Culture of microalgae in hatcheries

Microalgae gold microscopic algae grow in either marine or freshwater systems. They are primary producers in the oceans that convert water and carbon dioxide to biomassand oxygen in the presence of sunlight. [1]

The oldest documented use of microalgae Was 2000 years ago, When the Chinese used the cyanobacteria Nostoc as a food source During a famine. [2] Another type of microalgae, the cyanobacteria Arthrospira ( Spirulina ), was a common food source among populations in Chad and Aztecs in Mexico as far back as the 16th century. [3]

Today cultured microalgae is used as direct feed for humans and land-based farm animals, and as feed for cultured aquatic species such as molluscs and early larval stages of fish and crustaceans. [4] It is a potential candidate for biofuel production. [5] Microalgae can grow 20 or 30 times faster than traditional food crops, and has no need to compete for arable land. [5] [6] Since microalgal production is central to so many commercial applications, there is a need for production techniques that increase productivity and are economically profitable.

Commonly cultivated microalgae species

Microalgae are microscopic forms of algae , like this coccolithophorewhich are between 5 and 100 micrometers across
Species Application
Chaetoceros sp. [7] Aquaculture [7]
Chlorella vulgaris [8] Source of natural antioxidants [8]
Dunaliella salina [9] Produce carotenoids ( β-carotene ) [9]
Haematococcus sp. [10] Produce carotenoids ( β-carotene ), astaxanthin , canthaxanthin [10]
Phaeodactylum tricornutum [8] Source of antioxidants [8]
Porphyridium cruentum [8] Source of antioxidants [8]
Rhodella sp. [7] Colourant for cosmetics [7]
Skeletonema sp [7] Aquaculture [7]
Arthrospira maxima [11] High protein content – Nutritional supplement [11]
Arthrospira platensis [11] High protein content – Nutritional supplement [11]

Hatchery production techniques

A range of microalgae species are produced in hatcheries and are used in a variety of ways for commercial purposes. Studies Estimated hand-have factors in the success of a hatchery system microalgae have the dimensions of the container / bioreactor Where microalgae is cultured, exposure to light / radiation and concentration of cells dans le reactor. [12]

Open pond system

This method has been employed since the 1950s. There are two main advantages of microalgae culturing using the open pond system. [13] Firstly, an open pond system is easier to build and operate. [13] SECONDLY, open ponds are Cheaper than closed bioreactors Because closed bioreactors require a cooling system. [13] However, a downside to using open weight systems is also less important than commercially important strains such as Arthrospira sp. , where optimal growth is limited by temperature. [12]

Air-lift method

This method is used in outdoor cultivation and production of microalgae; where is growing in a microalgae is growing. [13] The culture is grown in transparent tubes that binds horizontally on the ground and is connected by a network of pipes. [13] Air is passed through the tube such that it rests inside the reactor that contains the culture and creates an effect like stirring. [13]

Closed reactors

The biggest advantage of culturing microalgae within a closed system provides the control of the physical, chemical and biological environment of the culture. [12] This means that evaporation, temperature gradients, and protection from ambient contamination are very difficult to control . [12] Photobioreactors are the primary example of a closed system where abiotic factors can be controlled for. Several closed systems have been tested for the purpose of culturing microalgae,

Horizontal photobioreactors

This system includes tubes on the ground to form a network of loops. Mixing of microalgal suspended culture occurs through a pump that raises the culture vertically at timed intervals into a photobioreactor . Studies have found pulsed mixing at intervals produces better results than the use of continuous mixing. Photobioreactors have also been better able to maintain better temperature gradients. [12] An example noted in higher production of Arthrospira sp. Used as a dietary supplement was increased because of a longer temperature range. [12]

Vertical systems

These reactors use vertical polyethylene sleeves hung from an iron frame. Glass tubes can also be used alternatively. Microalgae are also cultured in vertical alveolar panels (VAPs) that are a type of photobioreactor . [12] This photobioreactor is characterized by low productivity. However, this problem can be overcome by modifying the surface area to volume ratio; where a higher ratio can increase productivity. [12] Mixing and deoxygenation are drawbacks of this system and can be addressed by bubbling air in a flow rate. The two main types of vertical photobioreactors are the VAP Flow-through and the Bubble Column VAP. [12]

