Genetic engineering of algal chloroplasts: Progress and prospects
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The last few years has seen an ever-increasing interest in the exploitation of microalgae as recombinant platforms for the synthesis of novel bioproducts. These could be biofuel molecules, speciality enzymes, nutraceuticals, or therapeutic proteins, such as antibodies, hormones, and vaccines. This exploitation requires the development of new genetic engineering technologies for those fast-growing, robust species suited for intensive commercial cultivation in bioreactor systems. In particular, there is a need for routine methods for the genetic manipulation of the chloroplast genome, for two reasons: firstly, the chloroplast genetic system is well-suited to the targeted insertion into the genome and high-level expression of foreign genes; secondly, the organelle is the site of numerous biosynthetic pathways and therefore represents the obvious “chassis,” on which to bolt new metabolic pathways that divert the carbon fixed by photosynthesis into novel hydrocarbons, pigments, etc. Stable transformation of the algal chloroplast was first demonstrated in 1988, using the model chlorophyte, Chlamydomonas reinhardtii. Since that time, tremendous advances have been made in the development of sophisticated tools for engineering this particular species, and efforts to transfer this technology to other commercially attractive species are starting to bear fruit. In this article, we review the current field of algal chloroplast transgenics and consider the prospects for the future.
KeywordsChlamydomonas reinhardtii algae chloroplast genetic engineering transformation transplastomics
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- 10.Johanningmeier, U. and Fischer, D., Perspective for the use of genetic transformants in order to enhance the synthesis of the desired metabolites: engineering chloroplasts of microalgae for the production of bioactive compounds, Adv. Exp. Med. Biol., 2010, vol. 698, pp. 144–151.PubMedCrossRefGoogle Scholar
- 11.Boynton, J.E., Gillham, N.W., Harris, E.H., Hosler, J.P., Johnson, A.M., Jones, A.R., Randolph-Anderson, B.L., Robertson, D., Klein, T.M., and Shark, K.B., Chloroplast transformation in Chlamydomonas with high velocity microprojectiles, Science, 1988, vol. 240, pp. 1534–1538.PubMedCrossRefGoogle Scholar
- 17.Stern, D.B., The Chlamydomonas Sourcebook, New York: Academic, 2009, vol. 2.Google Scholar
- 38.Yoon, S.-M., Kim, S.Y., Li, K.F., Yoon, B.H., Choe, S., and Kuo, M.M.-C., Transgenic microalgae expressing Escherichia coli AppA phytase as feed additive to reduce phytate excretion in the manure of young broiler chicks, Appl. Microbiol. Biotechnol., 2011, vol. 91, pp. 553–563.PubMedCrossRefGoogle Scholar
- 39.Gregory, J.A., Li, F., Tomosada, L.M., Cox, C.J., Topol, A.B., Vinetz, J.M., and Mayfield, S., Algaeproduced Pfs25 elicits antibodies that inhibit malaria transmission, PLoS ONE, 2012, vol. 7: e37179.Google Scholar
- 40.Jones, C.S., Luong, T., Hannon, M., Tran, M., Gregory, J.A., Shen, Z., Briggs, S.P., and Mayfield, S.P., Heterologous expression of the C-terminal antigenic domain of the malaria vaccine candidate Pfs48/45 in the green algae Chlamydomonas reinhardtii, Appl. Microbiol. Biotechnol., 2012, May 18 [Epub ahead of print].Google Scholar
- 46.Szaub, J.B., Genetic engineering of green microalgae for the production of biofuel and high value products, Ph.D. Dissertation, London: Univ. College London, 2012.Google Scholar
- 47.Materna, A.C., Sturm, S., Kroth, P.G., and Lavaud, J., First induced plastid genome mutations in an alga with secondary plastids: PsbA mutations in the diatom Phaeodactylum tricornutum (Bacillariophyceae) reveal consequences on the regulation of photosynthesis, J. Phycol., 2009, vol. 45, pp. 838–846.CrossRefGoogle Scholar