Science

A new book, “Enzymatic Technologies for Marine Polysaccharides” contains an interesting chapter on seaweeds called, “The manufacture, characterization, and uses of fucoidans from macroalgae.

Fucoidans are sulfated, complex, fucose-rich, polymers found in brown seaweeds, most notably the order Fucales known as the fucoids. The chapter details extraction methods and uses in food supplements, pharmaceuticals, bio-materials, cosmetics, and animal/ agricultural applications.

The authors claim that most fucoidan available on the market are for dietary supplementation, however, they admit that the molecule species is hard to identify and robust identification assays should be employed in any bioactive study. There is a new interest in animal health relating to fucoidan, and could be an emerging market.

Focoidans are considered safe and have a variety of uses, again showing how a completely sustainable resource (seaweeds) have a variety of revenue streams.

Seaweed inspired organic sunscreen

As we leave winter behind, it will soon be time to dust off the sunglasses and purchase a bottle of your favorite sunscreen.

Sunscreens have received a lot of bad press lately, either because of their ability to damage skin or because they wash off into the ocean and are toxic to marine life. An Icelandic company Taramar has been working to address these issues. Taramar focuses on skin health by the use of natural molecules found in plants. Recently they turned their attention to seaweed.

Their result was the TARASÓL UV filter which lacks preservatives and is safe for the skin and body.

Professor Gudrun Marteinsdottir, founder and CEO of Taramar, says, “TARASÓL is the result of years of basic research in marine biology and nutritional science leading to new knowledge on the functional properties of seaweed.″

Taramar has not disclosed the molecule from seaweed. However, we know that plants have developed ways of avoiding UV damage and this could be a good way to harness what nature already knows to produce a safe organic alternative to traditional sunscreens.

Operation Crayweed: restoring Sydney's underwater forests.

Sydney Australia used to have a rich coastline teeming with life, and crayweed (Phyllospora comosa) stretched far and wide. Crayweed is a brown macroalga that forms dense bushy habitat for a variety of marine life. Sometime back in the 80s, crayweed largely disappeared, and much of the inhabitants with it. While the cause of the crayweed reduction was unclear, many point to prolonged poor water quality.

The water quality in Sydney has improved, but the crayweed didn’t bounce back as expected. Thus enters Operation Crayweed, an effort to restore the natural population of crayweed around Sydney. The group settles crayweed onto mats, then divers deploy and secure the mats so the crayweed can naturally spread.

Below is a wonderful video outlining the effort. What a good way to rebuild an ecosystem, from the bottom up! Read more about Operation Crayweed at http://www.operationcrayweed.com/

Seaweed in your garden: a good fertilizer and potential pest control

Many people around the world for centuries have known that seaweeds are an excellent fertilizer. Recently people have been reporting another benefit of using seaweeds in their garden, pest control.

When these reports started rolling in, researchers began experimenting on apple orchards, and so far have some conflicting data. One experiment in Washington found mite populations reduced when seaweed extracts were applied to the apples. However, in Vermont, another team found no difference in mite population but did report a reduction of maggots.

While the research remains inconclusive, many garden enthusiasts swear by it. Some claim that the timing of application is important, depending on where you are geographically and the type of pests you encounter.

Liquid seaweed is a common store item that can be used as fertilizer and pest control.

Further research into the mechanisms of these deterrents is needed. If conclusive, seaweeds could be an excellent organic pesticide for home or industrial use.

New review published on bioactive metabolites within seaweeds

A new review of bioactive metabolites in seaweeds was just published in Aquaculture. The review focused on carotenoids, polyunsaturated fatty acids, phycocolloids and sterols along with their chemical ecology.

Seaweeds are commonly harvested and consumed because of their high vitamin and antioxident content. However, secondary metabolites are widely used in the pharmaceutical and commercial sector for the production of algae derived phycocolloids like carrageenan, algin, steroids, lectins, agar, and carotenoids.

The review concluded that “seaweeds have a wide range of bioactive secondary metabolites which exhibits different pharmacological activity like anticancer, an-tifungal, anti-inflammatory, and antioxidant activity. The secondary metabolites obtained from the seaweeds are also widely used as healthier food ingredients in the manufacture of nutraceuticals throughout the world. The presence of diverse pharma-cologically effectual bioactive metabolites in the natural seaweeds makes it unique and indispensable in the identification of lead molecule for the new drug discovery.”

Pseudoscience in food health is extremely prevalent on the internet and social media. Rigorous studies and reviews on bioactives like these can help consumers separate true from perceived health benefits of their food.

New study examines the lipid profile of the sugar kelp (Saccharina latissima)

A recent study titled ”Polar lipid profile of Saccharina latissima, a functional food from the sea” was just published in the journal, Algal Research.

