Extracellular polymeric substances (EPSs) are highly hydrated polymers primarily consisting of polysaccharides, proteins, and DNA that are produced by a diverse range of microorganisms. EPSs are environmentally friendly, safe, and harmonious polymers. Antibacterial, antifungal, antiviral, antitumor, antioxidant, antidiabetic, anticoagulant, antiaging, immunomodulatory, wound healing, and cholesterol-lowering properties are just a few of their many bioactivities. Owing to their appealing physicochemical qualities and biological activity, microbial EPSs have extensive uses in different industries. Because the structure and composition of EPS have a significant influence on its functional properties, it is necessary to enhance their yield and maintain quality. A number of the most widely used EPSs are dextran from the Leuconostoc, Streptococcus, and Lactobacillus genera, alginate from the Azotobacter and Pseudomonas genera, xanthan from the genus Xanthomonas, hyaluronan from the Streptococcus sp., levan from Bacillus sp., Paenibacillus sp., Halomonas sp., Zymomonas sp., and others. The genes in charge of EPS synthesis usually reside together on the bacterial genome or large plasmids. The synthesis of EPS with various chemical structures and biological activities is typically directed by distinct EPS synthesis gene clusters. EPS synthesis and secretion can be controlled by 13 genes, ranging from epsA to epsM. Several genetic engineering techniques have been established to raise the EPS’s yield and quality. This chapter will cover a variety of cutting-edge techniques that have gained popularity recently. These techniques include a number of gene-editing techniques, overexpression of EPS-related genes, heterologous EPS synthesis, altering the chemical makeup of EPS, blocking pathways that compete with EPS synthesis, etc. Numerous studies have examined a variety of genes and gene clusters that encode enzymes known to be essential for the biosynthesis of EPS, including polymerases, branching enzymes and, glycosyltransferase. It has been suggested that overexpressing a whole EPS gene cluster in Lactococcus lactis results in increased levels of EPS production. According to another investigation, the nqrE gene in Azotobacter vinelandii encodes ubiquinone oxidoreductase, a subunit of the Na+-translocating NADH. Overproduction of alginate is caused by Tn5’s disruption of nqrE expression. Hence, these are the useful approaches to increase EPS production.