Biopolymer (PHAs)

Biosynthesis​
 

Enzymes secreted by microbes facilitate the formation of "ester" bonds between organic molecules at normal temperatures and pressures (the process is called a "dehydration" reaction because water is a by-product of bond formation)

(1). More starting material is joined to the compound via ester bonds, hence the term polyester

(2). Microbes store their polyester granules in water for later use as an energy and carbon source.