The present invention provides a method for the biological production of glycolic acid from a fermentable carbon source in a microorganism. In one aspect of the present invention, a process for the conversion of glucose to glycolic acid is achieved by the use of a recombinant organism comprising a host E. coli transformed i) to attenuate the glyoxylate consuming pathways to other compounds than glycolate ii) to use an NADPH glyoxylate reductase to convert glyoxylate to glycolate iii) to attenuate the level of all the glycolate metabolizing enzymes and iv) increase the flux in the glyoxylate pathway. In another aspect of the present invention, the process for the production of glycolic acid from a fermentable carbon source, using a recombinant E. coli, is improved by increasing the NADPH availability in the cells. Optionally the glycolic acid produced can be purified through a step of polymerization to at least glycolic acid dimers and recovered by depolymerization from glycolic acid dimers, oligomers and/or polymers.
