Open AccessGrowth temperature regulation of some genes that define the superficial capsular carbohydrate composition of Escherichia coli K92
Author(s) -
Navasa Nicolás,
RodríguezAparicio Leandro B.,
Ferrero Miguel Ángel,
MoteagudoMera Andrea,
MartínezBlanco Honorina
Publication year - 2011
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2011.02300.x
Subject(s) - polysialic acid , operon , escherichia coli , gene , gene cluster , biology , gene expression , biochemistry , dephosphorylation , biosynthesis , catabolism , regulation of gene expression , metabolism , chemistry , phosphorylation , cell , phosphatase , cell adhesion , neural cell adhesion molecule
We studied growth temperature as a factor controlling the expression of genes involved in capsular polymers of Escherichia coli K92. These genes are shown to be regulated by growth temperature. Expression levels of genes belonging to the kps cluster, responsible for polysialic acid (PA) biosynthesis, were significantly increased at 37 °C compared with at 19 °C, being up to 500‐fold increased for neuE and neuS genes. Similarly, the genes for the nan operon, responsible for PA catabolism, also reached higher expression levels at 37 °C, although with slightly lower values (39–141‐fold). In contrast, genes of the cps operon, which are implicated in colanic acid (CA) metabolism, were upregulated when the bacteria were grown at 19 °C, albeit to a much lesser extent (around twofold). This different regulation of genes involved in the biosynthesis of polysialic and CAs correlates with the reported maximal production temperatures for the two polymers. The results suggest that the metabolism of PA is predominantly regulated by changes in gene expression, while CA production may be regulated mainly by post‐transcriptional processes such as phosphorylation–dephosphorylation reactions.