COMPARATIVE-STUDIES ON ATP PRODUCTION FROM ADENOSINE BY A METHANOL YEAST

An ATP production system involving the oxidation of methanol, oxidative phosphorylation of ADP and phosphorylation of adenosine with sorbitol-treated cells of Candida boidinii (Kloeckera sp.) No. 2201 was studied with regard to the metabolism of adenosine and the role of sorbitol. Analysis by high performance liquid chromatography showed the accumulation of IMP in the reaction mixture, possibly due to catalysis by AMP deaminase. The efficiency of energy conversion from methanol to nucleotides was improved 30% by preventing the evaporation of methanol. Among osmoregulatory compounds that plasmolyzed the yeast cells, only sorbitol caused high ATP production activity on addition to the reaction mixture. The sorbitol effect was attributed to the supplying of NADH by the oxidation in parallel with the methanol oxidation. The ability of ATP production from adenine and adenosine was found in many methanol yeasts belonging to the genera, Hansenula, Pichia, Candida and Torulopsis. C. boidinii had especially high ability to accumulate ATP from adenosine.