Diversity and enzymatic characterization of <i>Bacillus</i> species isolated from traditional cassava starters used for <i>attiéké</i> production

Abstract

Fermentation plays an important role in the production of cassava-based foods in West Africa. In Cote d'Ivoire, this step requires the use of a traditional cassava starter. Thus, the objective of this study was to identify and evaluate the enzymatic profile of the different Bacillus species present in these traditional cassava starters. Technique based on the analysis of the 16S rDNA sequence was used for the identification of Bacillus species. Enzymatic activity of different species identified was carried out with API ZYM system. Based on the 16S r DNA sequence analysis, seven species of Bacillus (Bacillus subtilis, Bacillus cereus, Bacillus pumilus, Bacillus amyloliquefaciens, Bacillus methylotrophicus, Bacillus vallismortis and Bacillus toyonensis ) were identified. B. subtilis was the most identified species with a frequency of 30% followed by B. amyloliquefaciens (18%) , B. methylotrophicus (10%), B. cereus (6%), B. toyonensis (6%), B. vallismortis (4%) and B. pumilus (4%). Many of these species have been able to produce osidases, phosphatases, lipases and proteases. Seventeen enzymes from these different enzyme groups were synthesized by the identified Bacillus species. The dominant and enzyme-producing species could be used for the development of a starter culture. Keywords : Bacillus species, enzymes, traditional cassava starter.