Microbial growth on C1 compounds. 6. Oxidation of methanol, formaldehyde and formate by methanol-grown Pseudomonas AM 1

Several studies have been made of the oxidation of C, compounds by micro-organisms grown on such compounds as sole source of carbon. In some cases, rather different results have been obtained by different workers. Kaneda & Roxburgh (1959) obtained evidence for an NAD+-linked methanol dehydrogenase in methanol-grown Pseudomonas PRL-W 4, whereas neither Harrington & Kallio (1960) nor Anthony & Zatman (1963) found such an enzyme in methanol-grown Pseudomonas methanica or Pseudlomonas sp. M 27 respectively. Instead, Harrington & Kallio ( 1960) suggested that methanol was oxidized by P. methanica '...via a catalase- linked peroxidase to formaldehyde which in turn is oxidized by a substrate specific aldehyde de- hydrogenase requiring NADI and GSH. . . '. M 27 was independent of catalase and instead found a methanol dehydrogenase that could be linked to phenazine methosulphate. It is somewhat un- expected that such closely similar bacteria should display different oxidation pathways for methanol, and to furnish further information on this question we present below a study of the oxidation of C1 com- pounds by methanol-grown Pseudomonas AM 1 and a comparative study of the oxidation of C1 com- pounds by three other types of bacteria.