Saccharina latissima is a brown alga (kelp). It is known by the common name sugar kelp, and also sea belt or Devil's apron, due to its shape. Sugar kelp grows relatively fast and large (about 5 meters, or 16 feet long), and its ability to be grown on a long line also makes it an appealing species for near shore cultivation. Indeed sugar kelp farms have been on the rise within the USA.

The researchers examined all the lipids within sugar kelp important for either nutrition or other commercial use. They reported high levels of PUFAs (polyunsaturated fatty acids), such as the highly prized omega-3s, EPA and DHA that are typically sourced from fish oils. Western diets present high levels of omega-6 PUFAs, with a nutritional ratio omega-6/omega-3 greater than 2, which has been associated with increased risk of mortality due to cancer, cardiovascular, inflammatory and autoimmune diseases. However, marine macroalgae, such as S. latissima, present a much higher prevalence of omega-3 PUFAs than land vegetables. A diet rich in omega-3 PUFAs can reduce Omega-6/Omega-3 ratio, being nutritionally more healthful and contributing to the prevention of chronic diseases

Scientists sequence the genome of popular Japanese seaweed (Cladosiphon okamuranus) in preparation for climate change

Each year, thousands of tons of seaweed is harvested along the coast of Okinawa, Japan. However, scientists are warning that anthropogenic climate change will lower the annual yield and create a demand for new farming methods.

Researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) have sequenced the genome a popular brown seaweed, mozuku (Cladosiphon okamuranus). As pollution and rising temperatures changes the ocean, this data may provide critical information for local seaweed farmers.

“My future plan is to establish new methods for cultivation of this species,” said Dr. Nishitsuji. “Using those markers, we can do cross-breeding. This is a popular method for making new varieties of land plants, especially wheat and potatoes, but in the case of seaweed, no one has succeeded in cross-breeding.”

As the ocean changes, seaweed farmers will need these genetic tools to enhance breeding programs.

The study can be viewed here at Scientific Reports

Using macroalgae as an indicator of ocean conditions through time.

Researchers in Japan recently published a study in the Journal of Oceanography on using position-dependent radiocarbon as an indicator of oceanographic conditions during algal growth.

The macroalga Undaria pinnatifida grows in a predictable way, older growth at the top and the new growth is at the bottom (image below)

undaria_growth.jpg

The researchers hypothesized that the age of the Undaria tissue would correlate with ocean conditions through time. Inorganic carbon ∆14C was tracked in tissues and ambient water through time. The study concluded that inorganic carbon in the Undaria tissues did correlate with oceanic samples through time.

They concluded that this technique “provides a new tool to better understand the role of oceanographic conditions in sustaining coastal ecosystem productivity.”

It will be interesting to see this new approach applied to other species, such as Pterygophora californica, which can live upwards of 15 years.

Flexible Conductors from Brown Algae for Green Electronics

Researchers recently published about novel conductors in Advanced Sustainable Systems. What makes these conductors so novel is they are made from brown algae or kelps.

Alginate from brown seaweeds are are used to make a flexible sodium alginate film. Ultrathin gold layers are then added to the alginate film. The resulting foils are thin, easy to handle, and shape, while showing good conductive properties.

The researchers believe this novel use of sodium alginate conductors is a “very promising candidate to be employed in green electronics, thanks to the reduced energy consumption required for their fabrication, the absence of toxic components or chemicals that are derived from oil, and the possibility to disassemble the devices at the end of their life in environmentally friendly conditions.”

The research can be viewed here

Carrageenan extracted from red seaweeds could be used as an antifungal

A recent study, published in the Journal of Applied Phycology, assessed if carrageenan could be used as an antifungal.

Carrageenan is a sugar extracted from some red seaweeds that is commonly used in a variety of food products as a thickening agent. A previous post went into great detail about carrageenan traits, uses, and impact on human health.

The recent study examined kappa/iota carrageenan belonging to the gametophyte phase and a hybrid xi/theta carrageenan in the tetrasporophyte phase of Chondracanthus teedei  applied to a few species in the genus Alternaria. Alternaria species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma.

Carrageenan induced the formation of swollen hyphal segments upon exposure to as little as 125 and 60 μg mL−1. These results are similar as to those induced by antifungals targeting the fungal cell wall.

The researchers concluded that carrageenan from Chondracanthus teedei  causes physical alterations of the cell wall in Alternaria sp. indicating antifungal activity.

New report: "Development of Offshore Seaweed Cultivation: food safety, cultivation, ecology and economy"

Offshore of northern Europe, a seaweed farm known as NSF (North Sea Farm). NSF was established in 2014 and is committed to developing a strong and healthy seaweed supply chain, in and from the Netherlands. This farm has been studied in a number of ways to assess ecological and economical impacts.

