Identification and characterization of bacteria from the skin of jackfruit

Abstract

Fresh-cut fruits industry is developing extensively in this global era due to busy lifestyle. However, the fresh-cut processing could be contaminated by microorganisms; resulting in food poisoning outbreaks. This study presented about the characterization and inhibition of bacteria isolated from the fresh skin of jackfruit. The isolation of single colonies was done by spread plate and streak plate method. The isolates were identified by 16S rRNA analysis. Gram staining, growth profiling and 15 biochemical tests were carried out to characterize each isolates.Lastly, the isolates were treated with various antimicrobial agents by disc agar diffusion technique and the fresh skin of jackfruit was treated with antimicrobialagent, XY-12 with different conditions by spread plate technique to study the effects of antimicrobial agents on microbial growth. Experimental results demonstrated that four types of bacterial single colonies were isolated with different morphology and designated as CE1, CE2, CE3 and CE4. The 16S rRNA analysis showed that the isolates of CE1 and CE4 were Bacillus sp. strain CY-b33. Isolates of CE2 and CE3were identified as Bacillus pumilus strain SBTBP-008 and Bacillus thuringiensis strain EA26.1 respectively. All the isolates were Gram positive and in rod shaped.The growth kinetics of CE3 was highest (0.2280 h-1) compared to CE1 (0.1317 h-1)which was the lowest. Bacteria CE1 and CE2 have the highest sensitivity againstXY-12 (0.6 mL/L) and Kanamycin Sulfate respectively. Bacteria CE3 and CE4 have the highest sensitivity against Ampicillin Trihydrate and Tetracycline Hydrochloride respectively. The fresh skin of jackfruit treated with XY-12 (0.6 mL/L) and incubated at 4°C revealed high efficiency in microbial reduction at day 2 (100%) and 4 (99.72%).