Search Results (196)

Restricting the use of chemical pesticides in forestry requires the search for alternative solutions. These could be volatile organic compounds produced by three investigated species of bacteria (Bacillus amyloliquefaciens (ex Fukumoto) Priest, B. subtilis (Ehrenberg) Cohn and B. thuringiensis Berliner), which inhibit the growth of the pathogen F. oxysporum Schltdl. emend. Snyder & Hansen in forest nurseries. The highest inhibition of fungal growth (70%) was observed with B. amyloliquefaciens after 24 h of antagonism test, which had a higher content of carbonyl compounds (46.83 ± 8.41%) than B. subtilis (41.50 ± 6.45%) or B. thuringiensis (34.62 ± 4.77%). Only in the volatile emissions of B. amyloliquefaciens were 3-hydroxybutan-2-one, undecan-2-one, dodecan-5-one and tetradecan-5-one found. In contrast, the main components of the volatile emissions of F. oxysporum were chlorinated derivatives of benzaldehyde (e.g., 3,5-dichloro-4-methoxybenzaldehyde) and chlorinated derivatives of benzene (e.g., 1,4-dichloro-2,5-dimethoxybenzene), as well as carbonyl compounds (e.g., benzaldehyde) and alcohols (e.g., benzyl alcohol). Further compounds were found in the interactions between B. amyloliquefaciens and F. oxysporum (e.g., $\alpha$-cubebene, linalool, undecan-2-ol, decan-2-one and 2,6-dichloroanisole). Specific substances were found for B. amyloliquefaciens (limonene, nonan-2-ol, phenethyl alcohol, heptan-2-one and tridecan-2-one) and for F. oxysporum (propan-1-ol, propan-2-ol, heptan-2-one and tridecan-2-one). The amounts of volatile chemical compounds found in B. amyloliquefaciens or in the bacterium–fungus interaction can be used for further research to limit the pathogenic fungus. In the future, one should focus on the compounds that were found exclusively in interactions and whose content was higher than in isolated bacteria. In order to conquer an ecological niche, bacteria increase the production of secondary metabolites, including specific chemical compounds. The results presented are a prerequisite for creating an alternative solution or supplementing the currently used methods of plant protection against F. oxysporum. Understanding and applying the volatile organic compounds produced by bacteria can complement chemical plant protection against the pathogen, especially in greenhouses or tunnels where plants grow in conditions that favour fungal growth. Full article

This study investigates the valorization of carrot discard, a carbohydrate-rich agricultural residue, for the production of 2,3-butanediol (2,3-BDO). The fermentation process was evaluated using two strains, Bacillus licheniformis DSM 8785 and Bacillus amyloliquefaciens DSM 7. Two process configurations were compared: separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). Additionally, to determine substrate and product inhibition thresholds, fermentation assays were conducted in semi-defined media with glucose concentrations ranging from 20 to 120 g/L. The SHF strategy proved more effective than the SSF configuration. Under the SHF configuration, B. amyloliquefaciens demonstrated superior performance, yielding 16.7 g/L of 2,3-BDO. In contrast, B. licheniformis was notable for its high capacity for acetoin synthesis, producing 24.2 g/L of acetoin in addition to 10.9 g/L of 2,3-BDO. Therefore, these findings demonstrate that carrot discard is a viable feedstock for the co-production of 2,3-BDO and acetoin. Full article

As one of the decay-resistant woods, Korean pine is widely used in the construction industry. However, even the most corrosion-resistant wood is still susceptible to decay under the right humidity and temperature conditions. In this study, Bacillus amyloliquefaciens (B. amyloliquefaciens) bacterial liquid and filter bacterial solution were prepared for the anti-corrosion treatment of Korean pine wood, aiming to improve its decay-resistant property. Through the plate confrontation test, it was discovered that B. amyloliquefaciens AW3 could significantly inhibit the growth of Fomitopsis pinicola (F. Pinicola). The results of mass loss rate, mechanical properties test, XRD, FTIR and SEM analysis showed that the preserved Korean pine wood had significant improvement in various properties compared with the decayed wood, which was manifested in the significant reduction of mass loss, improvement of mechanical properties, and increased wood cellulose diffraction peak intensity. There is no mycelium infection of F. pinicola in Korean pine wood, and the antiseptic liquid can penetrate into the wood evenly, which plays an effective antiseptic role. The B. amyloliquefaciens bacterial liquid exhibited superior preservative performance compared to the B. amyloliquefaciens filter bacterial solution. In conclusion, B. amyloliquefaciens, as an efficient and environmentally friendly biological preservative, holds broad application prospects in improving the anti-corrosion performance of Korean pine wood. Full article

