Search Results (587)

The increasing prevalence of pests and diseases in agriculture necessitates innovative strategies for crop protection that mitigate environmental impacts. This review paper investigates the synergistic potential of combining microbial biocontrol agents and phytochemical biopesticides as sustainable alternatives to chemical pesticides. Through a comprehensive review of recent literature, we analyze the mechanisms by which beneficial microbes (e.g., Trichoderma, Bacillus, and Pseudomonas) enhance plant resilience and suppress pathogens, and how plant-derived phytochemicals such as essential oils, alkaloids, and flavonoids contribute to pest deterrence and disease resistance. The integration of these bio-based resources forms an actionable framework for sustainable crop protection—enabling reduced chemical dependence, improved soil health, and enhanced biodiversity. Examples of synergistic success, such as the combined use of Bacillus thuringiensis with neem extract and Trichoderma with lemongrass oil, illustrate their field potential. Future research should prioritize the formulation of stable microbial–phytochemical consortia, field validation of synergistic efficacy, and optimization of delivery systems to support commercial-scale adoption. Ultimately, this study promotes a paradigm shift toward eco-efficient pest management, bridging fundamental research and applied innovation for resilient agroecosystems. Full article

The microbial removal of antibiotics is an environmentally friendly solution to antibiotic contamination in water. However, the main limitations for its application are the difficulty of direct utilization of antibiotics by bacteria and incomplete removal. In this study, a strain of Bacillus thuringiensis ZY that removed tetracycline (TC) as a sole carbon source was applied. Strain ZY was able to remove 50 mg/L TC at an efficiency higher than 70%, while the removal efficiency was increased to 100% after the immobilization by Loofah (Lfr). Meanwhile, the removal time was shortened from 6 to 4.5 d. Compared with the free ZY, the TC removal efficiency of Lfr-ZY was significantly improved under various conditions (temperature, pH and NaCl concentration). The removal efficiency of Lfr-ZY was still higher than 50% after 11 cycles, with strong removal ability and stability. In addition, the enhancement of TC bio-removal by Lfr-ZY involved the combination of the protection, adsorption, detoxification, putative nutrient release and solubilization effects of Lfr. The promising results suggest that the Lfr-based strategy has the potential for solving the problems of a lack of nutrient substrate for TC removal and the inability to remove it completely. Full article

The bioinsecticide Bacillus thuringiensis subsp. kurstaki (Btk) is applied over large areas to reduce defoliation caused by the spruce budworm, an insect which affects millions of hectares of coniferous forests every 30 to 40 years in eastern North America. The aim of our study was to determine whether, in addition to its direct lethal effects, aerial spraying of Btk had sublethal effects on spruce budworm populations and their parasitism. Four sites were sprayed with Btk and compared to four control sites in two regions, one where the outbreak had started three years earlier and the other where it had been going on for 10 years. Insects were collected to compare budworm pupal mass and parasitism at different stages (L₅, L₆ and pupae). Budworm pupae were significantly lighter in Btk-treated sites than in controls, and in the older population than in the younger one. However, pupae collected from Btk-treated sites had the same mass in both regions, suggesting a minimum pupal mass threshold, which may affect population dynamics. Larval parasitism was low, but pupal parasitism was high and strongly influenced by an interaction between Btk and region, with a higher parasitism observed in Btk-treated sites of the younger population than in those of the older population. A significant interaction was observed between Btk treatment and region on the proportion of larvae that failed to complete development, which was particularly high in Btk-treated sites of the older population. Our study confirms the effectiveness of Btk in controlling spruce budworm populations directly but also indirectly through sublethal effects on budworm development, capacity to complete development, pupal size and parasitism. To maximize control efficacy, the timing of Btk applications could vary according to the age of populations during the budworm outbreak cycle. Full article

