Modelling the growth and ethanol production of Brettanomyces bruxellensis at different glucose concentrations

Abstract

Aim: To study the effect of glucose concentrations on the growth by Brettanomyces bruxellensis yeast strain in batch experiments and develop a mathematical model for kinetic behaviour analysis of yeast growing in batch culture. Methods and Results: A Matlab algorithm was developed for the estimation of model parameters. Glucose fermentation by B. bruxellensis was studied by varying its concentration (5, 9·3, 13·8, 16·5, 17·6 and 21·4%). The increase in substrate concentration up to a certain limit was accompanied by an increase in ethanol and biomass production; at a substrate concentration of 50–138 g l−1, the ethanol and biomass production were 24, 59 and 6·3, 11·4 g l−1, respectively. However, an increase in glucose concentration to 165 g l−1 led to a drastic decrease in product formation and substrate utilization. Conclusions: The model successfully simulated the batch kinetic observed in all cases. The confidence intervals were also estimated at each phase at a 0·95 probability level in a t‐Student distribution for f degrees of freedom. The maximum ethanol and biomass yields were obtained with an initial glucose concentration of 138 g l−1. Significance and Impact of the Study: These experiments illustrate the importance of using a mathematical model applied to kinetic behaviour on glucose concentration by B. bruxellensis.

A mathematical model of cocoa bean fermentation

“…Specifically, for the maximum specific growth rate of Y on Glc (m Y Glc max ), the obtained parameter values ranged from 0.06 to 0.37 h 21 . These values agree with the reported ones for species of this microbial group, between 0.0781 and 0.53 h 21 [44][45][46][47][48][49][50][51] for Camu et al [4] and box 2 [24] (green cells in table 3), while the estimate for box 1 [24] is far from the range in less than the estimate divided by 10 (orange cell in table 3). In a similar fashion, the estimated parameters for the maximum growth rate of LAB (m LAB max ) varied across the three datasets between 0.36 and 0.5 h 21 , falling within the range of reported values in the literature between 0.0072 and 1.41 h 21 [54 -59] (all parameters are within green cells in table 3).…”

“… n.a. Y Glc | Y 33.400 (11.255) 240.926 (59.899) 119.672 (35.155) 2.47* 1.56–66.67 [ 44 – 46 , 50 , 51 , 65 , 66 ] Y Glc | LAB 29.259 (10.852) 20.217 (13.24) 3.323 (3.417) 1.75* 4.50–200 [ 59 , 67 ] Y Fru | Y 41.105 (11.215) 244.153 (46.219) 232.383 (62.958) 0.21 43.48–200 [ 51 , 52 ] 7.436 (4.526) 11.941 (6.061) 8.201 (4.503) 0.70 1.39–21.49 [ 46 , 49 , 50 , 68 ] 5.927 (3.351) 11.195 (5.005) 6.008 (3.882) 1.16 5.7878 [ 49 ] Y EtOH | AAB 1298.070 (637.461) 378.452 (152.674) 170.44 (56.123) …”

“…In more detail, the estimated yield coefficient of Y-to-EtOH from Glc ( ) was the only one that agreed in all three datasets with those reported in the literature (green cells in table 3 ). Their estimated values ranged between 7.44 and 11.94 mg(EtOH)mg(Y) −1 , falling in the referenced range of 1.39–21.49 mg(EtOH) mg(Y) −1 [ 46 , 49 , 50 , 68 ]. For the yield coefficient of LAB-to-Glc ( Y Glc | LAB ), the fits corresponding to the data of Camu et al [ 4 ] and box 1 [ 24 ] were contained in the referenced range of 1.56–66.67 mg(Glc) mg(LAB) −1 [ 59 , 67 ] (green cells in table 3 ) with values of 29.23 and 20.22 mg(Glc) mg(LAB) −1 , respectively.…”

Assessing Population Diversity of Brettanomyces Yeast Species and Identification of Strains for Brewing Applications

“…Different sugar consumption patterns have been reported, with variations in maltose and maltotriose utilization (Crauwels et al, 2017;Smith and Divol, 2018). Ethanol production is closely linked to sugar utilization, and Brettanomyces has been widely described as a potential bioethanol producer (Blomqvist et al, 2010;Aguilar-Uscanga et al, 2011;Schifferdecker et al, 2016). A unique property of Brettanomyces yeasts is their high β-glucosidase activity, conferring the capability to break beta linked substrates (Daenen et al, 2004(Daenen et al, , 2008b.…”

Growth characteristics of freeze-tolerant baker’s yeast Saccharomyces cerevisiae AFY in aerobic batch culture

“…In the Erlenmeyer-flask culture, for example, the optimum culture medium for the culture of yeast AFY contains: 220 g/L glucose, 49 g/L yeast-extract, 20 ml/L inorganic-ion solution (with 60 g/L potassium phosphate monobasic, 20 g/L magnesium sulphate, 0.2 g/L calcium chloride) and 20 ml/L vitamin solution (with 2 g/L inositol, 0.5 g/L thiamine) (Chen 2015 ). In comparison, ordinary yeasts grow well in culture media with a sugar concentration below 138 g/L (Wang et al 2007 , 2010 ; Aguilar-Uscanga et al 2011 ). It is considered that the yeast AFY may withstand a higher osmotic pressure than ordinary yeasts do (Zhang et al 2015 ).…”