Antimicrobial activity of locally isolate bacteria from fruit skins (Mango and Papaya)

Abstract

Nowadays, the minimal processed products have become more popular. Prevention of the growth of bacteria in cut fruits is one of the critical points in the processing steps. Characterization of bacteria from fruits and the effects of antimicrobial agents in inhibiting the growth of these bacteria are the important aspects to be studied in order to minimize the contamination of bacteria in fruits. Therefore, this study aimed to isolate the bacteria from mango and papaya fruit skins followed by the characterization of the bacteria using biochemical tests. In addition, this study also aimed to study the effect of antibacterial agent and temperature in inhibiting the growth of bacteria from fruit skins. A total of 8 different types of bacteria from mango and papaya fruit skins were successfully isolated. Then, 9 types of biochemical tests with the gram staining have been performed in the strains. As a result, M1 and M2 assign as Bacillus, M3 and M4 assign as Streptococcuss or Enterococcus, P1 assign as Aeromonas, P2 as Micrococcus or Staphylococcus, P3 as Neisseria or Veillonella and P4 as Lactobacillus. Effect of two parameters, which were antibacterial agent (XY-12; a chlorine based agent) and temperature, in retarding the growth of bacteria in mango and papaya were investigated. The fruit skins which were treated with XY-12 at 4˚C followed by incubation at 4˚C were the best condition in inhibiting the growth of bacteria with almost 100 % percentage of inhibition of bacterial growth for mango and papaya, respectively. Meanwhile, fruit skins samples which were treated with XY-12 at 30˚C and incubated 30˚C showed the lowest percentage of inhibition.