Bacterial cutinases

The best characterized PET hydrolases are the fungal enzymes from F. solani, T. insolens, T. lanuginosus, and A. oryzae, and the bacterial cutinases from T. fusca and P. mendocina (Table 2). 

Chen S, Tong X, Woodard RW, Du G, Wu J, Chen J (2008) Identification and characterization of bacterial cutinase. J Biol Chem 283 25854-25862... 

When polyester-hydrolyzing activity was isolated using synthetic polyesters such as polycaprolactone, and the enzyme was examined in detail, it was found that it was a cutinase that was responsible for the hydrolysis [113]. Similarly, the polyester domains of suberin were found to be degraded by cutinase. Cutinase is a polyesterase, and similar enzymes may be widely distributed and can degrade a variety of natural and synthetic polyesters. Microbial polyhydroxy-alkanoic acids that are attracting increasing attention as biodegradable polyesters can be hydrolyzed by bacterial polyesterases that share some common features with cutinases [114] and this area is covered in another chapter [115]. 

Various bacterial, fungal and plant lipases have been described to hydrolyze PET (Table 15.1). Lipases catalyze the hydrolysis of long chain water insoluble triglycerides and, unlike cutinase they are interfacially activated in the presence of a water-lipid interface [63-65]. The active site of lipases is covered with a peptide segment called lid while upon opening the active site becomes accessible to the substrate. Consequently, it as been indicated that PET hydrolysis by lipase can be improved in the presence of detergents [55, 66]. Apart from typical lipases and cutinases, other esterases have been shown to hydrolyze PET. Nevertheless, it is not quite clear yet what constitues a PET-hydrolase. On the one hand a comprehensive comparison of all reported enzymes on typical lipase and cutinase substrates in addition to PET is not available. On the other hand, apart from the active site architecture and specificities on water soluble substrates, the adsorption behavior onto polymers will also play a major role. 

Sebastian J, Kolattukudy PE (1988) Purification and characterization of cutinase from a fiuorescent Pseudomonas putida bacterial strain isolated from phyllosphere. Arch Biochem Biophys 263 77-85... 

---