Pseudomonas putida strain U can be grown using, as sole carbon sources, the biogenic amines putrescine or cadaverine, as well as their catabolic intermediates, ɣ-aminobutyrate or δ-aminovalerate, respectively. Several paralogs for the genes that encode some of the activities involved in the catabolism
[...] Read more.
Pseudomonas putida strain U can be grown using, as sole carbon sources, the biogenic amines putrescine or cadaverine, as well as their catabolic intermediates, ɣ-aminobutyrate or δ-aminovalerate, respectively. Several paralogs for the genes that encode some of the activities involved in the catabolism of these compounds, such as a putrescine-pyruvate aminotransferase (
spuC1 and
spuC2 genes) and a ɣ-aminobutyrate aminotransferase (
gabT1 and
gabT2 genes) have been identified in this bacterium. When the expression pattern of these genes is analyzed by qPCR, it is drastically conditioned by supplying the carbon sources. Thus,
spuC1 is upregulated by putrescine, whereas
spuC2 seems to be exclusively induced by cadaverine. However,
gabT1 increases its expression in response to different polyamines or aminated catabolic derivatives from them (i.e., ɣ-aminobutyrate or δ-aminovalerate), although
gabT2 does not change its expression level concerning no-amine unrelated carbon sources (citrate). These results reveal differences between the mechanisms proposed for polyamine catabolism in
P. aeruginosa and
Escherichia coli concerning
P. putida strain U, as well as allow a deeper understanding of the enzymatic systems used by this last strain during polyamine metabolism.
Full article
