| 초록 |
Most of the valuable compounds like biofuels are highly reduced state that NAD(P)H should be required for their synthesis. In aerobic condition, cellular reducing equivalent are competitively consumed between reduced-chemical production and respiration. We tried to knock-down the activity of electron transfer chain to increase cellular NADH pools. Bacterial respiration complex are composed of NADH dehydrogenase, Quinone(ol), cytochrome oxidase and ATP synthase. We made combinatorial mutations in two types of NADH dehydrogenase and cytochrome oxidase respectively. The mutant strains exhibited slightly growth defection and increase of acetate production. Although the fitness of mutants were slightly deteriorated, intracellular NADH pools was higly improved. When NADH consuming pathway (i.e. 2,3-butanediol and isobutanol pathway) was introduced to the mutants, their production were enhanced. Furthermore the mutants maintained high NADH/NAD+ ratio independent of variation in aeration. |
