Poly(ethylene succinate) (PES) is an aliphatic synthetic polyester with a melting point from 103–106 °C. It is synthesized from dicarboxylic acids; either by ring-opening polymerization of succinic anhydride with ethylene oxide or by polycondensation of succinic acid and ethylene glycol.[1] Thermophilic Bacillus sp. TT96 is found in soil and can degrade PES. Mesophilic PES degrading microorganisms were found in the Bacillus and Paenibacillus species; strain KT102; a relative of Bacillus pumilus was the most capable of degrading PES film. The fungal species NKCM1003 a type of Aspergillus clavatus also degrades PES film. The solubility of lithium salts (e.g. lithium perchlorate, LiClO4) in PES made it a good alternative to poly(ethylene oxide) (PEO) during early development of solid polymer electrolytes for lithium ion batteries.[2]