Search Results (94)

Conventional plant disease management primarily depends on chemical pesticides. However, with the rising concerns related to human health, environmental sustainability, and the emergence of resistant pathogens, biocontrol agents (BCAs) have gained more attention as eco-friendly alternatives. Among the potential biocontrol agents, yeasts stand out due to their safety, adaptability, and diverse antagonistic mechanisms, ranging from competition and enzyme secretion to volatile compound production and immunity induction. Despite their potential, yeast-based BCAs face limitations in field efficacy, regulation, and an incomplete understanding of their molecular interactions. Most current studies focus on simple, pairwise interactions, overlooking the complexity of agroecosystems, where plants, pathogens, and BCAs interact within broader microbial communities. This review addresses the importance of understanding tripartite interactions among plants, pathogens, and yeasts, supported by integrated transcriptomic and comparative genomic approaches, as well as meticulous observations of phenotypic expressions to uncover strain-specific defense mechanisms and mode of action. By referring to well-studied models like Blumeria graminis f.sp. hordei–Hordeum vulgare–Pseudozyma flocculosa and Trichoderma tripartite systems, we highlight the underexplored potential of yeasts to modulate plant immunity and influence pathogen behavior through complex molecular crosstalk. Bridging these knowledge gaps through integrating proteomic, metabolomic, and transcriptomic analyses, we can better harness yeasts in sustainable and targeted biocontrol strategies. Full article

Postharvest blue mold in apples, caused by Penicillium expansum, leads to fruit decay and patulin (PAT) contamination, incurring major economic and health risks. This study developed a composite biocontrol agent (BCA) by co-cultivating three antagonistic yeasts (Meyerozyma caribbica, Metschnikowia zizyphicola, and Pichia rarassimilans). Mixed-culture conditions and protective additives formulation were optimized via response surface methodology. Optimal biomass production was achieved with a 1:2:3 (v/v/v) yeast ratio in medium containing sucrose (12.49 g/L), yeast extract powder (13.3 g/L), K₂HPO₄ (0.88 g/L), and NaCl (0.95 g/L) under pH 7.0, 1% total inoculum concentration, 24 °C, and a 60 h incubation. The liquid BCA formulation, stabilized with 0.27% gum arabic, 0.49% Tween-80, and 0.079% ascorbic acid, maintained high viability (9.15 log10 CFU/mL after 7 days). In vivo/in vitro trials all demonstrated that the composite BCA rapidly colonized, suppressed P. expansum infection, and significantly delayed pathogen spore germination and hyphal growth. Furthermore, the BCA effectively degraded 10 μg/mL PAT within 24–42 h in various fruit juices with minimal adverse effects on juice quality parameters. Storage at −20 °C preserved the highest bioactivity (7.93 × 10⁸ CFU/mL after 5 months). This optimized composite yeast formulation provides an efficient, eco-friendly strategy for integrated apple postharvest blue mold and PAT detoxification. Full article

Anastrepha fraterculus (Diptera: Tephritidae) is a major fruit pest in several countries of South America and is mass-reared for use in integrated pest control strategies, including the sterile insect technique (SIT), and as a host for rearing biocontrol agents. Optimizing these rearing protocols requires a deeper understanding of how larval diet impacts adult traits. This study investigated the effects of three larval diet formulations differing in nutrient composition on larval development and adult fitness traits. All diets contained inactive non-hydrolyzed brewer’s yeast and sucrose. Two of them included wheat germ, either alone (wheat germ diet) or combined with mashed carrot (carrot diet), whereas the corn flour diet did not contain wheat germ. The carrot diet produced the heaviest pupae, adults with longer wings, and the lowest rate of deformed adults. The corn flour diet prolonged larval and pupal development and increased adult lipid and carbohydrate content. Both the corn flour and carrot diets led to greater glycogen accumulation and more skewed weight distributions compared to the wheat germ diet. Present results highlight how larval diet composition determines developmental traits with direct consequences on adult physiology in A. fraterculus. These characteristics could enhance the effectiveness of control programs such as SIT and other biological control strategies. Full article

The increasing interest in natural preservatives has driven the search for effective microbial agents capable of controlling spoilage molds in cured meat products. In this study, the efficacy of Debaryomyces hansenii strains as biocontrol agents against spoilage molds in dry-cured meat products was evaluated through a dual experimental approach using both synthetic (PDA) and meat-derived media (LBM). While all D. hansenii strains demonstrated strong antifungal activity in nutrient-rich synthetic media, their performance in meat-like conditions was moderate to high, with significant differences depending on the mold species, the yeast strain, and their interaction with the culture medium. Our results highlight that antifungal efficacy is strongly influenced by the growth environment, underscoring the limitations of traditional in vitro assays that depend solely on synthetic media. Incorporating food-mimicking systems early in the screening process proved critical to identify strain–mold–medium combinations with the highest potential. These findings support the potential application of native D. hansenii strains as natural preservatives to enhance the safety and shelf life of dry-cured meats, emphasizing the importance of testing in conditions that closely resemble the target food environment to select the most effective biocontrol solutions. Full article

