Science

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

How ocean acidification could restructure natural seaweed communities

Sean Connell, of the Environment Institute at the University of Adelaide, recently conducted a study on the effects of ocean acidification (OA) on seaweed communities.

The study was completed in New Zealand’s Bay of Plenty where volcanic vents raise CO2 and increase the water acidity. What the researchers found was that kelp domination was replaced by fast growing turf species. Not only did the volcanic vents increase the growth of turf species, but also inhibited the production of a primary grazer (urchins). These coupled effects allowed turf species to become the dominant in simulated future ocean conditions.

The upper graph showing the control plot where kelp becomes the dominant. The lower graph shows plots with elevated CO2 that become turf dominated.

The upper graph showing the control plot where kelp becomes the dominant. The lower graph shows plots with elevated CO2 that become turf dominated.

Predictive studies are full of ambiguity, and fail to address longer term trends such as geographical shifts and adaptions, however, knowing these case studies allows us to be mindful of what we might expect along our own coast.

This study was published in Ecology and can be viewed here

Sodium alginate and human stem cells used to 3D-print tissues

Researchers at Penn State University found sodium alginate from seaweed can be used to “print” human tissues. Alginate mixed with human stem cells can be 3D-printed into tiny particles that create breathable tissues.

Currently the technology is limited to small strands, however, the researchers are confidant they will be able to create larger tissue patches in the future. The researchers believe these tissues could be used for bone and cartilage surgery , such as knee restoration, cartilage defects, and osteoarthritis.

Read the article here

New study uses matrix approach to evaluate ecosystem services by seaweeds

A new study recently came out from the Department of Conservation, Wellington, New Zealand, that uses a matrix approach to evaluate ecosystem services provided by a number of marine species.

The list of species evaluated included seaweeds, crustaceans, worms, and more. The services provided were broken into three main categories: habitat & supporting services , regulating services, and provisioning services.

While this study was New Zealand focused, it serves as a good reference of positive impacts by a species. Furthermore, a number of the study species are currently farmed and this study could be useful in aquaculture spatial planning.

The paper can be viewed here

Carrageenan and silver to combat drug resistant bacteria

Carrageenan is a sugar within some red seaweeds that gets a lot of attention in relation to human health and food additives. We covered this topic thoroughly here.

Lately carrageenan has been making headlines as a sustained release matrix for health applications. Researchers at Indian Institute of Technology, Roorkee (IIT-Roorkee), found that they could stabilize and extend the short shelf life of silver nanoparticles by adding a carrageenan matrix. The nano composite was able to kill both Gram-positive and Gram-negative bacteria, and had a shelf life of 6 months. The researchers believe this technology will be useful for wound dressing, food packing, and plan to investigate the possibilities as an anti-fungal and anti-viral agent as well.

The published research can be found here

Read more about the project from the Tech Explorist here

Climate change is raising iodine levels in seaweed. Cause for alarm? We think not.

A recent publication in Global Change Biology, reported that changing atmospheric and oceanic conditions, due to climate change, are raising the levels of iodine in seaweeds that can transfer up the food web. We think this is a great paper, and we strongly believe that many aspects of the ocean should be analysed to model future ocean conditions. Most work on algae in respects to climate change have been limited to calcifying reds, and the coral symbiot zooxanthellae. Seaweeds are the second largest biomass harvested from the oceans and more research is needed for that market.

A few news articles ran with the idea that seaweeds are becoming toxic, and are making headlines. While humans need iodine, too much can cause some of the same symptoms as iodine deficiency, including goiter (an enlarged thyroid gland) (NIH). However, we suggest caution when saying all seaweeds will become toxic.

For instance in the paper the study species Saccharina japonica was used, which is a species that is known to already have high concentrations of iodine. Saccharina and other species of brown seaweeds (kelp/ kombu) have much higher concentrations of iodine than other species (see figure below). Most consumed seaweeds (dulse, nori, wakame) have iodine levels 5x lower than Saccharina, and even with increases from climate change would not be considered dangerous.

People around the world choose to eat seaweeds because it’s rich in minerals including iodine, and we suspect this fact will not change. We encourage people to pay attention to the nutrition labeling on seaweed foods and monitor how much they consume. When reading papers or nutrition labels, note the seaweed condition (Dry vs. fresh). Most weight in seaweeds is attributed to water, and a serving size between dry and fresh can be a large difference. We also want to emphasize that iodine is not accumulated in your tissues, such as heavy metals.

We hope good studies like this continue, but use caution when reading news that oversimplifies the results.

Image from American Thyroid Association 2004.  Full article here

Image from American Thyroid Association 2004. Full article here

Seaweed common names: Kombu

There are many names for commonly consumed seaweeds. However, the species they refer to vary by region and culture. We will cover some of the most commonly used names for seaweeds, and review the differences between connotation and denotation. This series will review some of the most common common-names in use.