Flat plate reactors

Flat plate reactors (FPR) are built using narrow panels and are placed horizontally to maximize sunlight input to the system. [14] The concept behind FPR is to increase the area to such a volume that sunlight is efficiently used. [13] [14] This system of microalgae culture was originally thought to be expensive and incapable of circulating culture. [14] Therefore, FPRs have been considered to be unfeasible overall for the commercial production of microalgae. However, an experimental FPR system in the 1980s used to circulate across the culture of a gas exchange unit across horizontal panels. [14]This overcomes issues of circulation and provides an advantage of an oxygen transfer. [14] Examples of successful use of FPRs can be seen in the production of Nannochloropsis sp. used for its high levels of astaxanthin . [15]

Fermentor-type reactors

Fermentor-type reactors (FTRs) are where bioreactors are fermented . FTRs have not been developed in the field of microalgae and pose a disadvantage in the area to volume ratio and decreased efficiency in utilizing sunlight. [13] [14] FTR has been developed using a combination of lower and lower production costs. [14] However, information available on large scale counterparts to the laboratory-scale systems being developed is very limited. [14] The main advantage is that the extrinsic factors can be enhanced for the production of pharmaceuticals .[14]

Commercial applications


Microalgae is used to culture brine shrimp , which produces dormant eggs (pictured). The eggs can then be hatched on demand and fed to fish larvae and crustaceans.

Microalgae is an important source of nutrition and is used widely in the aquaculture of other organisms, directly or as a source of basic nutrients. [16] Aquaculture farms rearing larvae of molluscs , echinoderms , crustaceans and fishes use microalgae as a source of nutrition. [16] Low bacteria and high microalgal biomass is a crucial food source for shellfish aquaculture. [16]

Microalgae can form the start of a chain of further aquaculture processes. For example, microalgae is an important food source in the aquaculture of brine shrimp . Brine shrimp produces eggs, called cysts , which can be stored for long periods of time and provides a convenient method for the production of larval fish and crustaceans. [17] [18]

Other applications of microalgae within aquaculture include increasing the aesthetic appeal of finfish bred in captivity. [16] One such example can be noted in the aquaculture of salmon , where microalgae is used to make salmon flesh pinker. [16] This is achieved by the addition of natural pigments containing carotenoids such as astaxanthin produced from the microalgae Haematococcus to the diet of farmed animals. [19]

Biofuel production

In order to meet the demands of fossil fuels , alternate means of fuels are being investigated. Biodiesel and bioethanol are important with current potential. However, agriculture based renewable fuelsmay not be completely sustainable and thus may not be able to replace fossil fuels. [1] Microalgae can be remarkably rich in oils (up to 80% dry weight biomass ) suitable for conversion to fuel. [1]Furthermore, microalgae are more productive than land based agricultural crops and could be more sustainable in the long run. [1] Microalgae forbiofuel production is mainly produced using tubular photobioreactors . [1]

Cosmetic and health benefits

The main species of microalgae grown as Chlorella sp. and Spirulina sp. The main forms of production occur in small scale ponds with artificial mixers. [9] Novel bioactive chemical compounds can be isolated from microalgae like sulphated polysaccharides . [20] These compounds include fucoidans , carrageenans and ulvans That are used for Their beneficial properties. These properties are anticoagulants , antioxidants , anticancer agents that are being tested in research. [20]Red microalgae are characterized by pigments called phycobiliproteins that contain natural colors used in pharmaceuticals and / or cosmetics. [21] Production of long chain Omega-3 polyunsaturated fatty acids important for human diet can also be achieved through microalgal hatchery systems. [22]


Blue green algae was first used as a means of fixing nitrogen by allowing cyanobacteria to multiply in the soil. Nitrogen fixation is important as a way of allowing inorganic compounds such as nitrogen to be converted into organicforms which can be used by plants. [23] The use of cyanobacteria is an economically sound and environmentally friendly method of increasing productivity. [24] Rice production in India and Iran has employed this method of using cyanobacteria to supplement nitrogen content in soils. [23] [24]

