The stability of pH and dissolved inorganic carbon (DIC) in microalgal culture media

The use of culture media and sterile technique involving flaming of equipment in order to maintain unialgal or aseptic conditions is standard laboratory practice. However, as a result, atmospheric CO2 concentrations, especially within laminar flow units but also in the laboratory as a whole, can become quite elevated. Media exposed in these conditions during routine work was observed to absorb this CO2 and become increasingly acidic with time. This has consequences for long-term culture maintenance and eco-physiological studies. The degree of this effect will vary between laboratories, as well as over time as global ambient CO2 concentrations continue to increase. Various ways of mitigating this are discussed.

Automated summary

The use of culture media and sterile technique in laboratories can lead to elevated levels of CO2 in the atmosphere, affecting the acidity of the media and potentially impacting long-term culture maintenance and physiological studies. Ways to mitigate this effect are discussed.