Assessment of a bacteriocin-producing Lactobacillus strain in the control of spoilage of a cereal-based African fermented food.
As a part of a program to develop starter cultures aiding in the spoilage control and sanitation of African fermented foods, a cereal-based food ('ogi' and its solid form 'agidi' or 'eko') was prepared using a bacteriocin-producing Lactobacillus strain as the starter culture. The survival of an enterotoxigenic Escherichia coli strain was investigated in the naturally fermented food and in food fermented with the starter bacteriocin-producing Lactobacillus strain. An inhibition of E. coli was observed within 2 h of incubation in 'ogi' fermented with the bacteriocin producing strain. After 6 h, the viable count of E. coli in locally fermented 'ogi' was log 6.41 (2.54 X 10(6) CFU/mL), whereas in 'ogi' fermented with the bacteriocin producer it was reduced to log 1.70 (0.5 x 10(2) CFU/mL). Comparison of the shelf life of 'agidi' prepared from the naturally fermented food with that bacteriocin-producing starter culture showed that the latter had a better shelf life (kept for 11 d before spoilage occurred as compared with 7 d for the natural one). The results are discussed in terms of the potential of bacteriocin-producing cultures in the control and retardation of spoilage and food-forne infections in some African fermented foods.
Olasupo
N A
NA
Department of Botany and Microbiology, Faculty of Science, Lagos State University Ojo, Apapa, Nigeria.
Olukoya
D K
DK
Odunfa
S A
SA
D000349:Africa; D001430:Bacteriocins / Q000096:biosynthesis*; D015169:Colony Count, Microbial; D002523:Edible Grain; D004768:Enterotoxins / Q000096:biosynthesis; D004926:Escherichia coli / Q000302:isolation & purification / Q000378:metabolism / Q000472:pathogenicity; D005069:Evaluation Studies as Topic; D005285:Fermentation; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D007778:Lactobacillus / Q000378:metabolism*; D013997:Time Factors
D001430:Bacteriocins; D004768:Enterotoxins