Biodiversity and antibacterial screening of endophytic fungi isolated from Pelargonium sidoides

Abstract

To investigate the biodiversity of endophytic fungi isolated from indigenous Pelargonium sidoides plants using morphological and molecular techniques and also screen isolates for antibacterial activities. In the present study, a total of 50 Pelargonium sidoides plants were collected and the roots were analysed for the presence of endophytic fungi. The fungi were initially sorted according to morphological characteristics. Fungal identities were further confirmed through amplification of sequences encoding Translation Elongation Factor-1α (TEF-1α) gene for Fusarium species and Internal Transcribed Spacer (ITS) regions for all other fungi. Fungi were screened for antibacterial activity by adopting the standard Kirby-Bauer agar disc diffusion method using a pathogenic Escherichia coli strain (Code from the collection) previously isolated from cattle. A total of 133 fungi belonging to 32 genera were successfully isolated and identified in the study based morphological analyses. Fungi belonging to the genus Penicillium were dominant (23%) among the isolates when compared with Fusarium species (12%) as well as Alternaria and Aspergillus that were detected at 11% respectively. Antibacterial agent producing data revealed that Aspergillus sp. (KM458796.1), Penicillium expansum (LC015096.1) and Aspergillus niger (KP172477.1) produced the strongest bactericidal activity against the E. coli strain with growth inhibition zone diameter data of 11 mm, 5 mm and 4 mm respectively. To the best of our knowledge, this is the first study in which the diversity of fungi from Pelargonium sidoides has been assessed and the findings revealed that fungal diversity is directly related to their potential to produce bioactive compounds