Non-Volatile Metabolites from Trichoderma spp

Efficacy of entomopathogenic fungi against Philaenus spumarius, the vector of Xylella fastidosa

BACKGROUND

Xylella fastidiosa is an important causative agent of Olive Quick Decline Syndrome in the Apulia region of Italy. The current study evaluated the bioefficacy of three entomopathogenic fungal strains: Beauveria bassiana SGB7004, Metarhizium robertsii SGB1K, and Akanthomyces lecanii SGB4711 against Philaenus spumarius the main vector of this pathogen, under laboratory conditions. Pathogenicity bioassays were performed by dipping nymphs and adults of P. spumarius in an aqueous suspension of powdered fungal culture (PFC) or conidial suspension (CS) of the three fungal strains.

RESULTS

Both B. bassiana SGB7004 and M. robertsii SGB1K affected the viability of nymphs, resulting in more than 80% mortality at 48 h post treatment, while the effect of A. lecanii SGB4711 was not statistically significant. On adults, all three biocontrol strains were effective in a time- and concentration-dependent manner. The PFCs of B. bassiana SGB7004, M. robertsii SGB1K, and A. lecanii SGB4711 at the highest concentration tested (120 mg mL-1) resulted in 97%, 83% and 27% mortality at the trial endpoint (120 h), respectively. Mycelial growth was observed on 38.5%, 37.0% and 61.5% of dead insects treated with B. bassiana SGB7004 (2.3 × 108 CFU mL-1), M. robertsii SGB1K (3.8 × 106 CFU mL-1) and A. lecanii SGB4711 (5.4 × 108 CFU mL-1), respectively. None of the PFCs of the tested strains was pathogenic when injected into nymph spittle.

CONCLUSIONS

Beauveria bassiana SGB7004 and M. robertsii SGB1K significantly affected the survival of P. spumarius nymphs and adults, while A. lecanii SGB4711 was not effective on nymphs and only slightly effective against adults. © 2024 Society of Chemical Industry.

Mycoproteins and their health-promoting properties: Fusarium species and beyond

Filamentous fungal mycoproteins have gained increasing attention as sustainable alternatives to animal and plant-based proteins. This comprehensive review summarizes the nutritional characteristics, toxicological aspects, and health-promoting effects of mycoproteins, focusing on those derived from filamentous fungi, notably Fusarium venenatum. Mycoproteins are characterized by their high protein content, and they have a superior essential amino acid profile compared to soybeans indicating excellent protein quality and benefits for human nutrition. Additionally, mycoproteins offer enhanced digestibility, further highlighting their suitability as a protein source. Furthermore, mycoproteins are rich in dietary fibers, which have been associated with health benefits, including protection against metabolic diseases. Moreover, their fatty acids profile, with significant proportions of polyunsaturated fatty acids and absence of cholesterol, distinguishes them from animal-derived proteins. In conclusion, the future of mycoproteins as a health-promoting protein alternative and the development of functional foods relies on several key aspects. These include improving the acceptance of mycoproteins, conducting further research into their mechanisms of action, addressing consumer preferences and perceptions, and ensuring safety and regulatory compliance. To fully unlock the potential of mycoproteins and meet the evolving needs of a health-conscious society, continuous interdisciplinary research, collaboration among stakeholders, and proactive engagement with consumers will be vital.

Wheat rhizosphere dynamics of Trichoderma gamsii A5MH and suppression of a Pythium root rot-Fusarium crown rot disease complex over two consecutive cropping seasons

AIMS

Determine the wheat rhizosphere competence of Trichoderma gamsii strain A5MH and in planta suppression of the Pythium root and Fusarium crown rot pathogens Globisporangium irregulare and Fusarium pseudograminearum.

METHODS AND RESULTS

Wheat was continuously cropped (eight years) at a minimum tillage, low growing season rainfall (GSR ≤ 170 mm) site shown as highly conducive to Pythium root and Fusarium crown rots. Root isolation frequency (RIF) and qPCR were used to determine the rhizosphere dynamics of strain A5MH and the target pathogens at tillering, grain harvest, and in postharvest stubble over the final 2 years. Strain A5MH actively colonized the wheat rhizosphere throughout both growing seasons, had high root abundance at harvest [log 4.5 genome copies (GC) g-1] and persisted in standing stubble for at least 293-d postinoculation. Globisporangium irregulare was most abundant in roots at tillering, whereas F. pseudograminearum was only abundant at harvest and up to 9-fold greater in the drier, second year (GSR 105 mm). Strain A5MH decreased RIF of both pathogens by up to 40%, root abundance of G. irregulare by 100-fold, and F. pseudogaminearum by 700-fold, but was ineffective against crown rot in the second year when pathogen abundance was >log 6.0 GC g-1 root. Strain A5MH increased crop emergence and tillering biomass by up to 40%.

CONCLUSIONS

Further trials are required to determine if the A5MH-induced pathogen suppression translates to yield improvements in higher rainfall regions where non-cereal rotations reduce crown rot inoculum.

Chemistry and biology of marine-derived Trichoderma metabolites

Marine-derived fungi of the genus Trichoderma have been surveyed for pharmaceuticals and agrochemicals since 1993, with various new secondary metabolites being characterized from the strains of marine animal, plant, sediment, and water origin. Chemical structures and biological activities of these metabolites are comprehensively reviewed herein up to the end of 2022 (covering 30 years). More than 70 strains that belong to at least 18 known Trichoderma species have been chemically investigated during this period. As a result, 445 new metabolites, including terpenes, steroids, polyketides, peptides, alkaloids, and others, have been identified, with over a half possessing antimicroalgal, zooplankton-toxic, antibacterial, antifungal, cytotoxic, anti-inflammatory, and other activities. The research is highlighted by the molecular diversity and antimicroalgal potency of terpenes and steroids. In addition, metabolic relevance along with co-culture induction in the production of new compounds is also concluded. Trichoderma strains of marine origin can transform and degrade heterogeneous molecules, but these functions need further exploration.

Two new acorane-type sesquiterpenoids from an endophytic Trichoderma harzianum associated with Paeonia lactiflora Pall

Two new acorane-type sesquiterpenoids, harzianes A and B (1 and 2), together with two known cyclonerodiol-type sesquiterpenoids (3-4) and four known sterols (5-8) were isolated from the endophytic Trichoderma harzianum, associated with the medicinal plant Paeonia lactiflora Pall. Compounds 1 and 2 were identified as a pair of heterotropic isomers by spectroscopic analysis (HR-ESI-MS, 1D and 2D NMR), and their absolute configurations were determined by ECD calculations. All compounds were tested for anti-inflammatory activity, however, none demonstrated such activity.

Koningipyridines A and B, two nitrogen-containing polyketides from the fungus Trichoderma koningiopsis SC-5

Two novel koninginin derivatives, koningipyridines A and B (1 and 2), along with four known compounds (3-6) were isolated from the EtOAc extract of the endophytic fungus Trichoderma koningiopsis SC-5. Among them, koningipyridine A featured an unprecedented pentacyclic ketal skeleton with the formation of a fascinating 6/6/5/6/5 fused ring system and shared a characteristic pyridine core, which represents the first example of nitrogen-containing koninginin-type natural product. Moreover, koningipyridine B was the first member in the koninginin family sharing a unique 6/6/5 dihydropyridine skeleton, and it was suggested to be the critical biosynthetic precursor of koningipyridine A. The structures of 1 and 2 were elucidated by the interpretation of 1D and 2D NMR spectroscopy, HRESIMS data, as well as theoretical calculations of 13C NMR and electronic circular dichroism (ECD). Moreover, all isolates were screened for antimicrobial activities against Staphylococcus aureus, MRSA, and Escherichia coli as well as the cytotoxic effects against three cancer cell lines (A549, Hela, and HepG2).

