Some studies focused on metabolic relationships between plants and their endophytic bacterial associates, and more research is required to generate critical evidence for these relationships. In the current interest, we tried to confirm the relationship between the traditional medicinal plant, Calotropis procera (Aiton) W.T. Aiton, and its associated endophytes, Bacillus siamensis and Bacillus amyloliquefaciens, as the first matching study regarding the production of bioactive secondary metabolites from the plant vis-a-vis its bacterial endophytes. Secondary metabolites of both the plant and its endophytic bacteria were extracted using different solvents, e.g., water, methanol, and ethyl acetate. All extracts exhibited high quantities of phenolics, flavonoids, tannins, and saponins. In addition, they showed significant antioxidant capacity which was found to be positively correlated with total phenolic contents. The highest total antioxidant capacity (99.28 ± 0.0 mg AA equivalent/g extract) was measured for the aqueous extract of B. siamensis. Antibacterial activity of the different extracts was evaluated against certain pathogenic bacteria, i.e., Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae, Salmonella typhi, Serratia marcescens, and Staphylococcus aureus. It was strikingly found that the broadest antibacterial spectrum was revealed by extracts of both C. procera and its endophytic B. siamensis. Interestingly, antibacterial activity was significantly correlated to phenolic and flavonoid contents.

中文翻译：

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植物-细菌内生菌次生代谢物匹配：案例研究

一些研究侧重于植物与其内生细菌关联物之间的代谢关系，需要更多的研究来为这些关系提供关键证据。在当前的兴趣中，我们试图确认传统药用植物 Calotropis procera (Aiton) WT Aiton 与其相关内生菌暹罗芽孢杆菌和解淀粉芽孢杆菌之间的关系，这是关于从青蒿素生产生物活性次生代谢物的第一个匹配研究。植物相对于其细菌内生菌。使用不同的溶剂，例如水、甲醇和乙酸乙酯，提取植物及其内生细菌的次级代谢物。所有提取物都显示出大量的酚类、黄酮类、单宁和皂苷。此外，它们显示出显着的抗氧化能力，发现与总酚含量呈正相关。测量了暹罗双歧杆菌的水提取物的最高总抗氧化能力（99.28 ± 0.0 毫克 AA 等效物/克提取物）。评估了不同提取物对某些病原菌的抗菌活性，即大肠杆菌、肺炎克雷伯菌、无乳链球菌、伤寒沙门氏菌、粘质沙雷氏菌和金黄色葡萄球菌。令人惊讶地发现，最广泛的抗菌谱是由 C. procera 及其内生 B. siamensis 的提取物显示的。有趣的是，抗菌活性与酚类和类黄酮含量显着相关。0mg AA 等效物/g 提取物) 被测量为 B. siamensis 的水提取物。评估了不同提取物对某些病原菌的抗菌活性，即大肠杆菌、肺炎克雷伯菌、无乳链球菌、伤寒沙门氏菌、粘质沙雷氏菌和金黄色葡萄球菌。令人惊讶地发现，最广泛的抗菌谱是由 C. procera 及其内生 B. siamensis 的提取物显示的。有趣的是，抗菌活性与酚类和类黄酮含量显着相关。0mg AA 等效物/g 提取物) 被测量为 B. siamensis 的水提取物。评估了不同提取物对某些病原菌的抗菌活性，即大肠杆菌、肺炎克雷伯菌、无乳链球菌、伤寒沙门氏菌、粘质沙雷氏菌和金黄色葡萄球菌。令人惊讶地发现，最广泛的抗菌谱是由 C. procera 及其内生 B. siamensis 的提取物显示的。有趣的是，抗菌活性与酚类和类黄酮含量显着相关。和金黄色葡萄球菌。令人惊讶地发现，最广泛的抗菌谱是由 C. procera 及其内生 B. siamensis 的提取物显示的。有趣的是，抗菌活性与酚类和类黄酮含量显着相关。和金黄色葡萄球菌。令人惊讶地发现，最广泛的抗菌谱是由 C. procera 及其内生 B. siamensis 的提取物显示的。有趣的是，抗菌活性与酚类和类黄酮含量显着相关。