Full Length Research Paper

Characterization of lactic acid bacteria isolated from poultry farms in Senegal

Coulibaly Ibourahema¹*, Robin Dubois Dauphin¹, Destain Jacqueline¹ and Philippe Thonart^{1, 2}

¹Centre wallon de Biologie Industrielle (CWBI), Unité de Bio-industries, Faculté Universitaire des Sciences Agronomiques de Gembloux (FUSAGx), Passage des Déportés 2, B-5030 Gembloux, Belgium.

²Centre wallon de Biologie Industrielle (CWBI), Service de Technologie Microbienne, université de liège (ULg), Sart Tilman, B40, B-4000 Liège, Belgium.

*Corresponding author. E-mail: coulibaly.i@fsagx.ac.be.

Accepted 16 May, 2008

The group that includes the lactic acid bacteria is one of the most diverse groups of bacteria known and these organisms have been characterized extensively by using different techniques. In this study, thirty lactic acid bacterial strains were isolated from soils chicken faeces and feathers. A total of nineteen isolates were obtained and by sequential screening for catalase activity and Gram-staining, eight were determined to be LAB out of which six were established to be homofermentative by the gel plug test. Five isolates were identified by use of the API 50CHL kit and four Lactobacilli strains and one Lactococci strain were selected to study their growth and lactic acid production profiles in a time course experiment. The Lactobacilli strains, both isolated from faeces, produced higher amounts of cells and lactic acid from soils as compared to the lactococci strain isolated from feathers. L (+)-lactic acid is the only optical isomer for use in pharmaceutical and food industries because is only adapted to assimilate this form. The optical isomers of lactic acid were examined by L (+) and D (-) lactate dehydrogenase kit. Lactobacilli strains produced combination of both optical isomers of lactic acid. Among them, Lactobacillus casei subsp. casei produced the low amount of D (-)-lactic (2%). The optimum rates of glucose for lactic acid production by Lactobacillus strains were 180 and 120 g/l for Lactobacillus plantarum and Lactobacillus paraplantarum, respectively.

Key words: Characterization, lactic acid bacteria, Lactobacillus, L (+)-lactic acid, D (-)-lactic acid, optical isomers.