Cephus fumipennis, a significant pest of highland spring wheat, damages crops through larval boring and feeding within wheat stalks. This activity disrupts nutrient and water transport, causing severe yield reductions. To find microbial biocontrol agents targeting this pest, primary entomopathogenic microorganisms were isolated and identified from naturally infected, deceased C. fumipennis larvae. Morphological examination and ITS-based phylogenetic analysis tentatively identified the isolate as the entomopathogenic fungus Clonostachys sp. (strain CF01). Third-instar larvae of C. fumipennis were inoculated with conidial suspensions of the CF01 strain at concentrations of 1 × 10⁵, 1 × 10⁶, 1 × 10⁷, and 1 × 10⁸ spores/mL. Spore suspensions of different concentrations demonstrated pathogenicity against third-instar larvae of C. fumipennis. The optimal growth conditions for strain CF01 were identified as follows: PPDA medium, 25 °C, fructose as the carbon source, and yeast extract as the nitrogen source. Photoperiod exhibited no significant effect on either mycelial growth or sporulation. These findings indicate that the CF01 strain possesses considerable potential for the biocontrol of C. fumipennis. Full article

Plums are climacteric fruits with a short postharvest shelf-life, which makes them highly susceptible to spoilage by moulds and pathogens. Biological control using antagonistic yeasts offers a promising approach to extend shelf-life by inhibiting fungal growth. This study evaluated the effects of two yeast strains, Hanseniaspora uvarum L793 and Metschnikowia pulcherrima L672, on the quality of ‘Larry Ann’ Japanese plums during cold storage. Plums were divided into three batches: two treated by immersion in yeast suspensions (10⁸ cells mL⁻¹) and one untreated control. Quality parameters assessed over 12 weeks at 1 °C included weight loss, decay index, microbial counts, yeast colonisation, skin and flesh colour, texture, pH, titratable acidity, total soluble solids, and ripening index, with evaluations every week. M. pulcherrima L672 showed strong colonisation and persistence on the plum surface, significantly reducing skin damage and mould incidence. In contrast, H. uvarum L793 initially colonised well but declined over time, being replaced by native yeasts such as Aureobasidium spp. Both treatments maintained the physicochemical and organoleptic quality of the plums throughout storage. However, M. pulcherrima L672 was more effective in suppressing fungal growth and preserving fruit integrity. These findings suggest that M. pulcherrima L672 is a promising biocontrol agent for prolonging the shelf-life of Japanese plums during cold storage, maintaining their commercial quality for up to three months. Full article

Fruits and vegetables are essential for a healthy diet, providing vital nutrients and contributing to global food security. Fungal pathogens that interact with fruits and vegetables reduce their quality and shelf life and lead to economic losses and risks to human health through the production of mycotoxins. Chemical fungicides, used to control postharvest pathogens, are posing serious environmental and health risks, driving interest in safer alternative strategies. Biocontrol methods using antagonistic microbes, such as yeasts, are eco-friendly, sustainable, and the most promising, but they often have limited efficacy and specificity in diverse produce. There is growing interest in the innovative enhancement of biocontrol strategies. The present review shows that inducing, enhancing, co-application, encapsulation, and post-application treatments are common enhancement techniques, while environmental, host, and pathogen characteristics, antagonistic microbial traits, and chemical inputs are the major gearing factors for the best application methods. These methods do not involve genetic modification, which is adequate to reduce the proliferation of GMOs (Genetically Modified Organisms) while optimizing antagonistic microbial performance by promoting growth, inducing host resistance, enhancing antifungal properties, improving adhesion, and boosting stress tolerance. Most enhancers fall under groups of nutritional additives, protective carriers, growth stimulants, and encapsulants. Integrating these enhancers and best methods promises reduced postharvest losses, supports sustainable agriculture, and addresses economic losses and food security challenges. This study highlights the role of organic and natural elicitors, their application methods, their mechanisms in improving BCAs (Biological Control Agents), and their overall efficiency. This review concisely compiles recent strategies, calling for further research to revolutionize fungal pathogen management, reduce food waste, and promote responsible farming practices. Full article

