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Is it possible to use microalgae to produce food and live on it?

Is it possible to use microalgae to produce food and live on it?


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I know microalgae have not less protein and starch, grow quickly, require less. So, is it possible to use them for producing food (replace rice and wheat) and live on it?

Currently, I only saw people eat it as an extra-nutrition.


I don't see why microalgae couldn't be a main food source (putting aside the taste factor).

It contains many different lipids, carbohydrates, proteins and other essential nutrients that are digestible and would be beneficial to humans. I do know that microalgae has a very high lipid content (hence why they're often harvested for biofuels), but it can nonetheless provide nutritional value (ie. feed a starving man).

However, not how this is completely different from living solely off of microalgae. This likely wouldn't be possible, as us humans cannot synthesize all nutrients that we need from scratch. These nutrients are deemed essential nutrients. This problem usually arises when your diet is too restricted to certain types of food. So whether it's microalgae or any other type of consumable, you wouldn't be able to live by only eating that thing.

Another related problem is that growing microalgae is more difficult than it would seem, as is once again usually encountered in second-generation biofuel manufacturing. Temperature, light, cell density, nutrients, and much more must be precisely managed to obtain a increasingly growing population of microalgae. The pros and cons of farming microalgae for billion of hungry people would have to be contrasted with other current agricultures, like corn, soy and rice.


What Are Algae?

Algae are a diverse group of aquatic organisms that have the ability to conduct photosynthesis. Certain algae are familiar to most people for instance, seaweeds (such as kelp or phytoplankton), pond scum or the algal blooms in lakes. However, there exists a vast and varied world of algae that are not only helpful to us, but are critical to our existence.


Definitions of Micro and Macro

  • micro- or micr-pref.1.a. Small: microcircuitb. Abnormally small: microcephalyc. Requiring or involving microscopy: microsurgery.
  • macro- or macr-pref. 1. Large: macroscopic

Take this definition of algae and put it together with micro and macro to see what you get.


How to Grow Chlorella for a Food Supplement

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Growing your own stock of chlorella algae only requires some basic equipment that includes a simple glass aquarium (that should be placed at a window for maximum sunlight exposure), filtered or purified water, and plant nutrients.

The cultivation of chlorella has the longest tradition in Asiatic countries, especially Japan, where it has been used for human nutrition, pharmaceutics and cosmetics in an annual amount of several thousands of tones. The use has lately involved the so-called aquacultures - in which the alga is a valuable component of the food chain in directed intensive-breeding colonies for delicate fish and shrimp species.

Chlorella is easy to find and to select the starter strain because it grows in almost any pond or lake worldwide. Alternatively, just buy the starter strain from a local university or biology lab.


Microalgae: a sustainable feed source for aquaculture

The need for nutritional sources safer than traditional animal products has renewed interest generally in plants and particularly in microalgae. Microalgae have diverse uses in aquaculture, their applications are mainly to provide nutrition and to enhance the colour of the flesh of salmonids. The larvae of molluscs, echinoderms and crustaceans as well as some fish larvae feed on microalgae. Several studies have confirmed that a live multi-specific, low bacterial and microalgal biomass remains essential for shellfish hatcheries. Major advances are expected from new production system, designs and operations from batch run open tanks to more sophisticated continuously-run and closed loop reactors. Currently, studies are underway to examine the cost-effectiveness of the on- and off-site microalgal production systems which can only be achieved by substantial scaling-up and improved quality control. In order to attain sustainability in the usage of microalgae, a systems-based approach is required which integrates different fields such as biotechnology, bioprocess and management procedures.

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Cars, Carbon, and Chlamydomonas: How These Five Synthetic Biology Companies Will Disrupt the Automotive Industry

Imagine that your car runs on carbon emissions -- consuming rather than creating one of the main . [+] drivers of climate change. Such an idea is not as far-fetched as you might think.

By JMortonPhoto.com & OtoGodfrey.com, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=44599363

Imagine having a car that runs on carbon emissions - one of the main drivers in climate change. Imagine that your car seat is made with leather from fungi and the fabrics and carpets in your car are stain-repellent and made with algae. Imagine if the car was lightweight, yet strong and flexible - well, it can be, with spider silk. And what about the paint and the color of the car? Not just the color you choose but what if the paint process was sustainable, thanks to yeast, the tiny organism we usually thank for the fluffiness in the bread we eat.

These ideas are not so alien and far out in the future. If it were up to synthetic biology companies LanzaTech, Ecovative Design, Checkerspot, Spiber, and Lygos, this could indeed be your next car. Here are five companies that are changing the automotive industry through synthetic biology and the engineering of biological organisms.

