Search Results (13)

This study combines Oxford Nanopore (ONT) third-generation sequencing with targeted amino acid metabolomics to elucidate the mechanisms underlying the structural and metabolic responses of the microbial community in Golden Ear Mushroom (Naematelia sinensis) during Trichoderma infection. By comparing healthy tissue (MOCK), adjacent healthy areas (HAF) and the core lesion area (DiR), the results indicate that pathogen infection significantly reduces bacterial community diversity, with a progressive decline observed across these regions. In the DiR region, the fungal community underwent significant restructuring, with the abundance of the Trichoderma genus (T. lixii and T. afroharzianum) rising to over 45%, whilst that of host symbiotic fungi (Stereum and Tremella) decreased by 50–60%. Metabolomic analysis indicated that levels of various amino acids and antioxidant-related metabolites were significantly reduced in the host tissue of the DiR region, suggesting that amino acid metabolism was inhibited. Concurrently, changes were observed in certain metabolites associated with nitrogen metabolism (e.g., L-glutamine). KEGG analysis further revealed that amino acid biosynthesis and D-amino acid metabolic pathways were inhibited, whilst ABC transporters and arginine/proline metabolic pathways were activated. All metabolic changes originated from the host fungal tissue itself, rather than from commensal microorganisms. In summary, Trichoderma may promote the infection process by disrupting the host microbial community and metabolic networks, providing a theoretical basis for understanding the mechanisms of fungal diseases and their control. Full article

Chickpeas contribute to half of the pulses produced in India and are an excellent source of protein, fibers, carbohydrates, minerals, and vitamins. However, the combination of the wilt and root rot diseases drastically lowers its yield. The use of antagonist microbes that restrict the growth of other phytopathogens is an ecofriendly approach to combat the serious threats raised by the plant pathogens. Trichoderma spp. are well known as biocontrol agents, especially against soil- and seed-borne phytopathogens. In this study, 21 Trichoderma isolates that were collected from different rhizospheric soils were evaluated against two notorious soil-borne pathogens, such as Fusarium oxysproum f.sp. ciceri and Sclerotium rolfsii. The maximum percentage of inhibition against the tested pathogens was observed in Trichoderma isolate PBT13 (72.97%, 61.1%) followed by PBT3 (72.23%, 59.3%). The mycelial extension rate method, dual culture (antagonism), production of cell-wall degrading enzymes (CWDs), and antifungal metabolites (by GC-MS) were used as selection criteria for potent Trichoderma isolates. Among the 21 isolates, PBT3, PBT4, PBT9, and PBT13 exhibited high antagonistic activity, production of antifungal metabolites, and chitinase and β-1,3-glucanase activity. These four species were subjected to molecular characterization using an internal transcribed spacer (ITS 1 and ITS4). The results of molecular characterization identified the four species as T. virnes, T. asperellum, T. lixii, and T. harzianum. Moreover, significant chitinase and β-1,3-glucanase activities of all Trichoderma isolates were recorded in the growth medium. Trichoderma harzianum (isolate PBT13) was found to exhibit the highest chitinase activity in terms of zone formation (4.40 ± 0.17 cm), whereas Trichoderma virens (isolate PBT3) exhibited the highest β-1,3-glucanase activity1.511 μmole/min. A GC-MS analysis of ethyl extracts from two isolates of Trichoderma (PBT9, PBT13) revealed the presence of 28 VOCs. Overall, this study suggests that these four Trichoderma strains are promising biological control agents (BCAs) and could be developed as bio-pesticides after stringent field trials for the management of soil-borne diseases of chickpeas. Full article

The fungal genus Trichoderma is a rich source of structurally diverse secondary metabolites with remarkable pharmaceutical properties. The chemical constituents and anticancer activities of the marine-derived fungus Trichoderma lixii have never been investigated. In this study, a bioactivity-guided investigation led to the isolation of eleven compounds, including trichodermamide A (1), trichodermamide B (2), aspergillazine A (3), DC1149B (4), ergosterol peroxide (5), cerebrosides D/C (6/7), 5-hydroxy-2,3-dimethyl-7-methoxychromone (8), nafuredin A (9), and harzianumols E/F (10/11). Their structures were identified by using various spectroscopic techniques and compared to those in the literature. Notably, compounds 2 and 5–11 were reported for the first time from this species. Evaluation of the anticancer activities of all isolated compounds was carried out. Compounds 2, 4, and 9 were the most active antiproliferative compounds against three cancer cell lines (human myeloma KMS-11, colorectal HT-29, and pancreas PANC-1). Intriguingly, compound 4 exhibited anti-austerity activity with an IC₅₀ of 22.43 μM against PANC-1 cancer cells under glucose starvation conditions, while compound 2 did not. Full article

