Dynamic modelling of brewers' yeast and Cyberlindnera fabianii co-culture behaviour for steering fermentation performance.

Dynamic modelling of brewers' yeast and Cyberlindnera fabianii co-culture behaviour for steering fermentation performance. Food Microbiol. 2019 Oct;83:113-121 Authors: van Rijswijck IMH, van Mastrigt O, Pijffers G, Wolkers-Rooijackers JCM, Abee T, Zwietering MH, Smid EJ Abstract Co-cultivation of brewers' yeast (Saccharomyces cerevisiae) with Cyberlindnera fabianii makes it possible to steer aroma and alcohol levels by changing the inoculation ratio of the two yeasts. A dynamic model was developed based on mono-culture performance of brewers' yeast and C. fabianii in controlled bioreactors with aerated wort as medium, describing growth rate, carbohydrate utilization, ethanol production, maintenance, oxygen consumption and ergosterol biosynthesis/use for cell membrane synthesis (the last one only for brewers' yeast). The parameters were estimated by fitting models to experimental data of both mono-cultivations. To predict the fermentation outcome of brewers' yeast and C. fabianii in co-cultivation, the two models were combined and the same parameter settings were used. The co-cultivation model was experimentally validated for the inoculum ratios 1:10 and 1:100 brewers' yeast over C. fabianii. The use of predictive modelling supported the hypothesis that performance of brewers' yeast in co-cultivation is inhibited by oxygen depletion which is required for the biosynthesis of ergosterol. This dynamic modelling approach and the parameter...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research