Imagine if you could take carbon emissions and convert them to fuels and chemicals, cleaning the air and giving carbon a second chance - and a second use. That is the goal of LanzaTech’s technology. The technology takes pollution and recycles it, in hopes to eliminate single-use carbon. How is that possible? Microbes! LanzaTech co-founder and CSO Dr. Sean Simpson identified a microbe, isolated from the gut of a rabbit, that was able to live on gas emissions and produce ethanol. Through accelerated natural selection, LanzaTech isolated the microbes producing the highest level of ethanol. Now, instead of sending harmful gas emissions out into the open air, it can be sent into a fermentation tank where these microbes feed off the gas and turn it into ethanol. The ethanol can then be used in a variety of applications such as paint, personal care, or fuel. Just this August, LanzaTech announced a partnership with Danish Novo Holdings, who invested $72 million to further develop LanzaTech’s sustainable fuels and chemicals platform.

Mycelium is the thread-like vegetative part of a fungus — like the stem of a mushroom. Ecovative has an internationally patented process to grow mycelium into designed forms to make a sustainable product that is 100% home compostable. Ecovative is using mycelium to make food, textiles, packaging materials, and foam. Imagine sitting on a fluffy, foam-like leather car seat - all made of engineered fungi. Ecovative’s MycoFlex platform provides textiles that are breathable, heat-resistant, insulating, strong, resilient, and 100% natural. What more could you possibly ask for when you’re about to sit down on your car’s black leather seat on a hot July afternoon? The future of fashion belongs to fungi, and now fungi also belongs in our cars’ interior. Ecovative’s mycelium materials are sustainable, biological alternatives to plastics, textiles, and animal agriculture (leather), drivers of global pollution. The process of growing mycelium yields very little (mostly compostable) waste — it is fast growing and uses limited energy. What’s more, Ecovative recently launched a new company called Atlast Food Company, with the aim to create new food products by leveraging Ecovative’s mycelium foundry.

Imagine the ability to reinvent materials - what would you create? Using chemistry and engineered . [+] microalgae Checkerspot are creating new materials with new physical properties

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Imagine building a house of LEGOs. There are endless possibilities as to how the house will look. What style should it be? What color? Dimensions and size? But imagine now that you could instead design the LEGO brick itself. Checkerspot is enabling the design of new materials - at the molecular level. Hundreds of fatty acids exist in nature, but only 14 of them are used for industrial purposes. The disregarded fatty acids “don’t fit the ‘industrial complex’ due to commodity scale and pricing.” But Checkerspot is changing this, using chemistry and engineered microalgae to create new materials with new physical properties - starting with oils. Conventional petroleum-derived oils have a negative environmental impact, but replacing them with alternatives fermented by microalgae dramatically reduces the environmental impact. Imagine the endless possibilities if you could make the material of your car. You could make a hydrophobic, stain-repellent carpet, or baby seat - no need to worry about spilling or muddy shoes. With synthetic biology, Checkerspot is truly “at a new age of industrial material production.”

Here are the two ImPACT program prototypes (Created with synthetic spider silk composite materials)

A spider web made of pencil-thick spider silk fibers can catch a fully loaded Jumbo Jet Boeing 747 with a weight of 380 tons. With about the same strength as carbon fiber but with 40 times the toughness, spider silk is a material with unlimited possibilities. Imagine the applications it could have in the automotive industry - perhaps a safer, stronger chassis without compromising on weight? You may have heard about Spiber and the launch of their Moon Parka, in collaboration with The North Face Japan. But Spiber has also been innovating the automotive industry. Earlier this year Spiber finished up a Japanese national project named ImPACT in collaboration with partner companies. Together with Bridgestone and by utilizing their Brewed Protein™ materials, Spiber has developed a polyurethane composite foam for car seats. The idea is to make a thinner and lighter foam, while still maintaining the necessary comfort properties. Furthermore, in collaboration with several Toyota group companies, Spiber is reinventing the shock absorption in car doors. The goal is to create fiber-reinforced materials that are lighter, and have increased shock absorption. Many cars today use steel as the shock absorbent which is heavy and not sustainably produced. With Spiber’snew material, cars can potentially become lighter meaning less CO2 emissions and better gas mileage. Another innovator in the spider silk business is German AMSilk. AMSilk and Spiber are two of the few companies having succeeded in the bioengineering of spider silk. Last year AMSilk signed a deal with Airbus with the aim to create novel materials using their silk to build a high-performance, lightweight airplane.

