Rehovot, Israel-based Rosetta Green Ltd., which specializes in crop improvement for the agriculture and alternative fuel industries using unique genes called microRNAs, has successfully completed an experiment producing human growth hormone (HGH) and validated its biological activity. Proteins produced by both treated and control algae were tested with an in vitro activity test assay by an independent third party using the conventional proliferation method. The activity test assay found that Rosetta Green’s treated algae exhibited hormonal activity.
The project is part of a joint European effort to manufacture chemicals and proteins in algae, which is implemented and funded by the European Union as part of the European Commission’s Seventh Framework Program for Research and Technology Development (FP7). More than ten European organizations are participating in this project, including companies and leading universities, which has an estimated budget of about $7 million US. The project is being managed by Professor Sammy Boussiba of the Microalgal Biotechnology Laboratory of Ben Gurion University of the Negev.
Rosetta Green focuses on using microalgae to develop and produce human proteins for therapeutics, a process that reduces the currently steep drug production costs associated with using mostly mammalian cells and bacteria.
According to Amir Avniel, Rosetta Green’s CEO, “Algae may be an effective source for the production of proteins and vaccines. Rosetta Green has vast experience working with molecular methods in algae. The company worked on the development of designated algae in order to produce the protein in cooperation with the EU. Algae can be used for multiple applications such as producing chemicals, industrial food supplements, bio fuel and food. We believe that the technology that we develop provides significant advantage to improve various traits in plants and algae. We continually seek partners to develop our products and technologies.”
Growth hormone is a peptide hormone secreted by the pituitary gland. Among its functions are the regulation of protein production and the stimulation of bone growth in children. Growth hormone is normally secreted throughout a person’s life, but the amount decreases by 14% every decade after the age of 21. A deficiency in this hormone is known to cause growth block, short stature and dwarfism.
Currently, growth hormone is produced by major multi-nationals such as Pfizer, Lilly, and Merck Serono and used as a prescription medicine to treat children with growth problems and adults with hormone deficiency as well as other symptoms characterized by growth complications. Total annual sales of human growth hormone are estimated at approximately $3 Billion US.
Growth hormone is administered today primarily through daily injections over several years. The accumulated cost can reach hundreds of thousands of dollars per child. Rosetta Green believes that manufacturing the hormone using microalgae will likely reduce today’s high cost of production, which relies upon currently available techniques.
More info at http://www.rosettagreen.com/.
CCRES special thanks to Professor Sammy Boussiba of the Microalgal Biotechnology Laboratory of Ben Gurion University of the Negev.
CCRES ALGAE Project
Croatian Center of Renewable Energy Sources (CCRES)
Algae is one of nature′s most prolific and efficient photosynthetic plants; in fact, it is the source of the earth′s crude oil when algae bloomed millions of years ago. Nearly all of algae′s energy is concentrated in the chloroplast—the engine that turns sunlight and CO2 into organic carbon, resulting in oils easily refined into gasoline, diesel, and jet fuel. Further, algae has a short growing cycle and does not require arable land or potable water. Algae′s number one nutrient source is CO2, consuming 13 to 14 kg of C02 per gallon of green crude. Algae can be grown quickly in salt water in the desert.
Croatian Center of Renewable Energy Sources (CCRES)
theory to cancel out any of the benefits that biofuels were meant to bring.
The European Commission has run 15 studies on different biofuel crops, which on average conclude that over the next decade Europe’s biofuels policies might have an indirect impact equal to 4.5 million hectares of land – an area the size of Denmark.
Some in the biofuels industry argue that the Commission’s science is flawed and that the issue could be tackled by a major overhaul of agricultural strategy to improve productivity or by pressing abandoned farmland back into action. Waste products from biofuels production can also be fed to animals, they say, so reducing the pressure on land resources.
CROATIAN CENTER of RENEWABLE ENERGY SOURCES (CCRES)
Algae live on a high concentration of carbon dioxide and nitrogen dioxide. These pollutants are released by automobiles, cement plants, breweries, fertilizer plants, steel plants. These pollutants can serve as nutrients for the algae.
When fuels are burned there remains, besides ash, a certain number of gas components. If these still contain combustion heat, they are called heating gases. As soon as they have conveyed their energy to the absorbing surfaces of a heat exchanger, they are called flue or stack gases.
It further contains a small percentage of pollutants such as particulate matter, carbon monoxide, nitrogen oxides and sulfur oxides.
Carbon dioxide (CO2)
—the primary greenhouse gas responsible for global warming—along with other pollutants.
Its composition depends on what is being burned, but it usually consists of mostly nitrogen (typically more than two-thirds) derived from the combustion air, carbon dioxide (CO2) and water vapor as well as excess oxygen (also derived from the combustion air).
