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FAQ

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GENERAL     BIOLOGY     TECHNOLOGY    

GENERAL

Why are algae necessary?
  • Along with bacteria, algae are the oldest microorganisms in the world. Their importance in nature is above all their ability to photosynthesise. Algae are responsible for 50% of global oxygen production – although they comprise only 2% of the amount of plants in the world. Algae are the ancestors of all land plants. They are also the basis for petroleum. One can also describe algae as the organisms that have naturally perfected photosynthesis.
 
Are algae plants or animals?
  • Algae are difficult to classify. Green algae are plants. Brown algae, however, are usually classified as animals.
 
How are algae cultivated?
  • The oldest and most common practice are open ponds. Other cultivation techniques include various forms of photobioreactors: tubular photobioreactors, Christmas-tree photobioreactors, bubble column photobioreactors, plate photobioreactors, foil photobioreactors, and heterotrophic cultivation by fermentation.
 
How many species of algae exist?
  • At least 400,000, though the majority of species have yet to be described.

Is there demand for algal products?
  • Yes, several of various industries and research facilities require them
  • Industry: food, animal feed, cosmetics, pharmacy, energy, water purification
  • Research: biomedical engineering, bioplastics, synthetic fibers
 
Are there world market prices for algal products?
  • Yes. Pricing is highly transparent. There are public exchanges for algal products. Additionally, delivery contracts can be made with the processing industry.
 
What are omega fatty acids?
  • Omega-3 fatty acids are a group of fatty acids with omega numbering, all of which are polyunsaturated. They are essential nutrients in the human diet in that they are necessary for life and cannot be synthesised by the human body. The name is derived from the nomenclature for fatty acids. Before they were identified as fatty acids, they were known collectively as vitamin F.
  • Omega-3 means that the first double bond in the polyunsaturated hydrocarbon chain is in the third position from the terminal end. Omega (ω) is the last letter of the Greek alphabet and is used for the end of a hydrocarbon chain opposite the end with carboxylate. 
 
Why do we need omega-3 fatty acids?
  • Omega-3 fatty acids are considered to be essential because they cannot be produced by the human body, yet are required for bodily processes and must therefore be ingested as part of the diet.
  • The long-chained omega-3 fatty acid DHA (docosahexaenoic acid) is an important component of the human brain and of the retina. Incorporation of fatty acids in these organs begins in utero and continues during the first few years of development of the child. Sufficient uptake of DHA during the child's early years enables optimal development of the brain and the eyes.
  • Studies show that children provided with sufficient DHA have improved intellectual development, language skills, fine motor skills, social behaviour and acuteness of vision. Furthermore, EPA (eicosapentaenoic acid) and DHA have positive effects on the immune system and reduce the risk of developing allergies. Further, there is evidence that DHA can improve existing symptoms in children with attention deficit hyperactivity disorder (ADHD).
  • Omega-3s are not only important for childhood development, they also support the health of adults in myriad ways. This they do directly or through substances the human body makes with them. 
  • Normalisation of blood lipid levels
  • Reduction of high blood pressure
  • Boosts circulation
  • Reduction of risk of a second heart attack
  • Beneficial effects on cardiac arrhythmias
  • Reduction of intensity of chronic infections
  • Maintenance of eye health
  • Brain metabolism and function
 
Can omega-3s be produced by the human body?
  • No, the human body cannot synthesise omega-3 fatty acids and must therefore be ingested in the diet.
 
Can fish produce omega-3s?
  • Even fish cannot synthesise omega-3s and can only accumulate them through the food chain (algae, krill).
 
What else contains omega-3s?

BIOLOGY

Which algae are used?
  • Depending on the desired product, many different species can be used. In Europe, Chlorella vulgaris is the most used species.

How long does an individual alga live?
  • About 2-6 weeks, but through exponential cell division, algae effectively live as long as desired.
 
How much time do juvenile algae require before they begin to divide?
  • This is highly dependent on environmental conditions. Under optimal conditions (light, nutrients, temperature), cells can divide every 15-20 hours. 
  
What temperatures do algae require min/opt/max?
  • Min. 15°C, opt. 25°C, max. 32°C, with variation between species.

