Endophytism and bioactivity of endophytic fungi isolated from Combretum lanceolatum Pohl ex Eichler

Abstract

We report the isolation and identification of endophytic fungi from Combretum lanceolatum Pohl ex Eichler. Further, we evaluated the relationships of fungi with the host plant and tested bioactivities of isolates. The fungi were isolated from disinfected root fragments and plated onto potato dextrose agar. Root pieces were also used to quantify fungal structures associated with the roots. Identification of fungi was carried out by characterization of morphological features and sequencing of the ITS region. Endophytism was confirmed by inoculation of endophyte-free seedlings followed by microscopic examination. The extract was obtained by maceration of the mycelium in ethyl acetate for antioxidant and antimicrobial evaluations. A total of 112 strains belonging to nine different species were isolated, the major classes were Dothideomycetes and Sordariomycetes. C. lanceolatum is colonized by dark septate endophytes (DSE), evidenced by the presence of microsclerotia and melanized hyphae. There is also co-colonization with mycorrhizal fungi in the same root fragments. Seedling inoculation experiments revealed that C. perangustum-95C and M. phaseolina-46C showed association with the seedlings of C. lanceolatum and differentiated microsclerotia and dark septate hyphae, indicating that these species are DSE. In the antimicrobial test, the D. phaseolorum-92C extract had the highest zones of inhibition against S. aureus and E. coli, respectively. The results showed that 100 % of the extracts have antioxidant activity ranging from low to moderate. All endophyte species had antioxidant and antimicrobial activities that were directly proportional to the dose-responses. Future research will involve chemical characterization and structural elucidation of bioactive compounds.

Diversity and Bioactivity of Endophytes From Angelica sinensis in China

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Antimicrobial assay of endophytic fungi from Rumex madaio and chemical study of strain R1

“…All purified endophytic strains were subjected to antimicrobial assay. Taxonomic assignment was only deployed on bioactive endophytic strains with potent antimicrobial effects on basis of morphological properties and 18S rRNA sequence analysis according to the methods developed (Santos et al, 2012;de Siqueira et al, 2017). 18S rRNA fragments of bioactive strains were obtained by amplification of genomic DNA using forward primer NS1-GTAGTCATATGCTTGTCTC and reverse primer NS6-GCATCACAGACCTGTTATTG-CCTC.…”

Development and validation of an HPLC-DAD analytical method to quantify 5-methoxyflavones in methanolic extracts of Vochysia divergens Pohl cultured under stress conditions

“…For seven days, the endophytic fungi Zopfiella tetraspora (Zt), (GenBank access number KY230165, Similarity 95%) and Melanconiella elegans (Me), (GenBank access number KJ173701, Similarity 96%) isolated from V. divergens during the dry period in Pantanal (as described by Siqueira 18 were activated on BDA medium. DNA was extracted according to Specht et al 19 The primers ITS5 (TCC GTA GGT GAA CCT GCG G) and ITS4 (TCC TCC GCT TAT TGA TAT GC) were used for amplification of the ITS region.…”