Fermentation profile of Saccharomyces cerevisiae and Candida tropicalis as starter cultures on barley malt medium

Abstract

Saccharomyces cerevisiae C8-5 and Candida tropicalis F0-5 isolated from traditional sorghum beer were tested for kinetic parameters on barley malt extract, YPD (863 medium) and for alcohol production. The results showed that C. tropicalis has the highest maximum growth rate and the lowest doubling time. Values were 0.22 and 0.32 h −1 for maximum growth rate, 3 h 09 min and 2 h 09 min for doubling time respectively on barley malt extract and YPD. On contrary, glucose consumption was the fastest with S. cerevisiae (−0.36 and −0.722 g/l/h respectively on barley malt extract and YPD). When these two yeasts were used as starters in pure culture and co-culture at proportion of 1:1 and 2:1 (cell/cell) for barley malt extract fermentation, we noticed that maltose content increased first from 12.12 g/l to 13.62-16.46 g/l and then decreased. The highest increase was obtained with starter C. tropicalis + S. cerevisiae 2:1. On contrary, glucose content decreased throughout all the fermentation process. For all the starters used, the major part of the ethanol was produced at 16 h of fermentation. Values obtained in the final beers were 11.4, 11.6, 10.4 and 10.9 g/l for fermentation conducted with S. cerevisiae, C. tropicalis, C. tropicalis + S. cerevisiae 1:1 and C. tropicalis + S. cerevisiae 2:1. Cell viability measurement during the fermentation by using flow cytometry revealed that the lowest mean channel fluorescence for FL3 (yeast rate of death) was obtained with C. tropicalis + S. cerevisiae 2:1 after 48 h of fermentation.

Ethanol and phenylacetylcarbinol production processes of Candida tropicalis TISTR 5306 and Saccharomyces cerevisiae TISTR 5606 in fresh juices from longan fruit of various sizes

“…This was compared to the range of lower specific growth rates and longer doubling times of C. tropicalis TISTR 5306 between 0.0263 ± 0.0020 hr −1 and 26.4 ± 2.0 hr in FLJ‐AA to 0.0310 ± 0.0019 hr −1 and 22.4 ± 1.4 hr in FLJ‐B in comparison to S. cerevisiae TISTR 5606. This result was in contrast with Alloue‐Boraud et al () who cultivated both microbial strains in barley malt medium for 8 hr and found that C. tropicalis had the highest maximum growth rate and the lowest doubling time. In addition, dried biomass concentration level at 48 hr and dried biomass yield ( Y x/s ) between 24 and 48 hr of C. tropicalis TISTR 5306 for cultivation in FLJs were relatively higher than S. cerevisiae TISTR 5606 (Tables , ).…”

“…The combination effects of a statistically significant lower ( p ≤ 0.05) extracted total sugars (99.1 ± 1.8 g/L) concentration level (Table ) and higher specific composition level of gallic acid (99.1 ± 1.8 g/L) as in Table for FLJ‐AA might contribute to this phenomenon. Furthermore, Alloue‐Boraud et al () reported that S. cerevisiae had a higher ethanol concentration than C. tropicalis when cultivated in barley malt medium for 8 hr. But after 8 hr, ethanol production of S. cerevisiae and C. tropicalis were not significantly different ( p > 0.05).…”

Review: Pure non‐Saccharomycesstarter cultures for beer fermentation with a focus on secondary metabolites and practical applications

“…C. tropicalis does not produce many aroma compounds, as shown by the two studies of N'Guessan et al (108) and Allouse-Boraud et al (109). The fermentation temperatures in these studies were high in comparison with all the other studies in this review and might be reconsidered.…”

“…tropicalis does not produce many aroma compounds, as shown by the two studies of N'Guessan et al (108) and Allouse-Boraud et al (109). tropicalis does not produce many aroma compounds, as shown by the two studies of N'Guessan et al (108) and Allouse-Boraud et al (109).…”

“…Allouse-Boraud et al (109) used strain F0-5 (C. tropicalis) from the culture collection of the University of Nangui Abrogoua to ferment a wort made from malt extract (12 g/L maltose, 2 g/L glucose). The wort was pitched with 1 × 10 6 cells/mL at 30°C and samples were taken after 4, 8, 16 and 48 h. The initial pH value averaged about 5.8 and dropped to about 5.0 after 48 h. Low amounts of succinate (0.08 g/L) and lactate (0.15 g/L) were reported as well as an ethanol concentration of~1.5% (v/v).…”