Isolation and characterization of the bioactive metabolites from the soil derived fungus Trichoderma viride

Cinnamon essential oil induced microbial stress metabolome indicates its active food packaging efficiency when incorporated into poly vinyl alcohol, engineered with zinc oxide nanoparticles and nanocellulose

In the study, Poly Vinyl Alcohol (PVA) films engineered with the nanoparticles and essential oils have been developed as efficient alternative to the currently used food packaging materials. For this, impact of cinnamon essential oil (CEO), on the metabolomic profile of Staphylococcus aureus, Escherichia coli and Aspergillus flavus was analysed. Subsequently, PVA based nanocomposite films CEO, zinc oxide nanoparticles (ZnONPs), and nanocellulose (NC) were synthesised and characterized by FT-IR analysis. By the GC-MS analysis. The presence of ZnONPs enhanced the release of cinnamaldehyde from 31.16 to 44.23 and further enhancement to 71.82 was seen the presence of nanocellulose. The incorporation of NPs was found to enhance the hydrodynamic and mechanical properties of the prepared films. The final developed films, PZNCCEO, showed the least values for WHC and MC which were 56.31 ± 2.12 % and 13.30 ± 0 % respectively. Antimicrobial efficacy could also be demonstrated through the observation on changes in the morphological features of treated S. aureus and E. coli by the FE-SEM. Finally, the developed nanocomposite film was found to have the potential for food packaging as demonstrated through the protection of corn kernals and Vigna unguiculata.

Polyphenols-Rich Extract of Calotropis procera Alone and in Combination with Trichoderma Culture Filtrate for Biocontrol of Cantaloupe Wilt and Root Rot Fungi

Fungal diseases have always been a major problem for cantaloupe crops; however, synthetic fungicides are hazardous to humans and the environment. Consequently, a feasible alternative to fungicides without side effects could be by using bio agents and naturally occurring plants with antibacterial potential. This study has achieved a novel procedure for managing wilt and root rot diseases by potentially using Trichoderma sp. culture filtrates in consortium with plant extract of Calotropis procera, Rhizoctonia solani, Fusarium oxysporum, and Pythium ultimum, which were isolated from infected cantaloupe roots with identified root rot symptoms. The antagonistic activity of four Trichoderma isolates and analysis of antibiotics and filtrate enzymes of the most active Trichoderma isolate were determined as well as phytochemical analysis of C. procera plant extract using HPLC-UV. The obtained results showed that all Trichoderma isolates considerably lowered the radial growth of P. ultimum, R. solani, and F. oxysporum in varying degrees. The scanning electron micrographs illustrate the mycoparasitic nature of Trichoderma sp. on F. oxysporum. The phytochemical analysis of C. procera indicated that phenolic contents were the major compounds found in extracts, such as vanillin (46.79%), chlorogenic acid (30.24%), gallic acid (8.06%), and daidzein (3.45%) but including only a low amount of the flavonoid compounds rutin, naringenin, and hesperetin. The Pot experiment's findings showed that cantaloupe was best protected against wilting and root rot diseases when it was treated with both Trichoderma sp. culture filtrates (10%) and C. procera extract of (15 mg/mL), both alone and in combination. This study demonstrates that the application of bio agent Trichoderma spp. filtrate with C. procera phenol extract appears useful for controlling wilting and root rot disease in cantaloupe. This innovative approach could be used as an alternative to chemical fungicide for the control of wilting and rot root diseases.

Investigation of the potential roles of adipose stem cells and substances of natural origin in the healing process of E. coli infected wound model in Rats

Skin infections by pathogenic microorganisms are a serious problem due to the potential of dissemination through the bloodstream to various organs causing toxic effects that may be up to mortality. Escherichia coli (E. coli) is one of the most predominant Gram-negative bacterial species present globally with great attention for investigation. The current study is designed to investigate the possible role of adipose tissue-derived stem cells (ADSCs), as well as natural products such as Trichoderma viride (T. viride) extract, Saccharomyces boulardii (S. boulardii) solution in the enhancement of wound healing process in the infected skin with E. coli. Ninety-six female rats were divided into 8 groups (12 animal/group): normal skin, wounded skin, wounded skin infected with E. coli, infected-wounded skin treated by ADSCs, infected-wounded skin treated by T. viride extract, infected-wounded skin treated by S. boulardii solution, infected-wounded skin treated a combination of treatments, infected-wounded skin treated by gentamicin. At day 21 animal weights and bacterial count were detected and compared. Animals were sacrificed and skin from various groups was investigated using a light microscope for sections stained by (hematoxylin eosin, Masson trichrome, and PCNA) as well as transmission electron microscopy. Pro-inflammatory (IL-1β, TNF- α, and IL-13), anti-inflammatory cytokine (IL-4), and antioxidant enzymes (Superoxide dismutase, glutathione, and catalase) were assessed in various groups revealing that ADSCs lightly shift levels of these parameters in various rat groups to regular levels, while administration of T. viride extract, S. boulardii solution, their combination with ADSCs and gentamicin treatment drive the tested cytokines and enzymes to significant levels similar to a normal level where combination therapy gave the best result. The current findings revealed the possibility of using certain natural products as possible substitutes to regularly applied antibiotics with successive protective results in the wound infection model.