Previous posts include: Nori, Wakame, Laver


Kombu is a common name for seaweeds that typically belong to the group of brown seaweeds: Laminariaceae. Kombu is traditionally used for soup stocks, salads, and even fertilizer. Brown seaweeds are high in minerals and by adding them dishes one can improve the nutritional value of their food.

The word kombu is Japanese, but it’s thought to be borrowed from the Chinese. In old Japanese the word for seaweed was “me” as in “waka-me”. The predominant theory, is that kombu is derived from the Chinese word 昆布 kūnbù, which is traced back to the 3rd century in China. However, records from the 8th century are spotty at best in their descriptions of kūnbù, and it is impossible to know what species of seaweeds they were referring to.

Nowadays there are modifiers to separate the different species of kombu. (Borrowed from Wikipedia).

However, in other parts of the world the term kombu is used to describe other species of brown algae such as Saccharina or Laminaria. For example, the company Salt Point Seaweed calls Laminaria setchellii, California kombu.

Closing the nutrient loop with seaweed farming.

As discussed in the last post, agriculture runoff is a huge problem. Nutrients are running off the land and into our oceans.Today in a recent article from Scientific America, the idea was batted around to take up ocean nutrients with kelp then turn it into fertilizers. These fertilizers could then be used again on land to replenish the nutrients lost. Not only would this help close the nutrient loop, but also take excess carbon out of the oceans.

This is just another example how seaweeds can help reverse negative anthropogenic impacts to our oceans.

Seaweeds can facilitate symbiotic microbes in agriculture

Modern agriculture is a marvel of the 21st century. Crop production has surpassed our expectations, many times over, in the last 100 years. However, this production has come with a cost. What is now being called our nitrogen addiction, refers to the amount of fertilizers used on farmland. The traditional soaking of soil is inefficient and leads to runoff: where nutrients are leaked into other surrounding ecosystems or the waterways.

Doesn’t sound so bad, what the problem with extra nutrients in the water? Well, the added nutrients cause boom bust cycles of other plants and algae that can tip the balance of an ecosystem. Currently there are numerous microalgae blooms off the coast of the USA, all are said to be a factor of agriculture runoff. This has caused an outcry for more responsible farming practices in reducing their nutrient loading.

One group in the UK has started using algae extracts and microbes to help crop efficiency. They claim that the seaweed extract facilitates microbes that help crops take up more water and nutrients, and therefore can reduce the amount of farm input by 20%. By reducing the amount of water and fertilizer used, the runoff will be far less than without the seaweed’s help. This could end up being a key strategy for responsible farming practices.

Moss Landing Marine Labs gets funding to study macroalgae in livestock feed

As previously discussed on this blog back on October 22nd, we mentioned researchers at UC Davis discovered that methane from cows can be dramatically reduced by including some red algae in their diets.

It was just announced Friday (Oct. 26th, 2018) that Moss Landing Marine Labs was awarded Seagrant funding to investigate and culture other methane reducing alga species. This funding was a part of the $6 million invested in ocean research projects by the Ocean Protection Council.

Dr. Graham of Monterey Bay Seaweeds will be joining the research team and sharing his expertise on land based algal culturing.

Eating brown seaweed can aid in weight loss

Jamie Oliver is a well known chef in the UK who is a strong advocate for cooking with seaweeds. Recently an article in Magenta reported that Jamie owed his own weight loss to eating more seaweed.

The science of which goes back to a study published in the journal of Food Chemistry (2014). The study found that alginate, a sugar derived from brown seaweeds, inhibited pancreatic lipase by a maximum of 72.2% (±4.1) with synthetic substrate (DGGR) and 58.0% (±9.7) with natural substrate. Concluding that eating brown seaweeds could potentially reduce the uptake of dietary triacylglycerol aiding in weight management.

Weight loss is just one more reason why more chefs are starting to use seaweeds in their dishes. Jamie lists a few seaweed incorporated recipes on his website that are free to use.

Below is a video featuring Jamie on the Daily Mail explaining why he believes seaweeds are such a good superfood.

Seaweed and cow gas

Cows have gotten a lot of attention lately as they were found to be one of the largest producers of methane in the USA. Methane is a greenhouse gas that is 23 times more powerful than CO2 in it’s ability to heat the atmosphere, and the entire population of cows contributes just as much as cars to climate change. Cows digest their food by fermentation in their gut. Fermentation leads to gasses, which are then mostly belched out of the cow’s mouth.

This has lead many animal nutritionists to investigate alternative feed ingredients that could mitigate the amount of methane produced by cows. Researchers from the University of California, Davis, found that methane emissions were reduced by 24 to 58 percent in cows that ate a type of red seaweed.

While this tech is very promising, the bottleneck is currently the lack of red algae production. Land based aquaculture is costly, while offshore aquaculture comes with more regulatory hurdles. To have seaweed integrated into feeds, massive large scale aquafarming needs to become a reality.

