The potential anti-Methicillin resistant Staphylococcus aureus of Cleistocalyx operculatus Leaf Extract and Its Application in Kombucha Tea Fermentation in Vietnam

The clinical management of methicillin-resistant Staphylococcus aureus (MRSA) infections is more and more challenging due to its increasing incidence. In particular, MRSA bacteria exposed to ß-lactam antibiotics may exhibit genetic mutations that reduce their susceptibility to these antibiotics. The need to discover new and efficient alternatives is growing as multi-drug-resistant bacteria become more common. Plants are now recognized as natural sources of bioactive substances that have the potential to be highly effective in treating infectious diseases. Plants contain abundant secondary metabolites, several of which have demonstrated antibacterial properties in vitro. Vietnam frequently harnesses the well-known medicinal plant Cleistocalyx operculatus R. (C. operculatus R.) as an ingredient in tonic beverages. The antibacterial properties of an ethanolic extract derived from the leaves of C. operculatus R. are determined using the agar diffusion method. A kombucha culture, which is a symbiotic culture of bacteria and yeast, is used to aerobically ferment a sweetened tea infusion to create kombucha tea. Due to the supposed health benefits of kombucha, it has gained popularity among consumers. As the demand for high-quality kombucha beverages rises, brewers are seeking guidance from the scientific community to refine their products and meet evolving consumer expectations. Brewers are turning to the scientific community's understanding of kombucha in an attempt to better tailor their products to meet changing consumer expectations. Therefore, the use of C. operculatus leaves is employed in the fermentation process to produce Kombucha tea, as indicated in research on C. operculatus Kombucha. The anti-MRSA activity of the C. operculatus extract is reported with a diameter of the inhibited zone equal to 13.50 ± 0.71 mm at the concentration of 10 mg/mL, marking the first time such results have been achieved. The tea is made from C. operculatus leaves follows an optimal ratio between adding SCOBY and sugar tea solution is 1:3 mL/mL, and the time fermentation is 4 days, at room temperature (31.5 °C). Furthermore, the formulas of C. operculatus Kombucha, in synergy with sugarcane juice, are determined to have an optimal ratio of 1:3 mL/mL, preferred by approximately 40 % of customers. The results of this research contributed to the development of new Kombucha formulas, highlighting the synergy between the traditional medical plant fermented by SCOBY and the potent