Maltose-Enhanced Exopolysaccharide Synthesis of through CRP-like Protein

Carbon sources alter the synthesis of exopolysaccharides (EPS) in . Maltose increased the EPS production of 163 6.5-fold. Subsequently, EPS production, transcriptome, and proteome were analyzed using glucose or maltose to further clarify the regulatory mechanism. A cAMP receptor protein (UniProtKB: F9UNI5) has been identified to control EPS synthesis in the presence of cAMP by binding to the EPS synthesis promoter P. Overexpression of the cAMP synthesis gene increased cAMP content and EPS production 4.5- and 2.2-fold, respectively. Furthermore, yogurt produced with 163-cyaA had a similar viscosity to that of commercial Greek yogurt; it had 20 and 83.7% greater viscosity than that produced with 163 with maltose and glucose, respectively. These findings indicated that 163-cyaA has potential applications in the production of functional fermented dairy products.