Concerned about plastic pollution? Seaweed can help.

Plastics are everywhere. If you take a minute to look around your house, it’s really quite astonishing how much of it we use. It’s no wonder why plastics became so ubiquitous: it’s a cheap, flexible, and durable material. The issue is that these durable materials have been commonly used for single-use disposable items such as eating utensils, bags, containers, straws, packaging, bottles, the list goes on and on.

These single use items typically end up in the trash and can take up to 6 generations to breakdown. Plastics in the ocean have been accumulating at a far faster pace than their ability to break down. Some studies suggest at this rate there will be more plastic than fish in the oceans by 2050. To make matters worse, as plastics break down they create smaller and smaller plastic particles, commonly referred to as micro-plastics. Micro-plastics have made headlines in the last decade as, to our horror, we have discovered that we consume them constantly. Micro-plastics have been found in seafood, beer, salt, chicken, and water.

In response some cities have banned some plastic items, most notably bags and straws. However, this is a drop in the bucket and banning plastics entirely would be a political and economical nightmare. Luckily, seaweed is here to the rescue. A few clever groups have found ways to replace single use plastics by using seaweed extracts. So far we have seen seaweed replace packaging, straws, bottles, and even surf boards. These items are not only biodegradable, but generated from a sustainable resource. Look for more and more of these items to pop up in the near future.

What the heck is seaweed anyway?

Sometimes we take our phycological education for granted and forget that algal terminology can be a bit confusing. Let’s review some basic concepts to ensure that we are all on the same page when thinking about seaweed.

Alga = singular

Algae = plural

Algaes = not a real word

Microalgae = single cell algae species

Macroalgae = multi-cellular algae species = seaweed

3 branches of algae = red (Rhodophyta), green (Chlorophyta), brown (Ochrophyta)

Kelp = a branch of brown seaweeds (Laminariales)

Plant = Photosynthetic thing on land

A very brief overview of the evolution of photosynthetic organisms.

In the beginning there was a bacterium that learned a neat trick. This bacterium contained pigments that allowed it to capture sunlight and convert it into energy via photosynthesis. The bacterium was engulfed and incorporated by another single celled organism (a eukaryote), this event is called primary endosymbiosis. Its a partnership between the two cells (bacterium and eukaryote) similar to the photosynthetic algae that like inside corals. Through this process red, and then later green, algae came into existence. After this primary endosymbiotic union, secondary and even tertiary endosymbioses occurred - algal cells themselves getting engulfed and incorporated to give rise to other algal groups including macroalgae, browns, and terrestrial plants. If you want to dive into the specifics of how scientists discovered this, here is a good paper outlining how the genetic code of algae lead to the discovery.

pic.plastid.evol.scheme.jpg

It may seem a little complicated, and in fact it is, its very complicated. But it is super cool and for this reason we don’t like algae being called plants; it’s like calling “fish” … “humans.” On a more humorous note, we do encourage people to call plants, “land-adapted algae”. Again, check out algaebase.org to review all of this and see where your favorite seaweed fits in.

Could you survive by only eating seaweed?

If you look at the nutrient label on the packaging of any food item, you would see the groups: calories, protein, carbohydrates, fat, sodium, and occasionally other items such as minerals. We are all familiar with calories being the amount of energy within the food. “Calorie counting” is a common practice for people looking to watch their weight, as consuming calories faster than you can metabolize them can lead to weight gain. However, without calories your body wouldn’t have energy to survive.

Calories in your diet come from fat, proteins, organic acids, and especially carbohydrates. Carbohydrate is an umbrella term for all types of sugar, starch, cellulose, and even dietary fiber. The sugars in most algae though, are not digestible by most humans. The sugars in most algae are known to be β(1→4) linkages in glucan polysaccharides. Most of the human population lacks the ability to digest these types of sugars as we are adapted to eat alpha(1→4) linkages in glucan polysaccharides (i.e. sucrose), and therefore, we don’t get the energy associated with these calories from most seaweed sugars.

There is one human population in Japan, however, that can digest these sugars. Apparently these Japanese have become hosts to common gut bacterium (Bacteroides plebeius) that exhibits polysaccharide-degrading enzymes. This is likely due to many generations of seaweed consumption and adaptation.

Just for fun, let’s see how much seaweed you would need to consume to get enough energy to survive. Assuming you are not Japanese, the only calories will be protein derived. The average person needs 2000 calories a day to maintain. You get about 4 calories per gram of protein. Now let’s use dulse as our reference seaweed. Dulse has 3.5% protein content. That means you would need to eat at least 31.49 pounds of dulse to satisfy your caloric needs. Now this is only in reference to calories, almost no single food item has all the nutrients the body needs for survival, so please don’t try this diet at home.