Chlorella sp.

• According to Educalingo dictionary, the name Chlorella is taken from the Greek, chloros, meaning green, and the Latin diminutive suffix ella, meaning small.
• Chlorella sp. is very famous for their rapid growth and simple life cycles.
• They have been used as the model of study for photosynthesis (Nickelsen, 2007).
• Enormous studies in functional food supplements, nutraceuticals, cosmetics, and pharmaceuticals were carried out (Silva et al., 2019).
• Currently, SBC’s microalgae library has a total of 8 locally isolated Chlorella sp.

Natural Habitat

• Chlorella sp. can be generally found in several different freshwater habitats as well as marine. In SBC, there are 37 freshwater strains and 23 marine strains in SBC's microalgae library. 
• SBC’s strains were found in the following natural habitats:
  
  • Freshwater
  • Brackish
  • Marine
  • Pond
• Number of strains isolated in Sarawak:

Characteristics

• Size
  • Ranged from 2 to 10 µm in diameter (Masojidek and Torzillo, 2014).
  • The Chlorella strains in the SBC's microalgae library ranged from 2 to 15µm in diameter.
• Flagella
  • No flagella
• Motile
  • Non-motile
• Shape
  • Single-celled, ellipsoid or flattened cell
• Any other published scientific info
  • All species consists of pyrenoid of uniform structure and the cell wall represents 13.6% of the whole cell (Nemcova and Kalina, 2000).
  • It changes in colour from green to red or yellowish due to different types of pigments produced under different growing conditions (Azaman et al., 2017).
  • Multiple chloroplasts present in the Chlorella species to assist in the construction of larger cell through the accumulation of glycolytic lipid in storage vesicles (Azaman et al., 2017).
  • Starch granules can be found inside the chloroplast especially during undesired growing environment (Safi et al., 2014).
  • It’s a non-motile reproductive cell that divides asexually (Safi et al., 2014)
  • The nucleus is mostly simple and sometimes double which is composed only of chromatin.

Algae Bioeconomy/Industry

• Pigment (Carotenoids)
  • According to Mobin (2017), bioactive pigments such as carotenoids, canthaxanthin and astaxanthin were extracted from Chlorella vulgaris; zeaxanthin and violaxanthin were extracted from Chlorella ellipsoidea; lutein, zeaxanthin and canthaxanthin were extracted from Chlorella protothecoides.
• Fatty Acids
  • Lipid content of Chlorella vulgaris has been found to be very high (with neutral lipid content 87.7% of total lipids) which indicates its great potential for edible oil production (Huang et al., 2016).
  • Cooking oil produced by the Thrive ® was commercialised and marketed as health-promoting product.
• Animal feed/aquafeed
  • Chlorella sp. has been reported to enhance the immune response in both animal and human studies. (Kwak et al., 2012).
  • At Feed Resource Information Centre, Chlorella sp. is recommended as one of the nutritional algae for incorporation into animal feed (https://www.feedipedia.org).
  • Chlorella sp. serves as feed for zooplankton production (rotifers, copepods), which in turn is used as feed for rearing fish larvae and juveniles (Masojidek and Torzillo, 2014).
  • Superfresh Chlorella SV-12 is developed specifically for rotifer cultivation. (https://ptaqua.eu/rotifer-cultivation/super-fresh-chlorella/).
• Cosmetic
  • It has been reported that the extract of Chlorella vulgaris stimulates the synthesis of skin collagen (Mourelle et al., 2017).
  • They also help the regeneration of fibers and make the skin surface free from wrinkles (Mobin et al., 2017).
  • Sun Chlorella Cream is a cosmetic product from Japan as a skin moisturiser. (http://sunchlorella.sg/products.htm)
• Nutraceutical
  • According to Adam (2005), Chlorella’s nutritional profile has led to it well known as “super food”.
  • Chlorella sp. contains 50% protein and other beneficial nutrients such as Vitamin B12, Vitamin C and iron (Andrade et al., 2018).
  • Chlorella sp. also contains some Omega-3 and Vitamin B12 (Koyande et al., 2019).
  • Chlorella sp. contains B-1,3-glucan, a free radical scavenger that stimulates the immune response and is also responsible for lowering lipids in the blood (Koyande et al., 2019).
  • Chlorella sp. extract can lower blood sugar levels, increase hemoglobin concentration and acts as a hepatoprotective agent (Mobin et al., 2017; Varfolomeev et al., 2011).
  • Sun Chlorella A is a commercial nutritional product from Japan (http://sunchlorella.sg/products.htm)
• Biofuel
  • Chlorella vulgaris is one of the most attractive algae species for producing biofuels owing to its fast growth and easy cultivation (Liu et al., 2008).
  • Chlorella sp. is among the algae of major interest for biofuels because it can accumulate large amounts of lipids or synthesize starch under stress condition (Malcata et al., 2011).
• Bioplastic
  • Zeller et al. (2013) investigated bioplastics and thermoplastic blends from Chlorella sp. Tensile testing indicated that Chlorella bioplastics had low extension and high modulus. The mechanical properties of algae bioplastics are comparable to soy protein isolate, feather meal, and duckweed.
• Biofertilizer
  • Recently, a consortium containing Anabaena variabilis, Chlorella vulgaris and Azotobacter sp., was found to improve germination and growth of rice plants and it was recommended as a biostimulator and biofertilizer for crops. The growth of Zea may was also improved with the introduction of Chlorella oocystoides and Chlorella minutissima (Taha et al., 2015).