Indigenous Mexican fermented beverages, such as pulque, colonche, tepache, and water kefir, are pillars of the country’s cultural and gastronomic heritage. Their sensory attributes and health-promoting properties arise from complex microbial consortia, in which lactic acid bacteria (LAB), mainly Lactobacillus and Leuconostoc, acetic acid bacteria (AAB), primarily Acetobacter, and yeasts such as Saccharomyces and Candida interact and secrete exopolysaccharides (EPSs). Dextran, levan, and heteropolysaccharides rich in glucose, galactose, and rhamnose have been consistently isolated from these beverages. EPSs produced by LAB enhance the viscosity and mouthfeel, extend the shelf life, and exhibit prebiotic, antioxidant, and immunomodulatory activities that support gut and immune health. Beyond food, certain EPSs promote plant growth, function as biocontrol agents against phytopathogens, and facilitate biofilm-based bioremediation, underscoring their biotechnological potential. This review integrates recent advances in the composition, biosynthetic pathways, and functional properties of microbial EPSs from Mexican fermented beverages. We compare reported titers, outline key enzymes, including dextransucrase, levansucrase, and glycosyltransferases, and examine how fermentation variables (the substrate, pH, and temperature) influence the polymer yield and structure. Finally, we highlight emerging applications that position these naturally occurring biopolymers as sustainable ingredients for food and agricultural innovation. Full article

Plant Parasitic Nematodes (PPNs) are a major problem in agriculture. Damage caused by PPNs has been estimated at USD 80–157 billion annually. The estimates could be even worse in the future in the context of a growing world population in a climate change scenario and with the removal/reduction in the use of some nematodicides due to the strong ecological impact. Biocontrol Agents (BCAs) currently constitute only 8.8% of the general pesticide market. With a view to an ecological transition, the transition from pesticides to biopesticides represents an important challenge that appears necessary not only for organic farming, but also in so-called integrated agriculture. Among the possible BCAs, microorganisms, and in particular yeast, which enjoys the GRAS (Generally Recognized As Safe) status, have the advantage of being able to be produced on a large scale by fermentation on waste substrates at low cost. In this paper, as proof of concept we constructed yeast strains expressing short hairpin RNAs (shRNAs) targeting the daf-16 gene in C. elegans. We demonstrate that oral ingestion of yeast cells expressing DAF16 shRNA is efficient in lowering daf-16 expression and lifespan, suggesting a sustainable RNA interference-based strategy to inhibit the development of PPNs. Full article

Biocontrol is one of the most promising alternatives to chemical preservatives for food preservation. This study investigated the biocontrol potential of yeasts isolated from raw milk cheese against spoilage moulds. Eighty-four native yeast strains were screened for antagonistic activity against Penicillium commune, Fusarium verticillioides, and Mucor plumbeus/racemosus via confrontation using a milk-based culture medium. Fifteen strains from the species Pichia jadinii, Kluyveromyces lactis, Kluyveromyces marxianus, and Geotrichum candidum exhibited significant antagonistic activity (inhibition zone > 2 mm) against M. plumbeus/racemosus and F. verticillioides. The modelling of the impact of ripening conditions revealed that temperature was the primary factor influencing yeast antagonism. In addition, notable variability at both species and strain levels was found. The antagonist activity was associated with different mechanisms depending on the species and strains. K. lactis stood out for its proteolytic activity and competition for iron and manganese. Additionally, two strains of this species (KL890 and KL904) were found to produce volatile organic compounds with antifungal properties (phenylethyl alcohol and 1-butanol-3-methyl propionate). G. candidum GC663 exhibited strong competition for space, as well as the ability to parasitise hyphae linked to its pectinase and β-glucanase activity. The latter enzymatic activity was detected in all P. jadinii strains, with P. jadinii PJ433 standing out due to its proteolytic activity. In a cheese matrix, the efficacy of eight yeast strains against three target moulds was assessed, highlighting the potential of G. candidum GC663 and P. jadinii PJ433 as biocontrol agents, exhibiting high and moderate efficacy, respectively, in controlling the growth of F. verticillioides and M. plumbeus/racemosus. Nonetheless, further research is necessary to elucidate their full spectrum of antifungal mechanisms and to validate their performance under industrial-scale conditions, including their impact on cheese quality. Full article

In this study, the dominant pathogenic fungus of gray spot disease in loquat, which was isolated from postharvest decaying loquat fruits in Zhenjiang, was identified as Pestalotiopsis vismiae (P. vismiae) by morphological characteristics and DNA sequencing. At the same time, a strain of yeast E1, which could effectively inhibit the pathogen, was isolated from the loquat leaves and soil and identified as Metschnikowia pulcherrima (M. pulcherrima) by morphological and molecular biological characteristics. It significantly reduced the natural decay of loquat fruits without affecting fruit quality. Metschnikowia pulcherrima E1 (M. pulcherrima E1) exhibited significant biocontrol efficacy against P. vismiae, the causal agent of gray spot in loquat, reducing disease incidence to 22.73% compared to 100% in the control group. Transcriptome analysis revealed 1444 differentially expressed genes (DEGs) (1111 upregulated, 333 downregulated), with key genes (CML19, XTH23, GSTU10) validated by RT-qPCR. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis highlighted enrichment in plant–pathogen interactions, glutathione metabolism, and phenylpropanoid biosynthesis. These findings provided molecular insights into yeast-induced resistance, bridging biocontrol applications with mechanistic studies. Full article

