can be used to produce various deactivated mutant strains containing Tn5, it may be
broadly applicable in the future in analysis of marine blue-green alga genes.
Conjugative transfer with the wide-ranging host vector pKT230 has also been
used for introduction with Synechococcus sp., which has the fastest growth rate of
the marine blue-green algae used in research to date. pKT230 is a wide-ranging host
vector of the IncQ population with an RSF1010 replication unit, and codes for
resistance to kanamycin and streptomycin.
Similarly, conjugation with E. coli S17-1 resulted in strains with phenotypes for
kanamycin and streptomycin resistance appearing at a frequency of 10
−5 to 10
−4
conjugants per recipients. This wide-ranging host vector can be consistently
recovered and rotated with E. coli, suggesting ample potential for use as a marine
blue-green alga and E. coli shuttle vector. Successful introduction of pKT230 has
also been achieved with conjugation in the marine blue-green algae Synechococcus
sp. and Synechocystis sp., and in particular in Synechococcus ATCC29403
(PCC7335), a marine blue-green alga with complementary adaptation capabilities.
These findings testify to the broad applicability of the conjugative transfer approach
with marine blue-green algae.
To date, no blue-green algae (including freshwater varieties) with conjugation
capabilities or transfer plasmids have been found. Gene exchange has been found in
blue-green algae as a result of natural DNA absorption and cyanophage infection,
but gene donation through conjugation from other Gram-negative bacteria is
believed to have taken place. Hopefully, strains with conjugation capabilities can be
isolated in the future for marine blue-green algae as well (Matsunaga 1992).
7.5 Microalgae Use in CO 2 Fixation and Production
of Beneficial Substances
7.5.1 Biosolar Reactor CO 2 Fixation Using Marine Blue-Green
Algae
Culturing of blue-green algae to date has involved the issue of artificial ponds. This
method is also used today to culture Spirulina and other varieties in regions with
strong sunlight. When blue-green algae reach high concentrations, however, sunlight penetrates only 10 cm or so below the water’s surface, which presents natural
limitations. The use of artificial ponds is thus only suitable for production in sites
where land or staffing is inexpensive (Aresta et al. 2005).
When culturing microalgae, the area of light per unit volume must be greatly
increased to raise efficiency. Glass tube and foil reactors have been developed to
achieve this, but the area of light per unit volume never exceeded around 100 m
−1
in either case. The area can be increased to around 500 m
−1 with the use of optical
fibers, but uniform scattering is difficult to achieve. For example, scattering through
etching on a quartz fiber surface results in some surfaces that do not scatter light at
all and others that scatter it strongly.
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7 Microalgae, a Biological Resource for the Future
broadly applicable in the future in analysis of marine blue-green alga genes.
Conjugative transfer with the wide-ranging host vector pKT230 has also been
used for introduction with Synechococcus sp., which has the fastest growth rate of
the marine blue-green algae used in research to date. pKT230 is a wide-ranging host
vector of the IncQ population with an RSF1010 replication unit, and codes for
resistance to kanamycin and streptomycin.
Similarly, conjugation with E. coli S17-1 resulted in strains with phenotypes for
kanamycin and streptomycin resistance appearing at a frequency of 10
−5 to 10
−4
conjugants per recipients. This wide-ranging host vector can be consistently
recovered and rotated with E. coli, suggesting ample potential for use as a marine
blue-green alga and E. coli shuttle vector. Successful introduction of pKT230 has
also been achieved with conjugation in the marine blue-green algae Synechococcus
sp. and Synechocystis sp., and in particular in Synechococcus ATCC29403
(PCC7335), a marine blue-green alga with complementary adaptation capabilities.
These findings testify to the broad applicability of the conjugative transfer approach
with marine blue-green algae.
To date, no blue-green algae (including freshwater varieties) with conjugation
capabilities or transfer plasmids have been found. Gene exchange has been found in
blue-green algae as a result of natural DNA absorption and cyanophage infection,
but gene donation through conjugation from other Gram-negative bacteria is
believed to have taken place. Hopefully, strains with conjugation capabilities can be
isolated in the future for marine blue-green algae as well (Matsunaga 1992).
7.5 Microalgae Use in CO 2 Fixation and Production
of Beneficial Substances
7.5.1 Biosolar Reactor CO 2 Fixation Using Marine Blue-Green
Algae
Culturing of blue-green algae to date has involved the issue of artificial ponds. This
method is also used today to culture Spirulina and other varieties in regions with
strong sunlight. When blue-green algae reach high concentrations, however, sunlight penetrates only 10 cm or so below the water’s surface, which presents natural
limitations. The use of artificial ponds is thus only suitable for production in sites
where land or staffing is inexpensive (Aresta et al. 2005).
When culturing microalgae, the area of light per unit volume must be greatly
increased to raise efficiency. Glass tube and foil reactors have been developed to
achieve this, but the area of light per unit volume never exceeded around 100 m
−1
in either case. The area can be increased to around 500 m
−1 with the use of optical
fibers, but uniform scattering is difficult to achieve. For example, scattering through
etching on a quartz fiber surface results in some surfaces that do not scatter light at
all and others that scatter it strongly.
218
7 Microalgae, a Biological Resource for the Future