Biological control of some wood-decay fungi with antagonistic fungi

One of the most important biological factors that damage wood materials are wood-decay fungi (WDF). Chemical preservatives have traditionally been the most effective method for controlling WDF. However, due to environmental pressures, scientists are working on alternative protection methods. The aim of this study was to investigate the potential of some antagonistic fungi against wood-decay fungi as a biological control agent (BCA). For this purpose, the antagonistic effects of Trichoderma harzianum, Trichoderma viride, Aspergillus niger, and Penicillium brevicompactum fungi were investigated against the Trametes versicolor, Trametes hirsuta, Stereum hirsutum, Coniophora puteana, Neolentinus lepideus, and Postia placenta species of wood-decay Basidiomycetes fungi. In the study, firstly, inhibition rates were determined by comparing dual culture tests on agar medium, and then the performance of BCAs was compared by performing decay tests on wood blocks. As a result of the study, it was determined that the species belonging to the genus Trichoderma showed a very effective performance on WDF, increased the inhibition rate to 76-99%, and reduced the weight loss to 1.9-5.8%. Considering the inhibition rates, it was determined that the most effective rate of the BCAs was on P. placenta and the least on S. hirsutum species. According to the results obtained, it has been determined that some BCAs were very effective biological control agents of rot fungi on agar and wood blocks in vitro. However, in order to more clearly determine the effectiveness of BCAs in practice, this study, which was carried out in the laboratory environment, should be supported by tests performed in contact with the external field and soil.

In-vitro investigation on the biological activities of squalene derived from the soil fungus Talaromyces pinophilus

The consistent increase in multidrug resistance among pathogens and increased cancer incidence are serious public health concerns and threaten humans by killing countless lives. In the present study, Talaromyces pinophilus CJ15 was characterized and evaluated for its antibacterial, candidicidal and cytotoxic activities. The selected isolate Talaromyces pinophilus CJ15 with 18S rRNA gene sequence of 1021 base pairs exhibited antifungal activity on plant pathogens via dual culture. The GC-MS profiling of crude extract illustrated the existence of many bioactive macromolecules which include squalene belonging to the terpenoids family. The biological macromolecules in the bioactive fraction of CJ15 exhibited increasing antibacterial activity with an increase in concentration such that the highest activity was recorded against Shigella flexneri with 15, 18, 20, and 24 mm inhibition zones at 25, 50, 75 and 100 μl concentrations, respectively. The squalene, having a molecular weight of 410.718 g/mol, displayed candidicidal activity with a right-side shifted log phase in the growth curve of all the treated Candida species, indicating delayed exponential growth. In cytotoxic activity, the extracted squalene exhibited an IC50 concentration of 26.22 μg/ml against JURKAT cells and induced apoptosis-induced cell death. This study's outcomes encourage the researchers to explore further the development of new and improved bioactive macromolecules that could help to prevent infections and human blood cancer.

Fascinating Furanosteroids and Their Pharmacological Profile

This review article delves into the realm of furanosteroids and related isoprenoid lipids derived from diverse terrestrial and marine sources, exploring their wide array of biological activities and potential pharmacological applications. Fungi, fungal endophytes, plants, and various marine organisms, including sponges, corals, molluscs, and other invertebrates, have proven to be abundant reservoirs of these compounds. The biological activities exhibited by furanosteroids and related lipids encompass anticancer, cytotoxic effects against various cancer cell lines, antiviral, and antifungal effects. Notably, the discovery of exceptional compounds such as nakiterpiosin, malabaricol, dysideasterols, and cortistatins has revealed their potent anti-tuberculosis, antibacterial, and anti-hepatitis C attributes. These compounds also exhibit activity in inhibiting protein kinase C, phospholipase A2, and eliciting cytotoxicity against cancer cells. This comprehensive study emphasizes the significance of furanosteroids and related lipids as valuable natural products with promising therapeutic potential. The remarkable biodiversity found in both terrestrial and marine ecosystems offers an extensive resource for unearthing novel biologically active compounds, paving the way for future drug development and advancements in biomedical research. This review presents a compilation of data obtained from various studies conducted by different authors who employed the PASS software 9.1 to evaluate the biological activity of natural furanosteroids and compounds closely related to them. The utilization of the PASS software in this context offers valuable advantages, such as screening large chemical libraries, identifying compounds for subsequent experimental investigations, and gaining insights into potential biological activities based on their structural features. Nevertheless, it is crucial to emphasize that experimental validation remains indispensable for confirming the predicted activities.

