Time related total lactic acid bacteria population diversity and dominance in cowpea-fortified fermented cereal-weaning food
The total lactic acid bacterial community involved in the spontaneous fermentation of malted cowpea fortified cereal weaning food was investigated by phenotypically and cultivation independent method. A total of 74 out of the isolated 178 strains were Lactobacillus plantarum, 32 were Pediococcus acidilactici and over 60% were Lactobacillus strains. L. plantarum and P. acidilactici strains were the dominant strains during the fermentation process and were identified in all the three cereals used.Separation of amplified V3 region from 16S rDNA by denaturing gradient gel electrophoresis (DGGE) using species, specific primer was carried out. The results show that the total lactic acid bacterial species richness (R) decreased with increase in fermentation time, while the species diversity and dominance indices were not significantly (P < 0.05) affected by fermentation time but rather by cerealtype. Comparison of 16S rDNA sequences of pure culture isolates with those in Genbank database revealed that, the dominating lactic acid bacteria were L. plantarum and Pediococcus species.
Key words: Lactic acid bacteria, communities’ diversity, fortified weaning foods, polymerase chain reaction amplification-denaturing gradient gel electrophoresis (DGGE).