This study reports, for the first time, the successful application of chitosan oligosaccharide (COS) and 2-hydroxyethyl cellulose (HEC) coatings on electrospun poly(3-hydroxybutyrate) (PHB) materials for the immobilization of non-conventional yeast strains with fungal biocontrol potential. The coatings enhanced the surface wettability of PHB fibers, facilitating efficient yeast adhesion and viability maintenance. Among the tested strains, Pichia acaciae YD6 was newly isolated and characterized, while Pichia fermentans YP6 and Zygosaccharomyces bailii YE1 had previously been identified as endophytic colonizers. All three strains demonstrated high adaptability, efficient immobilization, and antagonistic activity, confirming their potential for biocontrol applications. COS-coated PHB fibers promoted greater colony expansion than those coated with HEC. Antifungal assays of the yeast-containing biocarriers showed significant inhibition of F. graminearum growth. These findings underscore the potential of PHB-based fibrous materials as sustainable, bioactive carriers for yeast immobilization, with desirable biological properties. This approach offers a promising and eco-friendly strategy for pest control and bioactive agent delivery in agricultural applications. Full article

Botryosphaeriaceae species were recently found to be responsible for heavy mango crop losses worldwide. In 2020, mango fruit samples showing fruit decay symptoms were collected from Glenn, Kent, Irwin, Palmer, Brokaw 2, and Gomera 3 accessions in 4 orchards located in Sicily (Italy). A molecular analysis of the ITS and tub2 regions performed on 41 representative isolates allowed for the identification of mainly Neofusicoccum parvum and occasionally Botryosphaeria dothidea (1/41) as the causal agents of fruit decay. Pathogenicity proofs were satisfied for both fungal pathogens. Ripe and unripe Gomera 3 mango fruits were used to compare the virulence among the N. parvum isolates. Postharvest experiments performed on Gomera 3 fruits and by using different biocontrol agents (BCAs) showed that the performance of treatments in reducing fruit decay depends on N. parvum virulence. The data show that unregistered Wickerhamomyces anomalus WA-2 and Pichia kluyveri PK-3, followed by the trade bioformulate Serenade™ (Bacillus amyloliquefaciens QST713), were the most effective in managing mango fruit rot. This paper shows, for the first time, the potential of different BCAs, including Trichoderma spp., for the controlling of postharvest decay caused by N. parvum on mango fruits. Full article

The escalating threats posed by plant pathogens and the environmental repercussions of conventional agrochemicals necessitate sustainable agricultural solutions. This review focuses on plant growth-promoting microorganisms (PGPMs) such as bacteria, filamentous fungi, and yeasts, which play a pivotal role as biocontrol agents. These organisms enhance plant growth and resilience through nutrient solubilization, phytohormone production, and antagonistic activities against pathogens, offering a dual benefit of disease suppression and growth enhancement. However, the effective application of PGPMs faces challenges, including variability in field performance, survival and colonization under field conditions, and regulatory hurdles. This paper discusses these challenges and explores recent advances in utilizing these bioagents in sustainable agriculture, underscoring the importance of integrated pest management systems that reduce chemical inputs, thus promoting ecological balance and sustainable farming practices. Full article

Enteric methane emissions from ruminants substantially contribute to global greenhouse gas emissions, necessitating effective mitigation strategies that also support animal productivity. This study assessed the efficacy of a multi-component feed additive that combines medium-chain fatty acids (MCFAs), live yeast, plant-based agents, and Vitamin B, in reducing methane emissions, improving feed efficiency, and enhancing growth and immune function in sheep. Twenty crossbred castrated male sheep (52 ± 3.7 kg) were divided into control and treatment groups (n = 10 each), with the treatment group receiving grass pellets supplemented with the multi-component feed additive (20 g/day) for 71 days, including a 30-day acclimatisation period. Feed intake, methane emissions, growth performance, and blood parameters were monitored using BioControl pens, GreenFeed units, and haematological analyses. The treatment group exhibited a 24% increase in daily feed intake (p < 0.001) and a 22.2% reduction in methane yield per kg of dry matter ingested (p < 0.001), which could be attributed to MCFAs’ anti-methanogenic properties and yeast’s rumen modulation. However, no significant improvements were observed in daily live weight gain, feed conversion efficiency, or immune parameters, suggesting limited energy utilisation for growth. These findings highlight this novel multi-component feed additive as a promising strategy for methane mitigation in forage-based systems. Further dosage optimisation and dietary integration could enhance its application across ruminant species, contributing to sustainable livestock production. Full article