African Journal of Biotechnology Vol. 6 (22), pp. 2616-2619, 19 November 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Bacteriocin and cellulose production by lactic acid bacteria isolated from West African soft cheese

Adetunji, V.O.¹* and G.O Adegoke²

¹Department of Veterinary Public Health and Preventive Medicine University of Ibadan, Ibadan, Nigeria.

²Department of Food Technology, University of Ibadan, Ibadan, Nigeria.

*Corresponding author. E-mail: vadetunji@gmail.com.

Accepted 5 November, 2007

Sixteen colonies of lactic acid bacteria (LAB) were selected and screened for their ability to produce bacteriocin by agar well diffusion method using the supernatant of centrifuged test cultures.  Four isolates inhibited the growth of Listeria monocytogenes and Escherichia coli. Lactobacillus plantarum (6) and Lactobacillus brevis (5) were the most dominant species. The remaining were Lactobacillus lactis (2), Streptococcus lactis (2) and Lactobacillus fermentum (1). Lactobacillus spp. accounted for 87.5% of all isolates. LAB4 (Lactobacillus plantarum) showed some levels of antimicrobial activity after 15, 20 and 25 min heat treatments at 100^oC  against Listeria  monocytogenes . While antimicrobial activity of LAB70 (Lactobacillus lactis) was against both Listeria monocytogenes (after 20 and 25 min) and E. coli 0157:H7 (after 15, 20 and 25 min) heat treatment at 100^oC. All the lactic acid bacteria used in this study produced cellulose. The correlation between cellulose production (an adhesion factor) and bacteria growth was highly significant after 72 h of incubation having a R² = 0.800. This study offers useful information on growth and cellulose production as factors affecting the efficacy of bacteriocin produced by these strains which could be good for biopreservation.

Key words: Lactic acid bacteria, antimicrobial, bacteriocin, cellulose, growth.