ROLE OF DISSOLVED-OXYGEN AS A REGULATOR FOR THE DIRECT OXIDATION OF GLUCOSE BY ERWINIA-HERBICOLA AND GLUCONOBACTER-OXYDANS

The influence of the dissolved oxygen concentration (DO) on direct glu cose oxidation leading to 2,5-diketogluconic acid (2,5-DKGA) productio n in Erwinia herbicola ATCC 21998 was studied, and a comparative analy sis with the results of similar studies made on Gluconobacter oxydans ATCC 9937, another 2,5-DKGA-accumulating organism, is presented. Contr ary to the positive influence of a high DO on direct oxidation in G. o xydans, a distinct negative influence was observed on cultures of E. h erbicola. While gluconate and ketogluconate dehydrogenase activities a re three-fold induced in G. oxydans at a high DO, the completely oppos ite phenomenon was observed in E. herbicola under similar DO condition s.