Current status and future trends of microbial and nematode-based biopesticides for biocontrol of crop pathogens.

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.

Statistical Experimental Design as a New Approach to Optimize a Solid-State Fermentation Substrate for the Production of Spores and Bioactive Compounds from Trichoderma asperellum.

Managing organic agricultural wastes is a challenge in today's modern agriculture, where the production of different agricultural goods leads to the generation of large amounts of waste, for example, olive pomace and vine shoot in Mediterranean Europe. The discovery of a cost-effective and environment-friendly way to valorize such types of waste in Mediterranean Europe is encouraged by the European Union regulation. As an opportunity, organic agricultural waste could be used as culture media for solid-state fermentation (SSF) for fungal strains. This methodology represents a great opportunity to produce secondary metabolites like 6-pentyl-alpha-pyrone (6-PP), a lactone compound with antifungal properties against phytopathogens, produced by Trichoderma spp. Therefore, to reach adequate yields of 6-PP, lytic enzymes, and spores, optimization using specific agricultural cheap local wastes from Southeastern France is in order. The present study was designed to show the applicability of an experimental admixture design to find the optimal formulation that favors the production of 6-PP. To conclude, the optimized formulation of 6-PP production by Trichoderma under SSF contains 18% wheat bran, 23% potato flakes, 20% olive pomace, 14% olive oil, 24% oatmeal, and 40% vine shoots.

Using bibliometrics to analyze the state of art of pesticide use in vineyard agrosystems: a review.

The production of wine dates to ancient civilization and has heavily influenced different landscapes around the globe. Nowadays, wine is still an important sector in terms of land use and income source in many countries, more specifically in the European Mediterranean region. However, to control pests and regulate wine growth, the extensive use of pesticides is common. The effects and persistence of agrochemicals in the environment is well known and defined in scientific literature as well as the environmental and human health risks of these compounds. The purpose of this review was to do a state of art of worldwide production of academic literature using bibliometric principles and analysis to identify thematic areas of this type of agriculture, and its challenges in a changing world. For this review, the focus is on current practices to see what may evolve for more sustainable viticulture. It was found that the three main producers of wine, i.e., Spain, France, and Italy, are also three top producers of scientific literature on this topic. The use of bibliometric methodologies defined the main thematic areas on this subject as follows: soil-plant transfer of agrochemicals, heavy metal accumulation in vineyard soils, management practices in viticulture, water pollution transport, effects of viticulture on the living part of soil, sustainable alternatives to pesticides. We found that Spain, France, and Italy work the most on developing sustainable alternatives for agricultural practices; however, sustainable alternatives and practices were also the least developed thematic in general.

Biotechnological potential of Zymotis-2 bioreactor for the cultivation of filamentous fungi.

BACKGROUND/AIM: A new prototype of Solid-State Fermentation Bioreactor, namely "Zymotis-2 ", was developed to produce fungal spores. MAIN METHODS AND MAJOR RESULTS: A fermentation process for fungal spores, and hydrolase enzymes (endo and exoglucanases, amylases) production by Trichoderma asperellum DWG3, Aspergillus niger G131 and Beauveria bassiana was scaled-up from flasks and glass Raimbault column packed with 20 g of solid substrates (dry weight) to 5 kg of solid substrate by using the new Zymotis-2 bioreactor. Fungi strains growth using a mix of vine shoots, wheat bran, and olive pomace was tested under similar experimental conditions in Zymotis-2 bioreactor, column bioreactor and flasks in a parallel fermentation system. Overall, significant spore production on Zymotis-2 bioreactor was obtained, achieving 22.01 ± 0.01×109 spores/g DM 16.30 ± 0.07 × 109 spores/g DM, and 3.30 ± 0.07 × 109 spores/g DM for B. bassiana, T. asperellum DWG3, and A. niger G131, respectively. Forced aeration increased the endoglucanases, exoglucanases and amylases activities for T. asperellum DWG3 but B. bassiana and A. niger G131 were affected negatively by the aerated process, showing the lowest enzyme activities. CONCLUSIONS AND IMPLICATIONS: In conclusion, a high yield of spores was obtained at 137 h of cultivation time, confirming the validity of the new Zymotis-2 bioreactor to produce virulent spores at low cost by T. asperellum, B. bassiana and A. niger G131.

Statistical approach to evaluate effect of temperature and moisture content on the production of antioxidant naphtho-gamma-pyrones and hydroxycinnamic acids by Aspergillus tubingensis in solid-state fermentation.

Non-ochratoxigenic Aspergillus tubingensis G131 is a filamentous fungus that can produce naphtho-gamma-pyrones (NγPs), polyketide pigments that exhibit interesting antioxidant properties. This study aims to investigate the effect of two critical parameters, temperature and moisture content on the fungus grown in solid-state fermentation using agricultural by-products (vine shoots and wheat bran) as sole medium. From the kinetic productions of secondary metabolites NγPs (asperpyrone E, dianhydroaurasperone C, fonsecin, fonsecin B and ustilaginoidin A), alkaloids (nigragilin and aspernigrin A), degradation products from the solid medium (ß-D-glucose, p-coumaric acid and trans-ethyl ferulate), ergosterol and conidia obtained for different temperatures and moisture contents, a principal component analysis (PCA) was carried out to highlight the production patterns of these compounds. This approach allowed us to determine that fonsecin, the compound of higher interest-exhibiting the most interesting antiradical potential-is particularly more produced at 25 °C and 66% of moisture content. This study underlines the importance of temperature and moisture content on naphtho-gamma-pyrones and hydroxycinnamic acid production using solid-state fermentation and contributes to the development of agroindustrial by-product valorization.

Naphtho-Gamma-Pyrones Produced by Aspergillus tubingensis G131: New Source of Natural Nontoxic Antioxidants.

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.