LACTIC-ACID BACTERIA AND YEAST ASSOCIATED WITH TRADITIONAL MOROCCAN SOUR-DOUGH BREAD FERMENTATION

Populations of microorganisms including yeasts and lactic acid bacteri a were evaluated in traditional sour dough bread ferment samples. Repr esentative isolates of both microorganisms were identified and charact erized. Yeast isolates were found to fit into two species identified a s Saccharomyces cerevisiae (46.6%) and Candida milleri (50%). The most frequent lactic acid bacteria were lactobacilli, L. plantarum (52%), L. brevis (14%), L. buchneiri (8%) and L. casei alactosus (8%) as majo r species and L. casei casei (6%), L. casei rhamnosus (2%) as minor sp ecies. Some cocci namely Leuconostoc mesenteroides and Pediococcus sp. were also present. Their numbers ranged from 10(6) to 10(8) CFU/g for lactic acid bacteria and 10(6) for yeasts. The evidence suggests that a yeast-lactic acid bacteria interaction is responsible for the ferme ntation of traditional Moroccan sour-dough bread.