The paint on your car was most likely cured in a mile-long oven heated to 450 degrees Fahrenheit . [+] using unsustainably made substances. With microbes, Lygos have come up with sustainable alternatives.

Malonic acid is a chemical with applications in automobile coatings, biodegradable polymers, surgical adhesives, and food and drug additives — to name a few. The global market for malonic acid is valued at USD$42 million and is expected to grow. But the production of malonic acid comes at a big environmental cost: It requires toxic chemistries based on petroleum sodium cyanide, a chemical that poses significant health and environmental risks. Bay Area-based Lygos has come up with a sustainable alternative production method: microbes! With his expertise in engineering microbes to convert sugar into fuel, co-founder and CEO Eric Steen managed to create a microbial strain that was acid-tolerant with the ability to produce malonic acid. Today, Lygos has optimized microbial strains to be even more efficient at converting sugars into malonic acid. One of the biggest areas of potential impact for sustainable malonic acid production, according to Steen, is the automotive industry. If you own a car, the paint on it was most likely cured in a mile-long oven heated to 450 degrees Fahrenheit. But one variant of malonic acid — malonate — could revolutionize the automotive industry by making low-temperature painting possible.

Thank you to Stephanie Michelsen for additional research and reporting in this post. Please note: I am the founder of SynBioBeta, the innovation network for the synthetic biology industry. Some of the companies that I write about are sponsors of the SynBioBeta conference (click here for a full list of sponsors).


Insects, Algae Might be the Way Out of a Future Food Crisis

It's estimated that two billion people don't have access to reliable sources of nutritious food - they are food insecure. This group includes about 600 million people who are undernourished, while about 340 million children are thought to have micro-nutrient deficiencies. Food distribution is already a major problem. We should also change how food is produced, maybe in radical ways, to ensure the sustainability of our food supply as it's challenged by climate change, loss of biodiversity and environmental degradation, and microbial threats, suggests a new report in Nature Food.

The study authors are calling attention to the need to integrate new technologies that can produce novel food products and maintain controlled environments into the food system to reduce its vulnerability. The study noted that there are a variety of farmed foods that could help mitigate the pressure on the food supply, like chlorella, spirulina, insect larvae, fungal proteins, and macro-algae like sugar kelp. Some of them are already considered healthy, so-called 'super' foods (like spirulina, a photosynthetic bacterium).

These futuristic foods might be useful in urban or isolated settings where there aren't many traditional resources for farming. They may help communities reduce their dependence on global food chains that are easily disrupted by calamitous events, or address malnutrition and hunger.

"Foods like sugar kelp, flies, mealworm and single-celled algae such as chlorella, have the potential to provide healthy, risk-resilient diets that can address malnutrition around the world," said first study author Dr. Asaf Tzachor, a researcher at the Centre for the Study of Existential Risk (CSER) at the University of Cambridge.

"Our current food system is vulnerable. It's exposed to a litany of risks - floods and frosts, droughts and dry spells, pathogens, and parasites, which marginal improvements in productivity won't change. To future-proof our food supply we need to integrate completely new ways of farming into the current system."

The researchers assessed about 500 studies on potential food production systems of the future and found that the most promising include controlled environments that give plants the natural resources they need while reducing hazards, insect breeding greenhouses, and devices that generate microalgae with light, called photo-bioreactors.

Conventional farming is at risk of serious disruption, and it's dangerous to rely on it, the researchers warned. The threats are often beyond our control, as highlighted by the ongoing pandemic, wildfires and droughts impacting Australia and North America, pigs afflicted with swine fever in Europe and Asia, and desert locust swarms in East Africa.

"Advances in technology open up many possibilities for alternative food supply systems that are more risk-resilient, and can efficiently supply sustainable nutrition to billions of people," said Catherine Richards, a doctoral researcher at Cambridge's Centre for the Study of Existential Risk and Department of Engineering. "The coronavirus pandemic is just one example of increasing threats to our globalized food system. Diversifying our diet with these future foods will be important in achieving food security for all."

It may be possible to overcome people's reservations about eating foods that are weird and unusual to them, like insects, by using them to create ingredients instead of just serving them cooked. There are already foods like energy bars and pasta that contain ground insect larvae or processed algae.


Is it possible to use microalgae to produce food and live on it? - Biology

Daphnia is a frequently used food source in the freshwater larviculture (i.e. for different carp species) and in the ornamental fish industry (i.e. guppies, sword tails, black mollies and plattys etc.)

