African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5233

Full Length Research Paper

Characteristics of the secretory expression of pectate lyase A from Aspergillus nidulans in Escherichia coli

Zhihua Han1,2, Qingxin Zhao1,3*, Huanli Wang1,3 and Yijun Kang1,3
1Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresource and Environmental Protection, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, China. 2Nanjing Institute of Environmental Sciences of State Environmental Protection Administration, No. 8 Jiangwangmiao Street, Nanjing, Jiangsu 210042, China. 3College of Life Science and Biotechnology, Yancheng Teachers University, Xiwang Road, Yancheng, Jiangsu 224002, China.
Email: [email protected]

  •  Accepted: 30 June 2011
  •  Published: 04 August 2011


Pectate lyases from Aspergillus spp. are a major kind of industrial pectinases, can improve the surface properties of natural fibers and have promising applications in medicine, food, textile and other industries. Pectate lyases catalyze the eliminative cleavage of de-esterified pectin, which is a major component of the primary cell walls of many higher plants. The Pectate lyase A (PelA) gene without an N-terminal signal peptide sequence from Aspergillus nidulans was recombinantly expressed using Escherichia colias the host strain and pET-20b(+) as expression vector with a pelB N-terminal signal pepetide. PelA biosynthesis reached the maximum production field (450 U ml-1 medium) at 0.5 mM IPTG, 37°C, 200 rpm, for 2 h and the expressed PelA primarily appeared in extracellular medium. Calcium ion had a more obvious promotion than glycine and SDS to the extracellular enzyme fields, and the C-terminal sequence of Pel A might have an important effect on the transportation through the outer-membrane of E. coli. The time (2 h) of reaching the maximum enzyme at 37°C implied that the PelA expression was very significant to pectate lyase industrial production.


Key words: Characteristics, extracellular expression, pectate lyase A, Aspergillus nidulans, Escherichia coli.