A recent report was just released evaluating economics, food safety, and ecological impacts of offshore seaweed farming.

Studies like these are extremely valuable to validate ecosystem services provided by seaweed farming, and should be conducted in numerous locations around the USA to be ecosystem specific.

General conclusions from the report below

  • high variability in chemical and contaminant composition of kelps, with only one month between sampling moments, was observed. This demonstrates the potential to harvest at the right moment, to provide the processing industry with desired products. However, it simultaneously shows the challenge to provide products with stable biochemical composition.

  • economic analysis indicates that relatively low-value markets such as the alginates are within reach for seaweed production in the North Sea, though for the near future a mix of medium- and low-value markets needs to be targeted

  • seaweed cultivation can have significant effect on the surrounding ecosystem, including biodiversity enhancement. But site specific information is required for the North Sea to evaluate how this activity relates to for example requirements by marine framework directives, and if farm management can further stimulate the ecosystem services provided by seaweed cultivation (through timing of harvest and/or technical adaptations to become more nature inclusive).

Seaweed Farmers in Japan are Creating new Varieties to Deal with Climate Change.

Undaria pinnatifida  (wakame) is a seaweed extensively cultivated, and is one of the most valuable edible seaweeds in Japan, Korea, and China. The cultivation season usually starts from autumn and runs through to spring, where the seaweed is grown on long lines suspended in the ocean.

However, the cultivation period has been delayed due to rising temperatures caused by global climate change. This prompted many germlings (juvenile sporophytes) of U. pinnatifida to fall from the strings during nursery cultivation. In response, seaweed farmers are creating new verities of seaweed, similarly to how a traditional land based farmer would cross pollinate varieties of fruits and vegetables. (For more information on the process read this article)

In a recent paper, researches crossed two varieties of U. pinnatifida to create a heat tolerant variety called NW-1. They then grew NW-1 along side with the standard variety HGU-1. The result was more juveniles remained attached to the long line and had more growth/ individual.

As oceans continue to heat, seaweed breading programs could help seaweed biomass and biodiversity loss due to climate change.

Brown Seaweeds Could be Used to Make Bioethanol

Bioethanol fuel is mainly produced by the sugar fermentation process, although it can also be manufactured by the chemical process of reacting ethylene with steam. The main sources of sugar required to produce ethanol come from fuel or energy crops. These crops are grown specifically for energy use and include corn, maize and wheat crops, waste straw, willow and popular trees, sawdust, reed canary grass, cord grasses, jerusalem artichoke, myscanthus and sorghum plants.

Recent research has turned to macroalgae as a potential source of sugars. The most abundant sugars in brown algae are alginate, mannitol, and glucan; whereby the degradation of these polysaccharides requires specific enzymes for the release of monosaccharides. Monosaccharides are most efficiently fermented into ethanol by Saccharomyces cerevisiae and Escherichia coli strains of bacteria.

Using brown seaweeds as a source of bioethanol could reduce pressure on food crops, and help draw down CO2 from the oceans. While biofuels still release CO2, they reduce the demand for finite fuel resources.

Here is a link to a chapter in Advances in Feedstock Conversion Technologies for Alternative Fuels and Bioproducts that outlines the process.

100 year old maps help create historic digital kelp distribution

There are concerns that the global distribution of kelp is dwindling due to climate change, pollution, or over grazing. However, incomplete records of kelp distribution and density make it hard to evaluate the actual kelp loss.

University of Victoria geography Prof. Maycira Costa was introduced to a collection of historical British nautical charts. Dr. Costa quickly realized that kelp distribution was noted on some of these charts.

Using those British admiralty charts from 1858 to 1956, Costa and her research team have now created the first historical digital map of B.C.'s coastal kelp forests. Now they will be able to compare the historical maps with the satellite images from 2002 until 2017 to better understand how much kelp has been lost.

Read the full article here

κ-Carrageenan Hydrogel as a Coating Material for Fertilizers

A recent study published in the Journal of Polymers and the Environment evaluated using k-Carrageenan as a coating for fertilizer granules.

The study focused on addressing one of the biggest problems facing the worlds waterways: nutrification from agriculture runoff. Carrageenan, which is natural sugar from some red seaweeds, was tested as a time release coating for NPK (Nitrogen, Phosphorus, and Potassium) fertilizer grains.

The results showed a 12-18% reduction in NPK loss to water washing without negatively effecting plant growth. The researchers argue this to be viable way to reduce amount of fertilizer applied to cops and the amount of nutrients washed into surrounding environments.

