Chlamydomonas reinhardtii is a motile, unicellular green microalga typically measuring around 10 µm in diameter. It is widely distributed, and is often isolated from soil and freshwater samples. C. reinhardtii has been used as a model organism for over 70 years for both basic and applied research, largely due to its ease of cultivation, rapid doubling time of 6-8 h, and established molecular toolbox (Harris, 2009). Noted areas of study include photosynthesis, phototaxis, cell wall biogenesis, cell cycle events, flagella assembly, mating processes, and nuclear/chloroplast interactions (Rochaix, 1995; Shimogawara et al., 1998; Merchant et al., 2007). Annotated sequences are available for the nuclear, chloroplast and mitochondrial genomes (Merchant et al., 2007, Scaife et al., 2015), and several extensive libraries of mutants have been generated. Transformation of all three genomes have been demonstrated, with nuclear and chloroplast manipulation becoming routine (Boynton et al. 1988; Kindle et al. 1989; Sodeinde and Kindle. 1993).
Recently C. reinhardtii has gained attention as a platform for commercial applications; these include recombinant protein expression (Mayfield et al., 2007; Rosales-Mendoza et al., 2012), biohydrogen production (Torzillo et al., 2015), and as a model testbed for biofuel technologies prior to shuttling into more industrially relevant, but less easy to manipulate, biofuel production strains.
Cultivation of C. reinhardtii is typically conducted mixotrophically on TAP (tris acetate phosphate) medium. Although suitable for lab-scale work, TAP medium is not appropriate for scale up due to its relatively high cost and susceptibility to contamination.
To compare the growth of C. reinhardtii CC1690 under mixotrophic (TAP medium) and phototrophic (HSM medium) conditions in the Algem photobioreactor.
Figure 2 - Temperature variation over the course of the above experiment (n=4)
Debuchy, R., Purton, S. and Rochaix, J.D. (1989) The argininosuccinate lyase gene of Chlamydomonas reinhardtii : an important tool for nuclear transformation and for correlating the genetic and molecular maps of the ARG7 locus. The EMBO journal , 8 (10), p. 2803
Boynton, J.E., Gillham, N.W., Harris, E.H., Hosler, J.P. and Johnson, A.M. (1988) Chloroplast transformation in Chlamydomonas with high velocity microprojectiles. Science , 240 (4858), p.1534
Day, A. and Goldschmidt‐Clermont, M. (2011) The chloroplast transformation toolbox: selectable markers and marker removal. Plant biotechnology journal , 9 (5), pp. 540-553
Harris, E.H. (2009) Chlamydomonas Sourcebook: Introduction to Chlamydomonas and Its Laboratory Use (Vol. 1), Academic Press
Kindle, K.L. (1990) High-frequency nuclear transformation of Chlamydomonas reinhardtii . Proceedings of the National Academy of Sciences , 87 (3), pp. 1228-1232
Kumar, S.V., Misquitta, R.W., Reddy, V.S., Rao, B.J. and Rajam, M.V. (2004) Genetic transformation of the green alga- Chlamydomonas reinhardtii by Agrobacterium tumefaciens. Plant Science , 166 (3), pp.731-738
Mayfield, S.P., Manuell, A.L., Chen, S., Wu, J., Tran, M., Siefker, D., Muto, M. and Marin-Navarro, J., 2007. Chlamydomonas reinhardtii chloroplasts as protein factories. Current opinion in biotechnology , 18 (2), pp. 126-133
Merchant, S.S., Prochnik, S.E., Vallon, O., Harris, E.H., Karpowicz, S.J., Witman, G.B., Terry, A., Rochaix, J.D. (1995) Chlamydomonas reinhardtii as the photosynthetic yeast. Annual review of genetics , 29 (1), pp.209-230
Rosales-Mendoza, S., Paz-Maldonado, L.M.T. and Soria-Guerra, R.E. (2012) Chlamydomonas reinhardtii as a viable platform for the production of recombinant proteins: current status and perspectives. Plant cell report s, 31(3), pp. 479-494
Scaife, M.A., Nguyen, G.T., Rico, J., Lambert, D., Helliwell, K.E. and Smith, A.G. (2015) Establishing Chlamydomonas reinhardtii as an industrial biotechnology host. The Plant Journal , 82 (3), pp. 532-546
Shimogawara, K., Fujiwara, S., Grossman, A. and Usuda, H. (1998) High-efficiency transformation of Chlamydomonas reinhardtii by electroporation. Genetics , 148 (4), pp. 1821-1828
Sodeinde, O.A. and Kindle, K.L. (1993) Homologous recombination in the nuclear genome of Chlamydomonas reinhardtii . Proceedings of the National Academy of Sciences, 90 (19), pp.9199-9203
Torzillo, G., Scoma, A., Faraloni, C. and Giannelli, L. (2015) Advances in the biotechnology of hydrogen production with the microalga Chlamydomonas reinhardtii . Critical reviews in biotechnology , 35 (4), pp.485-496