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Fermentation characteristics of a low‐oxygen inducible hmp promoter system in Bacillus subtilis LAB1886
Author(s) -
Han Mu Ri,
Shang LongAn,
Chang Ho Nam,
Han Se Jong,
Kim Yun Chul,
Lee Jong Won
Publication year - 2006
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.1534
Subject(s) - bacillus subtilis , nitrite , nitrate , inducer , chemistry , recombinant dna , fermentation , oxygen , biochemistry , cell , biology , food science , bacteria , gene , organic chemistry , genetics
In an attempt to find a low‐cost promoter system which could be used for producing recombinant proteins, a low oxygen inducible hmp promoter system in Bacillus subtilis (LAB1886) was characterized by studying the effects of cell density (OD 600 ), glucose concentration, pH, dissolved oxygen (DO) level, nitrate and nitrite concentration on cell growth and β‐galactosidase expression. The optimal cultivation strategy was found to be to grow the cells in the presence of nitrate to OD 600 = 0.2 at a high DO level (80%), and then to induce the hmp promoter by lowering the DO level to 1–2%. As a result, the specific β‐galactosidase activity increased continuously to the maximal value of 1750 Miller Units. Nitrite, as the apparent inducer of the hmp promoter, was produced from nitrate reduction, and had profound effects on cell growth and β‐galactosidase expression. Copyright © 2006 Society of Chemical Industry