Bioprospecting program identifies highly diverse candidate strains with special strain properties
The rational sampling approach and screening pipeline established by the partners have successfully identified robust strains with high productivities and industrial potential. The main focus will be on shifting towards specific characterization and functional evaluation of selected strains in collaboration with the industry partners in the MIRACLES consortium.
The joint bioprospecting campaigns by the WP2 partners in Norway, Spain and Chile, has contributed to the screening of almost 40 000 isolates sampled from a broad spectrum of extreme microalgae habitats in highly diverse climatological conditions (Arctic waters, Nordic fjords, sub-tropical islands, altiplanic desert and hot springs). Our rational sampling approach is taking into consideration how evolutionary pressure may have developed special strain properties needed for survival in extreme habitats. The sampling design is based on the input from our industry partners in WP4 who have provided their specific requests for compounds and functionalities with commercial potential. After the initial screening to promote the cultivation of robust and productive strains, a total of 255 clonal isolates have been established and incorporated in strain collections.
While the sampling and initial screening efforts are still ongoing, the focus of WP2 has now moved more towards cultivation experiments and the systematic evaluation of the industrial potential of these novel isolates. So far, the rationale of our sampling strategy has been successful, leading to high diversity and interesting strain properties, and the established screening pipeline has proven fit for purpose to identify a total of 27 candidate strains that match the industrial “wish-list” and pre-defined selection criteria. The current list of candidate strains covers the whole range of market application areas that has been high-lighted by industry partner: algae ingredients in food, aquafeed, biobased materials, and specialty compounds. In the following period, the selected strains will be further characterized, assessed for food safety, and functionally evaluated in collaboration with WP3 and WP4 partners, while we will continue to push more novel isolates through the screening pipeline in order to increase the number of candidate strains.
A major part of WP2 is toestablishidentical outdoor photobioreactor systems at each partner location, which will represent a unique possibility to compare hard productivity data of reference strains in identical reactor systems under different climatic conditions. The installed GWP-III reactor systems have been fully operational at the University of Bergen for a year, where local champion strains are currently being explored and compared with industrial strains. While the identical system is already installed at the University of Las Palmas, technical and bureaucratic issues have delayed the initial experiments in Gran Canarias and also in Chile. However, efforts are being made to have all three systems in operation during 2016, and use these for inter-comparison to monitor how the different climates and varying environmental conditions affect the growth, biochemical profiles and commercial potential of standard microalgae strains. This will contribute to assess the cultivation in areas with limited potential for agriculture, and contribute to broaden the resource base and product portfolio of the algae industry.
In addition to the tasks on bioprospecting and outdoor cultivation, WP2 partners at the University of Wageningen and FitoPlancton Marino are collaborating to understand the organization and regulation of the lipid pathways in Nannochloropsis gaditana to enable improved EPA and TAG production. Combined efforts are made to optimize productivity through metabolic modeling by an experimental approach studying the fatty acid metabolism of N.gaditana using 13C-labelling during N-starvation. In parallel, differential expression data from outdoor production cycles will improve the metabolic model, and contribute to a better understanding of how the metabolic flux can be optimized by either monitoring the cultivation conditions by early markers, tightly controlling the cultivation conditions by adjusting N-levels, or by employing strategies based on metabolic engineering.