3.1 Upstream Strategies
It is usually easier to optimize existing biofuel technologies rather than exploring
newly emerged capacities. Accordingly, to overcome the existing shortcomings of
algal biofuels production, selection of more productive strains to boost productivity
is considered as the first approach. As the subsequent approaches, reprogramming
of algal metabolism either by modifying growth conditions or by genetic engineering tools could be considered.
3.1.1 Selection of Algal Strain
Selection of appropriate algal strains is a prerequisite to successful and economically viable algae-based biofuel industry. In fact, proper strain selection results in
better breeding, engineering, and adaptation of strains to reach the most desirable
phenotypes. This is because each microalgal genus may need specific requirements
for growth and cultivation conditions, harvesting equipment, downstream processes
as well as extraction protocols due to cell different physiology or morphology.
Therefore, development of non-species specific and common devices can be
helpful in achieving a more successful algal-based bioenergy market. Numerous
patents are focused on specific genera of Chlorella, Spirulina, Dunaliella,
Haematococcus, Synechocystis, Microcystis, Desmodesmus, and Chlamydomonas.
US20140302569A1, US20090211150A1, and WO2008083352A1 are just a few
examples. Among algal species, Chlorella sp. is of largest interest in this field,
probably due to its high growth rate and comparatively lower production costs. For
instance, the more economical the produced lipid, the more competitive the produced biodiesel would be. The first patent related to this species in the EPO
database dates back the year 1977, but the number of records increased to 36 in the
year 2016 (de la Jara et al. 2016).
Further search in Espacenet showed that considering only quantitative growth
parameters would not be sufficient for an efficient biodiesel production and high
intracellular lipid content would also act as a key criterion for selection of candidate
microalgae strains for biodiesel production. On such a basis, Isochrysis galbana
was introduced as a productive strain by the patent ES2088366A1. Furthermore,
strains of Characium polymorphum and Ankistrodesmus braunii were also studied
as oil-rich microalgae which can be used as feedstock for biofuel production by the
US patent 20130157344A.
It should be mentioned that the selection of species for scaling-up an algal
biofuel production system would also depend on fatty acid (FA) composition and
lipid productivity. In line with that, Weiss in a US patent 20080220486A1 claimed
that the strains of Skeletonema costatum and Nannochloropsis sp. could be considered as prone oleaginous microalgal strains; according to their FA profile and
growth rate (20 g/m
2 /d) under certain conditions.
296
A. F. Talebi et al.
It is usually easier to optimize existing biofuel technologies rather than exploring
newly emerged capacities. Accordingly, to overcome the existing shortcomings of
algal biofuels production, selection of more productive strains to boost productivity
is considered as the first approach. As the subsequent approaches, reprogramming
of algal metabolism either by modifying growth conditions or by genetic engineering tools could be considered.
3.1.1 Selection of Algal Strain
Selection of appropriate algal strains is a prerequisite to successful and economically viable algae-based biofuel industry. In fact, proper strain selection results in
better breeding, engineering, and adaptation of strains to reach the most desirable
phenotypes. This is because each microalgal genus may need specific requirements
for growth and cultivation conditions, harvesting equipment, downstream processes
as well as extraction protocols due to cell different physiology or morphology.
Therefore, development of non-species specific and common devices can be
helpful in achieving a more successful algal-based bioenergy market. Numerous
patents are focused on specific genera of Chlorella, Spirulina, Dunaliella,
Haematococcus, Synechocystis, Microcystis, Desmodesmus, and Chlamydomonas.
US20140302569A1, US20090211150A1, and WO2008083352A1 are just a few
examples. Among algal species, Chlorella sp. is of largest interest in this field,
probably due to its high growth rate and comparatively lower production costs. For
instance, the more economical the produced lipid, the more competitive the produced biodiesel would be. The first patent related to this species in the EPO
database dates back the year 1977, but the number of records increased to 36 in the
year 2016 (de la Jara et al. 2016).
Further search in Espacenet showed that considering only quantitative growth
parameters would not be sufficient for an efficient biodiesel production and high
intracellular lipid content would also act as a key criterion for selection of candidate
microalgae strains for biodiesel production. On such a basis, Isochrysis galbana
was introduced as a productive strain by the patent ES2088366A1. Furthermore,
strains of Characium polymorphum and Ankistrodesmus braunii were also studied
as oil-rich microalgae which can be used as feedstock for biofuel production by the
US patent 20130157344A.
It should be mentioned that the selection of species for scaling-up an algal
biofuel production system would also depend on fatty acid (FA) composition and
lipid productivity. In line with that, Weiss in a US patent 20080220486A1 claimed
that the strains of Skeletonema costatum and Nannochloropsis sp. could be considered as prone oleaginous microalgal strains; according to their FA profile and
growth rate (20 g/m
2 /d) under certain conditions.
296
A. F. Talebi et al.