The Study can be viewed here

Umami- What it is and how you get it from seaweed

You may have come across the word umami, it’s commonplace in Japanese restaurants and on packaged foods such as ramen or seaweed. Umami can be described as a pleasant "brothy" or "meaty" taste with a long-lasting, mouthwatering and coating sensation over the tongue.

Umami, is a loan word from the Japanese  (うま味), umami can be translated as "pleasant savory taste." The word was first proposed in 1908 by Kikunae Ikeda. It wasn’t until 1985 the term was recognized as a scientific term to describe the taste of glutamates and nucleotides at the first Umami International Symposium in Hawaii. This symposium is still active today.

The English synonym would be Savory

Seaweeds are known to produce Umami flavor and are commonly used to make broths. A recent article published in the Journal of Food Measurement and Characterization outlined ideal flavor extraction process for Laminaria japonica, and showed all the flavor components. Below is a breakdown of the chemical constituents of the Umami taste in Laminaria japonica.

“Electronic tongue and electronic nose were used to assess the taste and flavor of the hydrolysate, respectively. Hexanal (43.31 ± 0.57%), (E)-2-octenal (10.42 ± 0.34%), nonanal (6.91 ± 0.65%), pentanal (6.41 ± 0.97%), heptanal (4.64 ± 0.26) and 4-ethylcyclohexanol (4.52 ± 0.21%) were the most abundant flavor compounds in the enzymatic hydrolysate with % peak areas in GC–MS. The contents of aspartic acid (11.27 ± 1.12%) and glutamic acid (13.79 ± 0.21%) were higher than other free amino acids in the enzymatic hydrolysate. Electronic tongue revealed a taste profile characterized by high scores on umami and saltiness .”

The shellfish industry needs a kelping hand in fighting ocean acidification

Ocean acidification is a daunting problem for shellfish farmers. It turns out that when the water becomes more acidic, the organisms aren’t so good at building their shells or reproducing. Oyster farms off the coast of Washington have already started to see the detrimental effects of increasing acidity.

In response, Paul G. Allen awarded $1.5 million to the Puget Sound Restoration Fund to investigate how kelp could help. Kelp and other seaweeds are able to take up CO2 out of the water, and therefore would make a micro climate of less acidic water. The research being led by Dr. Jonathan Davis , is specifically aimed at how kelps could be used around shellfish farms to create a acid buffer.

Davis is so optimistic, he has already began researching how the seaweed can be used as an additional commercial product for shellfish farmers. He is actively exploring kelp uses from food to fuel.

This multi-culture approach is really good idea. First off, these seaweeds would contribute to carbon drawdown, aiding in the removal of CO2 in the oceans. Additional benefits are protecting a farmers shellfish product while also adding a new revenue stream by selling seaweed products.

You can read more about the project here

You can read an article about Dr. Davis here

Extracting proteins from seaweed just got a little easier.

If you were to talk into your local GNC vitamin shop, you would quickly realize that there is a wide range of options for protein supplementation. Depending on your price range, dietary restrictions, and ethics, you can choose from a variety of protein sources: milk, soy, pea, egg, hemp, rice, and other plants.

Why don’t we see seaweed protein? Seaweeds are fast growing, rich in protein, and are highly sustainable. A recent publication in the Journal of Applied Phycology suggests that their complex polysaccharide matrix hinders protein extraction. Reported conventional methods for seaweed protein extraction include aqueous, acidic and alkaline methods where extraction yield varies from 24 to 59%. The study focused on using enzymes to enhance the extraction process and was able to extract 74% of the proteins from giant kelp (M. pyrifera)

These results establish a firm basis for further studies on seaweed protein extracts as potential functional ingredients, or towards the production of bioactive peptides through a straightforward, and environmentally sustainable methodology.

Shrimp farming is getting a boost from incorporating seaweeds

Aquaculture is beginning to shift from mono-culture to integrated multi-trophic aquaculture (IMTA). While IMTA is still relativity a new idea in the industry, nature has been doing it all along and new studies keep illustrating the benefits.

A study just came out this month (Jan 2019) that looked into adding seaweed to shrimp farms. The study added three seaweeds: Gracilaria vermiculophylla, Ulva lactuca,  and Dictyota dichotoma to ponds growing white legged shrimp Litopenaeus vannamei. Then shrimp were infected with V. parahaemolyticus and WSSV to assess disease resistance and response.

The use of macroalgae in co-culture with L. vannamei provided a nutritional benefit that achieved higher growth than the control organisms, as well as improvements of the ammonium concentration and immune response after infection with V. parahaemolyticus and WSSV.

The study concluded that these additional benefits were diet related, however, live seaweeds would change the water properties and testing water quality would be an interesting next step.

This is a good example how a company could change from one product to two while enhancing yield and quality of the original product with very little additional cost.

This research was published in the Journal of Fish & Shellfish Immunology