Other uses

Microalgae are a source of valuable molecules such as isotopes ie chemical variants of an element that contain different neutrons. Microalgae can effectively incorporate isotopes of carbon ( 13 C), nitrogen ( 15 N) and hydrogen ( 2 H) into their biomass. [25] 13 C and 15 are used to track the flow of carbon between different trophic levels / food webs. [26] Carbon, nitrogen, and sulfur isotopes can also be used to determine the degree of disturbance.[26]


Cell fragility is the biggest issue that limits the productivity of closed photobioreactors . [27] Damage to cells Can Be Attributed To the turbulent flow dans le bioreactor qui is required to create mixing so light is available to all cells. [27]

See also

  • Algae fuel
  • Microbiofuels


  1. ^ Jump up to:e Yusuf Chisti (2008). “Biodiesel from microalgae beats bioethanol”( PDF ) . Trends in Biotechnology . 26 (3): 126-131. doi : 10.1016 / j.tibtech.2007.12.002 . PMID  18221809 .
  2. Jump up^ Pauline Spolaore; Claire Joannis-Cassan; Elie Duran; Arsene Isambert (2006). “Commercial applications of microalgae” (PDF) . Journal of Bioscience and Bioengineering . 101 (2): 87-96. doi : 10.1263 / jbb.101.87 . PMID  16569602 .
  3. Jump up^ Whitton, B., and M. Potts. 2000. The ecology of cyanobacteria: their diversity in time and space p. 506, Kluwer Academic. ISBN 978-0-7923-4735-4.
  4. Jump up^ Barnabas, Gilbert (1994) Aquaculture: biology and ecology of cultured species p. 53, Taylor & Francis. ISBN 978-0-13-482316-4.
  5. ^ Jump up to:a Greenwell B HC, LML Laurens, RJ Shields, Lovitt RW and KJ Flynn (2010) “Placing microalgae on the biofuels priority list: a review of the challenges” JR Soc. Interface, 7 (46) 703-726. doi : 10.1098 / rsif.2009.0322
  6. Jump up^ McDill, Stuart (2009-02-10). “Can algae save the world – again?” . Reuters . Retrieved 2009-02-10 .
  7. ^ Jump up to:f John Milledge (2011). “Commercial application of microalgae other than as biofuels: a brief review” . Reviews in Environmental Science and Biotechnology . 10 (1): 31-41. doi : 10.1007 / s11157-010-9214-7 .
  8. ^ Jump up to:f Ignacio Rodriguez-Garcia; Jose Luis Guil-Guerrero (2008). “Evaluation of the antioxidant activity of three microalgal species for dietary supplements and the preservation of foods” . Food Chemistry . 108 (3): 1023-1026. doi : 10.1016 / j.foodchem.2007.11.059 .
  9. ^ Jump up to:c Michael A. Borowitzka (1999). “Commercial production of microalgae: ponds, tanks, tubes and fermenters” . Journal of Biotechnology . 70 (1-3): 313-321. doi : 10.1016 / S0168-1656 (99) 00083-8 .
  10. ^ Jump up to:b Lawrence Dufossé; Patrick Galaup; Anina Yaron; Shoshana Malis Arad; Philippe Blanc; Kotamballi N. Chidambara Murthy; Gokare A. Ravishankar (2005). “Microorganisms and microalgae as sources of pigments for food use: a scientific oddity or an industrial reality?” . Trends in Food Science and Technology . 16 (9): 389-406. doi : 10.1016 / j.tif.2005.02.006 .
  11. ^ Jump up to:a b c d Avigad Vonshak; Luisa Tomaselli (2000). “Arthrospira (Spirulina): systematics and ecophysiology”. In Brian A. Whitton; Malcolm Potts. The Ecology of Cyanobacteria: their Diversity in Time and Space. Boston: Kluwer Academic Publishers. pp. 505–522. ISBN 978-0-7923-4735-4.
  12. ^ Jump up to:i Mr. Tredici; R. Materassi (1992). “From open ponds to vertical alveolar panels: the Italian experience in the development of reactors for mass cultivation of phototrophic microorganisms” . Journal of Applied Phycology . 4 (3): 221-231. doi : 10.1007 / BF02161208 .
