First Insight into the Technological Features of Lactic Acid Bacteria Isolated from Algerian Fermented Wheat Lemzeiet

Fermented cereals are part of the main traditional diets of many people in Africa, usually obtained from artisanal production.The intensification of their manufacturing, responding to the consumers demand, requires a better control to ensure their sanitary, nutritional, and taste qualities, hence, the need of selecting accurate and safe starter cultures. In the present study, 48 lactic acid bacteria (LAB) strains, previously isolated from Algerian fermented wheat lemzeiet, were analyzed for different technological properties. 14 LAB strains, belonging to Pediococcus pentosaceus, Enterococcus faecium, Lactobacillus curvatus, Lactobacillus brevis, and Leuconostoc mesenteroides species, decreased rapidly the pH of the flour extract brothclose to 4 or below. 91% of strains showed extracellular protease activity, but only 12% were amylolytics. 18 LAB strains inhibited or postponed the growth of three fungal targets Rhodotorula mucilaginosa UBOCC-A-216004, Penicillium verrucosum UBOCC-A-109221, and Aspergillus flavus UBOCC-A-106028. The strains belonging to Lactobacillus spp., Leuconostoc fallax, L. mesenteroides, and Weissella paramesenteroides were the most antifungal ones. Multiplex PCR for biogenic amines’ production did not reveal any of the genes involved in the production of putrescine, histamine, and tyramine for 17 of the 48 strains. The obtained results provided several candidates for use as starter culture in the future production of lemzeiet

Lemzeiet, a traditional algerian fermented food: first characterization of lactic acid bacteria flora

Algerian couscous named Lemzeiet is manufactured from fermented wheat and characterizedby a brown color and a particular flavors especially appreciated by consumers. Historicallyperformed in underground silos (Matmour) during several years, the fermentation of wheat isnow generally carried out in plastic jerrycans or drums during around one year with orwithout addition of vinegar at the beginning of the fermentation. Most of the cereal- basedfermented foods involve lactic acid fermentation including Lemzeiet. The aim of this workwas to determine the dynamic and the diversity of lactic acid bacteria populations over twoyears, in the presence or absence of vinegar. Culture dependent methods were used and 147isolates were selected based on phenotypic characteristics. 70 were retained for molecularcharacterization. They were identified by coupling different molecular methods (16SrRNA/pheS/rpoA genes sequencing and specific PCR) and the clonal diversity wasinvestigated with randomly amplified polymorphic DNA (RAPD) and pulse-field gelelectrophoresis analysis (PFGE). The population of lactic acid bacteria evolved during theperiod of fermentation. It was dominated by Lactobacillus and Pediococcus species in thewheat fermented without vinegar, and by Enterococcus and Pediococcus species in thepresence of vinegar. We also observed a high level of intra-species diversity. Analysis ofaroma compounds by head space trap-gas chromatography-mass spectrometry is underprogress to determine the impact of the lactic acid bacteria populations on the final aromaprofile of products. These results give a first insight in lactic acid bacteria population diversityin Lemzeiet and will contribute to a better control of the fermentation process

A large diversity of lactic acid bacteria species is involved in the fermentation of wheat used for the manufacture of lemzeiet

Algerian couscous named lemzeiet is manufactured from fermented wheat. Historically performedin underground silos called matmor, the fermentation of wheat is now generally carried out in plastic jerrycans withor without addition of vinegar at the beginning of the fermentation. Culture-dependent and culture-independentmethods (PCR-TTGE) were used to characterize lactic acid bacteria and to determine their dynamic and diversity over a two-year period, with and without the addition of vinegar.Fungi, physicochemical characteristics, and volatile compoundprofiles were also monitored. The isolates obtained from different stages of fermentation and from both processes were characterized by coupling different molecular methods (16SrRNA/pheS/rpoA gene sequencing, speciesspecific PCR, RAPD and PFGE). PCR-TTGE revealed very similar profiles for both processes. Sixty-nine isolates were identified as belonging to six genera of 16 species(Enterococcus, Lactobacillus, Leuconostoc, Pediococcus, Weissella, and Streptococcus). The profiles of volatile aroma compounds showed a marked effect of the fermentation process, compared to non-fermented wheat, with 35 of the 40 volatiles detected at amounts 20- to 30-fold higher in fermented wheat samples. This study gives the first insight into lactic acid bacteria population diversity and activity in fermented wheat and will contribute to a better control of the fermentation process