Characterization and Selection of Potential Starters of Bacillus Sp. Involved in the Fermentation of Néré Seeds (Parkia biglobosa) in Côte d'Ivoire

Abstract

Aims: The present study highlights about Bacillus sp. starter strains to control fermentation of Parkia biglobosa (néré) seeds. Place and Duration of Study: Between February and August 2023, this work was performed at Laboratory of Biochemistry, Microbiology and Valorization of Agroresources, of the Agropastoral Management Institute, which is part of Peleforo Gon Coulibaly University (Korhogo, Côte d'ivoire). Methodology: Fermented néré seeds were collected from soumbara producers in the Korhogo region in northern Côte d'Ivoire. Néré seeds were subjected to a physicochemical analysis to determine the pH, titrable acidity, moisture, dry matter and ash content. These fermented seeds were used for the isolation and enumeration of Bacillus bacteria. Production of extracellular enzymes and the influence of stress conditions were carried out on these strains to select potential starters. Results: The study of the physicochemical analysis of fermented néré seeds showed that these seeds have a pH of 6.59 ± 0.04, close to neutrality, with a very low titrable acidity of 0.06 ± 0.00%. The moisture content of the néré seeds is 38.76 ± 0.13% with a high dry matter content of 61.24 ± 0.22% coupled with a low ash content of 3.18 ± 0.05%. Thirty-three (33) Gram-positive bacilli were isolated from néré seeds with a microbial load of 7.1 log10 cfu/g. The production of extracellular enzymes and the influence of stress conditions led to the selection of five Bacillus strains (BS 08, BS 14, BS 19, BS 22 and BS 31) as potential starters. Conclusion: The control of the fermentation of néré seeds involves selecting strains with the best potential. Thus, five Bacillus sp. Isolates (BS 08, BS 14, BS 19, BS 22 and BS 31) were selected as potential starters for obtaining a soumbara of exceptional nutritional and organoleptic quality.