A Simple Formula of the Endophytic Trichoderma viride, a Case Study for the Management of Rhizoctonia solani on the Common Bean

The utilization of beneficial endophytic microorganisms presents a promising and innovative strategy for attaining environmental sustainability and fostering development. The majority of microbial bioagents are unsuitable for preparation in a suitable granular formula, and few are prepared in complicated formulas. In this work, Trichoderma viride was simply prepared in a marketable granular formula to manage Rhizoctonia solani and improve common bean growth. The GC-MS analysis showed several antimicrobial compounds in the fungal filtrate. T. viride was able to suppress the phytopathogenic R. solani in the laboratory. The formula had up to 6 months of shelf-life viability. Under greenhouse conditions, the formula improved plant resistance against R. solani. Moreover, the vegetative plant growth and physiological performance (peroxidase, polyphenol, total phenols, phenylalanine ammonia-lyase, and photosynthetic pigments) of the common bean showed obvious promotion. The formula reduced the disease incidence by 82.68% and increased the yield by 69.28%. This work may be considered a step in the right direction for producing simple bioactive products on a large scale. Moreover, the study's findings suggest that this method can be considered a novel approach to enhancing plant growth and protection, in addition to reducing costs, improving handling and application, and maintaining fungal viability for enhancing plant growth and protecting against fungal infections.

Aspergillus niger CJ6 extract with antimicrobial potential promotes in-vitro cytotoxicity and induced apoptosis against MIA PaCa-2 cell line

Nowadays, the increased number of multidrug-resistant strains among pathogens is a severe public health concern and cancer is posing a great threat for humans. These problems should be tackled with the development of novel and broad-spectrum antimicrobials from microbial origin. During the present study, the bioactive secondary metabolites from Aspergillus niger CJ6 were extracted, characterized; their biological properties were evaluated by subjecting them for antimicrobial, antifungal and anticancer activities. The potent isolate Aspergillus niger CJ6 with nucleotide sequence of 959 base pairs showed antagonistic activity against fungal pathogens in dual culture. The chemical profiling of crude ethyl acetate extract indicated the presence of various bioactive molecules belonging to phenolic, hydrocarbons, and phthalate derivative classes. In antimicrobial activity, the crude extract displayed increasing activity with increased concentration; the highest activity observed against Shigella flexneri with 15 ± 1.0, 19 ± 0.5, 20 ± 1.0 and 24 ± 1.0 mm zones of inhibition at 25, 50, 75 and 100 μl concentrations. The MTT assay illustrated deformed cells of MIA PaCa-2 cell line in in-vitro cytotoxic activity; outflow of cell matrix and membrane rupture; the IC₅₀ of 90.78 μg/ml suggested moderate potential of extract to prevent cancer cell growth. The apoptosis/necrosis study by flow cytometer exhibited 8.98 ± 0.85% early and 73 ± 0.7% of late apoptotic population with 3.8 ± 1.1% necrotic cells; only 14.22 ± 0.6% of healthy cells suggested the increased apoptosis inducing capacity of Aspergillus niger CJ6 crude extract. The outcomes of this study persuade further exploration on the identification, purification and development of novel bioactive agents that could help battle fatal diseases in humans.

Bioactive secondary metabolites from Trichoderma viride MM21: structure elucidation, molecular docking and biological activity

Four bioactive metabolites; ergosterol (1), peroxy ergosterol (2), α-cyclopiazonic acid (3) and kojic acid (4), were isolated from the fungal sp. Trichoderma viride MM21. Their structures were assigned by cumulative analysis of NMR and mass spectra, and comparison with literature. The antimicrobial activity of the fungus supernatant, mycelial cake, cumulative crude extract and compounds 1-4 was broadly studied against 11 diverse pathogens, revealing auspicious activity results. Based on the molecular docking, ergosterol (1) and peroxy ergosterol (2) were picked up to be computationally tested against topoisomerase IV of Staphylococcus aureus. The nominated enzyme is a possible target for the antibacterial activity of triterpenoidal/steroidal compounds. Compounds 1, 2 showed a deep inserting inside the enzyme groove recording a good binding affinity of -8.1 and -8.4 kcal/mol, respectively. Noteworthy that the antibacterial activity of ergosterol was higher (14-17 mm) than peroxy ergosterol (11-14 mm), although ergosterol formed only one hydrogen bond with the target, while peroxy ergosterol formed three hydrogen bonds. Such higher antibacterial activity of ergosterol may be attributed to its interference with other proteins included in this inhibition. The cytotoxic activity was tested against brine shrimp, revealing 100% mortality for the supernatant, crude extract and whole isolated compounds. Such strong cytotoxicity is attributed most likely to the abundant productivity/concentration of α-cyclopiazonic acid and kojic acid.