Bacterial chondronecrosis with osteomyelitis (BCO) is a major cause of lameness in broiler chickens. This condition arises when bacteria from the gastrointestinal or aerosol tract migrate to infect bone microfractures, often exacerbated by rapid growth, reduced blood flow, and mechanical stress. As concerns about antibiotic resistance grow, probiotics have gained attention for their potential to improve gut health and reduce systemic bacterial load. This study evaluated the efficacy of a probiotic program comprising an Enterococcus faecium-based spray (2 × 10⁹ CFU/bird at hatch) and a triple-strain Bacillus-based feed additive (B. subtilis 597, B. subtilis 600, and B. amyloliquefaciens 516 at 500 g/t feed from day 1 to 56), applied individually or in combination. A wire-flooring challenge model was used to simulate BCO transmission. A total of 1560 Cobb 500 broilers were randomly assigned to five groups: T1 (positive control), T2 (negative control), T3 (E. faecium spray only), T4 (Bacillus feed supplement only), and T5 (combined treatment). Lameness was evaluated daily from day 21 to 56 through clinical observation and necropsy. The challenge model was validated with >70% lameness in T1. All probiotic treatments significantly reduced lameness compared to T2 (p < 0.05): 35.4% in T3, 36.7% in T4, and 47.6% in T5. The combined treatment resulted in the statistically highest reduction in lameness incidence, indicating a synergistic rather than merely additive effect compared to individual treatments. These findings support the use of targeted probiotic strategies to reduce BCO lameness and enhance skeletal health and welfare in broilers. Full article

Chestnut blight, caused by Cryphonectria parasitica (Murrill) M.E. Bar, is a destructive fungal disease threatening chestnut cultivation and production. In response to the limitations of chemical control, biological control using antagonistic microbes has gained increasing attention. A rhizosphere-derived bacterium, strain D39, was isolated from healthy chestnut trees and identified as Bacillus amyloliquefaciens based on morphological characteristics and the phylogenetic analysis of 16S rRNA and gyrA genes. The antifungal activity of strain D39 against C. parasitica was evaluated using dual-culture and double-layer Oxford cup assays. The strain exhibited broad-spectrum and stable antagonistic effects and harbored five key genes associated with antimicrobial compound biosynthesis (srfAA, ituC, fenD, bmyB, and bacA), as confirmed by PCR. A 145 kDa extracellular protein with strong antifungal activity was extracted and purified by ammonium sulfate precipitation, DEAE ion-exchange chromatography, and Sephadex G-75 gel filtration. LC-MS analysis identified the protein as a serine peptidase belonging to the S8 family, and its structure was predicted using multiple bioinformatic tools. In pot experiments, treatment with the strain D39 significantly reduced disease severity, achieving control efficiencies of 66.07% and 70.89% at 10 and 20 days post-inoculation, respectively. These results demonstrate that B. amyloliquefaciens D39 has strong potential as a biocontrol agent against chestnut blight, offering an effective and environmentally friendly alternative for disease management. Full article

The increasing demand for industrial enzymes calls for cost-effective and sustainable production strategies. This study investigates the potential of industrial wastewater as an alternative fermentation medium for enzyme synthesis, aligning with the principles of the circular bioeconomy. Four wastewater types from Québec, Canada—beverage wastewater (BW), pulp and paper mill activated sludge (PPMS), food industry wastewater (FIW), and starch industry wastewater (SIW)—were evaluated for their potential to support protease, amylase, and lipase production using Bacillus licheniformis, Bacillus amyloliquefaciens, and Bacillus megaterium. Initial screening identified SIW as optimal for amylase production with B. amyloliquefaciens, and PPMS for protease production with B. megaterium. Optimization using the Box–Behnken design was then performed, followed by scale-up experiments in 5 L bioreactors. B. amyloliquefaciens achieved 5.73 ± 0.01 U/mL of amylase at 48 h under 40 g/L total solids, 30 °C, and a 2% inoculum size, while B. megaterium produced the highest protease of 55.41 ± 3.54 U/mL at 24 h. Lipase production remained negligible across all media and strains. These findings demonstrate the feasibility of the potential of wastewater-based enzyme production, reducing reliance on expensive synthetic substrates, mitigating environmental burdens, and contributing to the transition to a circular bioeconomy. Full article

