmed that AsL-1 significantly decreased anthracnose lesion size and disease incidence. Protein analyses (SDS-PAGE, gel overlay, and LC-MS/MS) identified two antifungal proteins (24 and 16 kDa), corresponding to β-1,3-1,4-glucanase and flagellin. The detected β-1,3-1,4-glucanase activity indicates its role in degrading fungal cell walls and interfering with melanin biosynthesis pathways essential for pathogenicity. Overall, these findings highlight B. amyloliquefaciens AsL-1 as a promising protein-based biocontrol agent and show that latex-associated microbes may serve as valuable sources of new antifungal strategies. Full article

Banana anthracnose, caused by Colletotrichum musae, causes substantial postharvest losses worldwide, yet effective biocontrol remains limited. Although Hanseniaspora thailandica shows potential, its direct application provides inadequate control. This study demonstrates that alginate oligosaccharide (AOS) potently enhances the biocontrol efficacy of H. thailandica Lg 3 against this disease. Through in vivo fruit assays, H. thailandica Lg 3 that was cultured in AOS-supplemented medium significantly elevated key defense enzymes, specifically ployphenol oxidase (PPO), peroxidase (POD), chitinase (CHI) and β-1,3-glucanase (GLU) in bananas, and enhanced yeast biofilm formation. This led to higher yeast populations in banana wounds and effective suppression of C. musae expansion. Furthermore, AOS boosted the activity of critical antioxidant enzymes (CAT, SOD, GPX) in H. thailandica Lg 3 under in vivo conditions. RNA-seq analysis of H. thailandica Lg 3 revealed corresponding alterations in glutathione metabolism and oxidative phosphorylation pathways following the addition of 10 mg/L AOS to the medium. The 10 mg/L AOS concentration proved most effective, robustly enhancing biocontrol efficacy. Our findings identify AOS-induced H. thailandica Lg 3 as a practical, ready-to-test biocontrol strategy that could be developed into a commercial formulation to reduce chemical fungicide dependence in postharvest banana protection. Full article

Rice sheath blight caused by Rhizoctonia solani is a devastating global rice disease. This study aimed to isolate biocontrol bacteria from the medicinal plant Bletilla striata for managing the disease. Strain A1 demonstrated the strongest antagonistic activity, with a 91.92% inhibition rate against R. solani in vitro. It also exhibited a broad antifungal spectrum against ten plant pathogenic fungi. Morphological and molecular (16S rRNA and recA genes) analysis identified strain A1 as Pseudomonas koreensis. In detached leaf assays, lesion length was significantly reduced. Pot and field trials showed control efficacies of 65.54% and 72.53%, respectively, comparable to the chemical agent Jinggangmycin. Strain A1 secreted extracellular enzymes (protease, β-1,3-glucanase), siderophores, and auxin (IAA), and possessed phosphate-solubilizing and nitrogen-fixing capabilities. The strain significantly enhanced the activities of key defense enzymes (POD, PAL, PPO, CAT, SOD) in rice. Furthermore, both its sterile culture filtrate and the corresponding crude ethyl acetate extract exhibited strong, direct suppression of R. solani growth. LC-MS analysis identified potential antifungal compounds, including Pseudomonic Acid, Artemisinin, and Tetradecane, in the extract. In conclusion, P. koreensis A1 is a promising biocontrol and plant growth-promoting candidate for sustainable management of rice sheath blight. Full article

Background: Sunflower meal (SFM), a promising feed material, is constrained by its high content of crude fiber (CF) and chlorogenic acid (CGA). Methods: This study utilized a synergistic solid-state fermentation process involving the Bacillus subtilis strain B3 and the enzyme β-glucanase to enhance SFM’s application potential. Results: The synergistic treatment notably reduced CF by 12.7% and CGA by 99.77%, while simultaneously increasing acid-soluble protein and reducing sugar by 111.3% and 283.1%, respectively. Positive impacts on its physical structure, characterized by a looser network with visible pores, and on its microbial community, evidenced by an enriched abundance of fungal species such as Cyberlindnera and Aspergillus, were also observed. In vitro assays indicated improved digestibility of dry matter, neutral detergent fiber, and crude protein, along with a non-significant reduction in methane production. Conclusions: These results demonstrate that microbial-enzymatic synergy effectively enhances SFM’s nutritional profile. Full article

Litchi downy blight, caused by Peronophythora litchii, is a major postharvest disease that leads to severe pericarp browning and fruit decay, significantly reducing market quality. Strengthening the fruit’s innate defense systems represents a promising strategy for minimizing these losses. This study investigated the efficacy and underlying mechanisms of ethephon treatment in controlling postharvest litchi downy blight. The results showed that treatment with 400 mg·L⁻¹ ethephon solution via a 2-min immersion significantly suppressed P. litchii infection, reduced the disease index and pericarp browning index, and enhanced the rate of ethylene production. Ethephon application notably increased 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, and the activities of key antioxidant and defense-related enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), chitinase (CHI), β-1,3-glucanase (GLU), and phenylalanine ammonia lyase (PAL). Concurrently, it up-regulated the expression of corresponding genes LcCAT, LcAPX, LcCHI, LcGLU, LcPAL. In contrast, ethephon treatment reduced the accumulation of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA). In summary, ethephon treatment suppresses postharvest litchi downy blight likely through the enhancement of both antioxidant and pathogen defense capacities. These findings provide valuable insights into the potential application of ethephon for maintaining postharvest quality in litchi fruit. Full article

Fusarium wilt disease, caused by Fusarium oxysporum f. sp. cucumerinum (FOC), leads to widespread yield losses and quality deterioration in cucumber. Endophytes, as environmentally friendly control agents that enhance pathogen resistance in their host plants, may mitigate these problems. In this study, we isolated 14 endophytic bacteria from invasive Ambrosia artemisiifolia and screened the strain Bacillus subtilis TCX1, which exhibited significant antagonistic activity against FOC (inhibitory rate of 86.0%). TCX1 killed Fusarium oxysporum by being highly likely to produce lipopeptide and producing wall hydrolytic enzymes including protease, cellulase, and β-glucanase, thereby inhibiting mycelial growth and spore germination and causing peroxidation of FOC’s cytoplasmic membrane. In addition to its direct effects, TCX1 exerts indirect effects by inducing cucumber resistance to FOC. When cucumber seedlings were inoculated with TCX1, antioxidant enzymes related to disease resistance, including Superoxide dismutase (SOD), Peroxidase (POD), Polyphenol oxidase (PPO) and Phenylalanine ammonialyase (PAL) in cucumber, were significantly increased. The marker genes involved in induced systemic resistance and the salicylic acid signaling pathway, such as npr1, pr1a, pr2, pr9, lox1, and ctr1, were also dramatically upregulated, indicating these pathways played an important role in improving cucumber resistance. Notably, TCX1 can also promote cucumber growth through producing indole-3-acetic acid, solubilizing phosphate, and secreting siderophores. Given that TCX1 has dual functions as both a biological control agent and a biofertilizer, it offers an effective strategy for managing cucumber seedling blight while enhancing plant productivity. Full article

Chili (Capsicum annuum L.) is a herbaceous vegetable grown and consumed worldwide. In Thailand, chili plants are severely hampered by anthracnose disease, leading to severe yield losses. This study aimed to investigate endophytic bacteria (EPB) for their potential as a biocontrol agent and plant growth promoter (PGP). Among a total of 108 isolates, strain KKU-RE-018 was identified by partial 16S rRNA gene sequencing as belonging to the genus Bacillus. This isolate exhibited strong antifungal activity against Colletotrichum capsici; its activity occurred through the production of hydrolytic enzymes, including chitinase and β-1,3-glucanase, and exhibited PGP properties. This endophytic bacterium significantly reduced anthracnose severity compared with the control, achieving a disease reduction index (DRI) of over 60%. Moreover, chili plants treated with the bacterium showed higher plant growth parameters under greenhouse conditions. The levels of phenolic compounds and salicylic acid in plants treated with Bacillus sp. KKU-RE-018 could activate systemic acquired resistance (SAR). Taken together, these findings demonstrate that Bacillus sp. KKU-RE-018 plays a multifaceted role, capable of suppressing anthracnose and simultaneously promoting chili growth. Full article