3. Biological and biotechnological issues

3.1 Laboratory handling

Microalgae can be manipulated in a conventional microbiology laboratory with illuminated culture systems. Once collected from the natural environment, for example following an oceanographic exploration campaign, the first task is to successfully isolate a microalgae of interest from any contaminants, a phase known as "axenization", by successive dilutions in sterile media, in the presence of antibiotics, and by seeking to start a culture from clean microalgae. Several culture media are available, including artificial seawater, enriched to varying degrees with nutrients such as phosphate, nitrogen or even organic matter as an additional source of carbon. These media are referred to as "enriched" because they contain higher levels of nutrients (particularly...