Isolation and selection of autochthonous strains of Trichoderma spp. with inhibitory activity against Sporisorium reilianum

Head smut is a worldwide disease caused by the fungus Sporisorium reilianum. In Mexico, this phytosanitary problem has been described in the central part of the country, specifically in the Mezquital Valley in the state of Hidalgo, where this basidiomycete causes significant economic losses. In this work, seven strains of Trichoderma spp. were isolated from corn rhizospheres collected from crops in the affected zone. The isolates were identified as Trichoderma asperellum MH1, T. asperellum T4H1, T. harzianum T1H1, T. harzianum T1H3, T. atrobrunneum T1H2, T. tomentosum T2H4, and T. brevicompactum T3H1. All strains showed the ability to grow on the phytopathogen but with distinct degrees of mycoparasitism. SEM observations demonstrated the ability of T. asperellum T4H1 to invade the S. reilianum yeast growth. All the strains produced volatile compounds with antifungal activity. With the exception of T. asperellum MH1, all strains inhibited the development of the pathogen by means of non-volatile compounds. Production of the extracellular enzymes (lipase, cellulase, chitinase, protease, and laccase) was evaluated, with most strains presenting high lipolytic activity and low proteolytic activity. The production of cellulase and chitinase was observed only in five strains. Laccase production was found in three isolates. Evaluations at the greenhouse of the sequential application of three mixtures of the isolates were conducted in a greenhouse; findings showed that the phytopathogen was not detected by specific PCR in the plants that received the treatment.

Proteomics analysis of resistance mechanism of Trichoderma harzianum under U(VI) stress

Trichoderma harzianum has a certain resistance to Hexavalent Uranium (U(VI)), but its resistance mechanism is unknown. Based on proteomics sequencing using DIA mode, differentially expressed proteins (DEPs) of Trichoderma harzianum under U(VI) stress were identified. GO enrichment, KEGG annotation analysis and DEPs annotation were performed. The results showed that 8 DEPs, 8 DEPs and 15 DEPs were obtained in the low-dose, medium-dose and high-dose groups, respectively. The functional classification of GO demonstrated that DEPs were associated with 17 molecular functions, 5 biological processes, and 5 cellular components. Furthermore, DEPs were enriched in transport and catabolism, energy metabolism, translation, and signal transduction. These findings showed that Trichoderma harzianum was significantly changed in protein expression and signaling pathway after U(VI) exposure. Therefore, these results have provided Trichoderma harzianum with a theoretical background that can be applied to environmental cleanup.

Koninginins X-Z, Three New Polyketides from Trichoderma koningiopsis SC-5

Koninginins X-Z (1-3), three novel polyketides, were isolated from the solid fermentation of the endophytic fungus Trichoderma koningiopsis SC-5. Their structures, including the absolute configurations, were comprehensively characterized by a combination of NMR spectroscopic methods, HRESIMS, 13C NMR, DFT GIAO 13C NMR, and electronic circular dichroism calculations as well as single crystal X-ray diffraction. In addition, all the compounds were evaluated for antifungal activity against Candida albicans.

Structures and Biological Activities of Secondary Metabolites from the Trichoderma genus (Covering 2018-2022)

Trichoderma, a genus with more than 400 species, has a long history of use as an industrial bioreactor, biofertilizer, and biocontrol agent. It is considered a significant source of secondary metabolites (SMs) that possess unique structural features and a wide range of bioactivities. In recent years, numerous secondary metabolites of Trichoderma, including terpenoids, polyketides, peptides, alkaloids, and steroids, have been identified. Most of these SMs displayed antimicrobial, cytotoxic, and antifungal effects. This review focuses on the structural diversity, biological activities, and structure-activity relationships (SARs) of the SMs isolated from Trichoderma covered from 2018 to 2022. This study provides insights into the exploration and utilization of bioactive compounds from Trichoderma species in the agriculture or pharmaceutical industry.

Biocontrol Potential of Trichoderma asperellum Strain 576 against Exserohilum turcicum in Zea mays

Maize is a crucial cereal crop in China, serving both as a staple food and an essential industrial resource. Northern corn leaf blight (NCLB) is a disease of corn caused by a fungus, Exserohilum turcicum (sexual stage Setosphaeria turcica). This study aimed to assess the biocontrol potential of various Trichoderma strains against Exserohilum turcicum 101 in Jilin, China. Through dual culture tests, the Trichoderma strains were categorized into four groups based on their antagonistic abilities. Eleven Trichoderma strains exhibited strong antagonistic behavior, with comparable or faster growth rates than E. turcicum 101. Microscopic observations confirmed that T. asperellum 576 hyphae effectively encircled E. turcicum 101 hyphae, reinforcing their antagonistic behavior. The production of non-volatile and volatile substances by the Trichoderma strains was evaluated, with T. asperellum 576 showing the highest potency in producing non-volatile and volatile substances, leading to an impressive 80.81% and 65.86% inhibition of E. turcicum 101 growth. Remarkably, co-culture suspensions of T. asperellum 576 + E. turcicum 101 and T. atroviride 393 + E. turcicum 101 exhibited strong antifungal activity. Furthermore, the activities of chitinase, β-1.3-glucanase, and cellulase were evaluated using the 3, 5-dinitrosalicylic acid (DNS) method. T. asperellum 576 + E. turcicum 101 displayed stronger cell wall degradation enzyme activity compared to T. atroviride 393 + E. turcicum 101, with values of 8.34 U/mL, 3.42 U/mL, and 7.75 U/mL, respectively. In greenhouse conditions, the application of a 107 spores/mL conidia suspension of T. asperellum 576 significantly enhanced maize seed germination and plant growth while effectively suppressing E. turcicum 101 infection. Maize seedlings inoculated/treated with both E. turcicum 101 and T. asperellum 576 demonstrated substantial improvements compared to those inoculated solely with E. turcicum 101. The T. asperellum 576 treatment involved a 107 spores/mL conidia suspension applied through a combination of foliar spray and soil drench. These findings highlight T. asperellum 576 as a promising biocontrol candidate against northern leaf blight in maize. Its antagonistic behavior, production of inhibitory compounds, and promotion of plant growth all contribute to its potential as an effective biocontrol agent for disease management.

Assessment of Biochemical and Neuroactivities of Cultural Filtrate from Trichoderma harzianum in Adjusting Electrolytes and Neurotransmitters in Hippocampus of Epileptic Rats

BACKGROUND

Epilepsy is a serious chronic neurological disorder, which is accompanied by recurrent seizures. Repeated seizures cause physical injuries and neuronal dysfunction and may be a risk of cancer and vascular diseases. However, many antiepileptic drugs (AEDs) have side effects of mood alteration or neurocognitive function, a reduction in neuron excitation, and the inhibition of normal activity. Therefore, the present study aimed to evaluate the effect of secondary metabolites of Trichoderma harzianum cultural filtrate (ThCF) when adjusting different electrolytes and neurotransmitters in the hippocampus of epileptic rats.

METHODS

Cytotoxicity of ThCF against LS-174T cancer cells was assessed using a sulforhodamine B (SRB) assay. Quantitative estimation for some neurotransmitters, electrolytes in sera or homogenate of hippocampi tissues, and mRNA gene expression for ion or voltage gates was assessed by quantitative Real-Time PCR.