Trichoderma asperellum empowers tomato plants and suppresses Fusarium oxysporum through priming responses

Plant-associated microbes play crucial roles in plant health and promote growth under stress. Tomato (Solanum lycopersicum) is one of the strategic crops grown throughout Egypt and is a widely grown vegetable worldwide. However, plant disease severely affects tomato production. The post-harvest disease (Fusarium wilt disease) affects food security globally, especially in the tomato fields. Thus, an alternative effective and economical biological treatment to the disease was recently established using Trichoderma asperellum. However, the role of rhizosphere microbiota in the resistance of tomato plants against soil-borne Fusarium wilt disease (FWD) remains unclear. In the current study, a dual culture assay of T. asperellum against various phytopathogens (e.g., Fusarium oxysporum, F. solani, Alternaria alternata, Rhizoctonia solani, and F. graminerarum) was performed in vitro. Interestingly, T. asperellum exhibited the highest mycelial inhibition rate (53.24%) against F. oxysporum. In addition, 30% free cell filtrate of T. asperellum inhibited F. oxysporum by 59.39%. Various underlying mechanisms were studied to explore the antifungal activity against F. oxysporum, such as chitinase activity, analysis of bioactive compounds by gas chromatography–mass spectrometry (GC–MS), and assessment of fungal secondary metabolites against F. oxysporum mycotoxins in tomato fruits. Additionally, the plant growth-promoting traits of T. asperellum were studied (e.g., IAA production, Phosphate solubilization), and the impact on tomato seeds germination. Scanning electron microscopy, plant root sections, and confocal microscopy were used to show the mobility of the fungal endophyte activity to promote tomato root growth compared with untreated tomato root. T. asperellum enhanced the growth of tomato seeds and controlled the wilt disease caused by the phytopathogen F. oxysporum by enhancing the number of leaves as well as shoot and root length (cm) and fresh and dry weights (g). Furthermore, Trichoderma extract protects tomato fruits from post-harvest infection by F. oxysporum. Taking together, T. asperellum represents a safe and effective controlling agent against Fusarium infection of tomato plants.

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.

Biosynthesis of zinc oxide nanoparticles via endophyte Trichoderma viride and evaluation of their antimicrobial and antioxidant properties

The biogenic method for synthesis of nanoparticles is preferred over the traditional strategies, on account of its ease, environmental friendliness, and cost-effectivity, wherein fungi endorse themselves to be the most appropriate precursor for the same. In recent times numerous metal nanoparticles have been reported to exhibit significant therapeutic activities, out of which Zinc Oxide nanoparticles (ZnO NPs) stand apart on account of their multidimensional nature. Thus, this study was carried out with an aim to biosynthesize ZnO NPs utilizing endophyte Trichoderma viride, isolated from the seeds of Momordica charantia. The physicochemical characterization of NPs was done via employing a combination of spectroscopic and microscopic techniques. The NPs were found to have a hexagonal shape and possessed an average particle size of around 63.3 nm. The antimicrobial activity of NPs was evaluated against multi-drug resistant organisms and it was observed to be an appreciable one whereas the antioxidant activity was deduced to be dose-dependent. Thus, these ZnO NPs can be considered as a probable active ingredient of any future therapeutic conceptualization after undertaking a thorough toxicological assessment.

Genome-Based Analysis of Verticillium Polyketide Synthase Gene Clusters

Simple Summary

Fungi can produce many types of secondary metabolites, including mycotoxins. Poisonous mushrooms and mycotoxins that cause food spoilage have been known for a very long time. For example, Aspergillus flavus, which can grow on grains and nuts, produces highly toxic substances called Aflatoxins. Despite their menace to other living organisms, mycotoxins can be used for medicinal purposes, i.e., as antibiotics, growth-promoting compounds, and other kinds of drugs. These and other secondary metabolites produced by plant-pathogenic fungi may cause host plants to display disease symptoms and may play a substantial role in disease progression. Therefore, the identification and characterization of the genes involved in their biosynthesis are essential for understanding the molecular mechanism involved in their biosynthetic pathways and further promoting sustainable knowledge-based crop production.

