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Lactic Acid Production by Lactobacillus paracasei 168 in Discontinuous Fermentation Using Lucerne Green Juice as Nutrient Substitute

Domenii publicaţii > Stiinte ingineresti + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: D.C.VODNAR, J.Venus, R. Schneider, C.Socaciu

Editorial: Chemical Engineering and Technology, 33 (3), p.468-474, 2010.


The aim of this study was the utilization of lucerne green juice (LGJ), obtained in 2005 and 2008, as nutrient substitute in lactic acid fermentation using Lactobacillus paracasei 168, in a discontinuous fermentation process with the addition of 55 g/L glucose and 15 g/L yeast extract. The LGJ after pressing fresh green mass contains a series of nitrogen-containing compounds and inorganic salts that are essential for cell growth. The strain used, L. paracasei 168, achieved at 40.5 °C and pH 6.0 a maximum productivity of up to 2.56 g L–1 h–1 and a lactic concentration close to 45.97 g/L in trial A (LGJ 2008/glucose), 2.19 g L–1 h–1, 47.23 g/L in trial B (LGJ 2005/glucose), 2.93 g L–1 h–1, 42.27 g/L in trial C (LGJ 2008/glucose/yeast extract), and 2.68 g L–1 h–1, 47.33 g/L in trial D (LGJ 2005/glucose/yeast extract). Addition of yeast extract in trials C and D induced faster growth of L. paracasei 168. Lactate yields of about 87 % were obtained in all trials. The lactic acid formed was the optically pure L-(+)-isomer at up to 97 % in trial B. Pearson’s analysis showed that the level of lactic acid in the control trial was positively and significantly correlated with trial A (r2 = 0.9899), B (r2 = 0.9582), C (r2 = 0.9901), and D (r2 = 0.9938), with p <0.0001.

Cuvinte cheie: Lactobacillus paracasei 168, Fermentatii, Acid lactic, Suc de lucerna // Lactobacillus paracasei 168, Fermentation, Lactic acid, Lucerne green juice