regulation of desaturases, and optimization of FA chain length with thioesterases
are among various biomimetic approaches proposed to enhance the quality and
yield of the produced biodiesel from microalgae (Talebi et al. 2013a, b).
Apart from enhancing metabolic lipid synthesis, other targets of genetical
modification of microalgae concern improving light utilization, enhancing photosynthetic efficiency, as well as modifying carbon assimilation and trophic conversion pathways. For example, methods for enhancing cell growth of microalgae by
transgenic expression of a bicarbonate transporter, carbonic anhydrase, and
light-driven proton pump were introduced by the US patents 2014/0120623 and
US20170211086A1.
Light penetration characteristic (also known as chlorophyll engineering) is a new
interesting area being explored by related patents such as the US patent
20090023180A1 presenting methods to increase the efficiency of light utilization of
photosynthetic microorganisms.
In conclusion, it worth quoting that although the aim of the upstream strategies is
not to cover all topics involved in algal biofuels production, it is important to
highlights that potential achievements made in this category could play key roles in
overcoming the economic challenges faced by industries dealing with large-scale
microalgal biofuels production. Microalgae can be selected or modified to express
different valuable byproducts. On the other hand, the nutritional requirements,
compatibility to available facilities, tolerance to biotic and abiotic stress could also
be engineered through proper upstream processes, since the possibilities of both
selection (genetic diversity) and genetic engineering seem infinite.
3.2 Mainstream Strategies
Different patents exist with an aim to improve the production of biomass and/or
biocompounds. It is worth highlighting that economically produced algal biomass is
an essential part of successful large-scale algal fuels industries. This clearly
explains major efforts put into this category. Photobioreactor (PBR) designs for
cultivating microalgae might be the most important challenge, but there are other
mainstream bottlenecks as well, such as controlling systems. While harvesting
systems, extraction and conversion of microalgal biomass to various biofuel are the
subjects of downstream strategies considered when an ideal large-scale model plant
producing algal biofuels is discussed.
3.2.1 Improving Algal Cultivation Systems
As mentioned earlier, sustainable large-scale cultivation of microalgae is a prerequisite for successful production of algal biofuels such as algal biodiesel. To
identify the most relevant activities carried out in the development of microalgal
cultivation, patents issued pertaining to this topic are summarized in this
298
A. F. Talebi et al.
are among various biomimetic approaches proposed to enhance the quality and
yield of the produced biodiesel from microalgae (Talebi et al. 2013a, b).
Apart from enhancing metabolic lipid synthesis, other targets of genetical
modification of microalgae concern improving light utilization, enhancing photosynthetic efficiency, as well as modifying carbon assimilation and trophic conversion pathways. For example, methods for enhancing cell growth of microalgae by
transgenic expression of a bicarbonate transporter, carbonic anhydrase, and
light-driven proton pump were introduced by the US patents 2014/0120623 and
US20170211086A1.
Light penetration characteristic (also known as chlorophyll engineering) is a new
interesting area being explored by related patents such as the US patent
20090023180A1 presenting methods to increase the efficiency of light utilization of
photosynthetic microorganisms.
In conclusion, it worth quoting that although the aim of the upstream strategies is
not to cover all topics involved in algal biofuels production, it is important to
highlights that potential achievements made in this category could play key roles in
overcoming the economic challenges faced by industries dealing with large-scale
microalgal biofuels production. Microalgae can be selected or modified to express
different valuable byproducts. On the other hand, the nutritional requirements,
compatibility to available facilities, tolerance to biotic and abiotic stress could also
be engineered through proper upstream processes, since the possibilities of both
selection (genetic diversity) and genetic engineering seem infinite.
3.2 Mainstream Strategies
Different patents exist with an aim to improve the production of biomass and/or
biocompounds. It is worth highlighting that economically produced algal biomass is
an essential part of successful large-scale algal fuels industries. This clearly
explains major efforts put into this category. Photobioreactor (PBR) designs for
cultivating microalgae might be the most important challenge, but there are other
mainstream bottlenecks as well, such as controlling systems. While harvesting
systems, extraction and conversion of microalgal biomass to various biofuel are the
subjects of downstream strategies considered when an ideal large-scale model plant
producing algal biofuels is discussed.
3.2.1 Improving Algal Cultivation Systems
As mentioned earlier, sustainable large-scale cultivation of microalgae is a prerequisite for successful production of algal biofuels such as algal biodiesel. To
identify the most relevant activities carried out in the development of microalgal
cultivation, patents issued pertaining to this topic are summarized in this
298
A. F. Talebi et al.