화학공학소재연구정보센터
Process Biochemistry, Vol.56, 171-176, 2017
Cell thermolysis - A simple and fast approach for isolation of bacterial laccases with potential to decolorize industrial dyes
Laccases belong to multicopper oxidases and are widespread in nature. Currently, mainly fungal laccases are applied in biotechnological processes. One reason for this is that fungal laccases are much better studied. Compared to fungal laccases, bacterial laccases possess some advantageous characteristics like high stability at elevated temperatures and alkaline pH values. Intracellular recombinant expression of bacterial laccases in E. coli makes however downstream processing more complex and time-consuming compared to extracellular expression of fungal enzymes. Here, we demonstrate that cell disruption by cell thermolysis is an efficient and simple method for the isolation and partial purification of recombinant bacterial laccases. Three different laccases, Tth from Thermus thermophilus, CotA from Bacillus subtilis and SsI1 from Streptomyces sviceus, were used to compare cell disruption by cell thermolysis with sonication and high-pressure homogenization, with and without subsequent heat treatment. Cell thermolysis resulted in high laccase activities per gram of cell wet weight and in the highest specific activities of the laccases. For example, specific activity of Tth laccase after cell thermolysis was 469-fold higher than after sonication. Furthermore, high decolorization activity towards indigo carmine and alizarin red S of these laccases, isolated via cell thermolysis, demonstrate their potential for technical applications. (C) 2017 Elsevier Ltd. All rights reserved.