Why do algae produce oil?
  • Algae use oils and lipids as a reserve for times when poor growth conditions prevail. Fats have a high energy density, making them an ideal medium for storing energy. Algae produce these fatty acids within days. 
 
What kind of oil do they produce?
  • The oil is made up of fatty acids of varying chain lengths (C12 – C22). The majority of these fatty acids are unsaturated.
 
What portion of algae oil is omega-3 fatty acids?
  • Depending upon the species and growth conditions, about 20 – 40 %
 
How is oil extracted from algae?
  • There are numerous methods for extracting oil from algal biomass, including extraction via supercritical carbon dioxide. 
 
What is the source of CO2?
  • In principle any CO2 can be used. Polluted sources (e.g. from industry) must be treated before use with algae.
 
How can I make fuel out of algae oil?
  • For this, the short-chained fatty acids in algae oil must be esterified.
 
Why are algae green?
  • Because algae contain chlorophyll, which they use for photosynthesis.
 
What is the liquid contained in the plates?
  • Water with small added amounts of nitrates, phosphates and trace elements.
 
How much sunlight do algae need?
  • 100 – 500 micromoles of photons per square meter per second
 
Are algae able to grow with synthetic light?
  • Yes! The question of whether to use natural or synthetic light is primarily a question of economic expedience. 
 
What does light dilution mean?
  • It means that the light entering the photobioreactor is spread out over a larger surface area. You can observe this effect with a torch: when you shine a torch directly on a tabletop (that is, at a right angle), you produce a well-defined circle of light. The more you decrease the angle of the torch to the table, the larger, more spread out and less circular will be the area of light that strikes the tabletop.
 
What is the spectrum of light that algae require?
  • Primarily the red and blue portions of visible light.
 
Does algae production increase as light increases?
  • Yes, up to a certain point. More light leads to faster and better photosynthesis. At the same time, too much light stresses the algae. This renders them less able to photosynthesise and leads to oxidation reactions in the cell.
 
Is UV light harmful to algae?
  • Yes, UV light leads to oxidation reactions and can damage their DNA, which can lead to mutations.
 
Do algae need periods of rest?
  • Yes. Algae need a certain amount of time without light. They are adapted to the rhythm of day and night.
 
What can be done with algae that have been fed with dirty CO2?
  • Biofuels, bio-plastics, burned in biogas plant
   
How is water prepared for use in algaculture?
  • It is filtered to remove coarse impurities and germs and sterilised with UV light to kill any remaining germs.
 
Does the ecoduna system accommodate freshwater and saltwater?
  • Yes, our system can be run with either freshwater or saltwater.

TECHNOLOGY

What are the advantages of ecoduna technology?
  • Technological benefits:
    • Increase of photoactive volume via upright modules – “hanging gardens”
    • Optimal lighting (light dilution) through sun-tracking modules
    • 100% photoactive volume
    • Pure cultures – no contamination by virtue of being a closed system
    • Constant oxygen emissions – hence no “poisoning” of microorganisms
    • Specific process controls
    • Continuous sensor technology
    • Online monitoring available
    • Scant water loss thanks to water preparation and recycling
    • No stress-causing pumps necessary as hydrostatic transport is used for optimal algae growth and low energy costs
    • Optimised supply and even distribution of nutrients
    • System can be cleaned while in operation
    • Salt- and freshwater compatible
    • Biological know-how specific to our systems and processes
    • Continuous production instead of batch production
    • Highly-efficient, gentle, continuous harvesting process
 
Why does water flow up in ecoduna modules?
  • As the CO2 mixture is introduced, a higher volume is blown into every other chamber. Rising bubbles then carry water and microalgae with it. By introducing an exact amount of gas mixture, circulation is triggered in that water carried upward in this way then flows back downward through gravity.
 
Does the ecoduna system truly function completely without pumps?
  • For water transport within each module, ecoduna technology requires no pumps. For flows between modules, gentle flow dividers (desmodromic valves) are used.
 
How many metres of run per plate/module/line? 
  • 392 m/4.7 km/103.4 km
 
How far does an agla travel until it is harvested?
  • 35.9 km