title: An acid-stable bacterial laccase identified from the endophyte Pantoea ananatis Sd-1 genome exhibiting lignin degradation and dye decolorization abilities.
abstract: OBJECTIVE
  Isolation and identification of a novel laccase (namely Lac4) with various industrial applications potentials from an endophytical bacterium.
  
  
  RESULTS
  Endophyte Sd-1 cultured in rice straw showed intra- and extra-cellular laccase activities. Genomic analysis of Sd-1 identified four putative laccases, Lac1 to Lac4. However, only Lac4 contains the complete signature sequence of laccase and shares at most 64 % sequence identity with other characterized bacterial multi-copper oxidases. Recombinant Lac4 can oxidize non-phenolic and phenolic compounds under acidic conditions and at 30-50 °C; Km values of Lac4 for ABTS at pH 2.5 and for guaiacol at pH 4.5 were 1 ± 0.15 and 6.1 ± 1.7 mM, respectively. The activity of Lac4 was stimulated by 0.8 mM Cu(2+) and 5 mM Fe(2+). In addition, Lac4 could decolorize various synthetic dyes and exhibit the degradation rate of 38 % for lignin.
  
  
  CONCLUSIONS
  The data suggest that Lac4 possesses promising biotechnological potentials.
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Shi
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Jiangshan
authors.initials: J
authors.lastname: Ma
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Hongdong
authors.initials: H
authors.lastname: Liao
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Xianqiu
authors.initials: X
authors.lastname: Xiong
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Keke
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Tengfei
authors.initials: T
authors.lastname: Wang
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Xuanmin
authors.initials: X
authors.lastname: Liu
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Xu
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Yuan
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China. zyh20@hotmail.com.
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004396:Coloring Agents / Q000378:metabolism*; D016680:Genome, Bacterial; D042845:Laccase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008031:Lignin / Q000378:metabolism*; D008969:Molecular Sequence Data; D020636:Pantoea / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014874:Water Pollutants, Chemical / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004396:Coloring Agents; D011994:Recombinant Proteins; D014874:Water Pollutants, Chemical; D008031:Lignin; D042845:Laccase
keywords: Acid-tolerant laccase; Bacterial laccase; Dye decolorization; Endophyte; Genome sequencing; Lac4; Laccase; Lignin degradation; Pantoea ananatis