title: Molecular cloning and heterologous expression of an acid-stable endoxylanase gene from Penicillium oxalicum in Trichoderma reesei.
abstract: An endoxylanase gene (PoxynA) that belongs to the glycoside hydrolase (GH) family 11 was cloned from a xylanolytic strain, Penicillium oxalicum B3-11(2). PoxynA was overexpressed in Trichoderma reesei QM9414 by using a constitutive strong promoter of the encoding pyruvate decarboxylase (pdc). The high extracellular xylanase activities in the fermentation liquid of the transformants were maintained 29~35-fold higher compared with the wild strain. The recombinant POXYNA was purified to homogeneity, and its characters were analyzed. Its optimal temperature and pH value were 50 degrees C and 5.0, respectively. The enzyme was stable at a pH range of 2.0 to 7.0. Using beechwood as the substrate, POXYNA had a high specific activity of 1,856 +/- 53.5 IU/mg. In the presence of metal ions, such as Cu2+, and Mg2+, the activity of the enzyme increased. However, strong inhibition of the enzyme activity was observed in the presence of Mn2+ and Fe2+. The recombinant POXYNA hydrolyzed birchwood xylan, beechwood xylan, and oat spelt xylan to produce short-chain xylooligosaccharides, xylopentaose, xylotriose, and xylobiose as the main products. This is the first report on the expression properties of a recombinant endoxylanase gene from Penicillium oxalicum. The properties of this endoxylanase make it promising for applications in the food and feed industries.
authors: College of Life Science, Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen University, Shenzhen, Guangdong, P.R. China.
authors: Juan
authors: J
authors: Wang
authors: Guoqin
authors: G
authors: Mai
authors: Gang
authors: G
authors: Liu
authors: Shaowen
authors: S
authors: Yu
mesh_terms: D000143:Acids / Q000737:chemistry*; D002413:Cations, Divalent / Q000378:metabolism; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D020536:Enzyme Activators / Q000378:metabolism; D004795:Enzyme Stability; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008670:Metals / Q000378:metabolism; D008969:Molecular Sequence Data; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013696:Temperature; D014242:Trichoderma / Q000201:enzymology* / Q000235:genetics; D014934:Wood / Q000378:metabolism; D014990:Xylans / Q000378:metabolism
chemical_list: D000143:Acids; D002413:Cations, Divalent; D004271:DNA, Fungal; D020536:Enzyme Activators; D008670:Metals; D011994:Recombinant Proteins; D014990:Xylans; D043364:Endo-1,4-beta Xylanases