RESULTS

Treatment with ThCF reduces the proliferative percentage of LS-174T cells in a concentration-dependent manner. ThCF administration improves hyponatremia, hyperkalemia, and hypocalcemia in the sera of the epilepticus model. ThCF rebalances the elevated levels of many neurotransmitters and reduces the release of GABA and acetylcholine-esterase. Also, treatments with ThCF ameliorate the downregulation of mRNA gene expression for some gate receptors in hippocampal homogenate tissues and recorded a highly significant elevation in the expression of SCN1A, CACNA1S, and NMDA.

CONCLUSION

Secondary metabolites of Trichoderma (ThCF) have cytotoxic activity against LS-174T (colorectal cancer cell line) and anxiolytic-like activity through a GABAergic mechanism of action and an increase in GABA as inhibitory amino acid in the selected brain regions and reduced levels of NMDA and DOPA. The present data suggested that ThCF may inhibit intracellular calcium accumulation by triggering the NAADP-mediated Ca2+ signaling pathway. Therefore, the present results suggested further studies on the molecular pathway for each metabolite of ThCF, e.g., 6-pentyl-α-pyrone (6-PP), harzianic acid (HA), and hydrophobin, as an alternative drug to mitigate the side effects of AEDs.

Trichoderols B-G, Six New Lipids from the Marine Algicolous Fungus Trichoderma sp. Z43

Six new lipids, trichoderols B-G (1-6), along with a known one, triharzianin B (7), were isolated from the culture of Trichoderma sp. Z43 obtained from the surface of the marine brown alga Dictyopteris divaricata. Their structures and relative configurations were identified by interpretation of 1D/2D NMR and MS data. Compounds 1-7 were assayed for inhibiting the growth of three phytopathogenic fungi (Fusarium graminearum, Gaeumannomyces graminis, and Glomerella cingulata), four marine phytoplankton species (Amphidinium carterae, Heterocapsa circularisquama, Heterosigma akashiwo, and Prorocentrum donghaiense), and one marine zooplankton (Artemia salina). Compounds 1, 4, and 7 exhibited weak antifungal activities against three phytopathogenic fungi tested with MIC ≥ 64 μg/mL. All compounds displayed moderate antimicroalgal activity with IC50 ≥ 15 μg/mL and low toxicity to the brine shrimp Artemia salina.

Chemical Characterization of Trichoderma spp. Extracts with Antifungal Activity against Cocoa Pathogens

Ecuador is one of the major cocoa producers worldwide, but its productivity has lately been affected by diseases. Endophytic biocontrol agents have been used to minimize pathogenic effects; however, compounds produced by endophytes are minimally understood. This work presents the chemical characterization of the Trichoderma species extracts that proved inhibition against cocoa pathogens. Solid-liquid extraction was performed as a partitioning method using medium with the fungal mycelia of Trichoderma reesei (C2A), Trichoderma sp. (C3A), Trichoderma harzianum (C4A), and Trichoderma spirale (C10) in ethyl acetate individually. The extract of T. spirale (C10) exhibited the growth inhibition (32.97-47.02%) of Moniliophthora perniciosa at 10 µg/mL, while a slight stimulation of Moniliophthora roreri was shown by the extracts of T. reesei (C2A) and T. harzianum (C4A) at higher concentrations. The inhibitory activity could be related to alkaloids, lactones, quinones, flavonoids, triterpenes, and sterols, as indicated by chemical screening and antifungal compounds, such as widdrol, β-caryophyllene, tyrosol, butyl isobutyrate, sorbic acid, palmitic acid, palmitelaidic acid, linoleic acid, and oleic acid, which were identified by gas chromatography-mass spectrometry (GC-MS). The results showed that the extracts, particularly T. spirale (C10), have the potential as biocontrol agents against witches' broom disease; however, further studies are needed to confirm their effectiveness.

Biocontrol of Diseases Caused by Phytophthora capsici and P. parasitica in Pepper Plants

The main objective of this study was to evaluate the ability of Trichoderma aggressivum f. europaeum, T. longibrachiatum, Paecilomyces variotii, and T. saturnisporum as biological control agents (BCAs) against diseases caused by P. capsici and P. parasitica in pepper. For this purpose, their antagonistic activities were evaluated both in vitro and in vivo. We analysed the expression patterns of five defence related genes, CaBGLU, CaRGA1, CaBPR1, CaPTI1, and CaSAR8.2, in leaves. All BCAs showed a high in vitro antagonistic activity, significantly reducing the mycelial growth of P. capsici and P. parasitica. The treatments with T. aggressivum f. europaeum, T. longibrachiatum, and P. variotii substantially reduced the severity of the disease caused by P. capsici by 54, 76, and 70%, respectively, and of the disease caused by P. parasitica by 66, 55, and 64%, respectively. T. saturnisporum had the lowest values of disease reduction. Reinoculation with the four BCAs increased the control of both plant pathogens. Markedly different expression patterns were observed in the genes CaBGLU, CaRGA1, and CaSAR8.2. Based on the results, all four BCAs under study could be used as a biological alternative to chemicals for the control of P. capsici and P. parasitica in pepper with a high success rate.

Two new octahydronaphthalene derivatives, trichodermic acids C and D produced by Trichoderma sp. HN-1.1

Two new octahydronaphthalene derivatives, trichodermic acid C (1) and trichodermic acid D (2), along with known analogs, trichodermic acid (3), trichodermic acid A (4) and trichodermic acid B (5), were isolated from an ethyl acetate extract of endophytic strain Trichoderma sp. HN-1.1. The structures of compounds 1 and 2 were elucidated using spectroscopic methods including UV, IR, HRESITOFMS, ECD, 1 D and 2 D NMR. The cytotoxic activity of the isolated compounds was evaluated on the rat hepatoma cell line H4IIE, using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. According to the results, only compound 3 showed a significant reduction of H4IIE cells from 75 to 21% (p < 0.01) with an IC₅₀ value of 50% cell survival estimated as 143.1 µM, which indicated weak cytotoxic activity.

Trichoderma Species: Our Best Fungal Allies in the Biocontrol of Plant Diseases-A Review

Biocontrol agents (BCA) have been an important tool in agriculture to prevent crop losses due to plant pathogens infections and to increase plant food production globally, diminishing the necessity for chemical pesticides and fertilizers and offering a more sustainable and environmentally friendly option. Fungi from the genus Trichoderma are among the most used and studied microorganisms as BCA due to the variety of biocontrol traits, such as parasitism, antibiosis, secondary metabolites (SM) production, and plant defense system induction. Several Trichoderma species are well-known mycoparasites. However, some of those species can antagonize other organisms such as nematodes and plant pests, making this fungus a very versatile BCA. Trichoderma has been used in agriculture as part of innovative bioformulations, either just Trichoderma species or in combination with other plant-beneficial microbes, such as plant growth-promoting bacteria (PGPB). Here, we review the most recent literature regarding the biocontrol studies about six of the most used Trichoderma species, T. atroviride, T. harzianum, T. asperellum, T. virens, T. longibrachiatum, and T. viride, highlighting their biocontrol traits and the use of these fungal genera in Trichoderma-based formulations to control or prevent plant diseases, and their importance as a substitute for chemical pesticides and fertilizers.

