Isolation and characterization of laccase producing bacteria in termites

Laccase is one of the important enzymes in terms of applicability and versatility in industries, however the isolation of bacterial laccases present several difficult. This study was carried out with aim of screening for extracellular laccase producing bacteria. Six laccase positive strains were isolated from termite: CA, A3, A5, A6, A7 and A8. The strains A7, A8 and CA was identified as Bacillus sp, and A3, A5 and A6 as Pseudomonas sp by analysis of 16S rRNA sequences. The laccase production was optimized at 37 °C, pH 6, and 0.5 mM guaiacol in 180 rpm. Laccase activity was determined by measuring the oxidation of guaiacol and ABTS. Guaiacol was the better substrate for quantification of laccase, at pH 5 and 6.2. The strain A5 showed values ranging of minimum 123 and maximum 168 U.mL-1 of extracellular laccase. Bacteria from termite can produce extracelular laccase with ativity at acid pH.