Enhancement of acid tolerance in Zymomonas mobilis by a proton-buffering peptide |
| |
Authors: | David J Baumler Kai F Hung Jeffrey L Bose Boris M Vykhodets Chorng M Cheng Kwang-Cheol Jeong Charles W Kaspar |
| |
Institution: | (1) Cellular and Molecular Biology, University of Wisconsin, 1925 Willow Drive, 53706-1187 Madison, Wisconsin;(2) Food Microbiology and Toxicology, University of Wisconsin, 1925 Willow Drive, 53706-1187 Madison, Wisconsin;(3) Molecular and Environmental toxicology, University of Wisconsin, 1925 Willow Drive, 53706-1187 Madison, Wisconsin |
| |
Abstract: | A portion of the cbpA gene from Escherichia coli K-12 encoding a 24 amino acid proton-buffering peptide (Pbp) was cloned via the shuttle vector pJB99 into E. coli JM105 and subsequently into Zymomonas mobilis CP4. Expression of Pbp was confirmed in both JM105 and CP4 by HPLC. Z. mobilis CP4 carrying pJB99-2 (Pbp) exhibited increased acid tolerance (p<0.05) in acidified TSB (HCl pH 3.0] or acetic acid pH 3.5]), glycine-HCl buffer (pH 3.0), and sodium acetate-acetic acid
buffer (pH 3.5) in comparison to the parent strain (CP4) and CP4 with pJB99 (control plasmid). Although the expression of
Pbp influenced survival at a low pH, the minimum growth pH was unaffected. Growth of Z. mobilis in the presence of ampicillin also significantly increased acid tolerance by an unknown mechanism. Results from this study
demonstrate that the production of a peptide with a high proportion of basic amino acids can contribute to protection from
low pH and weak organic acids such as acetic acid. |
| |
Keywords: | Z mobilis acid tolerance CbpA ampicillin pH homeostasis |
本文献已被 PubMed SpringerLink 等数据库收录! |
|