Deep Genotypic Species Delimitation of Aspergillus Section Flavi Isolated from Brazilian Foodstuffs and the Description of Aspergillus annui sp. nov. and Aspergillus saccharicola sp. nov

Aspergillus section Flavi is a fungal group that is important in food because it contains spoilage and potentially aflatoxigenic species. Aflatoxins are metabolites that are harmful to human and animal health and have been recognized as the primary natural contaminant in food. Therefore, recognizing the biodiversity of this group in food is necessary to reduce risks to public health. Our study aimed to investigate the diversity of Aspergillus section Flavi isolated from Brazilian foodstuffs such as cassava, sugarcane, black pepper, paprika, Brazil nuts, yerba-mate, peanuts, rice, and corn. A polyphasic approach integrating phenotypic data and multilocus genotypic analyses (CaM, BenA, and RPB2) was performed for 396 strains. Two new species in the Aspergillus subgenus Circumdati section Flavi are proposed using maximum-likelihood analysis, Bayesian inference, and coalescence-based methods: Aspergillus saccharicola sp. nov. and Aspergillus annui sp. nov. A. saccharicola sp. nov. belongs to the series Flavi, is a potentially aflatoxigenic species (B1, B2, G1, and G2), closely related to Aspergillus arachidicola, and was found mostly in sugarcane. A. annui sp. nov. was isolated from samples of sweet paprika. To accommodate A. annui sp. nov., a new series Annuorum was proposed.

New Insights into the Mechanism of Trichoderma virens-Induced Developmental Effects on Agrostis stolonifera Disease Resistance against Dollar Spot Infection

Trichoderma is internationally recognized as a biocontrol fungus for its broad-spectrum antimicrobial activity. Intriguingly, the crosstalk mechanism between the plant and Trichoderma is dynamic, depending on the Trichoderma strains and the plant species. In our previous study, the Trichoderma virens 192-45 strain showed better pathogen inhibition through the secretive non-volatile and volatile substrates. Therefore, we studied transcriptional and metabolic responses altered in creeping bentgrass (Agrostis stolonifera L.) with T. virens colonization prior to a challenge with Clarireedia homoeocarpa. This fungal pathogen causes dollar spot on various turfgrasses. When the pathogen is deficient, the importance of T. virens to the enhancement of plant growth can be seen in hormonal production and microbe signaling, such as indole-3-acrylic acid. Therefore, these substrates secreted by T. virens and induced genes related to plant growth can be the ‘pre-defense’ for ensuing pathogen attacks. During C. homoeocarpa infection, the Trichoderma–plant interaction activates defense responses through the SA- and/or JA-dependent pathway, induced by T. virens and its respective exudates, such as oleic, citric, and stearic acid. Thus, we will anticipate a combination of genetic engineering and exogenous application targeting these genes and metabolites, which could make creeping bentgrass more resistant to dollar spot and other pathogens.

Antibiofilm properties of bioactive compounds from Actinomycetes against foodborne and fish pathogens

In nature, bacteria can form biofilms, multi-layered structures that adhere microbial populations to solid surfaces by exopolysaccharides, proteins, and nucleic acids. In addition to causing foodborne infections, biofilms can be a major problem in aquaculture. Actinomycetes extracts have previously demonstrated antibiofilm activity against multiple foodborne and fish pathogens, and further characterization of these extracts is needed. In this study, we identified the chemical structures and antibiofilm properties of four extracts and determined the genetic similarity of the isolates to known Streptomyces isolates. We found that several extracts contained multiple antibiofilm compounds, and the antibiofilm activities of all extracts were most stable at pH 6. Furthermore, the antibiofilm inhibition and destruction activities of the isolates were stable at different temperatures. All of crude extracts demonstrated activity against biofilms formed by foodborne and fish pathogens on the surface of stainless-steel coupons as well as polystyrene that commonly used in industrial equipment. Using PCR 16S-rRNA gene and DNA sequencing analysis, the four Actinomycetes isolates were found to be 99% (1 AC), 97% (20 PM), 95% (16 PM), and 85% (18 PM) similar to Streptomyces. Biofilm structure were analyzed using Scanning Electron Microscopy coupled with Energy-Dispersive Spectrometry analysis. Coniine/(S)-2-propylpiperidine was the most active fraction of the crude extracts of the 1 AC, 20 PM, and 16 PM isolates, and piperidine, 2-(tetrahydro-2-furanyl) was most active in the 18 PM isolate.

Potential biocontrol efficiency of Trichoderma species against oomycete pathogens

Plant health is of utmost importance for optimal agricultural production and sustainability. Unfortunately, biotic and abiotic factors put a major constraint on crop safety and productivity. Plant diseases caused by oomycetes inflict serious damage to various crops. Moreover, the injudicious use of chemical pesticides poses threats related to pesticide resistance development in pathogens and environmental pollution. Biocontrol offers an effective solution for disease control; however, research on biocontrol of oomycete-related diseases is scarce. Thus, this study undertakes the screening of biocontrol resources for the effective management of oomycete-related plant diseases. In this regard, 86 isolates of Trichoderma spp. were assessed against Phytophthora nicotianae, P. capsici, Pythium vexans, P. ultimum, and P. dissotocum through dual culture assay. Furthermore, the antagonistic effect of selected isolates was studied against tobacco black shank disease and damping-off of cucumber seedlings in the greenhouse. The relative control effect of the three antagonistic Trichoderma strains AR-4, Tv-1, and ST4-1 on tobacco black shank was more than 60%, which was not significantly different from 6.88 gl⁻¹ fluopicolide–propamocarb. Whereas, the relative control effect of Trichoderma AR-4 and ST4-1 on damping-off of cucumber seedlings was 80.33% and 82.67%, respectively, which were significantly higher than Trichoderma Tv-1 (35.49%) and fluopicolide–propamocarb (47.82%). According to the morphological and molecular characterization, the fungal strains AR-4, Tv-1, and ST4-1 were identified as Trichoderma koningiopsis, T. asperellum, and T. gamsii, respectively. In conclusion, the strains exhibited a strong antagonistic effect against oomycete pathogens and can be integrated into disease management strategies.

β-Carboline Alkaloids From the Deep-Sea Fungus Trichoderma sp. MCCC 3A01244 as a New Type of Anti-pulmonary Fibrosis Agent That Inhibits TGF-β/Smad Signaling Pathway

Pulmonary fibrosis is a scarring disease of lung tissue, which seriously threatens human health. Treatment options are currently limited, and effective strategies are still lacking. In the present study, 25 compounds were isolated from the deep-sea fungus Trichoderma sp. MCCC 3A01244. Among them, two β-carboline alkaloids, trichocarbolines A (1) and C (4) are new compounds. The chemical structures of these compounds were elucidated based on their HRESIMS, 1D and 2D NMR spectra, optical rotation calculation, and comparisons with data reported in the literature. Trichocarboline B [(+)- and (–)-enantiomers] had previously been synthesized, and this is its first report as a natural product. Their anti-pulmonary fibrosis (PF) activity and cytotoxicity were investigated. Compounds 1, 11, and 13 strongly inhibited TGF-β1-induced total collagen accumulation and showed low cytotoxicity against the HFL1 cell line. Further studies revealed compound 1 inhibited extracellular matrix (ECM) deposition by downregulating the expression of protein fibronectin (FN), proliferating cell nuclear antigen (PCNA), and α-smooth muscle actin (α-SMA). Mechanistic study revealed that compound 1 decreased pulmonary fibrosis by inhibiting the TGF-β/Smad signaling pathway. As a newly identified β-carboline alkaloid, compound 1 may be used as a lead compound for developing more efficient anti-pulmonary fibrosis agents.

