8 Marine Biotechnology
301
8.4.2 Archaea and Bacteria
Bacteria and more recently archaea are important organisms in biotechnology
including the prokaryotes of marine origin. Complete genomes of hyperthermophilic bacteria and archaea have opened novel avenues for enzyme discovery.
Examples include enzymes used in research such as thermostable enzymes from
deep-sea hyperthermophilic Archaea, some of them already in common use in
molecular biology. Potential applications range from biomass processing in order
to produce ethanol and biofuel to organic chemistry and biohydrogen production.
Examples of the exploration of bacteria include Rhodopirellula baltica and
Zobellia galactanovorans. The first one was known to be densely associated with
“marine snow” in coastal waters and presumed to be an efficient degrader of organic
compounds. The second is frequently associated with macroalgae and potentially
involved in cell-wall degradation. Complete genome sequencing identified unprecedentedly high numbers of enzymes belonging to the sulfatase (Glockner et al. 2003)
and sulfotransferase families in both species (unpublished data). Based on these
results, functional genomics projects emerged in order to characterize both the
various substrates and the corresponding enzymes.
8.4.3 Algae
The marine algae, including cyanobacteria, is an extremely divergent group with
members from archaeplastida, chromalveolates and eubacteria (see Algal chapter)
and thus with an extensive metabolic diversity. Despite this, examples of genes
from marine algae that are used in biotechnology are sparse, but one success story
is the hexose oxidase gene from the red alga Chondrus crispus which has been
over-expressed in heterologous systems for the production of a commercial product. When added to food products hexose oxidase limits the Maillard reaction
and thereby limits coloration and can strengthen the gluten network (Hansen and
Stougaard 1997). Polyunsaturated fatty acids are also a good example of the role
of marine biotechnology and hence marine genomics since there is no significant
source of these important lipids outside of the marine world. Phytoplankton is considered as one of the major source for e.g. EPA and DHA. Algal genes involved
in fatty acid synthesis have indeed attracted some interest. Genes from the diatom
Thalassiosira have already contributed to research and commercial efforts aimed
at producing very long chain polyunsaturated fatty acids in transgenic crop plants
(Tonon et al. 2004a, b, 2005). An example of the use of algal products is the
use of purified laminarin from Laminaria digitata to elicit defence reactions in
tobacco (Klarzynski et al. 2000). This was the base for the development of Iodus by
Goëmar as a partial replacement product of fungicides in commercial cultivation of
cereals.
Indeed, one area that has attracted a lot of interest recently is algal biofuels and
marine genomics can potentially make an important contribution in this domain. The
world investment in biofuels research has risen dramatically in the last few years,
301
8.4.2 Archaea and Bacteria
Bacteria and more recently archaea are important organisms in biotechnology
including the prokaryotes of marine origin. Complete genomes of hyperthermophilic bacteria and archaea have opened novel avenues for enzyme discovery.
Examples include enzymes used in research such as thermostable enzymes from
deep-sea hyperthermophilic Archaea, some of them already in common use in
molecular biology. Potential applications range from biomass processing in order
to produce ethanol and biofuel to organic chemistry and biohydrogen production.
Examples of the exploration of bacteria include Rhodopirellula baltica and
Zobellia galactanovorans. The first one was known to be densely associated with
“marine snow” in coastal waters and presumed to be an efficient degrader of organic
compounds. The second is frequently associated with macroalgae and potentially
involved in cell-wall degradation. Complete genome sequencing identified unprecedentedly high numbers of enzymes belonging to the sulfatase (Glockner et al. 2003)
and sulfotransferase families in both species (unpublished data). Based on these
results, functional genomics projects emerged in order to characterize both the
various substrates and the corresponding enzymes.
8.4.3 Algae
The marine algae, including cyanobacteria, is an extremely divergent group with
members from archaeplastida, chromalveolates and eubacteria (see Algal chapter)
and thus with an extensive metabolic diversity. Despite this, examples of genes
from marine algae that are used in biotechnology are sparse, but one success story
is the hexose oxidase gene from the red alga Chondrus crispus which has been
over-expressed in heterologous systems for the production of a commercial product. When added to food products hexose oxidase limits the Maillard reaction
and thereby limits coloration and can strengthen the gluten network (Hansen and
Stougaard 1997). Polyunsaturated fatty acids are also a good example of the role
of marine biotechnology and hence marine genomics since there is no significant
source of these important lipids outside of the marine world. Phytoplankton is considered as one of the major source for e.g. EPA and DHA. Algal genes involved
in fatty acid synthesis have indeed attracted some interest. Genes from the diatom
Thalassiosira have already contributed to research and commercial efforts aimed
at producing very long chain polyunsaturated fatty acids in transgenic crop plants
(Tonon et al. 2004a, b, 2005). An example of the use of algal products is the
use of purified laminarin from Laminaria digitata to elicit defence reactions in
tobacco (Klarzynski et al. 2000). This was the base for the development of Iodus by
Goëmar as a partial replacement product of fungicides in commercial cultivation of
cereals.
Indeed, one area that has attracted a lot of interest recently is algal biofuels and
marine genomics can potentially make an important contribution in this domain. The
world investment in biofuels research has risen dramatically in the last few years,