Antibacterial activities of endophytic fungi isolated from six Sri Lankan plants of the family Cyperaceae

Abstract

<p class="Abstract">In a study designed to determine the antibacterial potential of endophytic fungi inhabiting plants of Cyperaceae family, 72 morphologically distinct endophytic fungi were isolated from six plants and their antibacterial activities against two Gram positive and three Gram negative pathogenic bacterial species were examined. Two antibacterial metabolites from two endophytes were also isolated and their chemical structures and minimum inhibitory concentrations were determined. Sixty six fungal extracts (92%) were active against at least one bacterium tested. Butyrolactone I isolated from the Aspergillus terreus and 9-epi viridol isolated from Trichoderma virens exhibited MIC values in the range 128-256 µg/mL against Gram positive Bacillus subtilits, Staphylococcus aureus, methicillin resistant S. aureus (MRSA) and Escherichia coli. Both compounds were inactive against other micro-organisms tested. This study confirmed that Cyperaceae plants harbor numerous endophytes that produce antibacterial metabolites active against both Gram positive and, to a lesser extent, Gram negative bacteria.</p><p><strong>Video Clip of Methodology:</strong></p><p>Column Chromatogrpahy: 15 min 34 sec <a href="https://www.youtube.com/v/CqF3GmhSHN4">Full Screen</a> <a href="https://www.youtube.com/watch?v=CqF3GmhSHN4">Alternate</a></p>

Antifeedant, contact toxicity and oviposition deterrent effects of phyllostine acetate and phyllostine isolated from the endophytic fungus Diaporthe miriciae against Plutella xylostella larvae

“…Seventeen endophytic fungi, twelve from aerial parts and five from roots, were isolated from C. iria plants. A previous study using the Cyperaceae plants C. brevifolius , C. melanospermus , C. alternifolius , C. bulbosus , C. rotundus and F. miliaceae reported that these plants are good reservoirs for endophytic fungi with a high species richness with no obvious preference for endophyte location in the plants, aerial or roots . In the current study, C. iria provided a similar number of fungi to C. melanospermus from the above‐mentioned report .…”

“…A previous study using the Cyperaceae plants C. brevifolius , C. melanospermus , C. alternifolius , C. bulbosus , C. rotundus and F. miliaceae reported that these plants are good reservoirs for endophytic fungi with a high species richness with no obvious preference for endophyte location in the plants, aerial or roots . In the current study, C. iria provided a similar number of fungi to C. melanospermus from the above‐mentioned report . The endophytic fungi isolated and antifeedant activities obtained from the no choice leaf disc assay are shown in Table .…”

“…Some grasses and sedges are used for food and herbal medicine, whereas others are used to keep insect pests away from crops. Previous studies have reported that grasses and sedges are reservoirs for a number of endophytic fungi . Endophytic fungi grow in the internal tissues of plants without causing any disease symptoms to the host .…”

“…Previous studies have reported that grasses and sedges are reservoirs for a number of endophytic fungi . Endophytic fungi grow in the internal tissues of plants without causing any disease symptoms to the host . It has been reported that the clavicipitaceous endophytes inhabiting grasses enhance host resistance to insect feeding and pathogenic attacks .…”

“…However, our recent investigation of the endophytic fungus Rhizoctonia solani , a common inhabitant of the sedge Cyperus rotandus , led to the isolation of solanioic acid, a potent antibiotic with a novel carbon skeleton . In addition, in a second study, two antibiotics, 9‐epi viridol and butyrolactone I, were isolated from endophytic fungi of C. meanospermus and C. bulbosus , respectively . These studies revealed that endophytes of the Cyperaceae are a potentially rich source of biologically active secondary metabolites that merit further investigation.…”