SCREENING AND MUTATIONAL IMPROVEMENT OF A D-RIBOSE SECRETING CANDIDA-PELLICULOSA STRAIN

The application of D-ribose in chemistry and pharmacy lately has recei ved much attention. In order to develop an efficient D-ribose producti on process, a screening strategy was established to isolate naturally occurring D-ribose secreting microorganisms. Of the more than two thou sand strains isolated, only four excreted D-ribose in a range from 0.0 4 to 0.36 g/l, starting from 30 g/l of D-glucose. One strain, identifi ed as Candida pelliculosa, quantitatively co-produced D-arabitol (up t o 7 g/l). This strain was subsequently submitted to UV-mutagenesis and a selective nystatin-based enrichment, leading to the isolation of a D-arabitol non-secreting mutant (C. pelliculosa PDW 43 ARA(-)), which synthesized 5 g/l of D-ribose from 30 g/l of D-glucose.