Journal
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
Volume 100, Issue 16, Pages 7115-7123Publisher
SPRINGER
DOI: 10.1007/s00253-016-7386-y
Keywords
Pullulanase; Brevibacillus choshinensis; Magnesiumions; Active form; Cell wall protein
Categories
Funding
- National Science Foundation for Distinguished Young Scholars [31425020]
- National Natural Science Foundation of China [31271813, 31401636]
- Project of Outstanding Scientific and Technological Innovation Group of Jiangsu Province
- Natural Science Foundation of Jiangsu Province [BK20140142]
- 111 Project [111-2-06]
Ask authors/readers for more resources
Addition of MgCl2 to the culture medium has been found to dramatically increase the activity of Bacillus deramificans pullulanase expressed by Brevibacillus choshinensis. The specific activity of the pullulanase obtained from medium supplemented with MgCl2 was also higher than that obtained in culture medium without added magnesium ions. In this work, the mechanism of this increase was studied. When cultured in medium without added magnesium ions, B. choshinensis mainly produced a thermolabile, inactive form of pullulanase. The addition of magnesium ions led to the production of a thermostable, active form of pullulanase. Circular dichroism assays revealed considerable differences in secondary structure between the active and inactive pullulanase forms. Transmission electron microscopy suggested that magnesium ion addition inhibits the shedding of cell wall protein (HWP) layers from the cell surface. Quantitative real-time PCR showed that magnesium ion addition represses transcription of HWP. Because the pullulanase gene and HWP have identical promoters, pullulanase gene transcription was also inhibited. These results suggest that when pullulanase is expressed slowly, it tends to fold into an active form.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available