Method for combining intracellular polyhydroxyalkanoate synthesis in microorganisms with an extracellular polysaccharide synthesis

摘要

So far, the commercialisation on a large scale of the environmentally harmless PHB and PHA biopolymers has failed because of the very high production costs involved in the production of these substances by biotechnological fermentation processes. The present invention allows these biopolymers to be produced at lower costs. The invention describes microorganisms which synthesize PHB or PHA intracellularly and permit the extracellular synthesis of at least one polysaccharide on account of the expression of at least one protein having the enzymatic activity of a hexosyltransferase. It also describes processes for preparing such microorganisms.