Antifungal and antibacterial effects of citrus fruit peel extracts and juices and their synergistic effect with fungal strain on Triticum aestivum growth

Citrus fruit extracts are a robust source of bioactive compounds that confer antifungal, antibacterial, and phyto-enhancing properties. Current research has been conducted to utilize citrus fruit peels for their pharmacological benefits as antimicrobial resistance has increased immensely. So, considering this green chemistry, this study examined the antifungal and antibacterial potential of citrus fruit peels and juices and their synergistic effect with fungal strains on wheat growth. Activity was assessed using well-diffusion and agar dilution methods, and antioxidant potential was determined using a DPPH assay. Afterward, phenolic and flavonoid content was ascertained, which was later screened out by GC-MS analysis. The profile of fungal role in plant-growth promotion was checked by phosphate-solubilization and nitrogen fixation assay. Cell viability percentage was checked by conducting an MTT assay. Results indicated that peels exhibited a superior bioactive potential compared to their juice counterparts. Lemon showed more efficacy in terms of its antibacterial and antifungal activity, but grapefruit demonstrated exceptional antioxidant potential and wheat growth enhancement, but synergy was only observed in lemon-fungal combined treatment group. GC-MS analysis revealed many significant bioactive compounds like gamma-sitosterol, linoleyl methyl ketone, tocopherol, longifolene, guaiacol, pentamethoxy flavone etc. Statistical analysis showed that citrus fruit extract concentration has a direct relation with the inhibition zone, while extract type and fungal species didn’t affect the inhibition zone. ANOVA test showed that the antifungal activity or the inhibition zone depends on the concentration of the extract type. P-value for the concentration of an extract was found to be 0.007, rendering it significant. To mitigate the adverse effects of inorganic chemicals, bioactive compounds in foods offer a promising natural alternative for reducing fungal infections. So, integrating natural remedies into conventional therapies should be emphasized to mitigate the emergence of drug-resistant pathogens. Moreover, their inculcation in conventional fertilizers also helps regulate weed management in plants and promotes optimum plant growth and signaling with fewer side effects. • The antifungal and antibacterial potential of citrus fruit peels was examined. • The GC-MS analysis revealed many significant bioactive compounds. • Citrus fruit peel extract, along with fungi, promotes optimum plant growth.