title: Efficient Expression of an Acidic Endo-polygalacturonase from Aspergillus niger and Its Application in Juice Production.
abstract: An endo-polygalacturonase gene (pga-zj5a) was cloned by reverse transcription from cDNAs synthesized from Aspergillus niger ZJ5 total RNA. The open reading frame of pga-zj5a was 1089 base pairs encoding 362 amino acids. Pga-zj5a lacking a signal peptide sequence was successfully amplified using A. niger ZJ5 cDNA as the template and was ligated into the pPIC9 vector. The resulting plasmid was transformed into competent cells of Pichia pastoris GS115 for heterologous expression. The polygalacturonase showed a maximum activity level of 10436 U/mL in the culture supernatant from a 3 L fermenter. Assays of enzymatic properties showed that the optimal pH and temperature of the recombinant PGA-ZJ5A were 4.5 and 40 °C, respectively. PGA-ZJ5A was effective in pear juice clarification, increased the volume of pear juice by 41.8%, and improved its light transmittance 3-fold.
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences , Beijing 100081, China.|College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology , Nanjing 211816, China.
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Wang
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences , Beijing 100081, China.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences , Beijing 100081, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Qin
authors.affiliation: Institute of Apicultural Research, Chinese Academy of Agricultural Sciences , Beijing 100093, China.
authors.forename: Lingyu
authors.initials: L
authors.lastname: Gao
authors.affiliation: Institute of Apicultural Research, Chinese Academy of Agricultural Sciences , Beijing 100093, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Han
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences , Beijing 100081, China.
authors.forename: Deqing
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences , Beijing 100081, China.
authors.forename: Jinyang
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology , Nanjing 211816, China.
authors.forename: He
authors.initials: H
authors.lastname: Huang
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences , Beijing 100081, China.
authors.forename: Wei
authors.identifier: http://orcid.org/0000-0003-2154-2485
authors.initials: W
authors.lastname: Zhang
mesh_terms: D001234:Aspergillus niger / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D055162:Biocatalysis; D003001:Cloning, Molecular; D004795:Enzyme Stability; D005285:Fermentation; D005638:Fruit / Q000378:metabolism / Q000382:microbiology*; D000067030:Fruit and Vegetable Juices / Q000032:analysis*; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D010843:Pichia / Q000235:genetics / Q000378:metabolism; D011096:Polygalacturonase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013696:Temperature
chemical_list: D005656:Fungal Proteins; D011994:Recombinant Proteins; D011096:Polygalacturonase
keywords: Aspergillus niger; Pichia pastoris; endo-polygalacturonase; juice production