Abstract

Polyketides are structurally diverse and physiologically active secondary metabolites produced by many organisms, including fungi. The biosynthesis of polyketides from acyl-CoA thioesters is catalyzed by polyketide synthases, PKSs. Polyketides play roles including in cell protection against oxidative stress, non-constitutive (toxic) roles in cell membranes, and promoting the survival of the host organisms. The genus Verticillium comprises many species that affect a wide range of organisms including plants, insects, and other fungi. Many are known as causal agents of Verticillium wilt diseases in plants. In this study, a comparative genomics approach involving several Verticillium species led us to evaluate the potential of Verticillium species for producing polyketides and to identify putative polyketide biosynthesis gene clusters. The next step was to characterize them and predict the types of polyketide compounds they might produce. We used publicly available sequences from ten species of Verticillium including V. dahliae, V. longisporum, V. nonalfalfae, V. alfalfae, V. nubilum, V. zaregamsianum, V. klebahnii, V. tricorpus, V. isaacii, and V. albo-atrum to identify and characterize PKS gene clusters by utilizing a range of bioinformatic and phylogenetic approaches. We found 32 putative PKS genes and possible clusters in the genomes of Verticillium species. All the clusters appear to be complete and functional. In addition, at least five clusters including putative DHN-melanin-, cytochalasin-, fusarielien-, fujikurin-, and lijiquinone-like compounds may belong to the active PKS repertoire of Verticillium. These results will pave the way for further functional studies to understand the role of these clusters.

Coculture of Trichoderma harzianum and Bacillus velezensis Based on Metabolic Cross-Feeding Modulates Lipopeptide Production

Cocultures have been widely explored for their use in deciphering microbial interaction and its impact on the metabolisms of the interacting microorganisms. In this work, we investigate, in different liquid coculture conditions, the compatibility of two microorganisms with the potential for the biocontrol of plant diseases: the fungus Trichoderma harzianum IHEM5437 and the bacterium Bacillus velezensis GA1 (a strong antifungal lipopeptide producing strain). While the Bacillus overgrew the Trichoderma in a rich medium due to its antifungal lipopeptide production, a drastically different trend was observed in a medium in which a nitrogen nutritional dependency was imposed. Indeed, in this minimum medium containing nitrate as the sole nitrogen source, cooperation between the bacterium and the fungus was established. This is reflected by the growth of both species as well as the inhibition of the expression of Bacillus genes encoding lipopeptide synthetases. Interestingly, the growth of the bacterium in the minimum medium was enabled by the amendment of the culture by the fungal supernatant, which, in this case, ensures a high production yield of lipopeptides. These results highlight, for the first time, that Trichoderma harzianum and Bacillus velezensis are able, in specific environmental conditions, to adapt their metabolisms in order to grow together.

Airborne bacterial and fungal concentrations and fungal diversity in bedrooms of infant twins under 1 year of age living in Porto

Exposure to airborne microorganisms has been linked to the development of health detriments, particularly in children. Microbial pollution can constitute a relevant health concern indoors, where levels of airborne microorganisms may be specially increased. This work aimed to characterize the airborne bacterial levels, and fungal concentration and diversity to which twins are exposed in their bedrooms (n = 30) during the first year of life. Bacterial and fungal levels varied widely across the studied bedrooms, with 10% of the rooms presenting values exceeding the national limit for both indoor bacterial and fungal counts. Cladosporium was the predominant genera, but Penicillium, Aspergillus, Alternaria, Trichoderma and Chrysonilia were also identified in the samples collected. In addition, two toxicogenic species, A. flavus and T. viride, were identified at counts that exceeded the established limit (12 CFU/m³) in 3 and 7% of the bedrooms surveyed, respectively. Based on indoor-to-outdoor concentration ratios, outdoor air seemed to be the main contributor to the total load of fungi found indoors, while airborne bacteria appeared to be mainly linked to indoor sources. Higher indoor nitrogen dioxide levels were negatively correlated with indoor fungi concentrations, whereas particulate matter and volatile organic compounds concentrations were associated with an increase in fungal prevalence. In addition, rooms with small carpets or located near outdoor agriculture sources presented significantly greater total fungal concentrations. Multiple linear regression models showed that outdoor levels were the single significant predictor identified, explaining 38.6 and 53.6% of the Cladosporium sp. and total fungi counts, respectively. The results also suggest the existence of additional factors contributing to airborne biologicals load in infants' bedrooms that deserve further investigation. Findings stress the need for investigating the existence of declared interactive effects between chemical and biological air pollutants to accurately understand the health risk that the assessed levels can represent to infants.

