School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.
J Appl Microbiol. 2021 Nov;131(5):2244-2256. doi: 10.1111/jam.15122. Epub 2021 Jun 11.
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.
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 Gram-negative bacteria.
Taken together, these results suggest that Australian bush medicines harbour diverse biosynthetically talented microbial endophytes capable of producing broad-spectrum antibacterial compounds.
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.
微生物内生菌产生具有特殊生物活性的代谢产物，包括抗生素和具有医药及农业价值的其他化合物。本研究旨在调查澳大利亚盖梅（植物学湾）达瓦拉人使用的药用植物内生菌的多样性和生物活性。
从 48 株内生菌中分离出 19 株，通过包含简并引物的聚合酶链反应检测到聚酮合酶或非核糖体肽合成酶基因呈阳性。通过 16S rRNA 基因测序鉴定具有生物合成潜力的内生菌，包括属于芽孢杆菌目、根瘤菌目和伯克霍尔德氏菌目的 4 种细菌和属于球腔菌目、丛赤壳目、球壳孢目、小丛壳目和外囊菌目的 15 种子囊菌真菌。采用圆盘扩散法进行的抗菌试验表明，19 株分离株中有 15 株对多种革兰氏阳性和革兰氏阴性细菌具有广谱活性。
综上所述，这些结果表明澳大利亚土生土长的药草蕴藏着具有产生广谱抗菌化合物能力的多样化生物合成潜力内生微生物。
本研究表明，内生菌产生的化合物可能有助于澳大利亚土生土长的药草的整体药用特性。值得注意的是，它强调了土著植物学知识和现代分子方法可以结合使用，优先选择产生具有药用价值的化合物的微生物。