Commercial production of the button mushroom, Agaricus bisporus (Lange) Imbach, is threatened by various pests and mycopathogenic microorganisms. Sciarid flies (Sciaridae) of the genus Lycoriella are considered as major pests, while major pathogens include the fungi Lecanicillium fungicola (Preuss), Zare and Gams, Hypomyces perniciosus Magnus, Cladobotryum spp., and Trichoderma aggressivum Samuels & W. Gams, the causative agents of dry bubble, wet bubble, cobweb, and green mold diseases, respectively. Control of mushroom pests and diseases has long relied on synthetic chemical pesticides. Pesticide resistance and various health and environmental issues have created a need for sustainable and eco-friendly alternatives to the use of synthetic chemical pesticides for mushroom pest and disease control. The concept of bioprotection, which involves using biological control agents (BCAs) and biopesticide products, offers a viable alternative. The entomopathogenic nematode Steinernema feltiae (Filipjev) and predatory mite Stratiolaelaps scimitus (Womersley) are the most important invertebrate BCAs, while the bacteria Bacillus thuringiensis Berliner, B. amyloliquefaciens, and B. velezensis stand out as the most widely used microbial BCAs/biopesticides. Azadirachtin- and pyrethrum-based products are the most important biochemical biopesticides. Bioprotection agents require inclusion in the integrated pest and disease management (IPDM) programs in order to achieve their full effectiveness. Full article

Many microbial agents, such as Bacillus amyloliquefaciens, have been reported to promote the growth of plant roots, which may enhance the uptake of systemic pesticides by plant roots. Through experimental methods, such as microscopic observation and HPLC (High Performance Liquid Chromatography) detection, the colonization behavior of B. amyloliquefaciens HN11 in sweet potato rhizosphere and its effects on sweet potato growth and fosthiazate uptake were studied. The results show that B. amyloliquefaciens HN11 could effectively colonize the rhizosphere of sweet potatoes and significantly promote the growth of sweet potato roots, leading to increase the yield of sweet potatoes. Moreover, the colonization of B. amyloliquefaciens HN11 promoted the absorption of fosthiazate by sweet potato roots under drip irrigation. The control efficiency against root knot nematodes of sweet potato also improved under this management approach. In summary, drip application of fosthiazate to sweet potato roots inoculated with B. amyloliquefaciens HN11 revealed a new approach to insecticide application. This method could improve the effective utilization rate of fosthiazate and the control efficiency of root knot nematodes, help farmers increase production and income, be environmentally friendly and meet the requirements of sustainable development. This study provides new references for the application direction of microbial agents. Full article

Fusarium graminearum is one of the most important pathogenic fungi with a wide range of plant and animal hosts. This study investigated the effects of F. graminearum infection on the rhizosphere microbiota and growth of two barley (Hordeum vulgare L.) cultivars, Baudin and Kenpi 7, and explored microbiota transplantation as a strategy to enhance disease resistance. By exchanging surface microbiotas between varieties and analyzing rhizosphere bacterial communities using 16S rRNA sequencing, researchers observed that F. graminearum infection increased bacterial diversity and abundance, especially in Baudin barley. Growth indicators (root length, plant height, fresh/dry mass) also exhibited that Baudin barley showed stronger resistance. Functional analysis underscored that the microbial community composition of Baudin barley promoted metabolic pathways related to plant resilience and was associated with improved seedling health. In contrast, Kenpi 7 barley showed weaker resistance, emphasizing the role of seed-specific microbiotas in pathogen defense. An effective antagonistic strain, Bacillus amyloliquefaciens B1, was isolated from Baudin barley, and its inhibition rate against F. graminearum was 80%. The results showed that microbiota transplantation enhanced the disease resistance of low-diversity seeds, and identified B. amyloliquefaciens B1 as a promising biocontrol agent, providing a potential application for sustainable agriculture and reducing dependence on chemical fungicides. This study highlights the importance of seed-associated microbial communities in plant–pathogen interactions and provides a basis for the development of microbiota-based strategies to mitigate crop diseases. Full article