West Nile Virus (WNV) is an emerging arboviral threat in Europe, with rising incidence in Spain since 2004. In 2024, Spain experienced its largest outbreak, primarily in small urban areas of south-western regions. We report a subset of an emergency integrated vector management program, focusing on six municipalities accounting for one-third of all human WNV cases nationwide. Over four months, 725 potential larval sites were inspected during 4026 visits. Adult mosquitoes (n = 2553) were collected with suction traps, and immature stages (n = 4457) with dipper techniques, yielding 11 species. Culex pipiens s.l. was predominant, while Cx. perexiguus, though less abundant, was epidemiologically significant. Cytochrome Oxidase I (COI) gene phylogenetic analysis confirmed Cx. perexiguus, forming a distinct clade from Cx. univittatus. Immature mosquitoes were found in 18.6% of sites, especially irrigation canals, ditches, and backwaters near urban areas. Habitat differences in larval abundance were analyzed using generalized linear mixed models. Targeted larviciding with Bacillus thuringiensis var. israelensis (Bti) and focal adulticiding with cypermethrin totaled 259 interventions (70.4% larviciding, 29.6% adulticiding). A significant 63.9% reduction in larval abundance was observed after five consecutive Bti treatments, with some variation among treatment cycles (52.2–75.5%). Adult activity persisted into late autumn. This study provides the first comprehensive characterization of larval mosquitoes in Spain’s main WNV hotspot, highlighting the need for rapid, coordinated expert interventions and extended seasonal control to prevent future outbreaks. Full article

Integrated pest management (IPM) in tomato (Solanum lycopersicum L.) on the Ecuadorian coast represents a critical challenge, given that pest persistence has led producers to abandon the crop, generating significant losses. This study compared pest population fluctuations in greenhouse and open field conditions under realistic management conditions and free infestation, considering the influence of environmental factors and applications of biorational, semisynthetic, and synthetic pesticides. In open fields, infestations were high and sustained, exceeding treatment thresholds, while in greenhouses, levels were lower, attributable to the protection of the aphid netting. Product efficacy depended on the pest and the level of infestation: Azadirachta indica, Bacillus thuringiensis, and Beauveria bassiana were effective in low infestations; spinetoram and abamectin reached efficacies between 80 and 100% in moderate infestations; neonicotinoids had variable efficacy, ranging from 47.8% to 89.9%. Since the system determines the type of pest and the level of infestation, monitoring becomes a key tool for timely decision-making. The findings show that the greenhouse limits the entry of the main pest, Prodiplosis longifila. While it does not prevent the presence of smaller pests, such as thrips and white mites, the combination of physical barriers and low-toxicity pesticides significantly reduces populations, minimizing the number of applications and the use of more toxic insecticides. The proposed strategy provides solid evidence for the effective implementation of a greenhouse to reduce pest pressure and promote IPM in protected coastal systems in Ecuador. Full article

A variety of pesticidal proteins derived from the bacterium Bacillus thuringiensis exhibit activity against the yellow fever mosquito Aedes aegypti and are used to control this insect vector. Several of these proteins, including Cry1Ca and Cry2Aa, additionally have activity against lepidopteran insects. Furthermore, the specificity of Cry2Aa has recently been shown to depend on domain I of the Cry protein, whereas it is generally recognized that domain II is the primary specificity-determining domain. This work has made use of disabled forms of three Cry proteins (Cry2Aa, Cry1Ca and Cry11Aa) and one naturally non-active protein (Cry2Ab) in an in vivo competition assay to investigate whether Cry2Aa and the dual-active Cry1Ca share a common receptor with the other pesticidal proteins. It was found that despite their differing specificities and potential modes of action, all of the Aedes-active proteins tested made use of a common receptor, although evidence is presented that Cry2Aa can use multiple receptors. When additional toxins (Cry41Aa, Cry1Aa, Cry1Ac) with no activity against this mosquito were tested, they too were found to share the same receptor, suggesting that Cry toxins may have evolved to utilize a common set of receptors in insects but that additional factors determine species specificity. Full article

