Australian bush medicines harbour diverse microbial endophytes with broad‐spectrum antibacterial activity

Abstract

Aims: Microbial endophytes produce specialized metabolites, including antibiotics and other compounds of pharmaceutical and agricultural value. This study aimed to investigate the diversity and bioactivity of endophytes from medicinal plants used by the Dharawal People of Gamay (Botany Bay), Australia. Methods and Results: Of the 48 endophytes isolated, 19 tested positive for polyketide synthase or non-ribosomal peptide synthetase genes via a PCR incorporating degenerate primers. The biosynthetically talented endophytes were identified by 16S rRNA gene sequencing and included 4 bacteria species belonging to the orders Bacillales, Rhizobiales and Burkholderiales and 15 Ascomycota fungi species belonging to the orders Botryosphaeriales, Cladosporiales, Glomerellales, Microascales and Eurotiales. Antimicrobial testing using the disc diffusion assay demonstrated that 15 of the 19 isolates had broad-spectrum activity against a range of Gram-positive and Gramnegative bacteria. Conclusions: Taken together, these results suggest that Australian bush medicines harbour diverse biosynthetically talented microbial endophytes capable of producing broad-spectrum antibacterial compounds. Significance and Impact of the Study: This study suggests that compounds produced by microbial endophytes likely contribute to the collective medicinal properties of Australian bush medicines. Significantly, it highlights that Indigenous botanical knowledge and modern molecular approaches can be used in tandem to prioritize microorganisms that produce pharmaceutically relevant compounds.

Fe-Based Nanomaterial-Induced Root Nodulation Is Modulated by Flavonoids to Improve Soybean (Glycine max) Growth and Quality

“…Especially, Rhizobiales participate in beneficial interactions with plants, inducing the nodule organogenesis and fixing atmospheric N 2 for better growth , Sphingomonadales are also considered PGPR due to their ability of fixing atmospheric N 2 in symbiosis with plants . The most ten significant changes in abundance after Fe-based NMs and EDTA-Fe treatments showed that Fe–P NMs significantly increased the relative abundances of four bacteria species ( Ramlibacter , Allorhizobium , Arcticibacter , and Amaricoccus ) but decreased six bacteria species (e.g., Sphingomonas and Iamia ) (Figure c,d, Figure S11).…”

“…63 Bacillales are well-known for their antibacterial abilities, which secrete antibacterial substances such as antimicrobial nonribosomal peptides and polyketides to deter invading pathogens, and thus are widely used as biological control agents for agriculture management. 64,65 Sphingomonadales are also considered PGPR due to their ability of fixing atmospheric N 2 in symbiosis with plants. 66 The most ten significant changes in abundance after Fe-based NMs and EDTA-Fe treatments showed that Fe−P NMs significantly increased the relative abundances of four bacteria species (Ramlibacter, Allorhizobium, Arcticibacter, and Amaricoccus) but decreased six bacteria species (e.g., Sphingomonas and Iamia) (Figure 4c,d, Figure S11).…”

Evaluation of Antibacterial and Antibiofilm Properties in Australian Native Plant Endophyte Metabolites for Wound care Applications

“…The findings indicate that Australian bush medicines encompass a variety of microbial endophytes with notable biosynthetic capabilities. These microbial endophytes offer potential as antibacterial agents, highlighting their promising application in therapeutic contexts [17].…”