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Efficient production of l-lactic acid from hydrolysate of Jerusalem artichoke with immobilized cells of Lactococcus lactis in fibrous bed bioreactors

Paper ID Volume ID Publish Year Pages File Format Full-Text
17215 42652 2012 6 PDF Available
Title
Efficient production of l-lactic acid from hydrolysate of Jerusalem artichoke with immobilized cells of Lactococcus lactis in fibrous bed bioreactors
Abstract

Hydrolysate of Jerusalem artichoke was applied for the production of l-lactic acid by immobilized Lactococcus lactis cells in a fibrous bed bioreactor system. Preliminary experiments had indicated that the high quality hydrolysate, which was derived from the 40 min acid treatment at 95 °C and pH 1.8, was sufficient to support the cell growth and synthesis of l-lactic acid. With the addition of 5 g/l yeast extract, the fermentative performance of free cell system was evidently improved. After the basal settlement of hydrolysate based fermentation, the batch mode and the fed-batch mode fermentation were carried out in the free cell system and the fibrous bed bioreactor system, respectively. In all cases the immobilized cells presented the superior ability to produce l-lactic acid. The comparison of batch mode and fed-batch mode also indicated that the growth-limiting feeding strategy could reduce the lag phase of fermentation process and enhance the production of l-lactic acid. The achieved maximum concentration of l-lactic acid was 142 g/l in the fed-batch mode. Subsequent repeated-batch fermentation of the fibrous bed bioreactor system had further exhibited the persistence and stability of this system for the high production of l-lactic acid in a long term. Our work suggested the great potential of the fibrous bed bioreactor system and hydrolysate of J. artichoke in the economical production of l-lactic acid at industrial scale.

► High yield of sugars from Jerusalem artichoke was obtained using mild acid treatment. ► JA hydrolysate could support the high level production of lactic acid in FBB. ► Immobilization of Lactococcus lactis greatly improved the lactic acid productivity.

Keywords
l-Lactic acid; Jerusalem artichoke; Lactococcus lactis; Fibrous bed bioreactor
First Page Preview
Efficient production of l-lactic acid from hydrolysate of Jerusalem artichoke with immobilized cells of Lactococcus lactis in fibrous bed bioreactors
Publisher
Database: Elsevier - ScienceDirect
Journal: Enzyme and Microbial Technology - Volume 51, Issue 5, 10 October 2012, Pages 263–268
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering