Articles
Influence of inoculum on the dynamics of Saccharomyces cerevisiae yeast biomass development
Article number
1387_35
Pages
255 – 260
Language
English
Abstract
The present paper presents the influence of liquid inoculum on cultivation on two media using different carbon sources to obtain yeast biomass for winemaking.
The isolated yeast strain was molecularly identified by the MALDI-TOF technique as S. cerevisiae and was used as a pre-inoculum culture for inoculation of the YPG liquid inoculum (yeast extract, peptone-hy soy and glucose) in bioreactor A and YSP liquid inoculum (yeast extract, peptone-hy soy and sucrose) in bioreactor B. Cultivation to obtain liquid inoculum was performed in an incubator shaker system at 240 rpm, 30°C, overnight.
The developed liquid inoculum was used at an inoculation ratio of 15% for fermentation media.
Fermentation was carried out in bioreactor with a working volume of 4 L (6 L total volume), at 30°C, 250-300 rpm and air flow 0.5 L air L‑1 medium min‑1. It was observed that the viable cell count was higher for the liquid inoculum in bioreactor B, which used sucrose as carbon source (3×1010 UFC mL-1) compared to bioreactor A (2×1010 UFC mL-1), which used glucose as carbon source.
The dynamics of the growth curve of the microorganism in a fed-batch system was analysed.
The lag phase lasted 2 h for bioreactor A and approximately 2 h for bioreactor B and the growth phase started after 4 h of cultivation; the accelerated growth phase reached the exponential phase around 10 h, then moving into the stationary phase and finally into the accelerated death.
After cultivation media processing, a quantity of 42 g L‑1 wet yeast biomass was obtained in the bioreactor A and 43.25 g L‑1 for bioreactor B, respectively.
The dried wet yeast biomass obtained through freeze-drying will be used in winemaking for the inoculation of grape juice.
The isolated yeast strain was molecularly identified by the MALDI-TOF technique as S. cerevisiae and was used as a pre-inoculum culture for inoculation of the YPG liquid inoculum (yeast extract, peptone-hy soy and glucose) in bioreactor A and YSP liquid inoculum (yeast extract, peptone-hy soy and sucrose) in bioreactor B. Cultivation to obtain liquid inoculum was performed in an incubator shaker system at 240 rpm, 30°C, overnight.
The developed liquid inoculum was used at an inoculation ratio of 15% for fermentation media.
Fermentation was carried out in bioreactor with a working volume of 4 L (6 L total volume), at 30°C, 250-300 rpm and air flow 0.5 L air L‑1 medium min‑1. It was observed that the viable cell count was higher for the liquid inoculum in bioreactor B, which used sucrose as carbon source (3×1010 UFC mL-1) compared to bioreactor A (2×1010 UFC mL-1), which used glucose as carbon source.
The dynamics of the growth curve of the microorganism in a fed-batch system was analysed.
The lag phase lasted 2 h for bioreactor A and approximately 2 h for bioreactor B and the growth phase started after 4 h of cultivation; the accelerated growth phase reached the exponential phase around 10 h, then moving into the stationary phase and finally into the accelerated death.
After cultivation media processing, a quantity of 42 g L‑1 wet yeast biomass was obtained in the bioreactor A and 43.25 g L‑1 for bioreactor B, respectively.
The dried wet yeast biomass obtained through freeze-drying will be used in winemaking for the inoculation of grape juice.
Publication
Authors
I.D. Barbulescu, R.I. Teodorescu, C. Dumitrache, M. Begea, D. Dragotoiu, M. Frincu, S.I. Marculescu, A.I. Cîrîc, D.C. Banita, V. Tudor, E.M. Boroiu
Keywords
MALDI-TOF, yeast, wine, bioreactor, S. cerevisiae
Online Articles (46)