Abstract: Described are genetically engineered C1-utilizing bacteria for the preparation of dicarboxylic acids, e.g. succinic acid. For instance, the bacteria comprise a mutation in a gene encoding a tricarboxylic acid cycle (TCA) succinate dehydrogenase (Sdh), preferably a mutation which inactivates or reduces Sdh's activity. Processes for the production of the modified bacteria as well as their use in the preparation of succinic acid on a C1-compound as carbon source are also discussed.

Abstract: The present invention relates to a method of producing a recombinant peptide, a recombinant protein, or a product from metabolic engineering using a genetically modified methylotrophic bacterium, and more particularly to Methylobacterium extorquens ATCC 55366. The method comprises introducing am expression vector into the methylotrophic bacterium, the expression vector comprising a polynucleotide sequence, coding for a peptide or protein, or allowing for production of a product from metabolic engineering under the control of a regulated promoter. the method also comprises growing the genectically modified methylotrophic bacterium in a minimal salts medium lacking organic sugars and containing methanol. A metal ion may be used for regulating the expression of the polynucleotide sequence by the promoter.