Daphnia belongs to the suborder Cladocera, which are small crustaceans that are almost exclusively living in freshwater. The carapace encloses the whole trunk, except the head and the apical spine (when present). The head projects ventrally and somewhat posteriorly in a beak-like snout. The trunk appendages (five or six pairs) are flattened, leaf-like structures that serve for suspension feeding (filter feeders) and for locomotion. The anterior part of the trunk, the postabdomen is turned ventrally and forward and bears special claws and spines to clean the carapace (Fig. 6.1.). Species of the genus Daphnia are found from the tropics to the arctic, in habitats varying in size from small ponds to large freshwater lakes. At present 50 species of Daphnia are reported worldwide, of which only six of them normally occur in tropical lowlands.

The adult size is subjected to large variations when food is abundant, growth continues throughout life and large adults may have a carapace length twice that of newly-mature individuals. Apart from differences in size, the relative size of the head may change progressively from a round to helmet-like shape between spring and midsummer. From midsummer to fall the head changes back to the normal round shape. These different forms are called cyclomorphs and may be induced, like in rotifers, by internal factors, or may be the result from an interaction between genetic and environmental conditions.

Normally there are 4 to 6 Instar stages Daphnia growing from nauplius to maturation through a series of 4-5 molts, with the period depending primarily on temperature (11 days at 10°C to 2 days at 25°C) and the availability of food. Daphnia species reproduce either by cyclical or obligate parthenogenesis and populations are almost exclusively female. Eggs are produced in clutches of two to several hundred, and one female may produce several clutches, linked with the molting process. Parthenogenetic eggs are produced ameiotically and result in females, but in some cases males can appear. In this way the reproductive pattern is similar to rotifers, where normally parthenogenetic diploid eggs are produced. The parthenogenetic eggs (their number can vary from 1 to 300 and depends largely upon the size of the female and the food intake) are laid in the brood chamber shortly after ecdysis and hatch just before the next ecdysis. Embryonic development in cladocerans occurs in the broodpouch and the larvae are miniature versions of the adults. In some cases the embryonic period does not correspond with the brood period, and this means that the larvae are held in the brood chamber even after the embryonic period is completed, due to postponed ecdysis (environmental factors). For different species the maturation period is remarkably uniform at given temperatures, ranging from 11 days at 10°C to only 2 days at 25°C.

Factors, such as change in water temperature or food depreviation as a result of population increase, may induce the production of males. These males have one or two gonopores, which open near the anus and may be modified into a copulatory organ. The male clasps the female with the first antennae and inserts the copulatory processes into the single, median female gonopore. The fertilized eggs are large, and only two are produced in a single clutch (one from each ovary), and are thick-shelled: these resting or dormant eggs being enclosed by several protective membranes, the ephippium. In this form, they are resistant to dessication, freezing and digestive enzymes, and as such play an important role in colonizing new habitats or in the re-establishment of an extinguished population after unfavourable seasonal conditions.

6.1.2. Nutritional value of Daphnia

The nutritional value of Daphnia depends strongly on the chemical composition of their food source. However, since Daphnia is a freshwater species, it is not a suitable prey organism for marine organisms, because of its low content of essential fatty acids, and in particular (n-3) HUFA. Furthermore, Daphnia contains a broad spectrum of digestive enzymes such, as proteinases, peptidases, amylases, lipases and even cellulase, that can serve as exo-enzymes in the gut of the fish larvae.

6.1.3. Feeding and nutrition of Daphnia

The filtering apparatus of Daphnia is constructed of specialized thoracic appendages for the collection of food particles. Five thoracic limbs are acting as a suction and pressure pump. The third and fourth pair of appendages carry large filter-like screens which filter the particles from the water. The efficiency of the filter allows even the uptake of bacteria (approx. 1µm). In a study on the food quality of freshwater phytoplankton for the production of cladocerans, it was found that from the spectrum blue-greens, flagellates and green algae, Daphnia performed best on a diet of the cryptomonads, Rhodomonas minuta and Cryptomonas sp., containing high levels of HUFA (more than 50% of the fatty acids in these two algae consisted of EPA and DHA, while the green algae were characterized by more 18:3n-3). This implies that the long-chained polyunsaturated fatty acids are important for a normal growth and reproduction of Daphnia . Heterotrophic microflagellates and ciliates up to the size of Paramecium can also be used as food for Daphnia . Even detritus and benthic food can be an important food source, especially when the food concentration falls below a certain threshold. In this case, the water current produced by the animals swimming on the bottom whirls up the material which is eventually ingested. Since daphnids seem to be non-selective filter feeders ( i.e., they do not discriminate between individual food particles by taste) high concentrations of suspended material can interfere with the uptake of food particles.

