Spirulina - Super Food

All about Spirulina. Spirulina as a human and animal food, spirulina as a medicine. Spirulina production and clutivation methods.

Thursday, July 07, 2005

Spirulina Production

The main commercial large-scale culture of microalgae started in the early 1960s in Japan with the culture of Chlorella, followed by Spirulina in the early 1970s at Lake Texcoco, Mexico. The third major microalgae industry was established in Australia in 1986.

The first plant in USA (Earthrise Farms) for the exploitation of Spirulina, built in 1981 in California, emerged as the result of a research work on its culture by Dainippon Ink & Chemicals, Inc. of Japan and Proteus Corporation of California. Spirulina grows quickly and produces 20 times more protein by surface unit that soy beams (Henrikson, 1994). When comparing the growth of Spirulina and the agricultural crop cycles, the difference in the time of production is noticeable. In agriculture, the harvest is obtained after several months of cultivation, while Spirulina is produced continually.

Production process of Spirulina requires clonal or unialgal cultures (isolation of a single algal unit or trichome). The method begins with the determination of physical and chemical parameters of the water sample, which constitutes the main ingredient of the growth medium. The Spirulina samples should remain under dim light or in darkness and at 20-25°C; freezing temperature is not recommended because it favors lysis and death (Rippka, 1988). Isolation of the microorganism is carried out under an intensely lighted microscope and with a capillary pipette so that one and only one filament is selected by its morphological attributes (color, size of trichomes, length and apical filament characteristics). If axenic cultures, specific for physiologic and biochemical studies of algae, are wanted, special treatments such as: centrifugation followed by ultrasonic treatments with antibiotics and potassium tellurite are required (Hoshaw and Rosowski, 1979).

Cyanobacteria are grown in many liquid and solid culture media such as: BG11, ASM-1, Z8, SAG, BBM, AA, KMC, Kn Cg-10, D (Rippka, 1988) and Spirulina grows in culture media such as: Zarrouk, SSM (Sea Saltpeter Medium).

Zarrouk medium (Zarrouk, 1966; Borowitzka, 1992) is frequently used during the isolation process and the SSM medium is preferred in the industrial production stage (Ayala, 2000). Eight mayor medium factors influence the productivity of Spirulina: luminosity, temperature (30°C), inoculation size, stirring speed, dissolved solids, pH (8.5-10.5), water quality, macro and micronutrient presence, (C, N, P, K, S, Mg, Na, Cl, Ca and Fe, Zn, Cu, Ni, Co, W).

Spirulina production may be carried out in closed and open systems. The first one involves laboratory photo bioreactors. This is not used in industrial production. The open system, denominated raceway, due to its low production cost, easy handling and high production of biomass, is frequently chosen for industrial production. This method uses a pond with a central islet, a motor operating a paddle wheel which allows continuous displacement of the liquid culture in the peripheral channel.

Productive process has nine stages:

1. Filtration and Cleaning, a nylon filter at the entrance of the water pond is needed;
2. Pre-concentration,
to obtain algal biomass which is washed to reduce salts content;
3. Concentration,
to remove the highest possible amount of interstitial water (located among the filaments);
4. Neutralization,
to neutralize the biomass with the addition of acid solution;
5. Disintegration,
to break down trichomes by a grinder;
6. Dehydration
by spray-drying; this operation has great economic importance since it involves about 20-30% of the production cost.
7. Packing
is done in sealed plastic bags to avoid hygroscopic action on the dry Spirulina; and
8. Storage,
in corrugate cardboard boxes, and in fresh, dry, dim, pest-free, and clean storeroom, preventing Spirulina pigments from deteriorating.

9. Quality control for Spirulina as a food includes microbiological standard tests, chemical composition test, and test for heavy metals, pesticides and extraneous materials (insect fragments, rodent hair and feather fragments).


At 6:41 AM, Blogger Sumudu said...

Thanks a lot for your article....,helped ma assignment
- Sumudu.


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