Sterile culture

Sterile culture vs. feed culture

While sterile cultures are guaranteed to be free of contamination and consist of 100% of a single phytoplankton species, feed or working cultures can always contain small amounts of other phytoplankton, for example.

Of course, we also try to avoid such mixtures in our feed cultures as much as possible, but in practice this cannot be completely ruled out. Such cultures can still run stably (e.g. 98% Tetraselmis with 1% Rhodomonas & 1% Nannochloropsis each; the latter never prevails, however) and can be fed and bred normally. Nevertheless, under new cultivation conditions (different lighting, etc.) it can happen that the previously "suppressed" species finally prevails and at some point, for example, only Nannochloropsis is cultivated.

Especially when cultivating sensitive phytoplankton species, it can be useful to start with sterile cultures.