Because agricultural wastes are abundant in biologically active substances, they can be used as a substitute source to produce highly valuable products while lowering pollution levels in the environment. Therefore, we aimed at determining the best agricultural wastes to increase the biomass production rate and the effectiveness of the biocontrol strain Trichoderma lixii SARS 111 in a solid-state fermentation system. The potential for its use in enhancing growth dynamics and controlling the Fusarium oxysporum NCAIM-F-00779-caused damping-off disease of cowpea plants grown in greenhouse conditions was also studied. Using a one-factor-at-a-time experiment, five cheap agricultural waste substrates (faba bean, cowpea, sweet potato, pumpkin, and cassava) were studied using the Plackett–Burman design (PBD) and the central composite design (CCD) to optimize the nutritional and growth conditions to maximize the production of Trichoderma conidia. The findings demonstrated that increasing Candida production quantitatively required the use of 3 g of sweet potato, 3 g of cassava, pH 6, 25 °C, and pre-treatment with dH₂O. The shelf life and viability of T. lixii strain were measured as log10 CFU g⁻¹ per substrate at room temperature (RT, 25 °C) at the beginning of month 0 and subsequently at 2-month intervals for 12 months. Data showed that the fungal counts increased with the use of 4 g of sweet potato + 2 g of cassava up to 7 months and then sharply decreased, lasting up to 12 months. Additionally, this bioformulation was applied to cowpea plants in a greenhouse experiment, where a significantly higher level of plant growth traits, photosynthetic pigments, antioxidant enzymes, and chemical content in the leaves, as well as lower incidence of the damping-off disease, were noted. Accordingly, it is possible to suggest 4 g of sweet potato and 2 g of cassava as a suitable bioformulation for the industrial-scale production of the T. lixii strain, which may be a potential biocontrol agent for preventing the cowpea damping-off disease caused by F. oxysporum and improving the growth dynamics. Full article

Five new lipids, tricholixins A–E (1–5), and two known terpenoids, brasilane A (6) and harzianone A (7), were discovered from a deep-sea strain (R22) of the fungus Trichoderma lixii isolated from the cold seep sediments of the South China Sea. Their structures and relative configurations were identified by meticulous analysis of MS and IR as well as NMR data. The absolute configuration of 5 was ascertained by dimolybdenum-induced ECD data in particular. Compounds 1 and 2 represent the only two new butenolides from marine-derived Trichoderma, and they further add to the structural diversity of these molecules. Although 6 has been reported from a basidiomycete previously, it is the first brasilane aminoglycoside of Trichoderma origin. During the assay against wheat-pathogenic fungi, both 1 and 2 inhibited Fusarium graminearum with an MIC value of 25.0 μg/mL, and 6 suppressed Gaeumannomyces graminis with an MIC value of 12.5 μg/mL. Moreover, the three isolates also showed low toxicity to the brine shrimp Artemia salina. Full article

Beneficial microorganisms, including members of the Trichoderma genus, are known for their ability to promote plant growth and disease resistance, as well as being alternatives to synthetic inputs in agriculture. In this study, 111 Trichoderma strains were isolated from the rhizospheric soil of Florence Aurore, an ancient wheat variety that was cultivated in an organic farming system in Tunisia. A preliminary ITS analysis allowed us to cluster these 111 isolates into three main groups, T. harzianum (74 isolates), T. lixii (16 isolates) and T. sp. (21 isolates), represented by six different species. Their multi-locus analysis (tef1, translation elongation factor 1; rpb2, RNA polymerase B) identified three T. afroharzianum, one T. lixii, one T. atrobrunneum and one T. lentinulae species. These six new strains were selected to determine their suitability as plant growth promoters (PGP) and biocontrol agents (BCA) against Fusarium seedling blight disease (FSB) in wheat caused by Fusarium culmorum. All of the strains exhibited PGP abilities correlated to ammonia and indole-like compound production. In terms of biocontrol activity, all of the strains inhibited the development of F. culmorum in vitro, which is linked to the production of lytic enzymes, as well as diffusible and volatile organic compounds. An in planta assay was carried out on the seeds of a Tunisian modern wheat variety (Khiar) by coating them with Trichoderma. A significant increase in biomass was observed, which is associated with increased chlorophyll and nitrogen. An FSB bioprotective effect was confirmed for all strains (with Th01 being the most effective) by suppressing morbid symptoms in germinated seeds and seedlings, as well as by limiting F. culmorum aggressiveness on overall plant growth. Plant transcriptome analysis revealed that the isolates triggered several SA- and JA-dependent defense-encoding genes involved in F. culmorum resistance in the roots and leaves of three-week-old seedlings. This finding makes these strains very promising in promoting growth and controlling FSB disease in modern wheat varieties. Full article

