EFFECT OF HEAT ON THE ANTIBACTERIAL ACTIVITY OF HONEY ON BACTERIAL ISOLATES

Robinson Victor Kasi* and Korobe Barikuula Patrick

ABSTRACT

In this study, the antibacterial activity of raw honey and commercially sold honey on Serratia marcescens, Proteus mirabilis and Vibrio cholera was evaluated. Raw honey which was gotten from farmers in Etche community and two processed honey (Rowse and Princenic global honey) were bought from a superstore. The different honey samples were divided into two set. The heated honey and the unheated honey. The heated honey samples were heated for three days in a water bath at 90 ºC. Their antibacterial activities were evaluated using the well in agar method. Different concentrations of the honey samples were transferred into 6mm holes in freshly prepared Mueller-Hinton agar plates which have been seeded with the test isolates. This was done in duplicates. The antibacterial activities of the different honey samples showed that the zones diameter increased with increased concentration with the 100% concentration having the highest zones of inhibition. The zone diameter (mm) of the heated raw honey at 100% concentration on Proteus, Serratia and Vibrio was 17.50±0.71, 21.50±0.71 and 19.50±0.71, respectively. Despite the difference in the zone diameter, there was no significant difference at P ≤0.05 in the zone diameters at the 100% concentration. The zone diameter of the unheated Raw honey at 100% concentration on Proteus, Serratia and Vibrio was 18.00±2.83, 28.50±7.78 and 22.00±0.00mm, respectively. The zone diameter (mm) of Rowse and Princein heated honey at 100% concentration on Proteus, Serratia and Vibrio were (20.00±0.00, 25.00±0.00, and 20.00±0.00mm) and (19.00±0.00, 26.00±1.41, and 24.50±3.54mm), respectively. More so, there was no significant difference of the efficiency of the Rows honey on the different isolates at 100% concentration. This is also similar to the PG honey at p = 0.005. The unheated honey showed higher zones of inhibition than the heated honey. Thus, the type of honey, the heat, the microorganism and the concentrations of honey were factors that affected the antimicrobial efficiency of the honey.

Keywords: Honey, Serratia, Vibrio cholera, Proteus mirabilis, raw honey, processed honey.