Identification and Enzymatic Potential of Bacillus Species Isolated from Traditional Cassava Starters: Potential for Attiéké Production

Abstract

Aims: Microbial enzymatic activities are important in cassava dough fermentation for attiéké production. The objective of this study was to describe the molecular identification and the amylolytic, pectinolytic and cellulolytic enzymes potential of four (4) Bacillus species involved in cassava mash fermentation for the preparation of attiéké. Place and Duration of Study: Laboratory of Biotechnology, UFR Biosciences, University Félix Houphouet-Boigny (Côte d’Ivoire), between February 2016 and April 2016. Methodology: Four Bacillus strains (Bas 04, Bas 13, Bas 58 and Bas 66) used for this study were isolated from the traditional cassava starter ‘’mangnan’’. By using the PCR amplification of ribosomal 16S genes, Bacillus strains were identified. After culture in nutrient agar, strains were suspended in a tryptone salt solution. When we obtain Bacillus cells absorbance (turbidity) of 1.00 at 600 nm, 100 µL of this suspension were used to inoculate 5 mL of liquid medium containing peptone (1%), meat extract (1%), NaCl (0.3%) and 1% of starch or Pectin or Carboxylmethyl cellulose for enzymes production. The enzymatic activities were studied at different temperatures ranged from 25°C to 50°C and pHs (4.5, 5.0 and 5.5).   Results: Bacillus thuringiensis was identified with 99% to 100% of similarity, referring to the NCBI database. The best amylase, cellulase and pectinase activities were obtained with Bas 66 (3.80 U/mg), Bas 13 (0.45 U/mg) and Bas 58 (1.09 U/mg) at different optimum temperatures (25, 40 and 50°C) and pHs (4.5, 5.0 and 5.5), respectively. Conclusion: These enzyme activities are important for cassava dough fermentation, using these Bacillus strains, contributing to the softening of the mash thus improving texture and allowing the digestibility of attiéké.