title: Chitinase genes LbCHI31 and LbCHI32 from Limonium bicolor were successfully expressed in Escherichia coli and exhibit recombinant chitinase activities.
abstract: The two chitinase genes, LbCHI31 and LbCHI32 from Limonium bicolor, were, respectively, expressed in Escherichia coli BL21 strain. The intracellular recombinant chitinases, inrCHI31 and inrCHI32, and the extracellular exrCHI31 and exrCHI32 could be produced into E. coli. The exrCHI31 and exrCHI32 can be secreted into extracellular medium. The optimal reaction condition for inrCHI31 was 5 mmol/L of Mn²⁺ at 40°C and pH 5.0 with an activity of 0.772 U using Alternaria alternata cell wall as substrate. The optimal condition of inrCHI32 was 5 mmol/L of Ba²⁺ at 45°C and pH 5.0 with an activity of 0.792 U using Valsa sordida cell wall as substrate. The optimal reaction condition of exrCHI31 was 5 mmol/L of Zn²⁺ at 40°C and pH 5.0, and the activity was 0.921 U using the A. alternata cell wall as substrate. Simultaneously, the optimal condition of exrCHI32 was 5 mmol/L of K⁺ at 45°C and pH 5.0, with V. sordida cell wall as the substrate, and the activity was 0.897 U. Furthermore, the activities of extracellular recombinant enzymes on fungal cell walls and compounds were generally higher than those of the intracellular recombinant enzymes. Recombinant exrCHI31 and exrCHI32 have better hydrolytic ability on cell walls of different fungi than synthetic chitins and obviously showed activity against A. alternata.
authors.affiliation: School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Liu
authors.affiliation: School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.affiliation: The College of Landscape, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China.
authors.forename: Rongshu
authors.initials: R
authors.lastname: Zhang
authors.affiliation: School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China.
authors.forename: Guiping
authors.initials: G
authors.lastname: Diao
authors.affiliation: School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China.
authors.forename: Haijuan
authors.initials: H
authors.lastname: Fan
authors.affiliation: School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China.
authors.forename: Zhiying
authors.initials: Z
authors.lastname: Wang
mesh_terms: D002688:Chitinases / Q000737:chemistry* / Q000502:physiology*; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D029606:Plumbaginaceae / Q000201:enzymology / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D014169:Transformation, Bacterial / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D011994:Recombinant Proteins; D002688:Chitinases