Abstract
Some Lactobacillus delbrueckii ssp. bulgaricus strains are able to synthesize exopolysaccharides (EPS) and are therefore highly important for the dairy industry as starter cultures. The aim of this study was to investigate the nutritional requirements for growth and EPS production of Lactobacillus delbrueckii ssp. bulgaricus DSM 20081. A medium was developed from a semi-defined medium (SDM) in which glucose was replaced by lactose and different combinations of supplements (nucleobases, vitamins, salts, sodium formate and orotic acid) were added. Constant pH batch fermentation with the modified medium resulted in an EPS yield of approximately 210. mg glucose equivalents per liter medium. This was a 10-fold increase over flask cultivation of this strain in SDM. Although not affecting cell growth, the mixture of salts enhanced the EPS synthesis. Whereas EPS production was approximately 12. mg/g dry biomass without salt supplementation, a significantly higher yield (approximately 20. mg/g dry biomass) was observed after adding the salt mixture. In continuous fermentation, a maximal EPS concentration was obtained at a dilution rate of 0.3. 1/h (80. mg EPS/L), which corresponded to a specific EPS production of 49. mg/g dry biomass.
| Original language | English |
|---|---|
| Journal | Journal of Bioscience and Bioengineering |
| Volume | 113 |
| Issue number | 2 |
| Pages (from-to) | 185-191 |
| Number of pages | 7 |
| ISSN | 1389-1723 |
| DOIs | |
| Publication status | Published - 2012 |
| Externally published | Yes |
Keywords
- Batch fermentation
- Broth supplementation
- Continuous fermentation
- Exopolysaccharide
- Lactobacillus delbrueckii ssp. bulgaricus
Cite this
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Growth and exopolysaccharide yield of Lactobacillus delbrueckii ssp. bulgaricus DSM 20081 in batch and continuous bioreactor experiments at constant pH. / Mende, Susann; Krzyzanowski, Leona; Weber, Jost; Jaros, Doris; Rohm, Harald.
In: Journal of Bioscience and Bioengineering, Vol. 113, No. 2, 2012, p. 185-191.Research output: Contribution to journal › Journal article › Research › peer-review
TY - JOUR
T1 - Growth and exopolysaccharide yield of Lactobacillus delbrueckii ssp. bulgaricus DSM 20081 in batch and continuous bioreactor experiments at constant pH
AU - Mende, Susann
AU - Krzyzanowski, Leona
AU - Weber, Jost
AU - Jaros, Doris
AU - Rohm, Harald
PY - 2012
Y1 - 2012
N2 - Some Lactobacillus delbrueckii ssp. bulgaricus strains are able to synthesize exopolysaccharides (EPS) and are therefore highly important for the dairy industry as starter cultures. The aim of this study was to investigate the nutritional requirements for growth and EPS production of Lactobacillus delbrueckii ssp. bulgaricus DSM 20081. A medium was developed from a semi-defined medium (SDM) in which glucose was replaced by lactose and different combinations of supplements (nucleobases, vitamins, salts, sodium formate and orotic acid) were added. Constant pH batch fermentation with the modified medium resulted in an EPS yield of approximately 210. mg glucose equivalents per liter medium. This was a 10-fold increase over flask cultivation of this strain in SDM. Although not affecting cell growth, the mixture of salts enhanced the EPS synthesis. Whereas EPS production was approximately 12. mg/g dry biomass without salt supplementation, a significantly higher yield (approximately 20. mg/g dry biomass) was observed after adding the salt mixture. In continuous fermentation, a maximal EPS concentration was obtained at a dilution rate of 0.3. 1/h (80. mg EPS/L), which corresponded to a specific EPS production of 49. mg/g dry biomass.
AB - Some Lactobacillus delbrueckii ssp. bulgaricus strains are able to synthesize exopolysaccharides (EPS) and are therefore highly important for the dairy industry as starter cultures. The aim of this study was to investigate the nutritional requirements for growth and EPS production of Lactobacillus delbrueckii ssp. bulgaricus DSM 20081. A medium was developed from a semi-defined medium (SDM) in which glucose was replaced by lactose and different combinations of supplements (nucleobases, vitamins, salts, sodium formate and orotic acid) were added. Constant pH batch fermentation with the modified medium resulted in an EPS yield of approximately 210. mg glucose equivalents per liter medium. This was a 10-fold increase over flask cultivation of this strain in SDM. Although not affecting cell growth, the mixture of salts enhanced the EPS synthesis. Whereas EPS production was approximately 12. mg/g dry biomass without salt supplementation, a significantly higher yield (approximately 20. mg/g dry biomass) was observed after adding the salt mixture. In continuous fermentation, a maximal EPS concentration was obtained at a dilution rate of 0.3. 1/h (80. mg EPS/L), which corresponded to a specific EPS production of 49. mg/g dry biomass.
KW - Batch fermentation
KW - Broth supplementation
KW - Continuous fermentation
KW - Exopolysaccharide
KW - Lactobacillus delbrueckii ssp. bulgaricus
U2 - 10.1016/j.jbiosc.2011.10.012
DO - 10.1016/j.jbiosc.2011.10.012
M3 - Journal article
C2 - 22074989
AN - SCOPUS:84856791646
VL - 113
SP - 185
EP - 191
JO - Journal of Bioscience and Bioengineering
JF - Journal of Bioscience and Bioengineering
SN - 1389-1723
IS - 2
ER -