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High cell density cultivation of probiotics and lactic acid production
Author(s) -
Schiraldi Chiara,
Adduci Vincenzo,
Valli Vivien,
Maresca Carmelina,
Giuliano Mariateresa,
Lamberti Monica,
Cartenì Maria,
De Rosa Mario
Publication year - 2003
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.10557
Subject(s) - lactic acid , bioprocess , lactobacillus casei , fermentation , food science , microorganism , biomass (ecology) , probiotic , lactobacillaceae , bacteria , chemistry , microaerophile , biology , industrial fermentation , lactobacillus , paleontology , genetics , agronomy
The commercial interest in functional foods that contain live microorganisms, also named probiotics, is paralleled by the increasing scientific attention to their functionality in the digestive tract. This is especially true of yogurts that contain strains of lactic‐acid bacteria of intestinal origin, among these, Lactobacillus delbrueckii ssp. bulgaricus is extensively used in the dairy industry and it has been demonstrated to be a probiotic strain. In this work we describe high cell density cultivations of this microorganism also focusing on the stereospecific production of lactic acid. Key parameters such as medium composition (bactocasitone concentration) and diverse aeration conditions were explored. The results showed that the final concentration of biomass in anaerobic fermentation was lower than the one obtained in microaerophilic conditions, while it gave a very high productivity of lactic acid which was present as a racemic mixture in the permeate. Fermentation experiments carried out with air sparging, even at very low flow‐rate, led to the production of the sole L(+) lactic acid giving sevenfold increase in biomass yield in respect to the batch cultivation. Finally, a mathematical model was developed to describe the microfiltration bioprocess applied in this research considering an inhibition kinetic and enucleating a suitable mathematical description for the decrease of the transmembrane flux. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 213–222, 2003.