Gene Structures and Catalytic Mechanisms of Microbial Enzymes Able to Blodegrade the Synthetic Solid Polymers Nylon and Polyester Polyurethaoe

Abstract

Since the middle of the 20th century, the chemical industry has generated various synthetic compounds as both industrial products and wastes material by-products. Among these synthetic compounds the water-insoluble solid polymers (with the exception of polymers synthesized specifically as biodegradable polymers, such as polylactic acid) are generally the most resistant to microbial attack, an attack which is essentially by enzyme action. An enzyme that is able to catalyze the degradation of a solid polymer must be able to access and bind to the polymer at a specific site, and to catalyze the degradation reaction extracellularly. In general, water-insoluble synthetic polymers are hydrophobic, rigid, and have a small specific surface area as compared to naturally occurring water-insoluble polymers such as cellulose. These properties make the degradation of the water-insoluble synthetic solid polymer difficult. However it has been reported that several water-insoluble synthetic solid polymers are vulnerable to microbial attack. In particular, the characteristics of the genetic sequences and catalytic mechanisms of the microbial enzymes which are able to degrade nylon and polyester polyurethane have been well studied, and this is what we will consider in this review.