Assembly and Operation of a Custom Carbon Dioxide and Air Gassing Manifold for Growth of Photoautotrophic Algal Cultures in Illuminated Incubators. v1

This protocol describes a method for setting up and operating an apparatus to enrich air with 5% CO2for growth of algal cultures. The main components of the apparatus consist of an air pump, a CO2gas cylinder, a mixer, a humidifier, a water catch, a manifold, air filters, and a gas bubbler. The flowrate of CO2can be adjusted to attain a final gas composition of 0% additional CO2(only air) up to 10% CO2in air. The maximum total flow rate of this system is 1.1 L / min and can steadily feed CO2enriched air to 10 culture vessels at a flow rate of up to 100 mL / min for each vessel. This protocol also describes a method for providing a 0.04% CO2 in 99.96% N2 pre-mixed gas mixture for anoxic growth of algal cells.