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Comparative proteomics of Mn ( II )‐oxidizing and non‐oxidizing R oseobacter clade bacteria reveal an operative manganese transport system but minimal Mn ( II )‐induced expression of manganese oxidation and antioxidant enzymes
Author(s) -
Learman D. R.,
Hansel C. M.
Publication year - 2014
Publication title -
environmental microbiology reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.229
H-Index - 69
ISSN - 1758-2229
DOI - 10.1111/1758-2229.12164
Subject(s) - oxidizing agent , bacteria , proteomics , manganese , chemistry , biochemistry , microbiology and biotechnology , biology , gene , genetics , organic chemistry
Summary Manganese ( Mn ) is an essential nutrient and precipitates as minerals with technological and environmental relevance. To gain a proteomic understanding of how bacteria respond to Mn ( II ) and its connection to oxidation, a comparative examination of the proteomic response of Mn ( II )‐oxidizing ( R oseobacter sp. AzwK ‐3b) and non‐oxidizing ( R uegeria sp. TM 1040) alphaproteobacteria was conducted. Both bacteria show an operative Mn ( II ) transport system. In the absence of Mn ( II ), both bacteria have higher expression of proteins that were homologous to SitA and SitB , known proteins in the Mn ( II ) transport system of other alphaproteobacteria. Overall, each bacterium demonstrated a varied response to Mn ( II ). R u . TM 1040 had a greater number of proteins differentially expressed in response to Mn ( II ) and also had a group of proteins related to chemotaxis at higher concentrations of Mn ( II ), suggesting a potential stress response. While both bacteria are able to generate extracellular superoxide and Mn ( II ) is a known antioxidant, the presence of Mn ( II ) did not significantly alter the expression of proteins related to antioxidant activity. Heme peroxidases, previously connected to Mn ( II ) oxidation, were found in the soluble protein extract of R . AzwK ‐3b, but only minor differential expression was observed as a function of Mn ( II ), indicating that their expression was not induced by Mn ( II ).