Isolamento e caracterização de bactérias produtoras de lacase

Abstract

Laccases are enzymes that play a fundamental role in several oxidation processes of phenolic and non-phenolic compounds. Several works report that plants, fungi and prokaryotes are producers of laccases. However, laccases produced by prokaryotes have been noted for industrial use. The objective of this work was to isolate and characterize bacteria producing laccases. Termite bacteria, present in decomposing wood, were isolated from nutrient agar culture medium containing kraft lignin. Six CA, A3, A5, A6, A7 and A8 isolates were selected and cultured in nutrient broth plus guaiacol. Laccase activity was observed in the culture supernatant using ABTS and guaiacol at pH 5, 6.2 and 7. The enzymatic values obtained were minimum of 123 and maximum of 168 U.mL-1. The isolates were genotypically identified as belonging to the genera Bacillus and Pseudomonas. The guaiacol substrate showed better results in all pH tested. Preliminary results indicated that the isolates tested are promising for the production of laccases and in action at different pHs of activity.