PRODUCTION OF BACTERIOCIN BY LACTIC ACID BACTERIA ISOLATED FROM CHEESE TO ENCHANCE THE SHELF LIFE OF MILLET DOUGH BALL (FURA)

Abstract

Bacteriocin for enhancing the shelf life of food is very promising in the food industry to substitute chemical preservatives due to been generally Regarded as Safe (GRAS). Consumer’s awareness over chemical free foods has led to the search for alternative method of food preservation using Lactic acid bacteria. The aim of this study was to enhance the shelf life of millet dough ball (fura) using bacteriocin producing bacteria isolated from fermented cheese. Two strains of lactic acid bacteria (LAB) of the genera Lactobacillus specie were isolated from cheese with mean count ranged from 2.3 x 107 ± 2.0 x 106 - 1.9 x 107 ± 2.3 x 106. The orgarnisms were identify as organisms as Lactobacillus plantarum strain AAAbd and Lactobacillus bulgaricus strain MN94590. They were tested for antibacterial activity against Staphylococcus aureus and Salmonella specie using agar well diffusion method, zones of inhibition were measured ranged from 6±0.00 to 12±2.00 Lactic acid bacteria strain were isolated and purified using ammonium sulphate precipitation, trichloroacetic acid (TC) precipitation and ultrafiltration studies to produce bacteriocin. Bacteriocins activity was determined at 2, 4, 6, 8, 10, and 12 pH range, storage conditions at 4 °C, 10 °C and 37 °C and heat temperatures at 60 °C, 100 °C and 121 °C for 15 min. Assessment of the biopreservative potential of bacteriocin on millet dough ball (fura) showed that the shelf life of millet dough ball (fura) was extended for 13 and 11 days on addition of bacteriocin produced by Lactobacillus plantarum strain AAAbd (plantaricin) and Lactobacillus bulgaricus strain MN945906 (bulgarican) respectively, while the initial shelf life of millet dough ball (fura) without bacteriocin (control) had a shelf life of 5 days, at 4° C. Proximate composition of millet dough ball (fura) sample such as Moisture content (54.36±0.09 – 53.21±0.02) of bacteriocin inoculated fura showed a significant difference (P˂0.05) compared with fura without bacteriocin (control). This study suggest the use of bacteriocins from Lactic acid bacteria as a natural preservative in fura has shown to be effective against foodborne pathogens.