The book "Metabolic Engineering of Microbial Hosts for the Biosynthesis of High Molecular Weight Hyaluronan" by Sandra Schulte offers a comprehensive analysis of biotechnological approaches for the production of high molecular weight hyaluronan (HA) through recombinant microbes. In recent years, numerous recombinant bacteria have been developed for HA production, which offer significant advantages over extraction from animal tissues or fermentation of pathogenic bacteria. These microbes require fewer organic solvents, are non-toxic, and do not degrade HA, reducing the need for extensive post-processing. However, these systems share a common limitation: the production of low molecular weight HA. The book describes the development of a recombinant microbe capable of producing HA with a molecular weight of 2 MDa or more. Two main strategies are presented, which include the use of Saccharomyces cerevisiae and various species of Streptococcus to optimize HA synthesis and leverage the physiological properties of the host organisms.