Evaluation of antimicrobial activity of endophytic fungi from Camptotheca acuminata (Nyssaceae)

Health-Promoting Effects of Bioactive Compounds from Plant Endophytic Fungi

The study examines the intricate relationship between plants and the endophytic fungi inhabiting their tissues. These fungi harmoniously coexist with plants, forming a distinct symbiotic connection that has caught scientific attention due to its potential implications for plant health and growth. The diverse range of bioactive compounds produced by these fungi holds significant promise for human health. The review covers various aspects of this topic, starting by introducing endophytic microorganisms, explaining their colonization of different plant parts, and illuminating their potential roles in enhancing plant defense against diseases and promoting growth. The review emphasizes the widespread occurrence and diversity of these microorganisms among plant species while highlighting the complexities and significance of isolating and extracting bioactive compounds from them. It focuses on the health benefits of these bioactive compounds, including their capacity to exhibit antioxidant, anti-inflammatory, antimicrobial, and anticancer effects. The review delves into the mechanisms behind these health-promoting effects, spotlighting how the compounds interact with cellular receptors, signaling pathways, and gene expression. In conclusion, the review provides a comprehensive overview of health-promoting bioactive compounds from plant endophytic fungi. It outlines their multifaceted impact, potential applications, and future research avenues in health and medicine.

Comparative Metabolomics Revealed the Potential Antitumor Characteristics of Four Endophytic Fungi of Brassica rapa L

Endophytic fungi of medicinal plants have attracted wide attention due to their various active biochemical substances that are similar to those of the host plants and can be easily fermented and cultured. As a traditional medicine and food homologous plant in Xinjiang, Brassica rapa L. has a long history of applications. Recently, it has been shown that B. rapa L. has hypoglycemic, antimicrobial, immunomodulatory, and antioxidant properties. However, there are no studies on the function and diversity of enophytic fungi of B. rapa L. Four endophytic fungus (pr6, pr7, pr8, and pr10) strains were isolated from B. rapa L. in our laboratory. The metabolic extracts from pr10 have significant effects in terms of antitumor activity. In this study, in terms of types and contents, compared with those of the other three endophytic fungi, the dominant metabolites of pr10 were determined by comparative metabolomics analysis. The results of metabolomics analysis indicated that the metabolites of pr10 are rich in amino acids and sugar derivatives such as trehalose, whose ability to inhibit the A549 cell line has been proved. This study provides a theoretical basis for the development and utilization of B. rapa L. and its endophytic fungi to form antitumor agents.

Endophytic Penicillium species and their agricultural, biotechnological, and pharmaceutical applications

Penicillium genus constituted by over 200 species is one of the largest and fascinating groups of fungi, particularly well established as a source of antibiotics. Endophytic Penicillium has been reported to colonize their ecological niches and protect their host plant against multiples stresses by exhibiting diverse biological functions that can be exploited for countless applications including agricultural, biotechnological, and pharmaceutical. Over the past 2 decades, endophytic Penicillium species have been investigated beyond their antibiotic potential and numerous applications have been reported. We comprehensively summarized in this review available data (2000-2019) regarding bioactive compounds isolated from endophytic Penicillium species as well as the application of these fungi in multiple agricultural and biotechnological processes. This review has shown that a very large number (131) of endophytes from this genus have been investigated so far and more than 280 compounds exhibiting antimicrobial, anticancer, antiviral, antioxidants, anti-inflammatory, antiparasitics, immunosuppressants, antidiabetic, anti-obesity, antifibrotic, neuroprotective effects, and insecticidal and biocontrol activities have been reported. Moreover, several endophytic Penicillium spp. have been characterized as biocatalysts, plant growth promoters, phytoremediators, and enzyme producers. We hope that this review summarizes the status of research on this genus and will stimulate further investigations.

Antifungal activity of Gallesia integrifolia fruit essential oil

Gallesia integrifolia (Phytolaccaceae) is native to Brazil and has a strong alliaceous odor. The objective of this study was to identify the chemical composition of G. integrifolia fruit essential oil and evaluate fungicidal activity against the main food-borne diseases and food spoilage fungi. The essential oil was extracted by hydrodistillation and identified by GC-MS. From 35 identified compounds, 68% belonged to the organosulfur class. The major compounds were dimethyl trisulfide (15.49%), 2,8-dithianonane (52.63%) and lenthionine (14.69%). The utilized fungi were Aspergillus fumigatus, Aspergillus niger, Aspergillus ochraceus, Aspergillus versicolor, Penicillium funiculosum, Penicillium ochrochloron, Penicillium verrucosum var. cyclopium, and Trichoderma viride. Minimal fungicidal concentration for the essential oil varied from 0.02 to 0.18mg/mL and bifonazole and ketoconazole controls ranged from 0.20 to 3.50mg/mL. The lower concentration of the essential oil was able to control P. ochrochloron, A. fumigatus, A. versicolor, A. ochraceus and T. viride. This study shows a high fungicidal activity of G. integrifolia fruit essential oil and can support future applications by reducing the use of synthetic fungicides.