Larch dieback disease, caused by Neofusicoccum laricinum, severely affects forest health and productivity. To effectively curb the occurrence of this disease, a powder formulation of Bacillus amyloliquefaciens JL54 was developed through spray drying. The research commenced with the optimization of fermentation medium and culture conditions through statistical design, aiming to maximize both bacterial viability and antagonistic activity. The optimal medium included 12 g/L yeast extract, 11.8 g/L yeast powder, and 7.2 g/L magnesium sulfate. Optimal culture conditions included 30% loading volume, 1% inoculum, 37 °C incubation temperature, 31.8 h shaking time, and initial pH 6.4. Under these conditions, the viable count of strain JL54 reached 4.45 × 10⁹ cfu/mL, a 296.67-fold increase compared with the unoptimized system. To evaluate its practical applicability, field trials were conducted, showing a 54% control efficiency against larch dieback disease, significantly suppressing disease progression. Subsequently, the spray drying process was optimized with a 1:10 protective agent-to-water ratio, 100 °C inlet temperature, and 630 mL/h feed flow rate, achieving a 78.41% powder recovery rate. Collectively, this study demonstrates the potential of B. amyloliquefaciens JL54 as an effective biocontrol agent for managing larch dieback and supports its application in spray-dried formulations for forest disease control. Full article

Background: Maize is easily contaminated by Aspergillus flavus, and the aflatoxin produced by A. flavus has been classified as a Group 1 carcinogen, for which there are currently no effective control measures. Biological control is regarded as an environmentally friendly and safe approach. Strains ZH179, ZH409, and ZH99 are three bacteria isolated from our laboratory that exhibit antagonistic effects against A. flavus. We conducted experiments to investigate their biocontrol efficacy. Results: The experimental results demonstrated that these three strains effectively inhibited A. flavus on plates and stored maize seeds. Identification revealed that ZH179 is Bacillus velezensis, while ZH409 and ZH99 are B. amyloliquefaciens. We also identified lipopeptide synthetase-related genes, including srfAA, srfAD, fenA, fenB, ituA, ituB, ituD, bmyA, bmyB, and bmyC, in these three strains. Furthermore, LC-MS analysis confirmed that these strains could produce lipopeptide compounds such as surfactin, fengycin, iturin, and bacillomycin. Using the Oxford cup method, we found that the lipopeptide compounds produced by these strains can inhibit the growth of A. flavus. Conclusion: These findings suggest that strains ZH179, ZH409, and ZH99 have good control effects on A. flavus during the storage of maize, primarily due to the lipopeptide compounds. This study provides a theoretical basis for using these three strains in the biological control of A. flavus. Full article

The tomato leafminer, Tuta absoluta, is a destructive invasive tomato pest worldwide. Bacillus amyloliquefaciens W10, a bacterium isolated from the rhizosphere of tomatoes, is classified as a plant growth-promoting rhizobacterium. However, whether B. amyloliquefaciens W10 can improve the resistance of tomato against T. absoluta remains unclear. In this study, we found that B. amyloliquefaciens W10 promoted the tomato growth and significantly reduced the fecundity of T. absoluta. To further evaluate the effects of B. amyloliquefaciens W10 on the tomato’s resistance to T. absoluta, the age-stage, two-sex life table, and oviposition preference test were carried out to investigate the individual fitness, population parameters, and preference behavior of T. absoluta. Compared to the control, the intrinsic rate of increase (r_m), net reproductive rate (R₀), and finite rate of increase (λ) of T. absoluta in the treatment group were significantly reduced, while the population doubling time (DT) was significantly increased. Meanwhile, the oviposition preferences of T. absoluta for the treated tomato plants were reduced. After T. absoluta infestation, electrical conductivity and hydrogen peroxide (H₂O₂) content in tomato leaves after B. amyloliquefaciens W10 treatment were significantly lower than those in the control, while peroxidase (POD), polyphenol oxidase (PPO), jasmonic acid (JA), and salicylic acid (SA) levels were significantly higher. In addition, the O₂⁻, superoxide dismutase (SOD), and catalase (CAT) levels were also affected. qRT-RCR analyses revealed that B. amyloliquefaciens W10 colonization induced the expressions of JA- and SA-related genes, including AOS1, AOC, PAL1, and SAMT, in tomato plants after T. absoluta infestation. These findings provide valuable insights and theoretical support for the application of beneficial endophytes to induce the resistance in tomatoes against T. absoluta. Full article

