Method for producing 3-hydroxybutyric acid with Halomonas bacteria

The present invention provides a method for preparing 3-hydroxybutyric acid and its salts with halophilic bacteria belonging to the genus Halomonas, to decompose the PHB accumulated in fungus body, high 3-hydroxybutyric acid in the culture broth secretion was produced efficiently, and an object thereof is to derive the means for recovering 3-hydroxybutyric acid from the culture. Characterized by culturing the halophilic bacteria belonging to the genus Halomonas under specific conditions, 3-hydroxybutyric acid or a salt thereof.