Extracellular enzymatic activity from tributyltin resistant microorganisms

Abstract

Enzymes are the most remarkable and highly specialized proteins. World production of industrial enzymes is mainly derived from a few dozens of microorganisms strains. Microorganisms from stressed environments develop adaptation mechanisms to extreme physico-chemical conditions. Being active and/or stable in those selective conditions,they frequently produce extra cellular enzymes with high biotechnological/industrial potential. Tributyltin (TBT) is a common contaminant in aquatic systems as it was widely used inanti-foulingpaintsinboatsandisamajorenvironmental concern as it has been recently considered by some authors to be the most toxic substance ever introduced into the marine environment. TBT resistant microorganisms (able to grow at 3mM TBT) were collected and isolated from 7 Portuguese harbors and ports. These isolates were characterized by REP-PCR and their extracellular enzymatic activity assessed. The concentration of TBT resistant isolates varied between 0.08% (in Setúbal harbor) and 7.67% (Peniche). Results show that most of these isolates exhibit extracellular activities such as proteolytic, lipolytic, and amylolytic activities. These crude extracellular extracts were assayed for optima pH and temperature. After wards,the most stable extracts were characterized by electrophoresis. Our data shows that these TBT resistant isolates have the capacity of producing enzymes with a large biotechnological potential.