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The ability of four Lactobacillus strains – Lactobacillus brevis LBRZ7 (isolated from fermented cabbage), Lactobacillus plantarum LBRZ12 (isolated from fermented cabbage), Lactobacillus fermentum LBRH9 (of human origin) and Lactobacillus casei ssp. rhamnosus LBRC11 (isolated from home-made cheese) – to grow in flour/water environment and to accumulate high concentrations of viable cells was examined. Two starters for sourdough were created for lab-scale production of wheat bread: a two-strain starter and a four-strain starter. Wheat bread with improved properties – greater loaf volume, enhanced flavour and softer and brighter crumb – was obtained from the 7% four-strain starter sourdough. The addition of sourdough in the production of wheat bread affected positively the technological and organoleptic characteristics of the final bread by inhibiting the growth of wild yeasts and mold and Bacillus spores without the addition of preservatives. The inclusion of 15% of the four-strain starter sourdough in the bread-making process led to enhanced safety and longer shelf life of the baked bread.

A method for formalization and analytical determination of the kinetic parameters of continuous alcohol fermentation in a reactor and in a cascade of reactors with ideal mixing was discussed in the present work. A fluidized bed bioreactor with immobilized yeast with elucidated structure of the flows was used. The method of formalization of the process kinetics involved two steps – determination of the optimal dilution rate of a continuous fermentation process, and determination of the total kinetic parameters of the cascade of reactors, including the minimum number of steps that can ensure production of maximum ethanol yield in the system.