Mycosporine-like amino acids in freshwater copepods: potential sources and some factors that affect their bioaccumulation

GARCÍA P. E; DIÉGUEZ, M. C.; FERRARO, M. A.; ZAGARESE H. E. & PÉREZ A. P

PHOTOCHEMISTRY AND PHOTOBIOLOGY

Allen Press

Año: 2010 vol. 86 p. 353 - 359

0031-8655

Mycosporine-like amino acids (MAAs) 1 are ubiquitous photo-protective compounds in aquatic environments. MAAs aresynthesized by a wide variety of organisms (i.e. bacteria, fungiand algae) and their production is photoinducible by ultravioletradiation (UVR) (280–400 nm) and ⁄ or photosynthetically activeradiation (400–750 nm). Most animals however, are unable tosynthesize MAAs and must acquire these compounds throughtheir diet or from symbiotic organisms. In this paper, weinvestigate the possible sources of MAAs and factors(temperature and initial MAA concentration) that may affecttheir bioaccumulation in freshwater copepods. We found thatMAA accumulation may occur even if the copepods are culturedon a MAA-free diet. In addition, we found that the bacteriostaticantibiotic, chloramphenicol, inhibits the bioaccumulation ofMAAs. These two pieces of evidence suggest that the source ofMAAs in these copepods may be prokaryotic organisms in closeassociation with the animals. The two factors investigated in thisstudy, temperature and initial MAA concentrations, were foundto affect the rates at which MAAs are accumulated. Temper-ature had positive effects on both uptake and elimination rates.On the other hand, the rate of uptake decreased at the highestassayed initial MAA concentration, probably because theconcentration of MAAs was already close to saturation.