Statistical modeling and optimization for exopolysaccharide production by Lactobacillus confusus in submerged fermentation under high salinity stress
In the last two decades, many studies have been reported that a high concentration of NaCl suppresses exopolysaccharide (EPS) production in lactic acid bacteria. In the present study, however, the enhancement of EPS production by Lactobacillus confusus under high salinity stress in submerged fermentation was demonstrated using response surface methodology via a full factorial design. Under the optimized conditions of 3.33% NaCl, 20 g/L sucrose, and 35 h of incubation, the EPS yield was 10.87 g/ L with 178% higher than the maximum yield (6.12 g/L of EPS) produced from the modified MRS medium without NaCl. Biomass production was independent of EPS production. A high yield of biomass was obtained in the culture with 0.23% NaCl. This results indicate that high salinity stress by NaCl can enhance EPS production in submerged fermentation in uncontrolled pH cultivations by inducing the production of cell-associated dextransucrase.
Keywordssubmerged fermentation exopolysaccharide (EPS) Lactobacillus confusus NaCl high salinity stress cell-associated dextransucrase
Unable to display preview. Download preview PDF.
- 14.Ahmed ZR, Siddiqui K, Arman M, Ahmed N. Characterization of high molecular weight dextran produced by Weissella cibaria CMGDEX3. Carbohyd. Res. 90: 441–446 (2012)Google Scholar
- 15.Kuntiya A, Hanmoungjai P, Techapun C, Sasaki K, Seesuriyachan P. Influence of pH, sucrose concentration, and agitation speed on exopolysaccharide production by Lactobacillus confusus TISTR 1498 using coconut water as a raw material substitute. Maejo Int. J. Sci. Tech. 4: 318–330 (2010)Google Scholar
- 17.Seesuriyachan P, Kuntiya A, Hanmoungjai P, Techapun C. Exopolysaccharide production by Lactobacillus confusus TISTR 1498 using coconut water as an alternative carbon source: The effect of peptone, yeast extract, and beef extract. Songklanakarin J. Sci. Technol. 33: 379–387 (2011)Google Scholar
- 23.Prasertsan P, Wichienchot S, Doelle H, Kennedy JF. Optimization for biopolymer production by Enterobacter cloacae WD7. Carbohyd. Res. 71: 468–475 (2008)Google Scholar
- 24.Dols M, Chraibi W, Remaud-Simeon M, Lindley ND, Monsan PF. Growth and energetics of Leuconostoc mesenteroides NRRL B-1299 during metabolism of various sugars and their consequences for dextransucrase production. Appl. Environ. Microb. 63: 2159–2165 (1997)Google Scholar
- 27.Cerning J. Exocellular polysaccharides produced by lactic acid bacteria. FEMS Microbiol. Rev. 7: 113–130 (1990)Google Scholar
- 28.Shukla S, Goyal A. 16S rRNA-based identification of a glucanhyperproducing Weissella confusa. Enzyme Res. doi:10.4061/2011/250842 (2011)Google Scholar