The present invention is related to an improved process for production of vitamin B2 using a genetically engineered host cell comprising a heterologous enzyme with pyridoxal phosphatase activity. Using said modified host cell, the yield of riboflavin production could be increased by at least about 5%.

Described is a method for the production of fructose-6-phosphate (F6P) from dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P) comprising the steps of: (a) enzymatically converting dihydroxyacetone phosphate (DHAP) into dihydroxyacetone (DHA); and (b) enzymatically converting the thus produced dihydroxyacetone (DHA) and glyceraldehyde-3-phosphate (G3P) into fructose-6-phosphate (F6P); or
comprising the steps of: (a′) enzymatically converting glyceraldehyde-3-phosphate (G3P) into glyceraldehyde; and (b′) enzymatically converting the thus produced glyceraldehyde together with dihydroxyacetone phosphate (DHAP) into fructose-1-phosphate (F1P); and (c′) enzymatically converting the thus produced fructose-1-phosphate (F1P) into fructose-6-phosphate (F6P).

Described is a method for the production of fructose-6-phosphate (F6P) from dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P) comprising the steps of: (a) enzymatically converting dihydroxyacetone phosphate (DHAP) into dihydroxyacetone (DHA); and (b) enzymatically converting the thus produced dihydroxyacetone (DHA) and glyceraldehyde-3-phosphate (G3P) into fructose-6-phosphate (F6P); or
comprising the steps of: (a′) enzymatically converting glyceraldehyde-3-phosphate (G3P) into glyceraldehyde; and (b′) enzymatically converting the thus produced glyceraldehyde together with dihydroxyacetone phosphate (DHAP) into fructose-1-phosphate (F1P); and (c′) enzymatically converting the thus produced fructose-1-phosphate (F1P) into fructose-6-phosphate (F6P).

The present invention relates to a microorganism of the genus Escherichia in which L-tryptophan productivity is improved by inactivating phosphatase activity. Further, the present invention relates to a method for producing L-tryptophan using the microorganism of the genus Escherichia.

The present invention relates to a microorganism of the genus Escherichia in which L-tryptophan productivity is improved by inactivating phosphatase activity. Further, the present invention relates to a method for producing L-tryptophan using the microorganism of the genus Escherichia.

The present invention is related to an improved process for production of vitamin B2 using a genetically engineered host cell comprising a heterologous enzyme with pyridoxal phosphatase activity. Using said modified host cell, the yield of riboflavin production could be increased by at least about 5%.