  13. ^ Jump up to:h Amos Richmond (1986). Handbook of Microalgal Mass Culture . Florida: CRC Press . ISBN  0-8493-3240-0 .
  14. ^ Jump up to:i Ana P. Carvalho; Luís A. Meireles; F. Xavier Malcata (2006). “Microalgal reactors: a review of enclosed system designs and performances” . Biotechnology Progress . 22 (6): 1490-1506. doi : 10.1021 / bp060065r . PMID  17137294 .
  15. Jump up^ Amos Richmond; Zhang Cheng-Wu (2001). “Optimization of a flat plate glass reactor for mass production of Nannochloropsis sp . Journal of Biotechnology . 85 (3): 259-269. doi : 10.1016 / S0168-1656 (00) 00353-9 . PMID  11173093 .
  16. ^ Jump up to:e Arnaud Muller-Feuga (2000). “The role of microalgae in aquaculture: situation and trends” ( PDF ) . Journal of Applied Phycology12 (3): 527-534. doi : 10.1023 / A: 1008106304417 .
  17. Jump up^ Martin Daintith (1996). Rotifers and Artemia for Marine Aquaculture: a Training Guide . University of Tasmania . OCLC  222006176 .
  18. Jump up^ Odi Zmora; Muki Shpigel (2006). Intensive Mass Production of Artemiain a recirculated system . Aquaculture . 255 (1-4): 488-494. doi :10.1016 / j.aquaculture.2006.01.018 .
  19. Jump up^ R. Todd Lorenz; Gerald R. Cysewski (2000). “Commercial potential forHaematococcus microalgae as a natural source of astaxanthin” ( PDF ) . Trends in Biotechnology . 18 (4): 160-167. doi : 10.1016 / S0167-7799 (00) 01433-5 . PMID  10740262 .
  20. ^ Jump up to:b Isuru Wijesekara; Ratih Pangestuti; Se-Kwon Kim (2010). “Biological activities and potential health benefits of sulfated polysaccharides derived from marine algae”. Carbohydrate Polymers . 84 (1): 14-21. doi : 10.1016 / j.carbpol.2010.10.062 .
  21. Jump up^ S. Arad; A. Yaron (1992). “Natural pigments from red microalgae for use in foods and cosmetics” . Trends in Food Science & Technology . 3 : 92-97. doi : 10.1016 / 0924-2244 (92) 90145-M .
  22. Jump up^ W. Barclay; K. Meager; J. Abril (1994). “Heterotrophic production of long chain omega-3 fatty acids utilizing algae and algae-like microorganisms”. Journal of Applied Phycology . 6 (2): 123-129. doi : 10.1007 / BF02186066 .
  23. ^ Jump up to:b H. Saadatnia; H. Riahi (2009). “Cyanobacteria from paddy fields in Iran as a biofertilizer in rice plants” ( PDF ) . Plant Soil Environment . 55(5): 207-212. permanent dead link ]
  24. ^ Jump up to:b Upasana Mishra; Sunil Pabbi (2004). “Cyanobacteria: a potential biofertilizer for rice” ( PDF ) . Resonance . 9 (6): 6-10. doi : 10.1007 / BF02839213 .
  25. Jump up^ Richard Radmer; Bruce Parker (1994). “Commercial applications of algae: opportunities and constraints” . Journal of Applied Phycology . 6(2): 93-98. doi : 10.1007 / BF02186062 .
  26. ^ Jump up to:b B. J. Peterson (1999). “Stable isotopes as tracers of organic matter input and transfer in benthic food webs: a review” . Acta Oecologica . 20(4): 479-487. Bibcode : 1999AcO …. 20..479P . doi : 10.1016 / S1146-609X (99) 00120-4 .
  27. ^ Jump up to:b Claude Gudin; Daniel Chaumont (1991). “Cell fragility – the key problem of microalgae mass production in closed photobioreactors” . Bioresource Technology . 38 (2-3): 145-151. doi : 10.1016 / 0960-8524 (91) 90146-B .

Leave a Reply

Your email address will not be published. Required fields are marked *