Figure 6.1. Schematic drawing of the internal and external anatomy of Daphnia.

6.1.4. Mass culture of Daphnia

6.1.4.1. General procedure for tank culture

Daphnia is very sensitive to contaminants, including leaching components from holding facilities. When plastic or other polymer containers are used, a certain leaching period will be necessary to eliminate toxic compounds.

The optimal ionic composition of the culture medium for Daphnia is unknown, but the use of hard water, containing about 250 mg.l -1 of CO 3 2- , is recommended. Potassium and magnesium levels should be kept under 390 mg.l -1 and 30-240 µg. l -1 , respectively. Maintenance of pH between 7 to 8 appears to be important to successful Daphnia culture. To maintain the water hardness and high pH levels, lime is normally added to the tanks. The optimal culture temperature is about 25°C and the tank should be gently aerated to keep oxygen levels above 3.5 mg.l -1 (dissolved oxygen levels below 1.0 mg.l -1 are lethal to Daphnia ). Ammonia levels must be kept below 0.2 mg.l -1 .

Inoculation is carried out using adult Daphnia or resting eggs. The initial density is generally in the order of 20 to 100 animals per litre.

Normally, optimal algal densities for Daphnia culture are about 10 5 to 10 6 cells. ml -1 (larger species of Daphnia can support 10 7 to 10 9 cells.ml -1 ). There are two techniques to obtain the required algal densities: the detrital system and the autotrophic system:

6.1.4.2. Detrital system

The “stable tea” rearing system is a culture medium made up of a mixture of soil, manure and water. The manure acts as a fertilizer to promote algal blooms on which the daphnids feed. One can make use of fresh horse manure (200 g) that is mixed with sandy loam or garden soil (1 kg) in 10 l pond water to a stable stock solution this solution diluted two to four times can then be used as culture medium. Other fertilizers commonly used are: poultry manure (4 g.l -1 ) or cow-dung substrates. This system has the advantage to be self-maintaining and the Daphnia are not quickly subjected to deficiencies, due to the broad spectrum of blooming algae. However, the culture parameters in a detrital system are not reliable enough to culture Daphnia under standard conditions, i.e. overfertilization may occur, resulting in anoxic conditions and consequently in high mortalities and/or ephippial production.

6.1.4.3. Autotrophic system

Autotrophic systems on the other hand use the addition of cultured algae. Green water cultures (10 5 to 10 6 cells.ml -1 ) obtained from fish pond effluents are frequently used but these systems show much variation in production rate mainly because of the variable composition of algal species from one effluent to another. Best control over the culture medium is obtained when using pure algal cultures. These can be monocultures of e.g. algae such as Chlorella , Chlamydomonas or Scenedesmus , or mixtures of two algal cultures. The problem with these selected media is that they are not able to sustain many Daphnia generations without the addition of extra vitamins to the Daphnia cultures. A typical vitamin mix is represented in Table 6.1.

Table 6.1. A vitamin mix for the monospecific culture of Daphnia on Selenastrum, Ankistrodesmus or Chlamydomonas. One ml of this stock solution has to be added to each litre of algal culture medium (Goulden et al ., 1982).

Concentration of stock solution (µg.1 -1 )

90

To calculate the daily algal requirements and to estimate the harvesting time, regular sampling of the population density must be routinely undertaken. Harvesting techniques can be non-selective irrespective of size or age group, or selective (only the medium sized daphnids are harvested, leaving the neonates and matured individuals in the culture tank).

Mass cultivation of Daphnia magna can also be achieved on cheap agro-industrial residues, like cotton seed meal (17 g.l -1 ), wheat bran (6.7 g.l -1 ), etc . Rice bran has many advantages in comparison to other live foods (such as microalgae): it is always available in large quantities, it can be purchased easily at low prices, it can be used directly after simple treatment (micronisation, defatting), it can be stored for long periods, it is easy to dose, and it has none of the problems involved in maintenance of algal stocks and cultures.

In addition to these advantages, there is also the fact that rice bran has a high nutritional value rice bran (defatted) containing 24% (18.3%) crude protein, 22.8% (1.8%) crude fat, 9.2% (10.8%) crude fibre, and being a rich source of vitamins and minerals. Daphnia can be grown on this food item for an unlimited number of generations without noticeable deficiencies.