A Novel Endophytic Trichoderma longibrachiatum WKA55 With Biologically Active Metabolites for Promoting Germination and Reducing Mycotoxinogenic Fungi of Peanut

Plant residuals comprise the natural habitat of the plant pathogen; therefore, attention is currently focusing on biological-based bioprocessing of biomass residuals into benefit substances. The current study focused on the biodegradation of peanut plant residual (PNR) into citric acid (CA) through a mathematical modeling strategy. Novel endophytic Trichoderma longibrachiatum WKA55 (GenBank accession number: MZ014020.1), having lytic (cellulase, protease, and polygalacturonase) activity, and tricalcium phosphate (TCP) solubilization ability were isolated from peanut seeds and used during the fermentation process. As reported by HPLC, the maximum CA (5505.1 μg/g PNR) was obtained after 9 days in the presence of 15.49 mg TCP, and 15.68 mg glucose. GC–MS analysis showed other bioactive metabolites in the filtrate of the fermented PNR. Practically, the crude product (40%) fully inhibited (100%) the growth and spore germination of three mycotoxinogenic fungi. On peanuts, it improved the seed germination (91%), seedling features, and vigor index (70.45%) with a reduction of abnormal seedlings (9.33%). The current study presents the fundamentals for large-scale production in the industry for the sustainable development of PNR biomass as a natural source of bioactive metabolites, and safe consumption of lignocellulosic-proteinaceous biomass, as well. T. longibrachiatum WKA55 was also introduced as a novel CA producer specified on PNR. Application of the resulting metabolite is encouraged on a large scale.

In-vitro compatibility assay of indigenous Trichoderma and Pseudomonas species and their antagonistic activities against black root rot disease (Fusarium solani) of faba bean (Vicia faba L.)

Background

Faba bean (Vicia faba L.) cultivation is highly challenged by faba bean black root rot disease (Fusarium solani) in high lands of Ethiopia. To ensure sustainable production of faba beans, searching for eco-friendly disease management options is necessary to curb the progress of the disease timely. The indigenous biocontrol agents that suit local environments may effectively strive with in-situ microorganisms and suppress local pathogen strains. This study aimed to screen antagonistic indigenous compatible Trichoderma and Pseudomonas strains against Fusarium solani. In the pathogenicity test, soil-filled pots were arranged in complete random block design and sown with health faba bean seeds. The effect of some fungicides was evaluated against Fusarium by food poisoning methods to compare with the biocontrol agents. The antagonistic efficacy of biocontrol agents and their compatibility was investigated on Potato dextrose agar medium.

Results

Fusarium solani AAUF51 strain caused an intense root rotting in faba bean plant. The effect of Mancozeb 80% WP at 300 ppm was comparable with Trichoderma and Pseudomonas strains against Fusarium. The mycelial growth of test the pathogen was significantly (P ≤ 0.05) reduced to 86.67 and 85.19% by Trichoderma harzianum AAUW1 and Trichoderma viridae AAUC22 strains in dual culture, respectively. The volatile metabolites of Pseudomonas aeruginosa AAUS31 (77.78%) found the most efficient in reducing mycelial growth of Fusarium followed by Pseudomonas fluorescens AAUPF62 (71.11%) strains. The cell-free culture filtrates of Pseudomonas fluorescens AAUPF62 and Pseudomonas aeruginosa AAUS31 were more efficient than the Trichoderma strain in reducing the growth of Fusarium isolates. There was no zone of inhibition recorded between Trichoderma harzianum AAUW1, Trichoderma viridae AAUC22, Pseudomonas aeruginosa AAUS31, and Pseudomonas fluorescens AAUPF62 strains, hence they were mutually compatible.

Conclusions

The compatible Trichoderma and Pseudomonas strains showed antagonistic potentiality that could be explored for faba bean protection against black root rot disease and might have a future dual application as biocontrol agents.

