While only racemic (i.e. optically inactive) dl-lactic acid is
∗ Corresponding author. Tel.: +82 62 530 1842; fax: +82 62 530 1849.
E-mail address: hwryu@chonnam.ac.kr (H.-W. Ryu).
produced by chemical synthesis from petrochemical resource
(e.g. ethylene), the optically pure l(+)- or d(−)-lactic acid can
be produced by biotechnological fermentation process from
renewable resources, if the proper microorganisms would be
chosen for lactic acid fermentation