caa a22 4500 605504660 CHVBK 20210128100617.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s00253-015-6843-3 doi (NATIONALLICENCE)springer-10.1007/s00253-015-6843-3 Characterization of a novel high-pH-tolerant laccase-like multicopper oxidase and its sequence diversity in Thioalkalivibrio sp [Elektronische Daten] [Luka Ausec, Miha Črnigoj, Marko Šnajder, Nataša Ulrih, Ines Mandic-Mulec] Laccases are oxidoreductases mostly studied in fungi, while bacterial laccases remain poorly studied despite their high genetic diversity and potential for biotechnological application. Our previous bioinformatic analysis identified alkaliphilic bacterial strains Thioalkalivibrio sp. as potential sources of robust bacterial laccases that would be stable at high pH. In the present work, a gene for a laccase-like enzyme from Thioalkalivibrio sp. ALRh was cloned and expressed as a 6× His-tagged protein in Escherichia coli. The purified enzyme was a pH-tolerant laccase stable in the pH range between 2.1 and 9.9 at 20°C as shown by intrinsic fluorescence emission spectrometry. It had optimal activities at pH5.0 and pH9.5 with the laccase substrates 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,6-dimethoxyphenol, respectively. In addition, it could oxidize several other monophenolic compounds and potassium hexacyanoferrate(II) but not tyrosine. It showed highest activity at 50°C, making it suitable for prolonged incubations at this temperature. The present study shows that Thioalkalivibrio sp. encodes an active, alkaliphilic, and thermo-tolerant laccase and contributes to our understanding of the versatility of bacterial laccase-like multicopper oxidases in general. Springer-Verlag Berlin Heidelberg, 2015 Laccases nationallicence Laccase-like multicopper oxidases (LMCO) nationallicence Bacterial laccases nationallicence Enzyme characterization nationallicence Thioalkalivibrio nationallicence Ausec Luka Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia aut Črnigoj Miha Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia aut Šnajder Marko Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia aut Ulrih Nataša Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia aut Mandic-Mulec Ines Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/23(2015-12-01), 9987-9999 0175-7598 99:23<9987 2015 99 253 https://doi.org/10.1007/s00253-015-6843-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-015-6843-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ausec Luka Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia aut NATIONALLICENCE 700 1- Črnigoj Miha Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia aut NATIONALLICENCE 700 1- Šnajder Marko Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia aut NATIONALLICENCE 700 1- Ulrih Nataša Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia aut NATIONALLICENCE 700 1- Mandic-Mulec Ines Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/23(2015-12-01), 9987-9999 0175-7598 99:23<9987 2015 99 253