title: Application of a novel alkali-tolerant thermostable DyP-type peroxidase from Saccharomonospora viridis DSM 43017 in biobleaching of eucalyptus kraft pulp.
abstract: Saccharomonospora viridis is a thermophilic actinomycete that may have biotechnological applications because of its dye decolorizing activity, though the enzymatic oxidative system responsible for this activity remains elusive. Bioinformatic analysis revealed a DyP-type peroxidase gene in the genome of S. viridis DSM 43017 with sequence similarity to peroxidase from dye-decolorizing microbes. This gene, svidyp, consists of 1,215 bp encoding a polypeptide of 404 amino acids. The gene encoding SviDyP was cloned, heterologously expressed in Escherichia coli, and then purified. The recombinant protein could efficiently decolorize several triarylmethane dyes, anthraquinonic and azo dyes under neutral to alkaline conditions. The optimum pH and temperature for SviDyP was pH 7.0 and 70°C, respectively. Compared with other DyP-type peroxidases, SviDyP was more active at high temperatures, retaining>63% of its maximum activity at 50-80°C. It also showed broad pH adaptability (>35% activity at pH 4.0-9.0) and alkali-tolerance (>80% activity after incubation at pH 5-10 for 1 h at 37°C), and was highly thermostable (>60% activity after incubation at 70°C for 2 h at pH 7.0). SviDyP had an accelerated action during the biobleaching of eucalyptus kraft pulp, resulting in a 21.8% reduction in kappa number and an increase of 2.98% (ISO) in brightness. These favorable properties make SviDyP peroxidase a promising enzyme for use in the pulp and paper industries.
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University, Beijing, PR China.
authors.forename: Wangning
authors.initials: W
authors.lastname: Yu
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University, Beijing, PR China.
authors.forename: Weina
authors.initials: W
authors.lastname: Liu
authors.affiliation: Feed Research Institute Chinese Academy of Agricultural Sciences, Beijing, PR China.
authors.forename: Huoqing
authors.initials: H
authors.lastname: Huang
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University, Beijing, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zheng
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University, Beijing, PR China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Materials Science and Technology, Beijing Forestry University, Beijing, PR China.
authors.forename: Yuying
authors.initials: Y
authors.lastname: Wu
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University, Beijing, PR China.
authors.forename: Kangjia
authors.initials: K
authors.lastname: Li
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University, Beijing, PR China.
authors.forename: Xiangming
authors.initials: X
authors.lastname: Xie
authors.affiliation: College of Biological Sciences and Technology, Beijing Forestry University, Beijing, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Jin
mesh_terms: D039903:Actinobacteria / Q000201:enzymology*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000378:metabolism; D005052:Eucalyptus / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010544:Peroxidases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D010544:Peroxidases