Polysaccharide alginate, which is composed of mannuronic acid (M) and guluronic acid (G), is used as a gel-former and viscosifier in a wide range of applications. The properties of gel-forming, water-binding, and immunogenicity are influenced by the fraction of M- and G-monomers in the alginate. In this study, we engineered an alginate synthesis using culture of Azotobacter vinelandii IAM 9046. The effect of growth conditions on the cell concentration, alginate synthesis, fraction of monomers, etc., were investigated. As a result, alginate with a high content of serial G-monomers was produced in a bubble column reactor. It is our goal to control the monomer fraction of alginate that is required for medical and industrial applications.