A cloned Bacillus halodurans multicopper oxidase exhibiting alkaline laccase activity
- 917 Downloads
The gene product of open reading frame bh2082 from Bacillus halodurans C-125 was identified as a multicopper oxidase with potential laccase activity. A homologue of this gene, lbh1, was obtained from a B. halodurans isolate from our culture collection. The encoded gene product was expressed in Escherichia coli and showed laccase-like activity, oxidising 2,2′-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid), 2,6-dimethoxyphenol and syringaldazine (SGZ). The pH optimum of Lbh1 with SGZ is 7.5–8 (at 45°C) and the laccase activity is stimulated rather than inhibited by chloride. These unusual properties make Lbh1 an interesting biocatalyst in applications for which classical laccases are unsuited, such as biobleaching of kraft pulp for paper production.
- Claus H, Filip Z (1997) The evidence of a laccase-like enzyme activity in a Bacillus sphaericus strain. Microbiol Res 152:209–216Google Scholar
- Sambrook J, Fritsch EF, Maniatis T (1989) Molecular cloning: a laboratory manual, 2nd edn. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.Google Scholar
- Takami H, Nakasone K, Takaki Y, Maeno G, Sasaki R, Masui N, Fuji F, Hirama C, Nakamura Y, Ogasawara N, Kuhara S, Horikoshi K (2000) Complete genome sequence of the alkaliphilic bacterium Bacillus halodurans and genomic sequence comparison with Bacillus subtilis. Nucleic Acids Res 28:4317–4331PubMedGoogle Scholar
- Yaver DS, Del Carmen Overjero M, Xu F, Nelson BA, Brown KM, Halkier T, Bernauer S, Brown SH, Kauppinen S (1999) Molecular characterization of laccase genes from the basidiomycete Coprinus cinereus and heterologous expression of the laccase Lcc1. Appl Environ Microbiol 65:4943–4948Google Scholar