C. vulgaris is a green eukaryotic microalga in the genus Chlorella, which has been present on earth since the Precambrian period.[3] This unicellular alga was discovered in 1890 by Martinus Willem Beijerinck as the first microalga with a well-defined nucleus.[4] At the beginning of the 1990s, German scientists noticed the high protein content of C. vulgaris and began to consider it as a new food source. Japan is currently the largest consumer of Chlorella,[3][5] both for nutritional and therapeutic purposes.[6]
The world annual production of the various species of Chlorella was 2000 tonnes (dry weight) in 2009, with the main producers being Germany, Japan and Taiwan.[3]C. vulgaris is a candidate for commercial production due to its high resistance against adverse conditions and invading organisms. In addition, the production of the various organic macromolecules of interest (proteins, lipids, starch) differ depending on the technique used to create biomass and can be therefore targeted.[3] Under more hostile conditions, the biomass decreases, but lipids and starch contents increase.[8] Under nutrient and light-replete conditions, protein content increases along with the biomass.[9] Different growth techniques have been developed. Different modes of growth (autotrophic, heterotrophic, and mixotrophic) has been investigated for Chlorella vulgaris; autotrophic growth is favoured as it does not require provision of costly organic carbon and relies on inorganic carbon sources (CO2, carbonates) and light for photosynthesis.[10]
Chlorella sp. cultivated in digested and membrane-pretreated swine manure is capable of improving the growth medium performance of microalgae cultivations in terms of final biomass productivity, showing that algal growth depends on the turbidity of liquid digestate streams rather than on their nutrient availability.[11]
Uses
Bioremediation
Chlorella vulgaris has been the microalgae of choice for several bioremediation processes. Owing to its ability to remove a variety of pollutants such as inorganic nutrients (nitrate, nitrite, phosphate and ammonium), fertilizers, detergents, heavy metals, pesticides, pharmaceuticals and other emerging pollutants from wastewater and effluents, carbon dioxide and other gaseous pollutants from flue gases, besides having high growth rates and simple cultivation requirements, Chlorella vulgaris has emerged as a potential microorganism in bioremediation studies for mitigation of environmental pollution.[12]
Bioenergy
C. vulgaris is seen as a promising source of bioenergy. It may be a good alternative to biofuel crops, like soybean, corn or rapeseed, as it is more productive and does not compete with food production.[13] It can produce large amount of lipids, up to 20 times more than crops[14] that have a suitable profile for biodiesel production.[15] This microalgae also contains high amounts of starch, good for the production of bioethanol.[3] However, microalgal biofuels are far from competitive with fossil fuels, given their high production costs and controversial sustainability.[3][16]
^"Chlorella vulgaris". NCBI taxonomy. Bethesda, MD: National Center for Biotechnology Information. Retrieved 5 December 2017. Other names: synonym: Chlorella vulgaris var. viridis Chodat includes: Chlorella vulgaris Beijerink IAM C-27 formerly Chlorella ellipsoidea Gerneck IAM C-27
^Duval B., Margulis L. (1995). "The microbial community of Ophrydium versatile colonies: endosymbionts, residents, and tenants". Symbiosis. 18: 181–210. PMID11539474.
^Beijerinck, M. W. (1890). "Culturversuche mit Zoochlorellen, Lichenengonidien und anderen niederen Algen". Bot. Zeitung. 48: 781–785.
^Kitada, K., Machmudah, S., Sasaki, M., Goto, M., Nakashima, Y., Kumamoto, S., & Hasegawa, T. (2009). "Supercritical CO2 extraction of pigment components with pharmaceutical importance from Chlorella vulgaris". Journal of Chemical Technology and Biotechnology. 84 (5): 657–661. Bibcode:2009JCTB...84..657K. doi:10.1002/jctb.2096.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Young, J. O. (2001). Keys to the freshwater microturbellarians of Britain and Ireland. Ambleside: Freshwater Biological Association. p. 92.
^Přibyl, P., Cepak, V., & Zachleder, V. (2012). "Production of lipids in 10 strains of Chlorella and Parachlorella, and enhanced lipid productivity in Chlorella vulgaris". Applied Microbiology and Biotechnology. 94 (2): 549–61. doi:10.1007/s00253-012-3915-5. PMID22361856. S2CID16442599.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Wang, K. G., Brown, R. C., Homsy, S., Martinez, L., & Sidhu, S. S. (2013). "Fast pyrolysis of microalgae remnants in a fluidized bed reactor for bio-oil and biochar production". Bioresource Technology. 127: 494–499. Bibcode:2013BiTec.127..494W. doi:10.1016/j.biortech.2012.08.016. PMID23069615.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ abBecker, E. W. (1994). Microalgae: biotechnology and microbiology. Vol. 10. Cambridge University Press.
