Microorganisms are omnipresent in all environments and play mainly the role of transformers, thanks to the multiple enzymes they are able to produce. In order to valorize fermented foods in the Republic of the Congo, ...Microorganisms are omnipresent in all environments and play mainly the role of transformers, thanks to the multiple enzymes they are able to produce. In order to valorize fermented foods in the Republic of the Congo, this work aimed to characterize and study some properties of microorganisms isolated from samples of peppers sold in three markets of Brazzaville. A numeration of the total aerobic mesophilic flora (TAMF) was made in a solid medium, allowing the evaluation of each sample’s microbial concentration. The microbial mass varied from 2.8 × 105 CFU/g for the Ouénzé sample to 1.8 × 104 CFU/g for the Total sample and 2 × 104 CFU/g for the Moungali market sample. The evaluation of the enzymatic properties of the Bacillus isolates showed that 68.42% were capable of producing cellulases and 78.94% were capable of producing amylases and proteases. Antimicrobial activities revealed that 63.15% of the isolates were able to secrete inhibitory substances against E. coli and Staphylococcus aureus. Molecular analysis by PCR amplification, sequencing of the 16S rRNA gene and BLAST bioinformatics analysis provides newly identified bacteria strains with new accession numbers in GenBank: Bacillus thuringiensis MBCBR322 (OP474008), Bacillus megaterium MBCBJ1822 (OP476493), Bacillus thuringiensis MBCBR222 (OP476494), Priestia megaterium MBCBJ2022 (OP476495) and Lactobacillus paraplantarum MBCBR1522 (OP476496). Multiple sequences alignment of identified sequences with their homologs of GenBank has shown high similarities. The phylogenetic inference assay has provided the two groups of strains observed in this study, and the two groups are very coherent with the phylogeny of the reference.展开更多
文摘Microorganisms are omnipresent in all environments and play mainly the role of transformers, thanks to the multiple enzymes they are able to produce. In order to valorize fermented foods in the Republic of the Congo, this work aimed to characterize and study some properties of microorganisms isolated from samples of peppers sold in three markets of Brazzaville. A numeration of the total aerobic mesophilic flora (TAMF) was made in a solid medium, allowing the evaluation of each sample’s microbial concentration. The microbial mass varied from 2.8 × 105 CFU/g for the Ouénzé sample to 1.8 × 104 CFU/g for the Total sample and 2 × 104 CFU/g for the Moungali market sample. The evaluation of the enzymatic properties of the Bacillus isolates showed that 68.42% were capable of producing cellulases and 78.94% were capable of producing amylases and proteases. Antimicrobial activities revealed that 63.15% of the isolates were able to secrete inhibitory substances against E. coli and Staphylococcus aureus. Molecular analysis by PCR amplification, sequencing of the 16S rRNA gene and BLAST bioinformatics analysis provides newly identified bacteria strains with new accession numbers in GenBank: Bacillus thuringiensis MBCBR322 (OP474008), Bacillus megaterium MBCBJ1822 (OP476493), Bacillus thuringiensis MBCBR222 (OP476494), Priestia megaterium MBCBJ2022 (OP476495) and Lactobacillus paraplantarum MBCBR1522 (OP476496). Multiple sequences alignment of identified sequences with their homologs of GenBank has shown high similarities. The phylogenetic inference assay has provided the two groups of strains observed in this study, and the two groups are very coherent with the phylogeny of the reference.
