Effect of antimicrobial agent toward bacteria from skin of cantaloupe fruit

Abstract

Fresh cut-fruits produce is one of the quickest developing food industries ever. Food poisoning has been connected with the utilization of poor quality of fruits. The present study was conducted to isolate bacteria from cantaloupe skin, characterize and identify the bacteria from cantaloupe fruit skins using biochemical tests and 16S rRNA gene analysis and to investigate the effect of antimicrobial agents on the growth of bacteria and all of these objective were successfully achieved. Four unique bacteria based on different morphology were isolated by using spread plate method. A total of ten biochemical tests were performed. For bacterial identification, the PCR products of the 16S rRNA gene were amplified, purified and sent for sequencing. Bacterium CG1, CG2, CG3 and CG4 bacteria were identified as Exigubactirum sp CG1, Exigubactirum sp. CG2, Pseudomonas sp. CG3, and Microbacterium sp. CG4. The XY-12 antimicrobial agent with two different concentrations (0.6 mL/ L and 0.3 mL/ L) were tested to inhibit the growth of bacteria in the fruit skins at two different temperatures (4 °C and 30 °C). It was observed that 100% of microbial reduction was achieved when the sample of fresh cantaloupe skins were immersed in 0.6 mL/ L of XY-12 and incubated at 4 °C incubated for 2 days. For 4 days of incubation under the same condition (0.6 mL/Lof XY-12; 4 °C), 99.98% of microbial reduction were observed. All isolated bacteria were also screened against four different antibiotics using disc-diffusion assay and discs impregnated with distilled water were used as negative control. The result of Kanamycin sulfate (1 mg/mL) found to be the most effective against bacterial strain of CG2 with the average zone of inhibition of 29 mm. No zones of inhibition were observed with negative control discs.