Two indigenous ascomycetes fungi, Trichoderma lixii strain FLU1 (TlFLU1) and Talaromyces pinophilus strain FLU12 (TpFLU12), were isolated from benzo(b)fluoranthene-enriched activated sludge and tested for bio-catalytically degrade fluoranthene as a sole carbon source. TlFLU1 and TpFLU12 degraded 98 and 99% of 400 mg/L of fluoranthene after 16 and 12 d incubation period, respectively. Degradation correlated with the upregulation of expression of ligninolytic enzymes. The GC-MS and FTIR analysis of the degradation products suggest that the degradation is initiated at the C1-C2 position of the compound ring via oxygenation and ring cleavage to form 9-oxo-9H-fluorene-1-carboxylic acid before undergoing ring cleavage to yield fluorenone, which then proceeds through the ß-Ketoadipate pathway via benzene-1,2,3-tricarboxylic acid. The degradation rate is better fitted in the first-order and zero-order kinetic model for TlFLU1 and TpFLU12, respectively. The metabolites from the TlFLU1 degradation media are shown to be toxic in Vibryo parahaemolyticus after 6 h of exposure with effective concentration (EC₅₀) and toxicity unit (TU) values of 14.25 mg/L and 7.018%, respectively, while also being observed as non-toxic from TpFLU12 degradation media with an EC₅₀ and TU values of 197.1 mg/L and 0.507%, respectively. Results from this study show efficient metabolism of fluoranthene into an innocuous state by TlFLU1 and TpFLU12. Full article

The spread of antibiotic-resistant opportunistic microbes is a huge socioeconomic burden and a growing concern for global public health. In the current study, two endophytic fungal strains were isolated from Mangifera Indica roots and identified as Aspergillus niger MT597434.1 and Trichoderma lixii KU324798.1. Secondary metabolites produced by A. niger and T. lixii were extracted and tested for their antimicrobial activity. The highest activity was noticed against Staphylococcus aureus and E. coli treated with A. niger and T. lixii secondary metabolites, respectively. A. niger crude extract was mainly composed of Pentadecanoic acid, 14-methyl-, methyl ester and 9-Octadecenoic acid (Z)-, methyl ester (26.66 and 18.01%, respectively), while T. lixii crude extract’s major components were 2,4-Decadienal, (E,E) and 9-Octadecenoic acid (Z)-, and methyl ester (10.69 and 10.32%, respectively). Moreover, a comparative study between the fungal extracts and dicationic pyridinium iodide showed that the combination of A. niger and T. lixii secondary metabolites with dicationic pyridinium iodide compound showed a synergistic effect against Klebsiella pneumoniae. The combined formulae inhibited the bacterial growth after 4 to 6 h through cell wall breakage and cells deformation, with intracellular components leakage and increased ROS production. Full article

The incidence of biotic perturbation in plants has been amplified due to increased resistance and the resurgence of pathogens. To mitigate stress and promote food production, agrochemicals are being used boundlessly and they have augmented the problem of disease re-occurrence and agroecosystem degradation. With the perception of urgency to reduce biotic stress sustainably, the present study was undertaken. Four native rhizospheric microbes: Trichoderma lixii, T. brevicompactum and two strains of Bacillus subtilis, were evaluated for their antagonistic potential toward soil-borne and foliar pathogens of tomato under pot conditions. The data obtained revealed T. lixii as the most effective isolate, which substantially reduced the disease severity and promoted plant growth. In two consecutive pot experiments, T. lixii was observed to reduce the fusarium wilt and early blight severity by 32% and 31%; and 30% and 25%, respectively, compared to the untreated control. Moreover, T. lixii was reported to colonize the plant roots, which was evident from the result obtained for biofilm formation and spores colonization on root cells. TvR1 also improved the photosynthetic content of both infected and non-infected plants. The conclusion drawn from the result suggested that the native microbial rhizospheric isolate T. lixii was effective in ameliorating the biotic stress, which might be due to root colonizing ability, and therefore, it could be designed into a bioinoculant for green agriculture. Full article

Mono- and polycyclic aromatic hydrocarbons (PAHs) are widespread and recalcitrant pollutants that threaten both environmental and human health. By exploiting the powerful enzymatic machinery of fungi, mycoremediation in contaminated sites aims at removing a wide range of pollutants in a cost-efficient and environmentally friendly manner. Next-generation sequencing (NGS) techniques are powerful tools for understanding the molecular basis of biotransformation of PAHs by selected fungal strains, allowing genome mining to identify genetic features of biotechnological value. Trichoderma lixii MUT3171, isolated from a historically PAH-contaminated soil in Italy, can grow on phenanthrene, as a sole carbon source. Here, we report the draft genome sequence of T. lixii MUT3171 obtained with high-throughput sequencing method. The genome of T. lixii MUT3171 was compared with other 14 Trichoderma genomes, highlighting both shared and unique features that can shed a light on the biotransformation of PAHs. Moreover, the genes potentially involved in the production of important biosurfactants and bioactive molecules have been investigated. The gene repertoire of T. lixii MUT3171 indicates a high degrading potential and provides hints on putative survival strategies in a polluted environment. Full article

