Using bioreactors, can algae be grown in the dark?
• It is possible to grow certain types of algae in the dark. However, to do this, you need to supply the algae with a carbon and energy source. Most often it is in the form of sugar. Think of it this way, for a gram of algal biomass you produce, you need to add at least 1 gram of sugar. It will actually be more since some of the sugar will be used for energy and given off as heat. So you will always have the cost of sugar, along with other nutrients. From an ecosystem perspective, this is very inefficient, since you are relying on some other plant to fix carbon and then transporting it to your system. It is unlikely that the financial or ecological economics of this type of system will ever balance.