Pantoea ananatis was recently described as the causative agent of late-season decline, a new bacterial disease first observed affecting field corn plants, in the Texas Panhandle. The rapid spread of the disease throughout the region and the patchy distribution of symptomatic plants in affected fields, as well as routine observations of edge effects, in which plants with severe symptoms are observed on the edges of affected fields, led us to hypothesize that vectors might be involved in the dissemination of the disease pathogen. In this study, we investigated the western corn rootworm (Diabrotica virgifera virgifera LeConte) and southern corn rootworm (Diabrotica undecimpunctata howardi Barber) for any naturally occurring association with P. ananatis and potential to acquire and transmit the bacterial pathogen. Additionally, we investigated the transgenic corn encoding insecticidal Bacillus thuringiensis proteins (Bt) pyramided with RNAi interference anti-rootworm technology for its potential to protect against any larval role in the transmission of the pathogen through their feeding activities on corn roots. We successfully recovered naturally occurring P. ananatis from samples of both rootworm species collected from corn plants in the field. Following acquisition assays, the acquired pathogen was successfully recovered from previously P. ananatis-free adult rootworms, their eggs, as well as first-instar larvae, suggesting an affinity of the bacteria to establish an endosymbiotic and transovarial association with both rootworm species. Additionally, the transgenic Bt corn with RNAi anti-rootworm technology was ineffective in preventing the transmission of the pathogen by the infected larvae. Findings from this study confirm a vector role in the transmission of the disease pathogen. Full article

Background: Airborne transmission of bacteria, viruses, and fungal spores poses a major threat in enclosed settings, particularly nursing homes where residents are highly vulnerable. Compressive Heating Air Sterilization Technology (CHAST) applies compressive heating to inactivate microorganisms without reliance on filtration or chemicals. Methods: CHAST efficacy was evaluated in laboratory and deployed for a feasibility and performance validation study of air sterilization in a nursing home environment. Laboratory studies tested prototypes (300–5000 CFM; 220–247 °C) against aerosolized surrogates including Bacillus globigii (Bg), B. stearothermophilus (Bst), B. thuringiensis (Bt), Escherichia coli, and MS2 bacteriophage. Viral inactivation thresholds were further assessed by exposing MS2 to progressively lower treatment temperatures (64.5–143 °C). Feasibility and performance validation evaluation involved continuous operation of two CHAST units in a nursing home, with pre- and post-treatment air samples analyzed for bacterial and fungal burden. Results: Laboratory testing demonstrated consistent microbial inactivation, with most prototypes achieving > 6-log (99.9999%) reductions across bacterial spores, vegetative bacteria, and viruses. A 5000 CFM prototype achieved > 7-log (99.99999%) elimination of B. globigii. MS2 was completely inactivated at 240 °C, with modeling suggesting a threshold for total viral elimination near 170 °C. In the feasibility study, baseline sampling revealed bacterial (35 CFU/m³) and fungal (17 CFU/m³) contamination, dominated by Bacillus, Staphylococcus, Cladosporium, and Penicillium. After 72 h of CHAST operation, discharge air contained no detectable viable organisms, and fungal spore counts showed a 93% reduction relative to baseline return air. Units maintained stable operation (464 °F ± 2 °F; 329–335 CFM) throughout deployment. Conclusion: CHAST reproducibly and scalably inactivated airborne bacteria, viruses, and fungi under laboratory and feasibility field studies, supporting its potential as a chemical-free strategy to improve infection control and indoor air quality in healthcare facilities. Full article

