Optimization of lactic acid production by immobilized Lactococcus lactis IO-1

  • Sarote Sirisansaneeyakul
  • Tiyaporn Luangpipat
  • Wirat Vanichsriratana
  • Thongchai Srinophakun
  • Henry Ho-Hsien Chen
  • Yusuf Chisti
Original Paper

DOI: 10.1007/s10295-007-0208-6

Cite this article as:
Sirisansaneeyakul, S., Luangpipat, T., Vanichsriratana, W. et al. J Ind Microbiol Biotechnol (2007) 34: 381. doi:10.1007/s10295-007-0208-6

Abstract

Production of lactic acid from glucose by immobilized cells of Lactococcus lactis IO-1 was investigated using cells that had been immobilized by either entrapment in beads of alginate or encapsulation in microcapsules of alginate membrane. The fermentation process was optimized in shake flasks using the Taguchi method and then further assessed in a production bioreactor. The bioreactor consisted of a packed bed of immobilized cells and its operation involved recycling of the broth through the bed. Both batch and continuous modes of operation of the reactor were investigated. Microencapsulation proved to be the better method of immobilization. For microencapsulated cells at immobilized cell concentration of 5.3 g l−1, the optimal production medium had the following initial concentrations of nutrients (g l−1): glucose 45, yeast extract 10, beef extract 10, peptone 7.5 and calcium chloride 10 at an initial pH of 6.85. Under these conditions, at 37 °C, the volumetric productivity of lactic acid in shake flasks was 1.8 g l−1 h−1. Use of a packed bed of encapsulated cells with recycle of the broth through the bed, increased the volumetric productivity to 4.5 g l−1 h−1. The packed bed could be used in repeated batch runs to produce lactic acid.

Keywords

Lactic acid Taguchi method Lactococcus lactis Immobilization Packed bed bioreactor 

Copyright information

© Society for Industrial Microbiology 2007

Authors and Affiliations

  • Sarote Sirisansaneeyakul
    • 1
  • Tiyaporn Luangpipat
    • 1
  • Wirat Vanichsriratana
    • 1
  • Thongchai Srinophakun
    • 2
  • Henry Ho-Hsien Chen
    • 3
  • Yusuf Chisti
    • 4
  1. 1.Department of BiotechnologyKasetsart UniversityBangkokThailand
  2. 2.Department of Chemical EngineeringKasetsart UniversityBangkokThailand
  3. 3.Department of Food ScienceNational Pingtung University of Science and TechnologyPingtungTaiwan, ROC
  4. 4.Institute of Technology and EngineeringMassey UniversityPalmerston NorthNew Zealand

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