Beneficial bacteria are recognised for their antimicrobial compounds, making them valuable for disease control in agriculture. Bacillus species stand out for their stability, versatility, and selectivity as biocontrol agents. This study aimed to identify potential antagonists within the rhizosphere microorganisms by isolating bacterial strains from grapevine roots and rhizosphere soil in Moroccan vineyards. The antimicrobial activities of these isolates against Allorhizobium vitis, the causative agent of grapevine crown gall, were evaluated in vitro using a disc diffusion assay, followed by in planta assessments under preventive and simulated inoculation conditions. Screening led to the isolation of 123 strains, with six showing strong antagonistic properties, achieving inhibition percentages up to 39.6%. 16S rRNA sequencing led to identifying five Bacillus species: B. amyloliquefaciens, B. velezensis, B. halotolerans, B. subtilis, and B. anthracis. These strains were further characterised by their biochemical traits and plant growth-promoting abilities. Compatibility assays identified optimal combinations for microbial consortia, demonstrating pathogen inhibition up to 37.4%. In planta bioassays confirmed the effectiveness of the isolates and consortia, reducing tumour size. These findings highlight the potential of these Bacillus strains as biocontrol agents and underscore the value of microbial consortia as a sustainable approach to managing grapevine crown gall. Full article

The substrate for button mushroom (Agaricus bisporus) cultivation includes a highly complex microbiome. The aim of the study was to evaluate ecological interactions (synergistic, antagonistic, or additive) between a commercial population of the entomopathogenic nematode Steinernema feltiae (EPN) and beneficial microorganisms, bacterium Bacillus amyloliquefaciens B-241 (BA) or actinobacterium Streptomyces flavovirens A06 (SF). Their relationships were evaluated in efficacy against the pathogenic fungus Trichoderma aggressivum and the fungus gnat Lycoriella ingenua. Moreover, their impact on mushroom yield was estimated. The synergy factor was calculated as the ratio of observed to expected values regarding their efficacy against T. aggressivum/L. ingenua and influence on mushroom production. Additive relationships in efficacy against T. aggressivum were observed between EPN and BA or SF. As for the impact on yield, synergistic interactions were indicated between each beneficial microorganism and EPN. Considering suppression of L. ingenua, a mild antagonistic reaction between EPN and each beneficial microorganism was observed in plots without T. aggressivum and additive in plots inoculated with the pathogenic fungus, although high efficacy was achieved in all combinations (>80%). Tested native strains of both beneficial microorganisms could be combined with the commercial EPN strain for successful biological pest and disease control in mushroom production. Full article

Bacterial chondronecrosis with osteomyelitis (BCO) is caused by several bacteria, including Salmonella, Staphylococcus spp., Escherichia coli, Enterococcus spp., and Mycoplasma spp., and BCO is a significant animal health and welfare issue in broiler production, causing 1–2% of bird condemnation at marketing age and resulting in annual losses of tens of millions of dollars. This study evaluated the efficacy of a probiotic program alone and combined with a multivalent electron beam (eBeam)-inactivated vaccine in reducing BCO lameness. The probiotic program included an Enterococcus faecium spray (E. faecium 669, at 2 × 10⁹ CFU/bird) at hatch and a triple-strain Bacillus-based product (B. subtilis 597, B. subtilis 600, and B. amyloliquefaciens 516 at 1 × 10⁹ CFU/bird/day) in drinking water from day 1 to day 56. An aerosol transmission challenge model simulated commercial bacterial exposure. Birds were divided into five groups: a positive control (PC) group (T1) and a negative control (NC) group (T2) receiving no treatment and three treatment groups receiving the probiotic program (T3), the multivalent vaccine (T4), or both the probiotic program and the multivalent vaccine (T5). Data analyzed via ANOVA (p < 0.05) showed T3, T4, and T5 had significantly lower lameness (43.7%, 40.3%, and 40.7%) than T2 (71.0%) and T1 (83.0%). T5 resulted in reductions comparable to T4, indicating no significant synergistic effect. These findings show that probiotics alone or with a vaccine effectively mitigate BCO lameness, enhance broiler welfare, and reduce economic losses. Full article