Enhanced seaweed, cultivated using the new research method. Credit: Doron Ashkenazi
Researchers from Tel Aviv University and the Israel Oceanographic and Limnological Research Institute (IOLR) have succeeded in significantly increasing the ability of seaweed to produce healthy natural materials. The current study focused on enhancing the production of bio-active compounds that offer medical benefits to humans, such as antioxidants. Results showed that the concentration of these compounds in the “enhanced” seaweed was doubled; natural sunscreen concentrations tripled; and unique protective pigments of great medical value were stimulated ten-fold.
According to the researchers, these findings may serve the pharmaceutical, cosmetics, food, and nutritional supplement industries. The study was carried out with the innovative and sustainable approach of integrated aquaculture, which combines seaweed with fish cultivation. This method benefits the seaweed while at the same time helping to purify the seawater and minimizing negative environmental Impacts.
“The seaweed living in the intertidal zone face extreme stress conditions,” said Ph.D. student Doron Ashkenazi, “which include changes in salinity, temperature, desiccation conditions, changes in the availability of nutrients, and high exposure to solar radiation, especially in the ultraviolet (UV) range. Therefore, to survive, the seaweed has developed a unique set of chemical defense mechanisms — natural chemicals that help them cope with these harsh environments. One could say that seaweed are highly efficient natural factories for production of valuable substances that may offer significant benefits to humans.”
In a previous study, the same group of researchers developed an innovative technology that enables the growth of seaweed enriched with proteins and minerals such as zinc, iron, iodine, magnesium, and calcium.
In the current study, they sought to examine whether and how it is possible to increase and maximize the seaweed’s production of bio-active compounds, and secondary metabolites, that offer significant health benefits. These substances include antioxidants, protective pigments, and natural UV radiation filters.
To this end, they established an original and practical cultivation approach, in which three local seaweeds: Ulva, Gracilaria and Hypnea, were initially grown alongside fish effluents, and subsequently exposed to various abiotic conditions (stressors), namely high irradiance, nutrient starvation, and high salinity. The researchers investigated how these changes affected the concentration of specific valuable biomaterials in the seaweed, with the aim of enhancing their production.
The results showed impressive increases in their concentrations. “We developed optimal cultivation conditions and invented a new and clean way to increase the levels of healthy natural bio-active compounds in seaweed to an unprecedented level,” said Mr. Ashkenazi. “We in fact produced ‘super seaweed’ tailor designed to be utilized by the emerging health industries for food and health applications.”
In the News…
Gross-Wen Harnessing Algae to Clean Water
A novel system called a Revolving Algal Biofilm (RAB) grows algae and removes nitrogen and phosphorous from wastewater.
Across the U.S., wastewater treatment plants are looking for cost-efficient solutions to meet new state and federal water quality requirements. This includes lower thresholds for how much nitrogen and phosphorous can be discharged into rivers and lakes.
Over the last two decades, Zhiyou Wen, director of Iowa State’s Center for Crops Utilization Research, has investigated the use of certain species of algae as food ingredients, and more recently, as an “effective, reliable, and economical” way to treat wastewater. He’s also a professor in the department of food science and human nutrition.
The researcher and one of his former students, Martin Gross, developed a novel system called Revolving Algal Biofilm (RAB) to grow algae and remove nitrogen and phosphorous. After a successful pilot project at Iowa State’s BioCentury Research Farm, they co-founded Gross-Wen Technologies in 2014. The two attracted state and federal grants and investors, and then licensed the patented RAB system through ISURF.
With the RAB system, algae grow on a series of large, vertical conveyor belts that rotate in and out of a wastewater reservoir. “Like skyscrapers, you can fit a lot more into a space by going up rather than out,” says Dr. Wen.
The microorganisms absorb nitrogen and phosphorus from the wastewater, and sunlight and carbon dioxide from the air. A greenhouse encloses the RAB system, which Wen says is more cost-efficient than artificial light. An adjustable blade scrapes off the algae once it reaches a certain thickness. “It’s like mowing the lawn,” says Dr. Wen. “We just cut the top, and it keeps growing. Harvest may happen every two to three days in summer compared to once a week in winter.”
Gross-Wen Technologies has experimented with turning harvested algae into slow-release fertilizer pellets for gardens and lawns. The founders say this, along with other potential applications like bioplastics, could give wastewater treatment facilities additional revenue streams.
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