There are
many algal species which are heterotrophic and they are able to
take up small organic molecules in the environments and turn
them into the building blocks of their own which are mainly fat
or oil and proteins. There are certain algal species which can use
either inorganic carbon (CO2) from atmosphere or organic carbon
from the environment and this process is called mixotrophy.
Through any of the three processes, algae can produce carbohydrates,
lipids and proteins over a short period of time, which can
then be processed to generate biofuels. Some algae can even serve
as self biorefinary for ethanol production during anaerobic dark
condition by utilizing their photosynthates. There are several reports
documenting the potential of algal biomass to generate biofuels