Defatted rice bran is preferred above raw rice bran because it prevents hydrolysis of the fatty acids present and, consequently, rancidity of the product. Micronisation of the bran into particles of less than 60 µm is generally carried out by treating an aqueous suspension (50 g.l -1 ) with a handmixer and filtering it through a 60 µm sieve, or by preparing it industrially by a dry mill process. The suspension is administered in small amounts throughout a 24 h period: 1 g of defatted rice bran per 500 individuals for two days (density: 100 animals.l -1 ). The food conversion ratio has an average of 1.7, which implies that with less than 2 kg of dry rice bran approximately 1 kg wet daphnid material can be produced (with a 25% water renewal per week De Pauw et al ., 1981).

6.1.4.4. General procedure for pond culture

Daphnia can also be produced in ponds of at least 60 cm in height. To produce 1 ton of Daphnia biomass per week, a 2500 m 3 culture pond is required. The pond is filled with 5 cm of sun-dried (for 3 days) soil to which lime powder is added at a rate of 0.2 kg lime powder per ton soil. After this the pond is then filled with water up to 15 cm. Poultry manure is added to the ponds on the 4th day at a rate of 0.4 kg.m -3 to promote phytoplankton blooms. Fertilization of the pond with organic manure instead of mineral fertilizers is preferred because cladocerans can utilize much of the manure directly in the form of detritus. On day 12 the water level is raised to 50 cm and the pond is fertilized a second time with poultry manure (1 kg.m -3 ). Thereafter, weekly fertilization rates are maintained at 4 kg poultry manure per m -3 . In addition, fresh cow dung may also be used: in this instance a suspension is prepared containing 10 g.l -1 , which is then filtered through a 100 µm sieve. During the first week a 10 l extract is used per day per ton of water the fertilization increasing during the subsequent weeks from 20 l.m -3 .day -1 in the second week to 30 l.m -3 .day -1 in the following weeks.

The inoculation of the ponds is carried out on the 15th day at a rate of 10 daphnids per litre. One month after the inoculation, blooms of more than 100 g.m -3 can be expected. To maintain water quality in these ponds, fresh hard water can be added at a maximum rate of 25% per day. Harvesting is carried out by concentrating the daphnids onto a 500 µm sieve. The harvested biomass is concentrated in an aerated container (< 200 daphnids.l -1 ). In order to separate the daphnids from unfed substrates, exuviae and faecal material, the content of the container is brought onto a sieve, which is provided with a continuous circular water flow. The unfed particles, exuviae and faeces will collect in the centre on the bottom of the sieve, while the daphnids remain in the water column. The unwanted material can then be removed by using a pipette or sucking pump. Harvesting can be complete or partial for partial harvesting a maximum of 30% of the standing crop may be harvested daily.

6.1.4.5. Contamination

Daphnia cultures are often accidentally contaminated with rotifers. In particular Brachionus, Conochilus and some bdelloids may be harmful, (i.e. B. rubens lives on daphnids and hinders swimming and food collection activities). Brachionus is simply removed from the culture by flushing the water and using a sieve of appropriate mesh size as Daphnia is much bigger than Brachionus . Conochilus , on the other hand, can be eliminated by adding cow dung to the culture (lowering the oxygen levels). Bdelloids are more difficult to remove from the culture since they are resistant to a wide range of environmental conditions and even drought. However, elimination is possible by creating strong water movements, which bring the bdelloids (which are bottom dwellers) in the water column, and then removing them by using sieves.

6.1.5. Production and use of resting eggs

Resting eggs are interesting material for storage, shipment and starting of new Daphnia cultures. The production of resting eggs can be initiated by exposing a part of the Daphnia culture to a combination of stressful conditions, such as low food availability, crowding of the animals, lower temperatures and short photoperiods. These conditions are generally obtained with aging populations at the end of the season. Collection of the ephippia from the wild can be carried out by taking sediment samples, rinsing them through a 200 µm sieve and isolating the ephippia under a binocular microscope. Normally, these embryos remain in dormancy and require a diapause inhibition to terminate this status, so that they can hatch when conditions are optimal. Possible diapause termination techniques are exposing the ephippia to low temperatures, darkness, oxygen and high carbon dioxide concentrations for a minimal period of several weeks (Davison, 1969).

There is still no standard hatching procedure for Daphnia. Generally the hatching process is stimulated by exposing the ephippia to higher temperatures (17-24°C), bright white light (70 W.m -2 ), longer photoperiods and high levels of dissolved oxygen. It is important, however, that these shocks are given while the resting eggs are still in the ephippium. After the shock the eggs may be removed from the ephippium. The hatching will then take place after 1-14 days.

