Abstract
Medicinal plants contain a vast range of bioactive compounds that are utilized for drug development. However, the over-harvesting of medicinal plants for drug development can lead to their extinction. Endophytes are symbiotic microorganisms to plants and alternative sources for bioactive secondary etabolites as they are capable of producing similar bioactive compounds as their plant hosts. In this study, multilocus sequence analysis (MLSA), was used to confirm the phylogenetic status and identity of six bacterial endophytes (Arthrobacter sp. MHSD1, Pantoea sp. MHSD2, Bacillus infantis strain MHSD3, Pantoea sp. strain MHSD4, Pantoea ananatis strain MHSD5 and Pantoea sp. MHSD6) isolated from Pellaea calomelanos; a medicinal plant isolated in Limpopo province South Africa. Multilocus sequence analysis confirmed the species to be Pseudarthrobacter phenanthrenivorans strain MHSD1, Pantoea sp. strain MHSD2, Bacillus infantis strain MHSD3 Pantoea sp. MHSD4, Pantoea ananatis MHSD5 and Enterobacter hormaechei strain MHSD6. In understanding the genetic profiles of bacterial endophytes and the genetic components that drive their symbitoc relationship with plants, P. phenanthrenivorans strain MHSD1 and E. hormaechei strain MHSD6 genomes were sequenced, assembled and annoted. The draft genome sizes and G+C contents of strains MHSD1 and MHSD6 were within the ranges of closely related bacterial species. Genome comparison analysis between bacterial endophytic isolates with their non-endophytic counterparts were done to identify genes that involved in bacterial endophyte lifestyle. Various genes involved in bacterial endophyte lifestyle and plant growth promotion were identified. A link between the genomic components of bacterial endophytes and non-endophytes was also established. These data has contributed to the onogoing research in understanding plantmicrobe interaction, through identification of bacterial putative genes involved in the interaction.
M.Sc. (Biotechnology)