The increasing public demand to avoid the use of synthetic pesticides and fertilizers in agricultural production systems, causing serious environmental damages, has challenged industry to develop new and effective solutions to manage and control phytopathogens. Biopesticides, particularly microbial-based biopesticides, are a promising new alternative with high biodegradability, specificity, suitability for incorporation into integrated pest management practices, low likelihood of resistance development, and practically no known human health risks. However: expensive production methods, narrow action spectra, susceptibility to environmental conditions, short shelf life, poor storage stability, legislation registry constraints, and general lack of knowledge are slowing down their adoption. In addition to regulatory framework revisions and improved training initiatives, improved preservation methods, thoughtfully designed formulations, and field test validations are needed to offer new microbial- and nematode-based biopesticides with improved efficacy and increased shelf-life. During the last several years, substantial advancements in biopesticide production have been developed. The novelty part of this review written in 2023 is to summarize (i) mechanisms of action of beneficial microorganisms used to increase crop performance and (ii) successful formulation including commercial products for the biological control of phytopathogens based on microorganisms, nematode and/or metabolites.

The polyketide, 6-pentyl-alpha-pyrone (6-PP), has a characteristic coconut aroma and is produced by many Trichoderma species. In this study, we screened formerly isolated Trichoderma strains for 6-PP production grown using solid-state fermentation (SSF). Sugarcane bagasse supplemented with a nutrient solution was used as the support material for the culture. We detected outstandingly strong 6-PP production in the case of two Trichoderma strains in this experiment. The strains were identified based on internal transcribed spacer (ITS) sequence analysis as Trichoderma asperellum (G7 and G18). We also investigated the production of 6-PP in the case of the best Trichoderma strain selected (T. asperellum G7) from two types of cultivation (SSF and liquid cultivation (LC)). The same liquid medium was used to impregnate sugarcane bagasse. Results led to a 6-PP production 80 times higher (85.11 μg·g·DM−1) in SSF than that found in LC (10.00 μg·L−1) after eight days of cultivation. For this, the SSF is the best option to produce 6-PP compared to liquid cultures.

In recent years, the production of biopesticides has gained great attention in the scientific word because it is an important alternative to replace the much debated chemical pesticides used on the field crops. Fungal lytic enzymes, conidia and secondary metabolites like 6 pentyl-alpha-pyrone (6-PP) play a very important role in the biological control of pests. On the present study, the influence of application of air through a solid-state fermentation using threeTrichoderma asperellumstrains to produce conidia, 6-PP and essential enzymes were evaluated. A mix of vine shoots, potatoes flour, jatropha, olive pomace and olive oil as substrates was used.T. asperellumTV104 showed the best 6-PP production (3.06 ± 0.15 mg g DM⁻¹), cellulases activities (34.3 ± 0.4 U g⁻¹), and amylase activity (46.3 ± 0.6 U g⁻¹) however,T. asperellumTF1 produced the higher levels of lipase (30.6 ± 0.3 U g⁻¹), under air conditions. The production of these same enzymes was less efficient without the application of forced aeration. The forced aeration increased the conidia production, the best value was observed withT. asperellumTF1 (2.23 ± 0.07 × 10⁹ g DM⁻¹).Graphic Abstract

Seven naphtho-gamma-pyrones (NγPs), including asperpyrone E, aurasperone A, dianhydroaurasperone C, fonsecin, fonsecinone A, fonsecin B, and ustilaginoidin A, were isolated from Aspergillus tubingensis G131, a non-toxigenic strain. The radical scavenging activity of these NγPs was evaluated using ABTS assay. The Trolox equivalent antioxidant capacity on the seven isolated NγPs ranged from 2.4 to 14.6 μmol L⁻¹. The toxicity and ability of the NγPs to prevent H₂O₂-mediated cell death were evaluated using normal/not cancerous cells (CHO cells). This cell-based assay showed that NγPs: (1) Are not toxic or weakly toxic towards cells and (2) are able to protect cells from oxidant injuries with an IC₅₀ on H₂O₂-mediated cell death ranging from 2.25 to 1800 μmol mL⁻¹. Our data show that A. tubingensis G131 strain is able to produce various NγPs possessing strong antioxidant activities and low toxicities, making this strain a good candidate for antioxidant applications in food and cosmetic industries.