Trichoderma-derived pentapeptides from the infected nest mycobiome of the subterranean termite Coptotermes testaceus

Termites live in a dynamic environment where colony health is strongly influenced by surrounding microbes. However, little is known about the mycobiomes of lower termites and their nests, and how these change in response to disease. Here we compared the individual and nest mycobiomes of a healthy subterranean termite colony (Coptotermes testaceus) to one infected and ultimately eradicated by a fungal pathogen. We identified Trichoderma species in the materials of both nests, but they were also abundant in the infected termites. Methanolic extracts of Trichoderma sp. FHG000531, isolated from the infected nest, were screened for secondary metabolites by UHPLC‐HR MS/MS‐guided molecular networking. We identified many bioactive compounds with potential roles in the eradication of the infected colony, as well as a cluster of six unknown peptides. The novel peptide FE011 was isolated and characterized by NMR spectroscopy. The function of this novel peptide family as well as the role of Trichoderma species in dying termite colonies therefore requires further investigation.

Genome Sequencing and Analysis of Trichoderma (Hypocreaceae) Isolates Exhibiting Antagonistic Activity against the Papaya Dieback Pathogen, Erwinia mallotivora

Erwinia mallotivora, the causal agent of papaya dieback disease, is a devastating pathogen that has caused a tremendous decrease in Malaysian papaya export and affected papaya crops in neighbouring countries. A few studies on bacterial species capable of suppressing E. mallotivora have been reported, but the availability of antagonistic fungi remains unknown. In this study, mycelial suspensions from five rhizospheric Trichoderma isolates of Malaysian origin were found to exhibit notable antagonisms against E. mallotivora during co-cultivation. We further characterised three isolates, Trichoderma koningiopsis UKM-M-UW RA5, UKM-M-UW RA6, and UKM-M-UW RA3a, that showed significant growth inhibition zones on plate-based inhibition assays. A study of the genomes of the three strains through a combination of Oxford nanopore and Illumina sequencing technologies highlighted potential secondary metabolite pathways that might underpin their antimicrobial properties. Based on these findings, the fungal isolates are proven to be useful as potential biological control agents against E. mallotivora, and the genomic data opens possibilities to further explore the underlying molecular mechanisms behind their antimicrobial activity, with potential synthetic biology applications.

In Vitro Assessment of Organic and Residual Fractions of Nematicidal Culture Filtrates from Thirteen Tropical Trichoderma Strains and Metabolic Profiles of Most-Active

The nematicidal properties of Trichoderma species have potential for developing safer biocontrol agents. In the present study, 13 native Trichoderma strains from T. citrinoviride, T. ghanense (2 strains), T. harzianum (4), T. koningiopsis, T. simmonsii, and T. virens (4) with nematicidal activity were selected and cultured in potato dextrose broth to obtain a culture filtrate (CF) for each. Each CF was partitioned with ethyl acetate to obtain organic (EA) and residual filtrate (RF) fractions, which were then tested on second-stage juveniles (J2s) of the nematodes Meloidogyne javanica and M. incognita in a microdilution assay. The most lethal strains were T. harzianum Th43-14, T. koningiopsis Th41-11, T. ghanense Th02-04, and T. virens Th32-09, which caused 51–100% mortality (%M) of J2s of both nematodes, mainly due to their RF fractions. Liquid chromatography–diode array detector-electrospray-high resolution mass spectrometry analysis of the most-active fractions revealed sesquiterpene and polyketide-like metabolites produced by the four active strains. These native Trichoderma strains have a high potential to develop safer natural products for the biocontrol of Meloidogyne species.

Litchi chinensis seed prevents obesity and modulates the gut microbiota and mycobiota compositions in high-fat diet-induced obese zebrafish

Obesity continues to be a global public health challenge. Litchi chinensis seed is rich in bioactive ingredients with pharmacological effects, such as hypoglycemic activity and anti-oxidation. This study aimed to...

Nigirpexin E, a new azaphilone derivative with anti-tobacco mosaic virus activity from soil-derived fungus Trichoderma afroharzianum LTR-2

A new compound classified as one new azaphilone derivative, nigirpexin E (1), was obtained from the soil-derived fungus Trichoderma afroharzianum LTR-2, together with seven known compounds (2-8). The structures of 1-8 were determined by their HRESIMS, optical rotation, and NMR spectroscopic data. The absolute configuration of nigirpexin E (1) was determined on the basis of comparisons of experimental and theoretically calculated ECD spectra. Compound 3 was firstly isolated from Trichoderma. Bioactivities of the isolated compounds were assayed their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compound 1 exhibited significant inactivation effect against TMV with an inhibition rate of 67.25% (0.5 mg ml^-1), which was higher than that of positive control ribavirin (56.74%). This is the first report of the anti-TMV activity of azaphilone derivatives.

Bioprospecting Trichoderma: A Systematic Roadmap to Screen Genomes and Natural Products for Biocontrol Applications

Natural products derived from microbes are crucial innovations that would help in reaching sustainability development goals worldwide while achieving bioeconomic growth. Trichoderma species are well-studied model fungal organisms used for their biocontrol properties with great potential to alleviate the use of agrochemicals in agriculture. However, identifying and characterizing effective natural products in novel species or strains as biological control products remains a meticulous process with many known challenges to be navigated. Integration of recent advancements in various "omics" technologies, next generation biodesign, machine learning, and artificial intelligence approaches could greatly advance bioprospecting goals. Herein, we propose a roadmap for assessing the potential impact of already known or newly discovered Trichoderma species for biocontrol applications. By screening publicly available Trichoderma genome sequences, we first highlight the prevalence of putative biosynthetic gene clusters and antimicrobial peptides among genomes as an initial step toward predicting which organisms could increase the diversity of natural products. Next, we discuss high-throughput methods for screening organisms to discover and characterize natural products and how these findings impact both fundamental and applied research fields.

A Genomic and Transcriptomic Study on the DDT-Resistant Trichoderma hamatum FBL 587: First Genetic Data into Mycoremediation Strategies for DDT-Polluted Sites

Trichoderma hamatum FBL 587 isolated from DDT-contaminated agricultural soils stands out as a remarkable strain with DDT-resistance and the ability to enhance DDT degradation process in soil. Here, whole genome sequencing and RNA-Seq studies for T. hamatum FBL 587 under exposure to DDT were performed. In the 38.9 Mb-genome of T. hamatum FBL 587, 10,944 protein-coding genes were predicted and annotated, including those of relevance to mycoremediation such as production of secondary metabolites and siderophores. The genome-scale transcriptional responses of T. hamatum FBL 587 to DDT exposure showed 1706 upregulated genes, some of which were putatively involved in the cellular translocation and degradation of DDT. With regards to DDT removal capacity, it was found upregulation of metabolizing enzymes such as P450s, and potentially of downstream DDT-transforming enzymes such as epoxide hydrolases, FAD-dependent monooxygenases, glycosyl- and glutathione-transferases. Based on transcriptional responses, the DDT degradation pathway could include transmembrane transporters of DDT, antioxidant enzymes for oxidative stress due to DDT exposure, as well as lipases and biosurfactants for the enhanced solubility of DDT. Our study provides the first genomic and transcriptomic data on T. hamatum FBL 587 under exposure to DDT, which are a base for a better understanding of mycoremediation strategies for DDT-polluted sites.