Wireworms are often referred as a hardly manageable group of pests due to their unstable lifestyle and uneven distribution in soils. The current strategy of wireworm control involves the heavy use of chemical pesticides. To find an effective and eco-friendly biological control agent against wireworms, evaluation of bacterial properties and insecticidal effects of six Bacillus thuringiensis (Bt) strains against Agriotes lineatus was performed under laboratory conditions. The presence of cry11, cyt2 and krsA gene was detected in Bt strain BHC 2.4, while the same strain had the ability to produce siderophores, protease, amylase and cellulase. Single inoculums of Bt strains (BHC 2.4; BHC 4.5; BHC 4.7; 1.5; 4.3; 6.1) showed mortality against Agriotes lineatus larvae in the range of 6.67–72.22%. However, the compatible Bt dual cultures showed significantly higher efficiency in comparison with the single inoculums, with the highest efficiency of 79.63% recorded for Bt strain BHC 2.4 + Bt strain 1.5. The efficiency of applied Bt strains might be associated with the presence of genes coding for antibiotics and toxins. Therefore, the use of selected Bt strains applied in a form of compatible mixes could offer a sustainable solution for wireworm management in wheat. Full article

Dioryctria abietella (Lepidoptera: Pyralidae) is a destructive forest pest for coniferous trees. Bacillus thuringiensis has been widely applied in forestry as a biological control agent to control it. However, the mechanisms of Bt-induced mortality in D. abietella, particularly its effects on gene expression and enzyme activities, remain unclear. Here, bioassay, enzyme assay, transcriptome sequencing, and gene expression profiling were employed to explore the relationship between the toxin-receptor, defense, and lethal mechanisms of D. abietella after Bt exposure. In a toxicity bioassay, Bacillus thuringiensis galleriae 05041 strain (Bt05041) was the most toxic insecticide to the larvae of D. abietella, with LC₅₀ values of 3.15 × 10⁸ Colony-Forming Units (CFUs) mL⁻¹ at 72 h after treatment. Transcriptome analysis revealed that the gene expression patterns of D. abietella after 8 h of Bt05041 exposure (Bt8) varied considerably from the Bt05041-treated for 2 h group (Bt2). In the Bt2 group, differentially expressed genes were significantly enriched in cellular and bioenergy pathways of lysosome, insulin signaling, cGMP-PKG signaling, etc. Immune-related pathways were activated, namely cAMP, AMPK, MAPK, Rap1, IMD, and Toll pathways. Meanwhile, Bt8 treatment caused metabolic changes in basic substances such as amino acids, glucose, nucleic acids, and fatty acids. Bt05041 exposure activated the activities of defense enzymes and induced gene expression changes in D. abietella larvae. Among them, most Bt-receptor genes had higher expression levels than defense enzyme genes. Overall, these findings reveal a possible mechanism underlying Bt-mediated death in D. abietella larvae. This work provides valuable information in terms of biological control strategies. Full article

Cadmium contamination in soil threatens ecological safety and human health. Phytoremediation has gained attention due to its cost-effectiveness and environmental sustainability. Studies show that plant growth-promoting rhizobacteria can enhance the ability of hyperaccumulator plants to remove heavy metals. This research aimed to isolate and identify plant-growth-promoting rhizobacteria under Cd stress and assess their impact on the growth and Cd accumulation of Solanum nigrum L. Six bacterial strains were isolated from the rhizosphere of S. nigrum, all showing high Cd tolerance. Among them, LKT25 exhibited multiple growth-promoting traits, including indole-3-acetic acid production, nitrogen fixation, 1-aminocyclopropane-1-carboxylate deaminase, and siderophore synthesis. Under varying Cd concentrations (5, 25, and 50 mg/kg), the Bacillus thuringiensis strain LKT25 significantly improved Cd removal by S. nigrum. At 5 mg/kg Cd, the removal efficiency reached 45.13%. LKT25 also enhanced plant growth, photosynthesis, and antioxidant activity, contributing to improved Cd remediation. This study provides new microbial resources and technical support for using rhizobacteria in remediating heavy metal-contaminated soils. Full article

