| abstract |
The invention relates to a process for biochemical synthesis of 1,4-butanediamine in a microorganism having an increased level of an ornithine decarboxylase activity (increased ODC activity) as compared to the native level of the ornithine decarboxylase activity, wherein the increased ODC activity is obtained by means of overexpression of an ornithine decarboxylase encoding gene with increased translational and/or transcriptional efficiency, and wherein 1,4-butanediamine produced in the microorganism is excreted into a fermentation broth, and is recovered from the fermentation broth. In preferred embodiments also increased enzyme activity is obtained by of overexpression of either (i) an arginine decarboxylase encoding gene speA and an agmatinase encoding gene speB; or (ii) an arginine decarboxylase encoding gene speA and an agmatine iminohydrolase encoding gene aguA, and an N-carbamoylputrescine amidohydrolase encoding gene aguB, and optionally also an agmatinase encoding gene speB. The invention also relates to vectors, plasmids and hosts carrying, at an increased level of activity, one or more of the enzyme activities as mentioned. |