First total synthesis of chromanone A, preparation of related compounds and evaluation of their antifungal activity against Candida albicans, a biofilm forming agent

A straightforward and convenient approach for the first total syntheses of chromanone A and a related 7-OMe substituted natural product is reported. These unique C-3 substituted 2-hydroxymethyl chromones were recently isolated as fungal metabolites. Chromanone A was synthesized in 25.3% overall yield from the readily available pyrocatechol, whereas the second natural product was prepared in 39.7% global yield. A small library of chromones, including both natural products and some of their synthetic heterocyclic precursors, was evaluated against Candida albicans ATCC 10231, a biofilm forming agent. It was found that 8-methoxy-3-methyl-4-oxo-4H-chromene-2-carbaldehyde, a partially oxidized form of chromanone A, exhibited a minimum inhibitory concentration of 7.8 μg mL-1 and significantly inhibited the yeast's virulence factors, including the adherence to buccal epithelial cells and the secretion of phospholipases, as well as the formation of germ tubes and the generation of the hyphal pseudomycelium. In addition, despite the heterocycle exhibiting non-significant inhibition of the formation of the Candida biofilm, it completely inhibited the growth of C. albicans in preformed biofilms at 62.5 μg mL-1.

Trichoderma harzianum metabolites disturb Fusarium culmorum metabolism: Metabolomic and proteomic studies

Trichoderma species are well known for producing various secondary metabolites in response to different fungal pathogens. This paper reports the effects of the metabolites produced during one-day cultivation of Trichoderma harzianum on the growth and development of the popular pathogen Fusarium culmorum. Inhibition of the growth of the pathogen and production of secondary metabolites including zearalenone was observed on Petri dishes. The presence of proteins such as cytochrome c oxidase subunit 4, glutathione-independent glyoxalase HSP31, and putative peroxiredoxin pmp20 in the extract-treated culture indicated oxidative stress, which was confirmed by the presence of a higher amount of catalase and dismutase in the later hours of the culture. A larger amount of enolase and glyceraldehyde 3-phosphate dehydrogenase resulted in faster growth, and the overexpression of stress protein and Woronin body major protein indicated the activation of defense mechanisms. In addition, a cardinal reduction in major mycotoxin production was noted.

Deciphering Trichoderma-Plant-Pathogen Interactions for Better Development of Biocontrol Applications

Members of the fungal genus Trichoderma (Ascomycota, Hypocreales, Hypocreaceae) are ubiquitous and commonly encountered as soil inhabitants, plant symbionts, saprotrophs, and mycoparasites. Certain species have been used to control diverse plant diseases and mitigate negative growth conditions. The versatility of Trichoderma’s interactions mainly relies on their ability to engage in inter- and cross-kingdom interactions. Although Trichoderma is by far the most extensively studied fungal biocontrol agent (BCA), with a few species already having been commercialized as bio-pesticides or bio-fertilizers, their wide application has been hampered by an unpredictable efficacy under field conditions. Deciphering the dialogues within and across Trichoderma ecological interactions by identification of involved effectors and their underlying effect is of great value in order to be able to eventually harness Trichoderma’s full potential for plant growth promotion and protection. In this review, we focus on the nature of Trichoderma interactions with plants and pathogens. Better understanding how Trichoderma interacts with plants, other microorganisms, and the environment is essential for developing and deploying Trichoderma-based strategies that increase crop production and protection.

Molecular methods unravel the biosynthetic potential of Trichoderma species

Members of the genus Trichoderma are a well-established and studied group of fungi, mainly due to their efficient protein production capabilities and their biocontrol activities. Despite the immense interest in the use of different members of this species as biopesticides and biofertilizers, the study of their active metabolites and their biosynthetic gene clusters has not gained significant attention until recently. Here we review the challenges and opportunities in exploiting the full potential of Trichoderma spp. for the production of natural products and new metabolic engineering strategies used to overcome some of these challenges.

Antibiotics from Extremophilic Micromycetes

Extremophilic microorganisms, which are capable of functioning normally at extremely high or low temperatures, pressure, and in other environmental conditions, have been in the focus of microbiologists' attention for several decades due to the biotechnological potential of enzymes inherent in extremophiles. These enzymes (also called extremozymes) are used in the production of food and detergents and other industries. At the same time, the inhabitants of extreme econiches remained almost unexplored for a long time in terms of the chemistry of natural compounds. In recent years, the emergence of new antibiotic-resistant strains of pathogens, which affect humans and animals has become a global problem. The problem is compounded by a strong slowdown in the development of new antibiotics. In search of new active substances and scaffolds for medical chemistry, researchers turn to unexplored natural sources. In recent years, there has been a sharp increase in the number of studies on secondary metabolites produced by extremophiles. From the discovery of penicillin to the present day, micromycetes, along with actinobacteria, are one of the most productive sources of antibiotic compounds for medicine and agriculture. Many authors consider extremophilic micromycetes as a promising source of small molecules with an unusual mechanism of action or significant structural novelty. This review summarizes the latest (for 2018-2019) experimental data on antibiotic compounds, which are produced by extremophilic micromycetes with various types of adaptation. Active metabolites are classified by the type of structure and biosynthetic origin. The data on the biological activity of the isolated metabolites are summarized.

Overexpression of Global Regulator Talae1 Leads to the Discovery of New Antifungal Polyketides From Endophytic Fungus Trichoderma afroharzianum

Transcription regulation caused by global regulators exerts important effects on fungal secondary metabolism. By overexpression of the global regulator Talae1 in a Ficus elastica-associated fungus Trichoderma afroharzianum, two structurally new polyketides (1 and 2) that were newly produced in the transformant were isolated and identified. Their structures, including the absolute configurations, were elucidated through a combination of high resolution mass spectrometer (HRMS), NMR, and electronic circular dichroism (ECD) calculations. The growth inhibitory activities of compounds 1 and 2 were evaluated against four bacteria and six plant-pathogenic fungi. Compound 1 showed the highest antifungal activity against Botrytis cinerea and Fusarium oxysporum f. sp. nicotianae with MIC of 8 μg/ml. To the best of our knowledge, this is the first study to report on the application of the global regulator in T. afroharzianum to activate the biosynthesis of bioactive secondary metabolites.

Aqueous Two-Phase System Extraction of Polyketide-Based Fungal Pigments Using Ammonium- or Imidazolium-Based Ionic Liquids for Detection Purpose: A Case Study

Demand for microbial colorants is now becoming a competitive research topic for food, cosmetics and pharmaceutics industries. In most applications, the pigments of interest such as polyketide-based red pigments from fungal submerged cultures are extracted by conventional liquid-liquid extraction methods requiring large volumes of various organic solvents and time. To address this question from a different angle, we proposed, here, to investigate the use of three different aqueous two-phase extraction systems using either ammonium- or imidazolium-based ionic liquids. We applied these to four fermentation broths of Talaromyces albobiverticillius (deep red pigment producer), Emericella purpurea (red pigment producer), Paecilomyces marquandii (yellow pigment producer) and Trichoderma harzianum (yellow-brown pigment producer) to investigate their selective extraction abilities towards the detection of polyketide-based pigments. Our findings led us to conclude that (i) these alternative extraction systems using ionic liquids as greener extractant means worked well for this extraction of colored molecules from the fermentation broths of the filamentous fungi investigated here; (ii) tetrabutylammonium bromide, [N4444]Br-, showed the best pigment extraction ability, with a higher putative affinity for azaphilone red pigments; (iii) the back extraction and recovery of the fungal pigments from ionic liquid phases remained the limiting point of the method under our selected conditions for potential industrial applications. Nevertheless, these alternative extraction procedures appeared to be promising ways for the detection of polyketide-based colorants in the submerged cultures of filamentous fungi.