Biochemical and Biotechnological Studies on Xylanase and β‐xylosidase Enzymes Produced by Trichoderma viride Under Solid State Fermentation

The current study concerns with enhancement of xylanase and β-xylosidase activities from lignocellulosic materials by soil derived fungi Trichoderma viride under solid state fermentation (SSF). Xylanase and β-xylosidase activities were found to affected by variety of factors. In this study, some agricultural wastes were selected and used as sources for carbon. Sugar beet pulp (SBP) was at the forefront of these types. Also, various sources for nitrogen were selected to determine the best one. Yeast extract was the best organic source. Maximum xylanase activity took place by using inoculum size 1.8 × 105 spores / ml at 30°C when the pH was 5.5 for eight days of incubation with the addition of 0.1 % of Tween 40. Moreover, spores of Trichoderma viride were irradiated with gamma–rays. The maximum activity was observed upon using 0.7 kilo-gray (kGy). Furthermore, mixed cultures of Trichoderma viride and Penicillium janthenellum (wt / wt) were enhanced xylanase degrading capability. From another standpoint, ammonium sulphate and gel filtration chromatography were the best methods for xylanase purification. Characterizations of the purified enzyme were also selected and studied. It was found that, β-xylosidase enzyme exhibited its maximum activity and stability when the pH was 6 at 40°C by the addition of CaCl2 metal ion. On the other hand, total protein contents and volatile constituents of Trichoderma viride and Penicillium janthenellum were separated and investigated using high performance liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GC/MS) techniques. It was found that, total protein contents for Trichoderma viride and Penicillium janthenellum were represented by fifteen and sixteen amino acids respectively. Also,29 compounds of the total volatile compounds for both Trichoderma viride and Penicillium janthenellum were identified. On the practical and applied field, crude enzyme was a good analyzer for agricultural residues as well showed antifungal and antibacterial effects.

Belowground fungal volatiles perception in okra (Abelmoschus esculentus) facilitates plant growth under biotic stress

Microbial volatile organic compounds (mVOCs) have great potential in plant ecophysiology, yet the role of belowground VOCs in plant stress management remains largely obscure. Analysis of biocontrol producing VOCs into the soil allow detailed insight into their interaction with soil borne pathogens for plant disease management. A root interaction trial was set up to evaluate the effects of VOCs released from Trichoderma viride BHU-V2 on soil-inhabiting fungal pathogen and okra plant growth. VOCs released into soil by T. viride BHU-V2 inhibited the growth of collar rot pathogen, Sclerotium rolfsii. Okra plants responded to VOCs by increasing the root growth (lateral roots) and total biomass content. VOCs exposure increased defense mechanism in okra plants by inducing different enzyme activities i.e. chitinase (0.89 fold), β-1,3-glucanase (0.42 fold), peroxidase (0.29 fold), polyphenol oxidase (0.33 fold) and phenylalanine lyase (0.7 fold) when inoculated with S. rolfsii. In addition, T. viride BHU-V2 secreted VOCs reduced lipid peroxidation and cell death in okra plants under pathogen inoculated condition. GC/MS analysis of VOCs blend revealed that T. viride BHU-V2 produced more number of antifungal compounds in soil medium as compared to standard medium. Based on the above observations it is concluded that okra plant roots perceive VOCs secreted by T. viride BHU-V2 into soil that involved in induction of plant defense system against S. rolfsii. In an ecological context, the findings reveal that belowground microbial VOCs may play an important role in stress signaling mechanism to interact with plants.

Antimicrobial Activity of Cultivable Endophytic and Rhizosphere Fungi Associated with "Mile-a-Minute," Mikania cordata (Asteraceae)

Endophytic and rhizosphere fungi are understood to be aiding the host plant to overcome a range of biotic and abiotic stresses (nutrition depletion, droughts, etc.) hence, they remain to be reservoirs of plethora of natural products with immense use. Consequently, this investigation of endophytic and rhizosphere fungi isolated from Mikania cordata (a perennial vine that is well established in Sri Lanka) for their antimicrobial properties was performed with the aim of future derivation of potential beneficial pharmaceutical products. Leaves, twigs, and roots of M. cordata were utilized to isolate a total of 9 endophytic fungi out of which the highest amount (44%) accounted was from the twigs. A sample of the immediate layer of soil adhering to the root of M. cordata was utilized to isolate 15 rhizosphere fungi. Fusarium equiseti and Phoma medicaginis were endophytes that were identified based on colony and molecular characteristics. The broad spectrum of antimicrobial activity depicted by F. equiseti (MK517551) was found to be significantly greater (p ≤ 0.05, inhibitory against Bacillus cereus ATCC 11778, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) than P. medicaginis (MK517550) (inhibitory against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) as assessed using the Kirby-Bauer disk diffusion method. Trichoderma virens and Trichoderma asperellum were rhizospere fungi that exhibited remarkable antimicrobial properties against the test pathogens chosen for the study. T. asperellum indicated significantly greater bioactivity against all four bacterial pathogens and Candida albicans ATCC 10231 under study. The ranges of minimum inhibitory concentrations (MICs) of the fungi depicting antimicrobial properties were determined. The results obtained suggest that F. equiseti, P. medicaginis, T. asperellum, and T. virens of M. cordata harness bioprospective values as natural drug candidates. This is the first report on isolation and evaluation of the antimicrobial properties of endophytic and rhizosphere fungi of Mikania cordata.

