Production of L-aspartic acid by biotransformation and recovery using reverse micelle and gas hydrate methods

Aydogan O., Bayraktar E., Parlaktuna M. , Mehmetoglu T., Mehmetoglu U.

BIOCATALYSIS AND BIOTRANSFORMATION, vol.25, no.5, pp.365-372, 2007 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 25 Issue: 5
  • Publication Date: 2007
  • Doi Number: 10.1080/10242420701510395
  • Page Numbers: pp.365-372


L-Aspartic acid (L-Asp) was produced using Escherichia coli (ATCC 11303), and its recovery from the reaction mixture was studied using reverse micelle and gas hydrate methods. The effect of initial substrate concentration on L-Asp production was also investigated, and inhibition was shown to occur above 0.75 mol L-1. The values of the kinetic constants were determined as r(max) = 2.33 x 10(-4) mol L-1 min(-1), K-M = 0.19 mol L-1, and K-ss = 3.98 mol L-1. The reverse micelle phase used for extraction contained Aliquat-336, 1-decanol and isooctane, and a micro-injection technique was used for extraction of L-Asp. The reverse micelle system is a useful technique for obtaining small particle sizes, which can be used for the synthesis of nanoparticle biomolecules. Recovery of L-Asp from reverse micelles using CO2 hydrates was carried out, giving a recovery of 55%. The formation of CO2 hydrate from the reverse micelle solution breaks the micelle by reducing the amount of water in the micelle structure, thus precipitating the L- Asp.