Antifungal Activity of Bioactive Metabolites Produced by Trichoderma asperellum and Trichoderma atroviride in Liquid Medium

Trichoderma spp. are known as biocontrol agents of fungal plant pathogens and have been recognized as a potential source of bioactive metabolites. The production of antimicrobial substances from strains T. atroviride (TS) and T. asperellum (IMI 393899) was investigated. The bioactivity of 10- and 30-day culture filtrate extracted with ethyl acetate was assessed against a set of pathogenic fungi and oomycetes. The 30-day extracts of both strains had significant cytotoxic effects against the tested pathogens, with values of minimum fungicidal concentration (MFC) ranging between 0.19 and 6.25 mg/mL. Dual culture assay (direct contact and nondirect contact) and the percentage inhibition of radial growth (PIRG) was calculated. The highest PIRG values were 76% and 81% (direct contact) with IMI 393899 and TS, respectively. Nondirect contact does not show inhibition on any of pathogens tested, indicating that the inhibition is not due to the secretion of volatile substances. Culture filtrates were analyzed by GC-MS and HPLC-Q-TOF-MS for the identification of volatile organic compounds (VOCs) and nonvolatile organic compounds (nVOCs), respectively. Seven classes of VOCs and 12 molecules of nVOCs were identified. These results indicate that these strains of Trichoderma had antimicrobial activities and they are potential natural sources of compounds with biological activity.

Effects of Lentil Genotype on the Colonization of Beneficial Trichoderma Species and Biocontrol of Aphanomyces Root Rot

Trichoderma species are opportunistic plant symbionts that are common in the root and rhizosphere ecosystems. Many Trichoderma species may enhance plant growth, nutrient acquisition, and disease resistance, and for these reasons, they are widely used in agriculture as biofertilizers or biocontrol agents. Host plant genotype and other microorganisms, such as root pathogens, may influence the efficacy of Trichoderma inoculants. Aphanomyces euteiches is an important soil-borne oomycete in western Canada that causes root rot in legume crops such as lentil and pea, and there is not yet any significantly resistant varieties or effective treatments available to control the disease. In this study, the composition of root-associated fungal communities and the abundance of Trichoderma species, T. harzianum strain T-22 and T. virens strain G41, was determined in the roots of eight Lens genotypes based on internal transcribed spacer (ITS) Illumina MiSeq paired-end sequencing, both in the presence and the absence of the root rot pathogen Aphanomyces euteiches. Biocontrol effects of T. harzianum on A. euteiches was also examined. Significant genotypic variations were observed in the composition of root-associated fungal communities and the abundance of the different Trichoderma species in the lentil roots. The presence of A. euteiches altered the composition of Trichoderma found associated to the lentil genotypes. Biocontrol of A. euteiches by T. harzianum T22 species was observed in vitro and positive correlations between the abundance of Trichoderma and plant root and shoot biomass were observed in vivo. These findings revealed that lentil genotype and infection by the phytopathogen A. euteiches greatly influenced the colonization of root-associated fungi and the abundance of the Trichoderma species, as well as the effect on plant growth promotion. The multipartite interactions observed among lentil genotypes, Trichoderma species and A. euteiches suggest possibilities to select compatible host-beneficial microbe combinations in lentil breeding programs and to develop application strategies to harness the beneficial effects of Trichoderma inoculants in sustainable crop production systems.

Antifungal activity of endophytic fungi from Cupressaceae against human pathogenic Aspergillus fumigatus and Aspergillus niger

Aspergillus is a fungal genus that strongly affects health of humans, animals, and plants worldwide. Endophytes are now widely considered as a rich source of bioproducts with potential uses in medicine, agriculture, and bioindustry. Cupressaceae plant family hosts a variety of bioactive ascomycetous endophytes. In this study, antifungal activity of a number of such endophytes were investigated against human pathogenic fungi Aspergillus fumigatus and Aspergillus niger. To this end, 16 superior bioactive endophytic fungi from Cupressaceae were used, including Alternaria alternata, Alternaria pellucida, Ascorhizoctonia sp., Aspergillus fumigatus, Aspergillus niger, Aurobasidium sp., Cladosporium porophorum, Fusarium oxysporum, Penicillium viridicatum, Phoma herbarum, Phoma sp., Pyrenochaeta sp., Trichoderma atroviride, Trichoderma atroviride and Trichoderma koningii. In vitro bioassays indicated anti-Asperilli activity of the endophytic fungi in dual cultures. Most notably, Trichoderma koningii CSE₃₂ and Trichoderma atroviride JCE₃₃ showed complete growth inhibition of both A. niger and A. fumigatus, within 3 to 7 days. Also, volatile compouds (VOCs) of T. koningii CSE₃₂ and T. atroviride JCE₃₃ exhibited 33-100% growth inhibition of A. niger, whithin 3 days. Moreover, on the day 7, growth of A. niger was less affected than that of A. fumigatus. In general, it appears that there is a direct relationship between the exposure time and the inhibitory activity of endophytes VOCs on the growth of target Aspergillus species. Furthremore, the extracellular secondary metabolites (SMs) of four selected fungal endophytes exhibited anti-Aspergillus activity at all treatment levels as shown by Agar-diffusion assay. SMs from T. koningii CSE₃₂ and Pyrenochaeta CSE₁₃₄ showed strongest activities against A. niger, and SMs from T. koningii CSE₃₂ and F. oxysporum CAE₁₄ showed strongest activities against A. fumigatus. In conclusion, given the globally recognized issue of antibiotic resistance and the urge to discover new antimicrobial substances, our findings provide new insights into the potential use of Cupressaceae's endophytic fungi in antifungal-based drug discovery programs.

Lipids, proteins and extracellular metabolites of Trichoderma harzianum modifications caused by 2,4-dichlorophenoxyacetic acid as a plant growth stimulator

Strains of Trichoderma harzianum are well-known producers of bioactive secondary metabolites and have a beneficial effect on plants. However, to the best of our knowledge, the effect of the commonly used pesticides on the activity of this fungus is not yet investigated. Therefore, in the present study, the effect of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on the lipidome and selected extracellular compounds synthesized by T. harzianum IM 0961 was examined. It was observed that the herbicide 2,4-D caused changes in the lipid composition of the mycelium and that the herbicide exhibited lipophilic properties. In addition, the herbicide disturbed the phosphatidylcholine (PC)/phosphatidylethanolamine (PE) ratio and increased membrane permeability. The higher amount of cardiolipin CL 72:7 and the lower amount of CL 72:8 could have been associated with a decreased ratio of 18:2 and 18:1 fatty acids in the herbicide-treated samples. Moreover, in the presence of 2,4-D, an increased lipid peroxidation (twofold), as well as a higher content of oxylipin (9-HODE and 13-HODE) and phosphatidic acid (PA), was noted, confirming that 2,4-D induced lipid peroxidation in the mycelium. The herbicide also exerted its toxic effect on the production of 14-aminoacid peptaibols and two compounds, harzianic acid and t22-azaphilone, exhibiting antibiotic and plant growth-promoting activity. During proteomic analysis, the synthesis of some proteins, such as calcineurin-like phosphoesterase metallophosphatases (MPPs), which modulate the properties of cell walls, was found to be inhibited by the herbicide. These presented findings may be of significant value in understanding the effect of 2,4-D on the activity of T. harzianum.

