摘要:
A method is disclosed for preparing 5-ketogluconate, which comprises the steps of: (a) genetically modifying a microorganism capable of microbiologically producing 5-ketogluconate to increase gluconate NADP.sup.+ -5-oxidoreductase gene expression of said microorganism; (b) culturing said microorganism in a medium to produce 5-ketogluconate; and (c) recovering 5-ketogluconate from said medium.
摘要:
A process is disclosed for obtaining sorbitol and gluconic acid, or gluconate, by fermentation in aqueous glucose/fructose mixtures. Zymomonas mobilis cells are used which have been permeabilized by the freeze technique and which have preferably been obtained by freezing cell centrifugates of pH 6 to 7 at about -20.degree. C., and thawing at room temperature. Cell concentrations of 20 to 60 g of cell dry matter of permeabilized cells/l are preferably used for the fermentation. By using cells which have been permeabilized by freezing and thawing, a considerably higher conversion rate of glucose/fructose into sorbitol and gluconic acid, or gluconate, is achieved.
摘要:
The invention relates to a nucleotide sequence coding for the mannitol 2-dehydrogenase and a method for producing D-mannitol. Previously known biocatalytic methods for producing D-mannitol yield only small production rates due to the small number of specific activities of mannitol 2-dehydrogenases used for transforming D-fructose into D-mannitol. D-mannitol production can be improved by supplying a nucleotide sequence which codes for a mannitol 2-dehydrogenase having a higher specific activity. Mannitol production can be increased in a particular manner by creating a regeneration system for reduction equivalents by introducing and/or strengthening a formiate dehydrogenase in a microorganism.
摘要:
A method of preparing tartaric acid in which 5-ketogluconate is oxidized in a carbonate buffer at an alkaline pH preferably in the range of 8 to 10 using vanadate.
摘要:
This invention relates to the nucleotide sequence of coryneform bacteria coding for proteins which are involved in L-serine metabolism with reduced and switched off L-serine dehydratase activity. The invention also relates to microorganisms used in methods for producing L-serine.
摘要:
L-lysine-producing strains of corynebacteria with enhanced lysE gene (lysine export carrier gene), in which strains additional genes chosen from the group comprising the dapA gene (dihydrodipicolinate synthase gene), the lysC gene (aspartate kinase gene), the dapB gene (dihydrodipicolinate reductase gene) and the pyc gene, but especially the dapA gene and the lysC gene (aspartate kinase gene), are enhanced and, in particular, over-expressed, and to a process for the preparation of L-lysine.
摘要:
The invention relates to a method for producing L-valine and to a suitable microorganism. The inventive method is characterized by preferably enhancing the transaminase C activity of a coryneform bacterium, especially Corynebacteriuim glutamicum. The organisms so modified have a yield in L-valine which is 35.8% higher than that of non-modified organisms.
摘要:
The invention relates to L-lysine-producing strains of corynebacteria with enhanced lysE gene (lysine export carrier gene), in which strains additional genes chosen from the group comprising the dapA gene (dihydrodipicolinate synthase gene), the lysC gene (aspartate kinase gene), the dapB gene (dihydrodipicolinate reductase gene) and the pyc gene, but especially the dapA gene and the lysC gene (aspartate kinase gene), are enhanced and, in particular, over-expressed, and to a process for the preparation of L-lysine.
摘要:
The invention relates to L-lysine-producing strains of corynebacteria with enhanced lysE gene (lysine export carrier gene), in which strains additional genes chosen from the group comprising the dapA gene (dihydrodipicolinate synthase gene), the lysC gene (aspartate kinase gene), the dapB gene (dihydrodipicolinate reductase gene) and the pyc gene, but especially the dapA gene and the lysC gene (aspartate kinase gene), are enhanced and, in particular, over-expressed, and to a process for the preparation of L-lysine.
摘要:
The invention relates to preferably recombinant DNA derived from Corynebacterium and replicable in coryneform microorganisms, which contains at least one nucleotide sequence that codes for the thrE gene, and a process for the production of L-threonine, which is characterised in that the following steps are carried out: a) Fermentation of microorganisms in which at least the thrE gene is amplified (overexpressed), optionally in combination with further genes, b) Enrichment of the L-threonine in the medium or in the cells of the microorganisms, and c) Isolation of the L-threonine.