Excretion of β-glucosidase and pectinase by microorganisms isolated from cassava traditional ferments used for attieke production in Cote d'Ivoire

This research work aimed at studying production kinetic of beta-glucosidase and pectinase by microbial strains isolated from two traditional cassava ferments; with a view of their potential use as starter cultures. The study was carried out on 230 strains and 28 were selected on the basis of their ability to hydrolyze limanarin and pectin. Results showed that the excretion of beta-glucosidase and pectinase by the preselected microorganisms is regulated by a repression mechanism. Only Lactobacillus plantarum LBZ46 produces beta-glucosidase whose activity is modulated by inactivation. Lactobacillus plantarum LBZ46 and Lactobacillus plantarum LBY9 were able to excrete beta-glucosidase greater than 50 +/- 5 EU/mL.The optimum temperature for beta-glucosidase excretion and biomass production was 35 degrees C for Lactobacillus plantarum LABY9 from the Alladjan ferment. With regard to Lactobacillus plantarum LABZ46 from ferment Ebrie, the optimum temperature for beta-glucosidase production was 30 degrees C, while the optimum temperature for biomass production was 35 degrees C.The optimum pH of beta-glucosidase excretion and biomass production ranges from pH 5 to pH6. Regarding the pectinolytic excretion, two strains of Bacillus and one strain of mould were able to excrete an amount of pectinase equivalent to 0.2 +/- 0.06 EU/mL. It is of the Bacillus amyloliquefaciens BY4, Bacillus subtilis BZ15 and Rhizopus oryzae MZ4. Considering the diversity of production kinetics of beta-glucosidase and pectinase, the use of these isolates for a controlled fermentation of cassava dough would be optimal in co-culture for the production of attieke Alladjan and Ebrie in Cote d'Ivoire.