318 Marine Macro- and Microalgae: An Overview
to isolate microorganisms for metagenomic analysis. DNA was isolated from the collected organisms,
and genome shotgun sequencing methods were used to identify more than 1.2 million new genes (Venter
et al. 2004).
After that successful pilot project in the Sargasso Sea in 2003, Venter and the expedition team set
out to evaluate the microbial diversity in the world’s oceans using the tools and techniques developed to
sequence the human and other genomes. With a better understanding of marine microbial biodiversity,
scientists will be able to understand how ecosystems function and to discover new genes of ecological
and evolutionary importance. The results of the first phase of the expedition have been published (Kannan
et al. 2007; Rusch et al. 2007; Yooseph et al. 2007).
Since then JCVI has conducted sampling in waters off California and the west coast of the United
States, and carried out sampling in extreme conditions such as Antarctica and deep sea ocean vents. The
research vessel Sorcerer II also sampled the waters of the Baltic, Mediterranean, and Black Seas. These
are scientifically important because they are among the world’s largest seas isolated from the major
oceans. Differences in gene content between samples can identify functions that reflect the lifestyles
of the community in the context of its local environment. The results highlight the astounding diversity
contained within microbial communities, as revealed through whole genome shotgun sequencing carried
out on a global scale. Much of this microbial diversity is organized around phylogenetically related,
geographically dispersed populations.
These efforts have produced a very large amount of genetic information much of which is presumably
from the so-called unculturable microorganisms. We expect that this collection of information will be
fruitful in discovery of new genes, many of microalgal origin, with different characteristics than those
of well know strains opening the possibility of, for example, greater metabolic efficiencies. Transfer of
those genetic codes to production strains will result in higher productivities of desired chemicals which
will improve the economic and environmental out look of microalgal technology. We can also envision
transfer of these novel genes to higher plants that could result in more efficient agricultural crops that
would also result in environmental and economic benefits.
Microalgae as factories
The genomes of microalgae can also be modified to convert them into factories for products that are now
produced in plant or mammalian platforms. For example, several research efforts have highlighted that
algae are an attractive platform for producing subunit vaccines because of the low cost of production,
genetic tractability, scalability, and short generation time. Furthermore, inflammatory issues, viral, or
prion contaminants have been not been observed to date. The Mayfield team at UCSD tested whether
algal chloroplasts can produce malaria transmission blocking vaccine candidates (Gregory et al. 2012).
Mayfield and his colleagues showed they could produce a mammalian serum amyloid protein and human
antibody protein in Chlamydomonas. Other therapies include delivery of drug or protein molecules to
specific cells. The chloroplast of the green alga Chlamydomonas reinhardtii has been shown to contain
the machinery necessary to fold and assemble complex eukaryotic proteins including eukaryotic toxins
that otherwise would kill a eukaryotic host. The expression and accumulation of immunotoxin proteins in
algal chloroplasts was demonstrated; these fusion proteins contain an antibody domain targeting CD22,
a B-cell surface epitope, and the enzymatic domain of exotoxin A from Pseudomonas aeruginosa. These
algal-produced immunotoxins bind target B cells and efficiently kill them in vitro and significantly
prolong the survival of mice with implanted human B-cell tumors (Tran et al. 2013).
Advances in this field may widen the usefulness of microalgae as manufacturing platforms for many
other products that would have applications in nutrition, chemistry, and environmental industries.
Use of biotechnology tools to transform algal production
Microalgal production needs to be transformed if promise of commodity-level products and services
is to be achieved; otherwise, production costs (Table 1) will result in the inability of expanding into
those markets. To lower costs we need to develop cultivation systems and strategies that result in
to isolate microorganisms for metagenomic analysis. DNA was isolated from the collected organisms,
and genome shotgun sequencing methods were used to identify more than 1.2 million new genes (Venter
et al. 2004).
After that successful pilot project in the Sargasso Sea in 2003, Venter and the expedition team set
out to evaluate the microbial diversity in the world’s oceans using the tools and techniques developed to
sequence the human and other genomes. With a better understanding of marine microbial biodiversity,
scientists will be able to understand how ecosystems function and to discover new genes of ecological
and evolutionary importance. The results of the first phase of the expedition have been published (Kannan
et al. 2007; Rusch et al. 2007; Yooseph et al. 2007).
Since then JCVI has conducted sampling in waters off California and the west coast of the United
States, and carried out sampling in extreme conditions such as Antarctica and deep sea ocean vents. The
research vessel Sorcerer II also sampled the waters of the Baltic, Mediterranean, and Black Seas. These
are scientifically important because they are among the world’s largest seas isolated from the major
oceans. Differences in gene content between samples can identify functions that reflect the lifestyles
of the community in the context of its local environment. The results highlight the astounding diversity
contained within microbial communities, as revealed through whole genome shotgun sequencing carried
out on a global scale. Much of this microbial diversity is organized around phylogenetically related,
geographically dispersed populations.
These efforts have produced a very large amount of genetic information much of which is presumably
from the so-called unculturable microorganisms. We expect that this collection of information will be
fruitful in discovery of new genes, many of microalgal origin, with different characteristics than those
of well know strains opening the possibility of, for example, greater metabolic efficiencies. Transfer of
those genetic codes to production strains will result in higher productivities of desired chemicals which
will improve the economic and environmental out look of microalgal technology. We can also envision
transfer of these novel genes to higher plants that could result in more efficient agricultural crops that
would also result in environmental and economic benefits.
Microalgae as factories
The genomes of microalgae can also be modified to convert them into factories for products that are now
produced in plant or mammalian platforms. For example, several research efforts have highlighted that
algae are an attractive platform for producing subunit vaccines because of the low cost of production,
genetic tractability, scalability, and short generation time. Furthermore, inflammatory issues, viral, or
prion contaminants have been not been observed to date. The Mayfield team at UCSD tested whether
algal chloroplasts can produce malaria transmission blocking vaccine candidates (Gregory et al. 2012).
Mayfield and his colleagues showed they could produce a mammalian serum amyloid protein and human
antibody protein in Chlamydomonas. Other therapies include delivery of drug or protein molecules to
specific cells. The chloroplast of the green alga Chlamydomonas reinhardtii has been shown to contain
the machinery necessary to fold and assemble complex eukaryotic proteins including eukaryotic toxins
that otherwise would kill a eukaryotic host. The expression and accumulation of immunotoxin proteins in
algal chloroplasts was demonstrated; these fusion proteins contain an antibody domain targeting CD22,
a B-cell surface epitope, and the enzymatic domain of exotoxin A from Pseudomonas aeruginosa. These
algal-produced immunotoxins bind target B cells and efficiently kill them in vitro and significantly
prolong the survival of mice with implanted human B-cell tumors (Tran et al. 2013).
Advances in this field may widen the usefulness of microalgae as manufacturing platforms for many
other products that would have applications in nutrition, chemistry, and environmental industries.
Use of biotechnology tools to transform algal production
Microalgal production needs to be transformed if promise of commodity-level products and services
is to be achieved; otherwise, production costs (Table 1) will result in the inability of expanding into
those markets. To lower costs we need to develop cultivation systems and strategies that result in