Authors: S SánchezFortún F Marvá M Rouco E Costas V LópezRodas
Publish Date: 2009/03/25
Volume: 18, Issue: 5, Pages: 481-487
Abstract
Anthropogenic water pollution is producing a challenge to the survival of phytoplankton populations From an ecological point of view the tolerance of these microorganisms to water pollution is of paramount importance since they are the principal primary producers of aquatic ecosystems The adaptation of a common chlorophyta species Scenedesmus intermedius exposed to selected doseresponse chloramphenicol CAP concentrations has been analyzed A fluctuation analysis demonstrated that CAPresistant cells arise due to spontaneous mutation which occurs randomly prior to the antibiotic exposure CAPinhibited growth and photosynthetic performance of algal cells at 028 mg/l and the IC5072 value was established in 010 mg/l for both parameters The mutation rate from CAP sensitivity to resistance was 101 × 10−5 mutations per cell division while the frequency of CAPresistant allele in nonpolluted environment was estimated to be 55 CAPresistant mutants per 103 sensitivecells These results demonstrate that resistant mutants exhibit a diminished fitness until 5 mg/l of CAP thus enabling the survival of microalgae populationThis work was supported by grants SOSOS/AMB/0374 CAM MAM 093/2002 CGL 200501938/BOS CGL 200728853E Thanks are given to Eva Salgado for her technical support We also wish to express our gratitude to David Bruhn for his review and stylistic changes to this manuscript
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