6.1.6. Use of Moina

Moina also belongs to the Cladocera and many of the biological and cultural characteristics that have been discussed for Daphnia can be applied to Moina .

Moina thrives in ponds and reservoirs but primarily inhabits temporary ponds or ditches. The period to reach reproductive maturity takes four to five days at 26°C. At maturity clear sexual dimorphic characteristics can be observed in the size of the animals and the antennule morphology. Males (0.6-0.9 mm) are smaller than females (1.0-1.5 mm) and have long graspers which are used for holding the female during copulation. Sexually mature females carry only two eggs enclosed in an ephippium which is part of the dorsal exoskeleton.

Moina is of a smaller size than Daphnia , with a higher protein content, and of comparable economic value. Produced biomass is successfully used in the larviculture of rainbow trout, salmon, striped bass and by tropical fish hobbyists who also use it in a frozen form to feed over sixty fresh and salt water fish varieties. The partial replacement of Artemia by Moina micrura was also reported to have a positive effect during the larviculture of the freshwater prawn Macrobrachium rosenbergii (Alam, 1992).

Enrichment of Moina can be carried out using the direct method, by culturing them on baker’s yeast and emulsified fish or cuttlefish liver oils. Experiments have shown that Moina takes up (n-3) HUFA in the same way, although slower, than rotifers and Artemia nauplii, reaching a maximum concentration of around 40% after a 24 h-feeding period.


Is it possible to use microalgae to produce food and live on it? - Biology

Algae are simple plants that can range from the microscopic (microalgae), to large seaweeds (macroalgae), such as giant kelp more than one hundred feet in length. Microalgae include both cyanobacteria, (similar to bacteria, and formerly called “blue-green algae”) as well as green, brown and red algae. (There are more varieties of microalgae, but these are the main ones.)

Algae can be grown using water resources such as brackish-, sea-, and wastewater unsuitable for cultivating agricultural crops. When using wastewater, such as municipal, animal and even some industrial runoff, they can help in its treatment and purification, while benefiting from using the nutrients present.

Most microalgae grow through photosynthesis – by converting sunlight, CO2 and a few nutrients, including nitrogen and phosphorous, into material known as biomass This is called “autotrophic” growth. Other algae can grow in the dark using sugar or starch (called “heterotrophic” growth), or even combine both growth modes (called “mixotrophic” growth).

Algae are very diverse and found almost everywhere on the planet. They play an important role in many ecosystems, including providing the foundation for the aquatic food chains supporting all fisheries in the oceans and inland, as well as producing about 70 percent of all the air we breathe.

UCSD’s Dr. Mitchell gives a lesson in algae 101

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How could biotechnology improve your life?

Experts on the World Economic Forum’s Council on Biotechnology have selected 10 developments which they believe could help not only meet the rapidly growing demand for energy, food and healthcare, but also increase productivity and create new jobs, should issues such as regulatory certainty, public perception and investment be tackled successfully. In this blog post, the council members make their case for each of these technologies and highlight their potential benefits:

1. Bioproduction of sustainable chemicals, energy and other materials

Over the past 100 years, humans have depleted about half the world’s known reserves of fossil fuels. These reserves, which took more than 600 million years to accumulate, are non-renewable, and their extraction, refining and burning are a major cause of greenhouse gases and the warming of the planet. One of the most promising hopes in the sustainability field is artificial biosynthesis, a process whereby living organisms, such as bacteria, fungus or plants, are used to create fuels, chemicals and other materials.

2. Genetically modified crops to increase sustainable food production

The continuing increase in our numbers and affluence are posing growing challenges to the ability of humanity to produce adequate food and animal feed, as well as meet the new demands for biofuel. Although controversial, genetic modification of crops can help to solve this problem. The evidence shows that, in places where they are allowed, modern GM crops are contributing to the growth of agricultural productivity. In 2011, for instance, 16.7 million farmers grew biotech crops on almost 400 million acres in 29 countries, including 19 developing countries. Existing GM commodity crops also contribute to crop sustainability by permitting the use of less pesticide and decreasing the need for erosion-promoting tillage. Such crops also contribute to human and animal welfare by increasing farm productivity and reducing fungal contamination of grain.