Volatile organic compounds from endophytic fungi as innovative postharvest control of Fusarium oxysporum in cherry tomato fruits

To assess their potential as biopesticides, the effect on the growth of phytopathogen Fusarium oxysporum of six volatile organic compounds from endophytic fungi was studied in vivo and in vitro; compounds were used both as a mixture and individually. In vivo studies were performed inoculating the pathogen into cherry tomatoes, while the in vitro antifungal effect was studied using agar dilution and gas phase methods. Also, the morphology of the hyphae exposed to these compounds was analyzed. Moreover, the possible mechanism of action of these compounds was determined by studying the respiration and cell membrane permeability. Results show that the compounds have a significant concentration-dependent antifungal effect individually and act in a synergic manner. Additionally, changes in cell membrane permeability, damage to the hyphal morphology, and an inhibitory effect on the respiration were observed. The mixture of the six compounds may be used for postharvest control of F. oxysporum in tomatoes.

Characterisation of the metabolites of an antibacterial endophyte Botryodiplodia theobromae Pat. of Dracaena draco L. by LC-MS/MS

Botryodiplodia theobromae Pat. belongs to the endophytic fungi that live within the tissues of medicinal plants and produce bioactive natural products. The endophyte was isolated from the leaves of Dracaena draco L. The LC-MS-based metabolite fingerprinting of the ethyl acetate extract of B. theobromae with antibacterial activity led to the identification of 13 metabolites pertaining to various classes: dipeptides (maculosin and L,L-cyclo(leucylprolyl), alkaloid (norharman), coumarin and isocoumarins (bergapten, meranzin and monocerin), sesquiterpene (dihydrocumambrin A), aldehyde (formyl indanone), fatty alcohol (halaminol A) and fatty acid amide (palmitoleamide, palmitamide, capsi-amide and oleamide). This study reports for the first time, the LC-MS and LC-MS/MS identification of 13 known bioactive metabolites from the antibacterial ethyl acetate extract of B.theobromae isolated from the leaves of D. draco L.

Endophytic fungi from the genus Colletotrichum are abundant in the Phaseolus vulgaris and have high genetic diversity

AIMS

To evaluate the diversity of endophytic fungi from the leaves of the common bean and the genetic diversity of endophytic fungi from the genus Colletotrichum using IRAP (inter-retrotransposon amplified polymorphism) and REMAP (retrotransposon-microsatellite amplified polymorphism) analyses.

METHODS AND RESULTS

The fungi were isolated by tissue fragmentation and identified by analysing the morphological features and sequencing the internal transcribed spacer (ITS) regions and the rDNA large subunit (LSU). Twenty-seven different taxa were identified. Colletotrichum was the most commonly isolated genera from the common bean (32.69% and 24.29% of the total isolates from the Ouro Negro and Talismã varieties, respectively). The IRAP and REMAP analyses revealed a high genetic diversity in the Colletotrichum endophytic isolates and were able to discriminate these isolates from the phytopathogen Colletotrichum lindemuthianum.

CONCLUSIONS

Fungi from the genus Colletotrichum are abundant in the Phaseolus vulgaris endophytic community, and the IRAP and REMAP markers can be used to rapidly distinguish between C. lindemuthianum and other Colletotrichum members that are frequently found as endophytes.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report of the diversity of endophytic fungi present in the common bean and the use of IRAP and REMAP markers to assess the genetic diversity of endophytic fungi from the genus Colletotrichum.

Endophytic Fungi Isolated from Coleus amboinicus Lour Exhibited Antimicrobial Activity

PURPOSE

Coleus amboinicus is a medicinal plant traditionally used to treat various diseases such as throat infection, cough and fever, diarrhea, nasal congestion and digestive problems. The plant was explored for endophytic fungi producing antimicrobial agents.

METHODS

Screening for endophytic fungi producing antimicrobial agents was conducted using agar plug method and antimicrobial activity of promising ethyl acetate extracts was determined by disc diffusion assay. Thin layer chromatography (TLC) - bioautography was performed to localize the bioactive components within the extract. TLC visualization detection reagents were used to preliminary analyze phytochemical groups of the bioactive compounds.

RESULTS

Three endophytic fungi were obtained, two of them showed promising potential. Agar diffusion method showed that endophytic fungi CAL-2 exhibited antimicrobial activity against P. aeruginosa, B. subtilis, S. aureus and S. thypi, whilst CAS-1 inhibited the growth of B. subtilis. TLC bioautography of ethyl acetate extract of CAL-2 revealed at least three bands exhibited antimicrobial activity and at least two bands showed inhibition of B. subtilis growth. Preliminary analysis of the crude extracts suggests that bioactive compounds within CAL-2 extract are terpenoids, phenolics and phenyl propanoid compounds whilst the antimicrobial agents within CAS-1 extract are terpenoids, propylpropanoids, alkaloids or heterocyclic nitrogen compounds.

CONCLUSION

These data suggest the potential of endophytic fungi of C. amboinicus as source for antimicrobial agents.