Effect of C : N molar ratio on monomer composition of polyhydroxyalkanoates produced by Pseudomonas mendocina 0806 and Pseudomonas pseudoalkaligenus YS1

Polyhydroxyalkanoates (PHAs) are biodegradable polymers produced by bacteri a. In this study, the effect of C:N molar ratio on the monomer composition of PHAs was investigated, including medium chain length PHA produced by Pse udomonas mendocina 0806 and PHA blends consisting of monomers of 3-hydroxyb utyrate and medium chain length hydroxyalkanoate produced by Pseudomonas ps eudoalkaligenus YS1. It was observed that there were some fixed ranges of C :N molar ratio that affect the monomer composition of PHA independently of the substrate. For strain 0806, the ranges were C:N < 20, 20 < C:N < 200, a nd C:N > 200. The monomer composition was constant among these ranges when using glucose and octanoate as the sole substrate. For strain YS1, the rang es were C:N < 20, 20 < C:N < 45, and C:N > 45. These results are useful for controlling monomer composition in PHA production.