Antibacterial and Antioxidant Activity of Ecoenzyme Solution Prepared from Papaya, Pineapple, and Kasturi Orange Fruits: Experimental and Molecular Docking Studies

Organic waste, particularly from fruits, remains an environmental issue if not properly managed. These wastes have the potential to be reprocessed into products, one of which is beneficial for human health. The trend of recycling fruit scraps into ecoenzyme (EE), a fermented product, has increased in recent years. Several health advantages of EE have been highlighted. Therefore, this study is aimed at evaluating the potential antibacterial and antioxidant activity of ecoenzyme solutions derived from papaya, pineapple, and Kasturi orange. In this study, pieces of papaya, pineapple, and Kasturi orange were fermented with brown sugar for 10 days and 3 months. The 10-day-and 3-month-old fermented solutions were used as samples to evaluate their inhibitory abilities against the growth of Escherichia coli and Staphylococcus aureus using the well diffusion method. In addition, the fermentation solutions were tested for their antioxidant capacity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Furthermore, a molecular docking study was conducted to evaluate the compounds found in these three fruits for their ability to interact with the DNA gyrase of the two indicator bacteria. The enzyme, which is a well-established antimicrobial target, is involved in bacterial DNA replication, repair, and decatenation. The in vitro results revealed that EE, both fermented for 10 days and 3 months, had strong inhibition against E. coli and S. aureus. The 3-month-old fermentation solution showed stronger inhibitory activity than the 10-day-old fermentation solution. Despite a slight decline in antioxidant activity with increasing fermentation time, both of these samples exhibited extremely potent antioxidant activities. Molecular docking studies revealed that hesperidin and ciprofloxacin interacted more strongly with the DNA gyrase of S. aureus than with E. coli. Hesperidin can therefore function as a potent antimicrobial. The present study concluded that EE solution fermented from papaya, pineapple, and Kasturi orange exhibits the potential to serve as a source of both antibacterial and antioxidant compounds.