This study was conducted in the scope of developing a sustainable effective approach against subterranean termite pests using entomopathogenic and endophytic fungus-based biopesticides. Termites, Odontotermes spp. workers, were tested for their susceptibility to 15 entomopathogenic fungal isolates through the direct spraying of conidia suspensions at 1 × 10⁸ conidia/mL. In general, all the isolates screened were pathogenic, with 100% mortality 4–7 days post-inoculation. However, the most virulent isolates were Metarhizium brunneum Cb15-III; the M. anisopliae isolates ICIPE 30 and ICIPE 60; Hypocrea lixii F3ST1; and the Beauveria bassiana isolates ICIPE 279, ICIPE 706 and ICIPE 662. These isolates were further tested for their endophytic colonization of cocoa seedlings using seed soaking, soil drench and foliar spray at 1 × 10⁸ conidia/mL. The colonization of the plant tissues by the fungi was determined using a culture-based technique. Only the B. bassiana isolates ICIPE 706 and ICIPE 279, and H. lixii F3ST1 colonized the cocoa seedlings, with varied colonization rates among isolates and inoculation methods. Three naturally occurring endophytes—Trichoderma asperellum, Fusarium solani and F. redolens—were also isolated from the cocoa seedling tissues. These findings suggest that cocoa seedlings are conducive to endophytic fungal growth either occurring naturally or from artificial inoculation Our findings could possibly lead to an innovative approach to the management of herbivory and subterranean termite pests in cocoa agroforests. Full article

In eastern Africa, Maize lethal necrosis (MLN) is caused by the co-infection of maize plants with Maize chlorotic mottle virus (MCMV) (Tombusviridae: Machlomovirus) and Sugarcane mosaic virus (SCMV) (Potyviridae: Potyvirus). With the disease being new to Africa, minimal effective management strategies exist against it. This study examined the potential of 10 fungal isolates to colonize maize plants and induce resistance against MCMV and SCMV. Maize seeds were soaked in fungal inoculum, sown and evaluated for endophytic colonization. Fungus-treated plants were challenge-inoculated with SCMV and/or MCMV to assess the effects of fungal isolates on the viruses in terms of incidence, severity and virus titers over time. Isolates of Trichoderma harzianum, Trichoderma atroviride and Hypocrea lixii colonized different plant sections. All plants singly or dually-inoculated with SCMV and MCMV tested positive for the viruses by reverse transcription-polymerase chain reaction (RT-PCR). Maize plants inoculated by T. harzianum and Metarhizium. anisopliae resulted in up to 1.4 and 2.7-fold reduced SCMV severity and titer levels, respectively, over the controls but had no significant effect on MCMV. The results show that both T. harzianum and M. anisopliae are potential candidates for inducing resistance against SCMV and can be used for the integrated management of MLN. Full article

Twenty-eight fungal strains have been isolated from different natural marine substrates and plate screened for their production of chitinolytic activity. The two apparent best producers, Trichoderma lixii IG127 and Clonostachys rosea IG119, were screened in shaken cultures in media containing 1% colloidal chitin, 1% yeast nitrogen base and 38‰ NaCl, for their ability to produce chitinolytic enzymes under halophilic conditions. In addition, they were tested for optimal growth conditions with respect to pH, salinity and temperature. The Trichoderma strain appeared to be a slight halotolerant fungus, while C. rosea IG119 clearly showed to be a halophilic marine fungus, its optimal growth conditions being very coherent for life in the marine environment (i.e., pH 8.0, salinity 38‰). Due to its high and relatively fast activity (258 U/L after 192 h of growth) accompanied by its halophilic behaviour (growth from 0 to 160‰ of salinity), C. rosea was selected for further studies. In view of possible industrial applications, its medium for chitinolytic enzyme production was optimized by Response Surface Methodology using 1% colloidal chitin and different concentrations of corn step liquor and yeast nitrogen base (0–0.5%). Time course of growth under optimized condition showed that maximum activity (394 U/L) was recorded after 120 h on medium containing Corn Steep Liquor 0.47% and Yeast Nitrogen Base 0.37%. Maximum of productivity (3.3 U/Lh) was recorded at the same incubation time. This was the first study that demonstrated high chitinolytic activity in a marine strain of C. rosea. Full article