Abstract

Many purple anoxygenic bacteria contribute significantly to the catabolic and anabolic processes in the oxic/anoxic zones of several ecosystems. However, these bacteria are incapable of degrading the benzenoid ring during the biotransformation of aromatic hydrocarbons. The key enzymes in the aromatic amin acids metabolism of purple bacteria include 3,4-dihydroxyphenylalanine minotransferase (EC 2.6.1.49), 3,4-dihydroxyphenylalanine reductive deaminase (EC 4.3.1.22), 3,4- dihydroxyphenylalanine oxidative deaminase (EC 1.13.12.15), L-tryptophan aminotransferase (EC 2.6.1.27), 3,4-dihydroxyphenylalanine aminotransferase (EC 2.6.1.49), phenylalanine ammonia lyase (EC 4.3.1.24), tyrosine ammonia lyase (EC 4.3.1.23), phenylalanine/tyrosine ammonia lyase (EC 4.3.1.25), phenylacetate-CoA ligase (EC 6.2.1.30); histidine ammonia lyase (EC 4.3.1.3), tryptophanase (EC 4.1.99.1), tryptophan 2,3-dioxygenase (EC 1.13.11.11) and kynurenineformidase (EC 3.5.1.49). These enzymes have biological significance since these are known to have highly antioxidant, anti-cancer, anti HIV, antifungal/microbial, cyclooxygenase inhibitory phytohormonal activities and also display an impressive array of pharmacological applications viz. pigmenta, toxins, enzyme inhibitors, pesticides herbicides, antiparasitics, mycotoxins, antitumor agents, cytotoxic activities and growth promoter of animal and plants. Here, we reviewed anoxygenic bacterial novel enzymes and their biotechnological applications.

Key words:Alkylester, biotransformation, bioprospect, indigo, indolmycin, purple bacteria, violacein.