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VOL. 75 (4), 883-899, 2009 A FASCINATING EXAMPLE OF MICROALGAL ADAPTATION...

monas dinobryonis Chlorophyta, son nuevos registros para la flora
de Argentina. Estas especies se aislaron, clonaron, mantuvieron en
cultivos clónicos en el laboratorio y caracterizaron. Estos cultivos
resultaron ser resistentes al petróleo del Arroyo Minero y al petróleo
de estándares analíticos. En contraste, el petróleo destruyó a espe-
cies semejantes aisladas de áreas no contaminadas.

Palabras clave: Adaptación; Vertidos de petróleo; Microalgas;
Chlamydomonas dinobryonis; Scenedesmus obtusus; Symploca dubia.

1. INTRODUCTION

Nowadays, we are living in a geological instant in which global
extinction rates are 500 times background and are increasing due to
those human activities that are contaminating biosphere. It is
supposed that several million populations and 300 to 30.000 species
go extinct annually from a total of > 10 million species (1). Distinctive
features of biosphere future could include a proliferation of
opportunistic species resistant to anthropogenic contaminants (2).
The biodiversity crisis is reasonably understood for animals
and plants, but is less predictable in microbes that succumb to
anthropogenic toxins (1).

The occurrence of crude oil spills is one of the most worrisome
environmental problems since the World’s energy dependence on
petroleum. Crude oil is a highly toxic mixture of more than 10.000
different hydrocarbons (with approx. 55% naphtenes, 20% aromatic
compounds and 20% paraffin) and variable quantities of sulphur
and others. Accidental spills of crude oil in environment cause severe
contamination of marine and continental ecosystems. Contamination
due to spill of processed petroleum derivates (especially diesel and
fuel) is an important problem in continental waters (3). Crude oil
spills are between the worst environmental catastrophes (i.e. Exxon
Valdes, Prestige).

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