Culturing and medias

Culture conditions for Mamiellales isolates
Contributed by Worden lab members

Many Mamiellales isolates can be grown at 21.5°C, although this is not necessarily the optimal temperature for each of them. A variety of medias and light levels can be used. The following information is what has worked for Worden lab members: A common media is K made in artificial sea water (KASW), we use this for Ostreococcus tauri and Micromonas strain RCC299 (both axenic). For more finicky strains, like Micromonas pusillaCCMP1545 we use an L1 media in Sargasso Sea water. We also use this media for Ostreococcus strain RCC141 (Clade O_II).  For other strains, including Bathycoccus prasinos, we use a variety of medias – often K made in a natural seawater (e.g. Gulf Stream seawater) source. Other than the Clade O_II, which likes low light conditions, most of these strains are happy at around 200 microein m-2sec-1 PAR. We use a 14:12 hour Day:Night cycle.

To give a sense of the response to change in irradiance, two figures are provided below. These detail the response by mid-exponential growthOstreococcus tauri cultures and Micromonas strain RCC299.

OTH95 growth curves_MLCuvelier RCC299 growth curves_MLCuvelier

Both the Culture Collection for Marine Phytoplankton (CCMP) and the Roscoff Culture Collection (RCC) provide details on temperatures and medias they use for their cultures on the individual pages for each strain. The CCMP also sells media stocks and pre-made media.