RANDOM MUTAGENESIS OF Phaeodactylum tricornutum AND SELECTION OF CLONES RICH IN NEUTRAL FATTY ACIDS WITH C75

Claudia Farfán, Josué Escárcega, Abelardo Campos, Carmen Vargas and Beatriz Cordero
Departamento de Acuicultura. Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California, México.
cfarfan@cicese.edu.mx
 

The application of mutation techniques in microalgae mainly targets the creation of over-producing strains of saturated fatty acids for biodiesel or highly polyunsaturated fatty acids (HUFAs) for human nutrition and aquaculture. There are several antibiotics and herbicides that can block the synthesis of fatty acids in microalgae and their lethal dose for the wild strains can be used to select mutant cells favoring the synthesis of saturated and/or unsaturated fatty acids. Cerulenin is one of these antibiotics, it is produced by the fungus Cephalosporium ceruleans  and has been successfully used as selector of mutants with high fatty acid content of several microalgal species.

This work reports for the first time the use of a synthetic analog of cerulenin, called C75, to select clones rich in HUFAs of P. tricornutum mutagenized with ethyl methyl sulfonate (EMS).  

P. tricornutum survival declined with EMS increasing concentrations; the optimum mutagenic dose was 0.15 M. The cytotoxic effect of C75 was dose and time dependent. The lethal dose of C75 was 100 µM. and successfully selected only mutant cells with significant higher contents of the commercially valuable fatty acids EPA and DHA than the parental strain.