References

Adam, M. (2005). Superfoods for optimum health: Chlorella and Spirulina. Truth Publishing International, Ltd.

Andrade, L.M., Andrade, C.J., Dias, M., Nascimento, C.A.O., Mendes, M.A. (2018). Chlorella and Spirulina microalgae as sources of functional foods, nutraceuticals, and food supplements; an overview. MOJ Food Process Technology, 6(2): 00144. doi: 10.15406/mojfpt.2018.06.00144.

Azaman, S.N. A., Nagao, N., Yusoff, F. M., Tan, S.W. and Yeap, S.K. (2017). A comparison of the morphological and biochemical characteristics of Chlorella sorokiana and Chlorella zofingiensis cultured under photoautotrophic and mixotrophic conditions. Peer Journal, 5:e3473 https://doi.org/10.7717/peerj.3473.

Guccione, A., Biondi, N., Sampietro, G., Rodolfi, L., Bassi, N. and Tredici, M. R. (2014). Chlorella for protein and biofuels: from strain selection to outdoor cultivation in a green wall panel photobioreactor. Biotechnology for Biofuels, 7(84), doi: 10.1186/1754-6834-7-84.

Huang, Y., Zhang, D., Xue, S., Wang, M., & Cong, W. (2016). The potential of microalgae lipids for edible oil production. Applied Biochemistry and Biotechnology, 180(3), 438–451. doi:10.1007/s12010-016-2108-6.

Koyande, A. K., Chew, K. W., Rambabu, K., Tao, Y., Chu, D. T. and Show, P. L. (2019). Microalgae: A potential alternative to health supplementation for humans. Food Science and Human Wellness, 8(1), 16-24.

Kwak, J.H., Baek, S.H., Woo, Y., Han, J.K., Kim, B.G., Kim, O.Y. & Lee, J.H. (2012). Beneficial immunostimulatory effect of short-term Chlorella supplementation: enhancement of natural killer cell activity and early inflammatory response (randomized, double-blinded, placebo-controlled trial). Nutritional Journal,11:53.

Liu, Z.Y., Wang, G.C., & Zhou, B.C. (2008). Effect of iron on growth and lipid accumulation in Chlorella vulgaris. Bioresource Technology, 99(11), 4717–4722. doi:10.1016/j.biortech.2007.09.073.

Masojidek, J. and Torzillo, G. (2014). Mass cultivation of freshwater microalgae. Reference Module in Earth Systems and Environmental Sciences, doi: https://doi.org/10.1016/B978-0-12-409548-9.09373-8.

Mourelle, M. L., Gomez, C. P. and Legido, J. L. (2017). The potential use of marine microalgae and Cyanobacteria in cosmetics and thalassotherapy. Cosmetics, 4(4), 46.

Mobin, S. & Alam, F. (2017). Some promising microalgal species for commercial application: A review. Energy Procedia, 110,510-517.

Nemcova, Y. and Kalina, T. (2000). Cell wall development, microfibrils and pyrenoid structure in type strains of Chlorella vulgaris, C. kessleri, C. sorokiana compared with C. luteoviridis (Trebouxiophyceae, Chlorophyta). Algological Studies. 100, 95-105.

Nickelsen, K. (2007). Otto Warburg’s first approach to photosynthesis. Photosynthesis Research, 92(1), 109-120, doi:10.1007/s11120-007-9163-3.

Safi, D. R., Merah, O., Zabib, B. and Pontalier, P. Y. (2014). Morphology, composition, production, processing and applications of Chlorella vulgaris: A review. renewable and sustainable. Energy Reviews. 35, 265-278.

Silva, J., Alves, C., Pinteus, S., Reboleira, J., Pedrosa, R. and Bernardino, S. (2019). Chapter 3.10- Chlorella.  In Nabavi, S. M. and Silva, A. S. (Eds), Nontavitamin and Nonmineral Nutritional Supplements (pp. 583). doi.org/10.1016/C2016-0-03546-5.

Taha, T. M. and Youssef, M. A. (2015). Improvement of growth parameters of Zea mays and properties of soil inoculated with two Chlorella Species. Report and Opinion, 7(8), 22-27.

Varfolomeev, S. D., & Wasserman, L. A. (2011). Microalgae as source of biofuel, food, fodder, and medicines. Applied Biochemistry and Microbiology, 47(9), 789–807. doi:10.1134/s0003683811090079.

Zeller, M. A., Hunt, R., Jones, A., & Sharma, S. (2013). Bioplastics and their thermoplastic blends from Spirulina and Chlorella microalgae. Journal of Applied Polymer Science, 130(5), 3263–3275. doi:10.1002/app.39559