Using algae for reducing the CO2 concentration in the atmosphere is known as algae-based Carbon Capture technology. The algae production facilities can thus be fed with the exhaust gases from these plants to significantly increase the algal productivity and clean up the air. An additional benefit from this technology is that the oil found in algae can be processed into a biodiesel. Remaining components of the algae can be used to make other products, including Ethanol and livestock feed.
This technology offers a safe and sustainable solution to the problems associated with global warming.
Croatian Center of Renewable Energy Sources (CCRES)
Open cultivation systems use ponds or lakes with added mechanical equipment to grow microalgae. Open ponds were the first cultivation technology for mass cultivation of microalgae. In this system water levels are kept no less than 15 cm, and algae are cultured under conditions identical to their natural environment. The pond is designed in a raceway configuration, in which a paddlewheel circulates and mixes the algal cells and nutrients.
The raceways are typically made from poured concrete or they are simply dug into the earth and lined with a plastic liner to prevent the ground from soaking up the liquid. Baffles in the channel guide the flow around the bends in order to minimize space. The system is often operated in a continuous mode, where the fresh feed (containing nutrients including nitrogen phosphorus and inorganic salts) is added in front of the paddlewheel, and algal broth is harvested behind the paddlewheel after it has circulated through the loop. Depending on the nutrients required by algal species, several sources of wastewater can be used for algal culture. For some marine-type microalgae, seawater or water with high salinity can be used.
Although open ponds cost less to build and operate than closed systems using PBRs, this culture system has its disadvantages. The ponds can be built on any type of land but need large land areas for considerable biomass yield. Because they are in the open air, the water levels are affected from evaporation and rainfall. Natural CO2 levels in the atmosphere (0.03%-0.06%) are not enough for continuous mass growth of microalgae. Biomass productivity is also limited by contamination with unwanted algal species, organisms that feed on algae or other poisonous particles. Only few species can be grown in normal conditions.
Other types of construction use: 1) circular ponds where circulation is provided by rotating arms; 2) inclined systems where mixing is achieved through pumping and gravity flow.
Closed cultivation systems use PBRs – containers made of transparent materials for optimised light exposure. Enclosed PBRs have been employed to overcome the contamination and evaporation problems encountered in open systems. These systems are generally placed outdoors for illumination by natural light. The cultivation vessels have a large surface area-to-volume ratio. The most widely used PBR is a tubular design, which has a number of clear transparent tubes, usually aligned with the sun’s rays. The tubes are generally less than 10 centimeters in diameter to maximize sunlight penetration. The medium broth is circulated through a pump to the tubes, where it is exposed to light for photosynthesis, and then back to a reservoir. A portion of the algae is usually harvested after it passes through the solar collection tubes, making continuous algal culture possible.
In some PBRs, the tubes are coiled spirals to form what is known as a helical-tubular PBR. These systems sometimes require artificial light for energy, which adds to production costs. Either a mechanical pump or an airlift pump maintain a highly turbulent flow within the reactor, which prevents the algal biomass from settling. The photosynthesis process generates oxygen. In an open raceway system, this is not a problem as the oxygen is simply returned to the atmosphere. In closed PBRS, the oxygen levels will build up until they inhibit and poison the algae. The culture must periodically be returned to a degassing zone—an area where the algal broth is bubbled with air to remove the excess oxygen. Also, the algae use CO2, which can cause carbon starvation and an increase in pH. Therefore, CO2 must be fed into the system in order to successfully cultivate the microalgae on a large scale.
PBRs require cooling during daylight hours, and the temperature must be regulated at night as well. This may be done through heat exchangers located either in the tubes themselves or in the degassing column.
The advantages of enclosed PBRs are obvious. They can overcome the problems of contamination and evaporation encountered in open systems. The biomass productivity of PBRs can average 16 times more than that of a traditional raceway pond. Harvest of biomass from PBRs is less expensive than from raceway ponds, because the typical algal biomass is about 30 times as concentrated as the biomass found in raceways. Controlled conditions in closed systems are suitable for genetic modification of algae cells and enable cultivation of better quality species (e.g. microalgae with higher oil content).
However, closed systems also have disadvantages. Technological challenges with PBRs are: overheating, bio-fouling, oxygen accumulation, difficulty in scaling up, cell damage by shear stress & deterioration and expensive building & maintenance. Light limitation cannot be entirely overcome because light penetration is inversely proportional to the cell concentration. Attachment of cells to the tubes’ walls may also prevent light penetration. Although enclosed systems can enhance biomass concentration, the growth of microalgae is still suboptimal due to variations in temperature and light intensity.
R&D in algae biotechnologies focus on developing innovative PBR designs and materials. Different developed designs are: serpentine, manifold, helical and flat containers. From these elevated reactors can be oriented and tilted at different angles and can use diffuse and reflected (artificial) light for growth. More specific information is available in PBRs section.
After growing in open ponds or PBRs, the microalgae biomass needs to be harvested for further processing. The commonly used harvest method is through gravity settlement or centrifuge. The oil from the biomass is extracted through solvent and further processed into biodiesel.