(718c) An Integrated Algal Culture System for Biofuel Production Based On Mixotrophic and Heterotrophic Growth Modes

The commercial reality of algae fuel production depends upon innovations ingeniously incorporating engineering and algal biology and efficient utilization of resources. The Bioprocessing and Bioproduct Engineering Laboratory (BBEL) at Washington State University has developed a novel algal culture system that (1) incorporates the dual-trophism capability of some algae species into a two-stage culture process, and (2) integrates heterotrophic and phototrophic processes for year around fuel production in cold climate regions. In this system, the first stage utilizes organic carbon as substrate for algae fermentation, growing seed cells at high efficiency for inoculating to open ponds for phototrophic culture. This system can significantly improve productivity and offers a strategy for contaminant control. In parallel to the mixotrophic process, additional algae production can be accomplished using organic carbon derived from waste materials and agricultural residues. Systematic research efforts have been made in BBEL to further the science discovery and technology development for refining the system. This paper will present a summary of the related progresses. The information will provide new insights for biomass production for algae-based biofuel systems.