270
metabolic analyses in microalgae have been focused on identification and quantification of economically valuable secondary metabolites like fatty acids, steroids,
carotenoids, polysaccharides, lectins, toxins, etc. (Jamers et al. 2009). Integrated
proteomic and metabolomic analysis in C. reinhardtii (Lee et al. 2012) reported
changes in general stress responses and carbon assimilation process with increases
in fatty acid and TAG biosynthetic machinery under nitrogen-limited conditions.
Wase et al. (2014) examined and correlated the metabolic and proteomic response of
C. reinhardtii under nitrogen stress. During nitrogen deprivation, there was a reduced
abundance of proteins and metabolites involved in photosynthesis, carbon assimilation and chlorophyll biosynthesis and an increase in abundance of proteins of oxidative phosphorylation, nitrogen metabolism and biosynthesis of lipid and starch.
13.7 Conclusion and Future Perspectives
Microalgae have the potential to be used as a feedstock for biofuel production, a
source for bioactive compounds, biomedical components and high value pigments.
This has increased their demand in cosmetic and pharmaceutical industries.
Microalgae constantly manage oxidative stress resulting from cellular metabolic
reactions and environmental stress conditions. To manage oxidative stress, microalgae have mechanisms similar to plants that include cellular antioxidant scavengers.
Generation of ROS and their subsequent signalling are key regulators in cell physiology and their responses to stress conditions. At high concentration, ROS impair
cellular damage while at sublethal level they act as a ‘signalling molecule’ initiating
defence genes and adaptive responses of the cell. However, there is much to learn
about the initiation of ROS signalling, the sensing and response mechanisms and
how the delicate balance between production and scavenging is controlled. It is also
very important to know about the interactions between pathways mediated by ROS,
cellular redox changes, hormonal changes, and other messenger molecules in
microalgae. Although the role of oxidative stress in carotenogenesis is well studied,
its link with the accumulation lipid and carbohydrate in microalgae is not well
established yet. Further research is required to know how different ROS affect the
synthesis of these metabolites under different stress conditions.
Algalomic analyses provide a wealth of information about the dynamics of genes,
proteins and metabolites directly involved in various metabolic processes.
Information gathered from omics studies can be used to direct genome editing of
other microalgal species more amenable to genetic manipulation or possessing more
desirable traits. As new algal species are identified and their genomes are sequenced,
strategies must be developed to quickly annotate and characterize genes and proteins
involved in lipid and starch metabolism. Principally omics projects should aim at
different microalgae features such as evolution, adaptation and divergence compared with other species, gene, protein and metabolite information and their interaction. This would facilitate an understanding of the biology of microalgae in detail
and the application of these concepts in the production of valuable products.
K. Chokshi et al.
metabolic analyses in microalgae have been focused on identification and quantification of economically valuable secondary metabolites like fatty acids, steroids,
carotenoids, polysaccharides, lectins, toxins, etc. (Jamers et al. 2009). Integrated
proteomic and metabolomic analysis in C. reinhardtii (Lee et al. 2012) reported
changes in general stress responses and carbon assimilation process with increases
in fatty acid and TAG biosynthetic machinery under nitrogen-limited conditions.
Wase et al. (2014) examined and correlated the metabolic and proteomic response of
C. reinhardtii under nitrogen stress. During nitrogen deprivation, there was a reduced
abundance of proteins and metabolites involved in photosynthesis, carbon assimilation and chlorophyll biosynthesis and an increase in abundance of proteins of oxidative phosphorylation, nitrogen metabolism and biosynthesis of lipid and starch.
13.7 Conclusion and Future Perspectives
Microalgae have the potential to be used as a feedstock for biofuel production, a
source for bioactive compounds, biomedical components and high value pigments.
This has increased their demand in cosmetic and pharmaceutical industries.
Microalgae constantly manage oxidative stress resulting from cellular metabolic
reactions and environmental stress conditions. To manage oxidative stress, microalgae have mechanisms similar to plants that include cellular antioxidant scavengers.
Generation of ROS and their subsequent signalling are key regulators in cell physiology and their responses to stress conditions. At high concentration, ROS impair
cellular damage while at sublethal level they act as a ‘signalling molecule’ initiating
defence genes and adaptive responses of the cell. However, there is much to learn
about the initiation of ROS signalling, the sensing and response mechanisms and
how the delicate balance between production and scavenging is controlled. It is also
very important to know about the interactions between pathways mediated by ROS,
cellular redox changes, hormonal changes, and other messenger molecules in
microalgae. Although the role of oxidative stress in carotenogenesis is well studied,
its link with the accumulation lipid and carbohydrate in microalgae is not well
established yet. Further research is required to know how different ROS affect the
synthesis of these metabolites under different stress conditions.
Algalomic analyses provide a wealth of information about the dynamics of genes,
proteins and metabolites directly involved in various metabolic processes.
Information gathered from omics studies can be used to direct genome editing of
other microalgal species more amenable to genetic manipulation or possessing more
desirable traits. As new algal species are identified and their genomes are sequenced,
strategies must be developed to quickly annotate and characterize genes and proteins
involved in lipid and starch metabolism. Principally omics projects should aim at
different microalgae features such as evolution, adaptation and divergence compared with other species, gene, protein and metabolite information and their interaction. This would facilitate an understanding of the biology of microalgae in detail
and the application of these concepts in the production of valuable products.
K. Chokshi et al.