A concise total synthesis and PPAR activation activity of hericerin from Hericium erinaceum

Hericerin is an isoindolinone meroterpenoid alkaloid isolated from medicinal mushroom Hericium erinaceum with some bioactivities. Herein, a concise total synthesis of hericerin was described, with four steps and 30% overall yield starting from commercially available methyl 3-hydroxy-5-methoxybenzoate and geranyl bromide. A comprehensive effect of hericerin on HepG2 cell line was observed and confirmed by transcriptomic analysis. Furthermore, hericerin was found to be a new PPARγ agonist.

Sesquiterpenes with Phytopathogenic Fungi Inhibitory Activities from Fungus Trichoderma virens from Litchi chinensis Sonn

A new monosesquiterpene diacetylgliocladic acid (1), a new dimeric sesquiterpene divirensol H (9), and two exceptionally novel trimeric sesquiterpene trivirensols A and B (11 and 12), together with another eight known congeners, were purified from an endophytic fungus Trichoderma virens FY06, derived from Litchi chinensis Sonn. whose fruit is a delicious and popular food. All of them were identified by comprehensive spectroscopic analysis, combined with biosynthetic considerations. Trivirensols A and B are unprecedented trimers of which three subunits are connected by two ester bonds of the sesquiterpene class. Relative to the positive control triadimefon, all the tested metabolites showed strong inhibitory activities against at least one phytopathogenic fungus among Penicillium italicum, Fusarium oxysporum, Fusarium graminearum, Colletotrichum musae, and Colletotrictum gloeosporioides. Notably, as metabolites of the endophytic fungus from L. chinensis, they all presented strong antifungal activities against C. gloeosporioides which causes anthracnose in L. chinensis.

Larvicidal, Histopathological, Antibacterial Activity of Indigenous Fungus Penicillium sp. Against Aedes aegypti L and Culex quinquefasciatus (Say) (Diptera: Culicidae) and Its Acetylcholinesterase Inhibition and Toxicity Assessment of Zebrafish (Danio rerio)

Fungal metabolites are considered to be most efficient tools to overcome the issues related to insecticide resistance and environmental pollution. The present study focus on the evaluation of the mosquito larvicidal efficacy of metabolites of seven indigenous fungal isolates (Penicillium sp. Aspergillus niger, A. flavus, A. parasiticus, Rhizopus sp. Mucor sp. and Aspergillus sp.) on the larvae of Aedes aegypti and Culex quinquefasciatus under the laboratory condition. The preliminary screening of the isolate, Penicillium sp. showed better larvicidal effect when compared to other fungi. The fungus was grown on Potato Dextrose Broth (PDB) in the laboratory (at 25°C) and maintained in the relative humidity (at 76 ± 4% for 15 days). Larvicidal potency of mycelial ethyl acetate extract (MEAE) of Penicillium sp. was performed against 1st to 4th instars larvae of Ae. aegypti and Cx. quinquefasciatus using four different concentrations (100, 200, 300, and 500 μg/ml) that showed better larval mortality values (μg/ml) of LC50 = 6.554, 5.487, 6.874, 6.892, and the LC90 = 11.486, 10.366, 12.879, 13.865 for Ae. aegypti and LC50 = 7.000, 13.943, 18.129, 25.212 and the LC90 = 12.541, 23.761, 30.923, 41.696 for Cx. quinquefasciatus. Exposure of metabolite to larvae resulted in behavior changes i.e., excitation, up and down with aggressive movement, anal papillae biting behavior. Further, the larvae treated with Penicillium sp. metabolite exhibited significant reduction in the levels of acetylcholinesterase. The 4th instar mosquito larvae treated with the 500 μg/ml mycelia extract showed severe histological damages. During the antibacterial analysis of Penicillium sp.- mycelium the maximum growth inhibition zone was recorded in Shigella dysenteriae (31.2 mm) and Klebsiella pneumoniae (31.1 mm) followed by others. In addition, to check the toxicity of Penicillium sp. MEAE against embryos of Zebrafish, a model system, using different concentrations of metabolites (1.0, 0.5, 0.125 mg/ml, 30, 3.0, and 0.5 μg/ml) and life-stage parameters were observed at 124 hpf. Furthermore, the Fourier Transformed Infrared and GCMS spectrum analysis of mycelium reflected several chemical compounds. The outcome of the study clearly shows that Penicillium sp. metabolites could serve as an ideal eco-friendly, single-step and inexpensive source for the control of Ae. aegypti and Cx. quinquefasciatus larvae.