Mycosporine-like amino acids (MAAs) are low molecular weight water soluble compounds wuich biosynthesis was thought to occur via shikimate pathway in bacteria, phytoplankton and macroalgae. Recently evidences show its biosynthesis via the pentose pathway in a cyanobacterium. Due to its high extinction molar coefficient in UV region, they provide protection against the damaging effects of UV radiation and have potential for use in sunscreens. In previous works it was described a biosynthetic cluster for shinorine with the enzymes dehydroquinate synthase, present in the shikimate pathway, O-methyltransferase, and ATP-grasp and NRPS-like enzymes. It was observed that the enzyme 2-epi-5-epi-valiolone synthase, which link the pentose pathway with MAAs production would lead to formation of 4-deoxygadusol, precursor of MAAs. In this work a genomics approach was carried out so find these genes so that MAAs production potential in Amazonian cyanobacteria of the Coleção Amazônica de Cianobactérias e Microalgas, CACIAM 14, CACIAM 53, CACIAM 54 and CACIAM 57 strains was assessed, as well as an analysis through capillary chromatography coupled to electrospray mass spectrometryof the metabolites in CACIAM 14. The genes Dehydroquinate synthase and o-methyltransferase were found in all the strains studied. The genes of pentose pathway Ribulose-phosphate-3-epimerase and transketolase were detected in the strains CACIAM 14, CACIAM 53 and CACIAM 57, what may suggest that in these strains MAAs could be produced by both pathways while in CACIAM 57 MAAs could be produced by shikimate pathway only. In CACIAM 14 strain, fragments of mass to charge relationship 186 and 197 were found in the same retention time of a precursor ion of m/z 333, what could be related to shinorine. Therefore, the strains CACIAM 53, 54 and 57 are potentially producers of MAAs due to possessing biosynthetic genes and CACIAM 14 is shinorine producer.
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