The synthetic polymer low-density polyethylene (LDPE) is a pervasive pollutant that poses serious environmental concerns and health hazards. PE plastic is rarely recycled, and therefore, biodegradation is a novel approach for managing PE plastic waste. However, few enzymes and organisms that degrade PE plastic have been identified to date. Herein, we demonstrate that a consortium of soil bacteria containing Pseudomonas and Bacillus species can grow on and degrade UV-treated PE film and powder as a sole carbon source, reducing its net mass by 7% and 13%, respectively, in 30 days. Changes in surface functional groups associated with chemical modification of PE were observed via ATR-FTIR analysis, and byproducts associated with PE biodegradation and alkane and carboxylic acid metabolism were observed via GC/MS. Using previously characterized PEases, we identified a gene, CYP102 A5, found in Bacillus thuringiensis strain 9.1, which encodes a cytochrome P450 reductase, whose expression was increased when grown on PE as a sole carbon source. Purified CYP102 A5 protein altered PE surface functional groups, determined by ATR-FTIR, giving evidence of PE oxidation. In sum, we identified a cytochrome P450 reductase that explains, in part, how a consortium of soil bacteria can grow on and degrade PE plastic. Full article

Aedes aegypti, a crucial vector mosquito that transmits many diseases that cause millions of deaths worldwide, can be controlled with Bacillus thuringiensis subsp. israelensis (Bti). The larvicidal activity of Bti against Ae. aegypti is due primarily to Cry4Aa, Cry4Ba, and Cry11Aa, and Cyt1Aa, a protein that synergizes the activity of the Cry proteins. Interestingly, Galectins-6 and Galectins-14, members of a family of β-galactoside-binding proteins that play a role in immune responses insects, have been shown to decrease the activity of Bti toxins. The activity of other Galectins, particularly Galectin-8A, against the Cry proteins is not known. Toward this end, we cloned the gene coding for galactin-8A and expressed the recombinant protein and purified protein. The bioassay results indicated that Galectin-8A can also reduce the toxicity of Cry11Aa, but it was much stronger than Galectin-6. To investigate the interactions among Galectin-8A, Cry11Aa, and toxin receptors, Octet Red System analysis, Western blot, far-Western blot, and ELISA assay were also performed. The Octet Red System result showed that Galectin-8A could also bind to BBMVs of Ae. aegypti, with a lower kDa value than that of Galectin-6, indicating that Galectin-8A had a stronger binding affinity to BBMVs than Galectin-6. Western blot, far-Western blot, and ELISA assay analyses also demonstrated that Galectin-8A bound to Ae. aegypti receptor ALP1 and APN2, consistent with the protein docking simulation results. These findings support the conclusion that Galectin-8A blocks with ALP1 and APN2 more effectively than Galectin-6, which may subsequently reduce the toxicity of Cry11Aa in Ae. aegypti. Full article

Bare soil expansion in urban forests, driven by persistent high-intensity trampling, degrades both macro-scale natural resources and micro ecological conditions. Targeted interventions are therefore essential. In this study, trampled bare ground in forest parks and artificially cultivated Ophiopogon japonicus were used as experimental models We employed trampled bare ground in forest parks as well as artificially cultivated O. japonicus as experimental models. Five treatments were implemented: enclosure control (CK), ploughing (F), Bacillus thuringiensis NL-11 application (J), biochar addition (C), and co-application of B. thuringiensis NL-11 with biochar (JC). Our results indicate that, compared with CK, biochar treatments reduced soil bulk density by 30%, increased soil porosity by 89%, and improved water-holding capacity. The soil nitrate nitrogen content in the NL-11 treatment was increased by 113.8% compared with CK, while the co-application of NL-11 with biochar exhibited the highest sucrase and urease activities. Notably, the co-application of B. thuringiensis NL-11 with biochar exhibited the most pronounced effects on aboveground biomass, plant height, and root development, followed by the B. thuringiensis NL-11 treatment. Microbial β-diversity shifts under co-application of B. thuringiensis NL-11 with biochar treatment strongly correlated with soil enzyme activation and plant growth enhancement (Mantel test, p < 0.05). Correlation analysis confirmed that exogenous nutrient inputs significantly influenced enzyme activities, thereby promoting plant development. These results highlight the effectiveness of integrating microbial inoculation with biochar to restore trampled urban forest soils. Full article