Abstract: An object of the present invention is to provide a method for efficiently producing heparosan by improving a heparosan-producing ability through genetic modification of a bacterium of the genus Escherichia which has a heparosan-producing ability. The present invention relates to a bacterium of the genus Escherichia which has a genetic modification that increases an expression of a kpsS gene, and which has a heparosan-producing ability; and a method for producing heparosan using the bacterium.

Abstract: The invention provides a method for producing sulfated polysaccharides by reacting a PAPS production/regeneration system utilizing the metabolic activity of a microorganism or a treated matter thereof with a microorganism expressing a sulfation enzyme or a treated matter or extract thereof upon mixing of inexpensive raw materials such as magnesium sulfate. The invention also provides a method for producing PAPS from inexpensive raw materials. The methods involve preparing a transformant (a) of a bacterium of the genus Corynebacterium, which contains a gene encoding an ATP sulfurylase and a gene encoding an APS kinase, which are expressible, and in which a cell plasma membrane of the transformant (a) is substance-permeable, or a treated matter of the transformant (a), and conducting a reaction for producing PAPS by using a reaction solution containing ATP or an ATP source, a sulfate ion source, and the transformant (a) or the treated matter thereof.