Bioprospection and development of metabolic models
By Hans Kleivdal, Uni Research, WP2 coordinator
WP2 focuses on bioprospecting new, robust, and productive algal isolates to evaluate their industrial potential, which is a cornerstone of the MIRACLES project.
During the first year almost 250 microalgae isolates have been secured in Norway, Spain and Chile, and subject to cultivation experiments and analyses of their commercial potential. Identical indoor and outdoor cultivation systems are being established at each bioprospecting partner for inter-comparison purposes. In addition, metabolic modelling is being used to enhance our knowledge of how growing conditions can be used to optimize metabolism, and to find possible gene targets to increase product yields using genetic modification.
Bioprospecting for new production strains in Norway, the Canary Islands and Chile
The MIRACLES project defined a need to identify strains that are more robust and have higher yields to unlock the full industrial potential of microalgae. One of the main focuses of MIRACLES is on bioprospecting these new, robust and productive algal isolates to evaluate their industrial potential.
In order to explore the biodiversity by establishing a sampling plan and harmonized screening program for novel microalgae isolates, partners in Norway, the Canary Islands in Spain and in Chile sample and screen the variety of unique, local strains for biochemical properties that are relevant for industrial application. Algae samples are collected from specifically chosen habitats with extreme environmental conditions (high/low temperatures, high/low irradiation, high saline conditions, extreme dryness, etc.) where the isolates have adapted special features, properties, or components needed for survival.
During the first year almost 250 microalgae isolates from extreme locations have been collected, have undergone cultivation experiments and have been analysed to determine their commercial potential. New microalgae isolates are continuously being obtained from the samples, and they will run through different screening pipelines. It is also important, in this context, to understand how the biochemical properties of the algal cells vary throughout the growth cycle and how these are related to varying environmental conditions.
Targets and selection criteria are developed together with the industrial partners in the MIRACLES project, based on their specific interests and needs. Existing isolates have been/are in the progress of being screened for different targets. There is still a need to refine the selection criteria and benchmark levels for product development target list, but this will be further reviewed as the screening progresses and the results can be evaluated against the predetermined criteria.
Most of the planning and strategy development was conducted during the first six months of the project. Development of the overall screening program has also been ongoing over the last six months. The screening program for the 3 bioprospecting partners has already been defined.
Establishment of outdoor cultivation systems for inter-comparison of climatic conditions
Outdoor cultivation of selected algal strains that are adapted to extreme climatological conditions will be evaluated. Selected microalgae strains with favourable properties will be cultivated in standardized small-scale outdoor cultivation systems that will be set up at each partner location. Different climates and varying environmental conditions will be monitored in relation to growth, biochemical profiles and commercial potential. This will make it possible 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.
Partners required an outdoor cultivation system with 3 separate units installed at each site to ensure good statistics. Several alternative outdoor systems were evaluated by the project partners before selecting a cost-effective and fit-for-purpose system, which is expected to be up and running by May 1st, 2015.
Metabolic modelling to maximize product yields
Project activities aim to perform metabolic modelling and optimization studies to enhance the yields of target products in the Nannochloropsis gaditana algal platform, with a focus on yield optimization of lipids.
The first metabolic modelling experiment has started and the results showed no big differences between the different nitrogen sources (ammonia and nitrate). During nitrogen starvation the dry weight still increased four times, of which half could be explained by the increase in fatty acids. This means that 50% of the dry weight that is formed after nitrogen depletion is made up of other partly unknown compounds.
A large sampling study has been performed by Fitoplancton Marino S.L. in their pilot scale photobioreactors, and a strategy for an improved sampling effort during both winter and summer has been designed in agreement with our partner, Wageningen University, for the next year.