Endophytic fungi occurring in Ipomoea carnea tissues and their antimicrobial potentials

The aim of this work was to study the endophytic fungi associated with the tissues of Ipomoea carnea, a common invasive plant of India. A total of 69 isolates belonging to ten taxa comprising 1.45% Zygomycetes, 10.14% Coelomycetes, 62.32% Hypomycetes, 18.84% sterile mycelia and 7.25% unidentified species were obtained. Species of Curvularia, Aspergillus, Fusarium, Colletotrichum and sterile fungus were isolated as dominant endophytes. Colonization frequency of Curvularia (7.25%) was highest which was isolated from all the tissues. The samples collected during the monsoon harbored more endophytes and showed higher species richness than the samples obtained in summer season. Of the total isolates, 15 isolates (21.74%) displayed antimicrobial activity, inhibiting at least one of the test microorganisms that comprised of pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhi, Pseudomonas fluorescens, Shigella dysentriae) and fungi (Trichophyton rubrum, Aspergillus fumigatus, Trichophyton sp). The results provided promising baseline information on the endophytic fungal diversity associated with I. carnea tissues and their potential exploitation as antimicrobial agents

Antimicrobial secondary metabolites of an endolichenic Aspergillus niger isolated from lichen thallus of Parmotrema ravum

A new 6-benzyl-γ-pyrone (1), named aspergyllone was isolated from the culture filtrates of an endolichenic fungus Aspergillus niger Tiegh, obtained from lichen thallus Parmotrema ravum (Krog & Swinscow) Serus, collected in India. 1 was isolated for the first time from an endolichenic fungus together with six other known metabolites identified as aurasperones A (2) and D (3), asperpyrone A (4), fonsecinone A (5), carbonarone A (6) and pyrophen (7). The compounds were tested against a panel of human, plant, food borne and fish pathogens. Aspergyllone showed strong selective antifungal activity against Candida parapsilosis (Ashford) Langeron & Talice, with an IC50 of 52 µg/mL. Aurasperone A and pyrophen showed moderate to strong antimicrobial activity inhibiting seven different test pathogens, being pyrophen active with IC50 ranging from 35 to 97 µg/mL.[Formula: see text].status: publishe