Antifungal compounds with anticancer potential from Trichoderma sp. P8BDA1F1, an endophytic fungus from Begonia venosa

Fungi in the genus Trichoderma are notorious producers of secondary metabolites with diverse applications, such as antibacterial, antifungal, and plant growth-promoting properties. Peptaibols are linear peptides produced by such fungi, with more than 440 compounds described to date, including tricholongins, longibrachins, trichobrachins, and trichovirins. Peptaibols are synthesized by non-ribosomal peptide synthetases and they have several biological activities. Our research group isolated four peptaibols (6DP2, 6DP3, 6DP4, and 6DP5) with antifungal activity against the plant pathogen Colletotrichum gloeosporioides and the proteasome (a cancer chemotherapy target) from Trichoderma sp. P8BDA1F1, an endophytic fungus from Begonia venosa. The ethyl acetate extract of this endophyte showed activity of 6.01% and 75% against C. gloeosporioides and the proteasome, respectively. The isolated compounds were identified by MS/MS and compared to literature data, suggesting the presence of trilongins BI, BII, BIII, and BIV, which are peptaibols containing 20 amino acid residues. The minimum inhibitory concentration against C. gloeosporioides was 40 μM for trilongin BI, 320 μM for trilongin BII, 160 μM for trilongin BIII, and 310 μM for trilongin BIV. BI-BIV trilongins inhibited proteasome ChTL activity, with IC₅₀ values of 6.5 ± 2.7; 4.7 ± 1.8; 6.3 ± 2.2; and 2.7 ± 0.5 μM, respectively. The compounds were tested ex vivo against the intracellular amastigotes of Leishmania (L.) infantum but showed no selectivity. It is the first report of trilongins BI-BIV with antifungal activity against C. gloeosporioides and the proteasome target.

Chemical Composition of an Aphid Antifeedant Extract from an Endophytic Fungus, Trichoderma sp. EFI671

Botanical and fungal biopesticides, including endophytes, are in high demand given the current restrictive legislations on the use of chemical pesticides. As part of an ongoing search for new biopesticides, a series of fungal endophytes have been isolated from selected medicinal plants including Lauraceae species. In the current study, an extract from the endophytic fungus Trichoderma sp. EFI 671, isolated from the stem parts of the medicinal plant Laurus sp., was screened for bioactivity against plant pathogens (Fusarium graminearum, Rhizoctonia solani, Sclerotinia sclerotiorum and Botrytis cinerea), insect pests (Spodoptera littoralis, Myzus persicae, Rhopalosiphum padi) and plant parasites (Meloidogyne javanica), with positive results against M. persicae. The chemical study of the neutral fraction of the active hexane extract resulted in the isolation of a triglyceride mixture (m1), eburicol (2), β-sitostenone (3), ergosterol (4) and ergosterol peroxide (5). The free fatty acids present in the acid fraction of the extract and in m1 (oleic, linoleic, palmitic and stearic) showed strong dose-dependent antifeedant effects against M. persicae. Liquid (potato dextrose broth, PDB and Sabouraud Broth, SDB) and solid (corn, sorghum, pearl millet and rice) growth media were tested in order to optimize the yield and bioactivity of the fungal extracts. Pearl millet and corn gave the highest extract yields. All the extracts from these solid media had strong effects against M. persicae, with sorghum being the most active. Corn media increased the methyl linoleate content of the extract, pearl millet media increased the oleic acid and sorghum media increased the oleic and linoleic acids compared to rice. The antifeedant effects of these extracts correlated with their content in methyl linoleate and linoleic acid. The phytotoxic effects of these extracts against ryegrass, Lolium perenne, and lettuce, Lactuca sativa, varied with culture media, with sorghum being non- toxic.

Biodegradation of Reactive Orange 16 azo dye by simultaneous action of Pleurotus ostreatus and the yeast Candida zeylanoides

The purpose was to investigate a simultaneous biodegradation of the recalcitrant monoazo dye Reactive Orange 16 (RO16) in a mixed culture consisting of a biofilm of Pleurotus ostreatus-colonizing polyamide carrier and a suspension of the yeast Candida zeylanoides to see their biological interactions and possible synergistic action during degradation. Decolorization in the mixed culture was more effective than in the fungal monoculture, the respective decolorizations reaching 87.5% and 70% on day 11. The proliferation of yeast was reduced compared with the C. zeylanoides monoculture but enabled the yeast to participate in decolorization. The interaction of P. ostreatus with the yeast resulted in a gradual decrease of fungal manganese-dependent peroxidase (MnP) and laccase activities. Gas chromatography-mass spectrometry (GC-MS) analysis of the degradation products brought evidence that P. ostreatus split the dye molecule asymmetrically to provide 4-(ethenylsulfonyl) benzene whose concentration was much decreased in the mixed culture suggesting its increased metabolization in the presence of the yeast. In contrast, C. zeylanoides split the azo bond symmetrically producing the metabolites 4-(ethenylsulfonyl) aniline and α-hydroxybenzenepropanoic acid. Those metabolites were rapidly degraded in the mixed culture. A novel aspect is represented by the evidence of a mutual cooperative action of the fungal and yeast microorganisms in the mixed culture resulting in rapid decolorization and degradation of the dye.

Trichoderma as a Model to Study Effector-Like Molecules

Plants are capable of perceiving microorganisms by coordinating processes to establish different forms of plant–microbe relationships. Plant colonization is governed in fungal and bacterial systems by secreted effector molecules, suppressing plant defense responses and modulating plant physiology to promote either virulence or compatibility. Proteins, secondary metabolites, and small RNAs have been described as effector molecules that use different mechanisms to establish the interaction. Effector molecules have been studied in more detail due to their involvement in harmful interactions, leading to a negative impact on agriculture. Recently, research groups have started to study the effectors in symbiotic interactions. Interestingly, most symbiotic effectors are members of the same families present in phytopathogens. Nevertheless, the quantity and ratio of secreted effectors depends on the microorganism and the host, suggesting a complex mechanism of recognition between the plant and their associated microorganisms. Fungi belonging to Trichoderma genus interact with plants by inducing their defense system and promoting plant growth. Research suggests that some of these effects are associated with effector molecules that Trichoderma delivers during the association with the plant. In this review, we will focus on the main findings concerning the effector molecules reported in Trichoderma spp. and their role during the interaction with plants, mainly in the molecular dialogue that takes place between them.

Trichoderma as a Model to Study Effector-Like Molecules

Plants are capable of perceiving microorganisms by coordinating processes to establish different forms of plant-microbe relationships. Plant colonization is governed in fungal and bacterial systems by secreted effector molecules, suppressing plant defense responses and modulating plant physiology to promote either virulence or compatibility. Proteins, secondary metabolites, and small RNAs have been described as effector molecules that use different mechanisms to establish the interaction. Effector molecules have been studied in more detail due to their involvement in harmful interactions, leading to a negative impact on agriculture. Recently, research groups have started to study the effectors in symbiotic interactions. Interestingly, most symbiotic effectors are members of the same families present in phytopathogens. Nevertheless, the quantity and ratio of secreted effectors depends on the microorganism and the host, suggesting a complex mechanism of recognition between the plant and their associated microorganisms. Fungi belonging to Trichoderma genus interact with plants by inducing their defense system and promoting plant growth. Research suggests that some of these effects are associated with effector molecules that Trichoderma delivers during the association with the plant. In this review, we will focus on the main findings concerning the effector molecules reported in Trichoderma spp. and their role during the interaction with plants, mainly in the molecular dialogue that takes place between them.