316 Marine Macro- and Microalgae: An Overview
The biorefinery concept attempts to illustrate how, by finding a use for every component of
microalgal biomass, one producer could, in principle, serve markets of different size and value: lipids and
carbohydrates for fuel, protein for feeds, and other small components (e.g., pigments, specialty lipids,
vitamins) for specialty markets like nutrition and cosmetics. Furthermore, those components of high
value could be used to raise revenue that would bring the net cost of microalgal biofuels production
within range of fossil fuels. However, it is not clear how the biorefinery concept will actually work:
if one produces microalgal biomass at a scale to be significant in the biofuels market, any secondary
component will be produced in quantities that will surely flood their respective markets and destroy any
price support. We suspect that one would have to be very careful with the microalgal strain chosen and
any secondary products that are accumulated. In the meantime, we predict continuation of the reverse
relationship between scale and value.
Strain selection and improvement
The success of microalgal technology will be highly dependent on selecting the proper strains. Specifically
strains need to be robust to withstand outdoor conditions such as temperature swings, changes in salinity as
water evaporates, and exposure to high oxygen concentrations and to contamination. Synthetic Genomics
has identified high-productivity photosynthetic eukaryotic algal strains by a multi-step process that begins
with the collection of novel environmental isolates followed by evaluation in advanced screening tests.
This broadly-sourced native algae culture collection contains about 2,000 strains selected for robustness
and biomass and oil productivity under production conditions. To create this culture collection, Synthetic
Genomics obtained permits and legal access to all sampling areas, primarily in North and Central America,
continental US and Pacific Islands, prior to collecting samples from environments with conditions similar
to those predicted for photobioreactors (PBRs) and open raceway ponds.
Our strategy for strain selection has resulted in the identification of several production strains (for
lipids, starch, and high value products) for which we are now investigating the best process options: type
and size of growth reactor, contamination mitigation, nutrient management, harvest, and downstream
processing. The identification of these production strains also permits us to concentrate efforts aimed
at further increasing biomass, starch, and lipid productivity of high-productivity strains through strain
engineering. These efforts are essential because a key factor impacting the cost of algal products is the
productivity (grams of biomass per square meter per day, Olaizola 2003a; Davis et al. 2011). Higher
productivity ultimately will reduce the cost of algal-based food, feed, and fuel components and improve
their environmental footprint. State of the art tools that SGI has developed include the use of novel
continuous culture methods to select for improved strains and analysis of changes to the strain via a
systems biology analysis (genomics, proteomics, transcriptomics, and lipidomics) performed using an
SGI proprietary software platform (Archetype™).
We believe that this multi-facetted approach encompassing the latest synthetic biology,
photosynthetic improvements, bioinformatics (transcriptomics, proteomics, metabolomics, lipidomics,
and fluxomics) and scale down physiology provides a sound basis for strain improvement for commercial
scale production.
Genetic resources of microalgae
Besides the well known products and processes that result from microalgal technology, microalgae can
also provide us with valuable genetic resources. Here we discuss the availability of microalgal genomes,
wild population genes, and the ability of transforming microalgae with other species’ genes into microbial
factories.
Microalgal genomes
Progress in genome sequencing is proceeding at an exponential pace, and new algal genomes are
becoming available every year. One of the challenges facing the community is the association of protein
The biorefinery concept attempts to illustrate how, by finding a use for every component of
microalgal biomass, one producer could, in principle, serve markets of different size and value: lipids and
carbohydrates for fuel, protein for feeds, and other small components (e.g., pigments, specialty lipids,
vitamins) for specialty markets like nutrition and cosmetics. Furthermore, those components of high
value could be used to raise revenue that would bring the net cost of microalgal biofuels production
within range of fossil fuels. However, it is not clear how the biorefinery concept will actually work:
if one produces microalgal biomass at a scale to be significant in the biofuels market, any secondary
component will be produced in quantities that will surely flood their respective markets and destroy any
price support. We suspect that one would have to be very careful with the microalgal strain chosen and
any secondary products that are accumulated. In the meantime, we predict continuation of the reverse
relationship between scale and value.
Strain selection and improvement
The success of microalgal technology will be highly dependent on selecting the proper strains. Specifically
strains need to be robust to withstand outdoor conditions such as temperature swings, changes in salinity as
water evaporates, and exposure to high oxygen concentrations and to contamination. Synthetic Genomics
has identified high-productivity photosynthetic eukaryotic algal strains by a multi-step process that begins
with the collection of novel environmental isolates followed by evaluation in advanced screening tests.
This broadly-sourced native algae culture collection contains about 2,000 strains selected for robustness
and biomass and oil productivity under production conditions. To create this culture collection, Synthetic
Genomics obtained permits and legal access to all sampling areas, primarily in North and Central America,
continental US and Pacific Islands, prior to collecting samples from environments with conditions similar
to those predicted for photobioreactors (PBRs) and open raceway ponds.
Our strategy for strain selection has resulted in the identification of several production strains (for
lipids, starch, and high value products) for which we are now investigating the best process options: type
and size of growth reactor, contamination mitigation, nutrient management, harvest, and downstream
processing. The identification of these production strains also permits us to concentrate efforts aimed
at further increasing biomass, starch, and lipid productivity of high-productivity strains through strain
engineering. These efforts are essential because a key factor impacting the cost of algal products is the
productivity (grams of biomass per square meter per day, Olaizola 2003a; Davis et al. 2011). Higher
productivity ultimately will reduce the cost of algal-based food, feed, and fuel components and improve
their environmental footprint. State of the art tools that SGI has developed include the use of novel
continuous culture methods to select for improved strains and analysis of changes to the strain via a
systems biology analysis (genomics, proteomics, transcriptomics, and lipidomics) performed using an
SGI proprietary software platform (Archetype™).
We believe that this multi-facetted approach encompassing the latest synthetic biology,
photosynthetic improvements, bioinformatics (transcriptomics, proteomics, metabolomics, lipidomics,
and fluxomics) and scale down physiology provides a sound basis for strain improvement for commercial
scale production.
Genetic resources of microalgae
Besides the well known products and processes that result from microalgal technology, microalgae can
also provide us with valuable genetic resources. Here we discuss the availability of microalgal genomes,
wild population genes, and the ability of transforming microalgae with other species’ genes into microbial
factories.
Microalgal genomes
Progress in genome sequencing is proceeding at an exponential pace, and new algal genomes are
becoming available every year. One of the challenges facing the community is the association of protein