^Morris, H. J., Almarales, A., Carrillo, O., & Bermúdez, R. C. (2008). "Utilisation of Chlorella vulgaris cell biomass for the production of enzymatic protein hydrolysates". Bioresource Technology. 99 (16): 7723–7729. Bibcode:2008BiTec..99.7723M. doi:10.1016/j.biortech.2008.01.080. PMID18359627.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Servaites, J. C., Faeth, J. L., & Sidhu, S. S. (2012). "A dye binding method for measurement of total protein in microalgae". Analytical Biochemistry. 421 (1): 75–80. doi:10.1016/j.ab.2011.10.047. PMID22138185.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Seyfabadi, J., Ramezanpour, Z., & Khoeyi, Z. A. (2011). "Protein, fatty acid, and pigment content of Chlorella vulgaris under different light regimes". Journal of Applied Phycology. 23 (4): 721–726. Bibcode:2011JAPco..23..721S. doi:10.1007/s10811-010-9569-8. S2CID31981379.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Brányiková, I., Maršálková, B., Doucha, J., Brányik, T., Bišová, K., Zachleder, V., & Vítová, M. (2011). "Microalgae—novel highly efficient starch producers". Biotechnology and Bioengineering. 108 (4): 766–776. doi:10.1002/bit.23016. PMID21404251. S2CID12940180.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Choix, F. J., de-Bashan, L. E., & Bashan, Y. (2012). "Enhanced accumulation of starch and total carbohydrates in alginate-immobilized Chlorella spp. induced by Azospirillum brasilense: II. Heterotrophic conditions". Enzyme and Microbial Technology. 51 (5): 300–309. doi:10.1016/j.enzmictec.2012.07.013. PMID22975128.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^de-Bashan, L. E., Bashan, Y., Moreno, M., Lebsky, V. K., & Bustillos, J. J. (2002). "Increased pigment and lipid content, lipid variety, and cell and population size of the microalgae Chlorella spp. when co-immobilized in alginate beads with the microalgae-growth-promoting bacterium Azospirillum brasilense". Canadian Journal of Microbiology. 48 (6): 514–521. doi:10.1139/w02-051. PMID12166678.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Fradique, M., Batista, A. P., Nunes, M. C., Gouveia, L., Bandarra, N. M., & Raymundo, A. (2010). "Incorporation of Chlorella vulgaris and Spirulina maxima biomass in pasta products. Part 1: Preparation and evaluation". Journal of the Science of Food and Agriculture. 90 (10): 1656–1664. Bibcode:2010JSFA...90.1656F. doi:10.1002/jsfa.3999. PMID20564448.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Li, H.-B., Jiang, Y., & Chen, F. (2002). "Isolation and purification of lutein from the microalga Chlorella vulgaris by extraction after saponification". Journal of Agricultural and Food Chemistry. 50 (5): 1070–1072. doi:10.1021/jf010220b. PMID11853482.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Liang, S., Liu, X., Chen, F., & Chen, Z. (2004). Ang, Put O (ed.). Current microalgal health food R & D activities in China. Asian Pacific Phycology in the 21st Century: Prospects and Challenges. pp. 45–48. doi:10.1007/978-94-007-0944-7. ISBN978-94-007-0944-7. S2CID12049767.{{cite book}}: CS1 maint: multiple names: authors list (link)
^Yamaguchi, K. (1996). "Recent advances in microalgal bioscience in Japan, with special reference to utilization of biomass and metabolites: a review". Journal of Applied Phycology. 8 (6): 487–502. Bibcode:1996JAPco...8..487Y. doi:10.1007/BF02186327. S2CID21226338.
^Kumudha A, Selvakumar S, Dilshad P, Vaidyanathan G, Thakur MS, Sarada R. (2015). "Methylcobalamin--a form of vitamin B12 identified and characterised in Chlorella vulgaris". Journal of Food Chemistry. 170: 316–320. doi:10.1016/j.foodchem.2014.08.035. PMID25306351.{{cite journal}}: CS1 maint: multiple names: authors list (link)