Development of Production Strains of Chlamydomonas using Breeding Technologies

In order to make large scale commercial production of microalgae based commodity food and fuel products, significant strides in algal productivity need to be achieved. With current regulatory guidelines, large scale outdoor cultivation of microalgae for these products restricts the use of transgenic algal strains, which in the laboratory thus far have been the primary strategy taken to effectively increase lipid and growth productivity. Traditional breeding methods would enable development of non-GMO improvement of algal strains. Though highly successful for increasing crop yields in terrestrial plants, breeding methodologies to improve overall productivity have been under-studied in microalgae production. This project will build off of the laboratory based methods developed to breed green algae and will develop new strains within this genus that possess improved growth and lipid performance in an outdoor photoautotrophic setting. The genetic and phenotypic diversity within the Chlamydomonas genus combined with the well-developed protocols to induce and control the sexual cycle allow for the opportunity to create elite, high yield production quality strains, without the use of genetic engineering. In Phase I, several different isolates containing the desired phenotypic traits, such has high pH and high salt tolerance, were bred and tested for improved growth under outdoor growth conditions. Species within the Chlamydomonas genus have long been used to conduct interspecific crossings in order to answer basic scientific questions, but there has been little application of this advanced technology toward improving and developing outdoor production strains. Due to the significant work already conducted in Chlamydomonas genetics, this project is low-risk with high reward, and seeks to reframe the research to be focused on optimization for outdoor production. Phase II work will be focused on developing new traits to further boost productivity, such as higher innate lipid, thermotolerance, O2 sensitivity, and tolerance to high light, and taking these strains outdoors at a large-scale production facility to demonstrate increased productivity. This methodology which uses traditional breeding to develop robust strains will ultimately boost aerial productivity in outdoor algal systems, further increasing the feasibility of this industry to provide alternative food and fuel sources to the United States.