3. Seawater bioprocesses to produce fuel and chemicals

More than 70% of the Earth’s surface is covered by seawater, and it is the most abundant water source available on the planet, but we are only starting to tap its potential. For instance, new bioprocesses can turn some types of seaweed grown in the oceans into biofuels, potentially providing an energy solution to countries that lack arable land and access to freshwater. Additionally, bacteria and microalgae that live and grow in seawater can be engineered to grow more efficiently and be used to produce chemicals, fuels and polymeric materials.

4. Zero-waste bio-processing

Environmentalists have long dreamed of a zero-waste society and new bio-processing techniques could help to make this a reality. Biorefineries – facilities that integrate biomass conversion processes and equipment to produce fuel, power, heat and value-added chemicals from biomass – can turn industrial waste streams into chemicals and fuels, thereby closing the production loop. Recent advances include using less-costly inputs in the bio-process, such as carbon dioxide, methane and waste heat. Other advances are also simplifying the waste streams, reducing their toxicity and moving society closer to the goal of zero waste.

5. Carbon dioxide as a raw material

Carbon dioxide and other carbon molecules are seen as a culprit in global warming, and the environmental consequences of more of these compounds entering the atmosphere is becoming increasingly clear. Recent advances are rapidly increasing our understanding of how living organisms consume and use carbon dioxide. By harnessing the power of these natural biological systems, scientists are engineering a new wave of approaches to convert waste carbon dioxide and other molecules into energy, fuel, chemicals, and materials that may help the world meet its needs.

6. Regenerative medicine to create new organs

Many societies that are grappling with the challenge of a rapidly ageing population are increasing the demand for regenerative medicine, which holds the promise of growing tissue and organs in the laboratory and allows surgeons to safely implant them when the body is unable to heal itself. Traffic accidents and war amputations are also spurring interest in the field. Scientists are already able to engineer tissue using various biomaterials, and believe that stem cells, especially ones called induced pluripotent stem cells (adult cells that have been genetically reprogrammed to an embryonic stem cell-like state) provide another significant opportunity in this field.

7. Rapid and precise development and manufacturing of medicine and vaccines

The ability of therapeutics and vaccines to treat and prevent diseases has been well documented. Biotechnology has been central to these advances, progressively offering the ability to make more complicated medicines and vaccines, opening up the treatment and prevention of a broader set of diseases. The leading edge of biotechnology is now offering the potential to rapidly produce therapeutics and vaccines against virtually any target. These technologies – including messenger therapeutics to stimulate the body’s natural ability to produce therapeutic proteins targeted immunotherapies to boost or restore the ability of the immune system to fight diseases by targeting specific cells conjugated nanoparticles, which combine antibodies and nanoparticles – have already produced potential treatments with substantial promise to improve human health globally.

8. Accurate, fast, cheap, and personalized diagnostics and prognostics

One of the most real and serious threats to the human race is a potential global pandemic. Biotechnology has the potential to provide the platforms needed for rapid identification of biological threats, development of potential cures and global manufacturing of the solutions. Identification of better targets and combined use of nanotechnology and information technology are making it possible to develop rapid, accurate, personalized and inexpensive diagnostics and prognostics systems.

9. Biotech improvements to soil and water

Arable land and fresh water are two of our most important, yet limited, resources. Sustained abuse and misappropriation have threatened these resources, much as the demand on them has increased. Advances in biotechnology have already yielded technologies that are beginning to restore the vitality and viability of these resources. A new generation of developing technologies, such as bioremediation to use microbial metabolism to remove pollutants, bioregeneration to renew or restore life-supporting resources using biological processes, and bioaugmentation to introduce a group of natural microbial strains or a genetically engineered variant to treat contaminated soil or water, offers great promise to not only further restore these resources but also to augment their potential.

10. Advanced healthcare through genome sequencing

It took more than 13 years and US$1.5 billion to sequence the first human genome and determine the precise order of the building blocks in our genetic information. Today, we can sequence a complete human genome in a single day for less than US$1,000. When we analyse in such a sequence the roughly 3 billion base pairs, which are the building blocks of the genome, we find that we differ from each other in several million of these base pairs. In the vast majority of cases these differences do not cause any issues, but in rare cases they cause disease or susceptibility to disease. New research and medicine will increasingly be driven by our understanding of such genetic variations and their consequences.

Author: This list has been compiled by the World Economic Forum’s Global Agenda Council on Biotechnology, of which Lee Sang Yup is currently chair. For a full list of the Council’s members see here.

Opinions expressed here are those of the author(s) and not those of the World Economic Forum.

Image: A research works in a biotechnology laboratory in Switzerland REUTERS/Sebastian Derungs