Potential application of waste fruit peels (orange, yellow lemon and banana) as wide range natural antimicrobial agent

The antimicrobial potential of three abundantly available fruits peel waste, (orange, yellow lemon and banana) was evaluated on wide range of microorganisms. Three solvents methanol, ethyl acetate, ethanol and distilled water were used for extraction. The resultant extracts were used to test a six gram positive and six gram negative pathogenic bacteria in addition to two microscopic filamentous fungi (MFF) and two yeast species. Presence of trace metals were determined by Atomic Absorption Spectrophotometer and GC-MS Analysis was carried out to find out the total phenolic compounds, which may be responsible for the antimicrobial activity. The antibacterial activity was assessed by the well-bore method, reflected by the diameter of the zones of growth inhibition. Minimum Inhibitory Concentration (MIC) was also determined to confirm the antimicrobial potential of extracts and get quantitative results. Results shows that among the used solvents the extracts exhibited better performance in the order of Distilled water > Methanol > Ethanol > Ethyl acetate which reflects the suitability of solvent for fruit peel extraction. Effectiveness of fruit peel extracts was evaluated and found Yellow lemon > Orange > Banana peel. It was found that gram negative bacteria are more sensitive to the extracts and among them Klebsiella pneumoniae show the highest sensitivity against extract of yellow lemon peel and show the highest zone of inhibition (28 ± 1.4 mm to 3.5 ± 1.3 mm). Similarly, the MIC value was found to be 130 µg/mL which is the least value among other tested microorganisms. This may be attributed to the presence of high concentrations of zinc, magnesium and total phenolic content in the extract of yellow lemon peel. As multidrug resistant strains of microorganisms are emerging and treatment of their infection is becoming difficult with time, infectious diseases are a global cause of increase in death rate. Present study confirms the potential of studied fruit peel waste to be used for therapeutic purpose to combat the multidrug resistant microorganism infection. This will also result in reduction of waste material, reusing it for beneficial purpose in an economical and environmental friendly manner.