Abstract: Provided are a recombinant microorganism comprising: a gene encoding a pyridoxine oxidase; and a gene encoding a pyridoxamine synthetase having an enzymatic activity of synthesizing pyridoxamine from pyridoxal, in which each of the gene encoding a pyridoxine oxidase and the gene encoding a pyridoxamine synthetase is introduced from outside of a bacterial cell, or is endogenous to the bacterial cell and has an enhanced expression, and a method of producing pyridoxamine or a salt thereof from pyridoxine or a salt thereof using the recombinant microorganism.

Abstract: A recombinant microorganism includes a gene encoding a pyridoxine dehydrogenase, a gene encoding a pyridoxamine synthetase having an enzymatic activity of synthesizing pyridoxamine from pyridoxal, and a gene encoding an amino acid regeneration enzyme having an enzymatic activity of regenerating an amino acid consumed by the pyridoxamine synthetase, in which at least two of the gene encoding the pyridoxine dehydrogenase, the gene encoding the pyridoxamine synthetase, or the gene encoding the amino acid regeneration enzyme, are introduced from outside of a bacterial cell, or are endogenous to the bacterial cell and have an enhanced expression. In addition, a recombinant microorganism into which a gene encoding a pyridoxine dehydrogenase is introduced is provided.

Abstract: A method for the production of human tissue type plasminogen activator (human t-PA) using cells is disclosed. The method comprises producing the human t-PA in parallel with the growth of the cells or after the cells have been grown. To the cell culture bicarbonate ion is added at a concentration equivalent to 3 to 10 g/l of NaHCO.sub.3 based on the true volume of the medium to increase the osmotic pressure of the medium to a range of 350 to 520 milliosmoles/liter.

Abstract: A method for the production of human tissue type plasminogen activator (tPa) using cells is disclosed. The method includes a supplementation of a p-aminomethyl benzoic acid derivative to a cell culture medium or a tPA producing medium and further an increase of osmotic pressure in the medium to 350 milliosmoles or more/liter. The invention provides a method for producing single-chain tPA in a high concentration and with a relatively small amount of double-chain tPA in the medium.