Utilizing global seaweed resources, Zhongda Agritech (ZDC) contributes to shaping a highly-efficient and sustainable agriculture

As an important marine resource, seaweed and its extracts are widely used in a variety of industries, such as food, medicine, health products, farming and daily chemicals. The earliest application of seaweed in agricultural production in human history dates back to the first century AD. Since the 1950s in regions with rich seaweed resources, such as the UK, Norway and Canada near the Arctic Circle, southern Australia and countries on the west coast of South America, many enterprises have been processing and utilizing local seaweed. Therefore, the application of seaweed in agriculture has developed rapidly. Moving into the 21st century, products derived from seaweed have become an important agricultural input category.

Through synthesis and metabolism, seaweed organism can gather mineral nutrients, such as Ca, Fe, Mn and Zn; marine polysaccharides like alginate, carrageenan, agar, brown algae starch, fucoidan and xylan; chemical compounds such as sugar alcohols, amino acids, vitamins, cytochromes, betaine and phenols, and natural hormone substances such as auxin, cytokinin, gibberellin and abscisic acid. These active ingredients exist in seaweed naturally and evenly in good balance.

ZDC utilizes advanced technology jointly developed with universities to produce various extracted seaweed products, which offer high activity, a full range of nutrients, stable traits and good mixability. ZDC adds seaweed extract as a special adjuvant to pesticide formulations to enhance the efficacy of pesticides while reducing the stress caused by pesticide application on crops. The mixture of a seaweed extract with a high content chemical fertilizer can significantly improve fertilizer efficiency, therefore, reducing fertilizer usage and farmers’ labor and input costs.

The development and application of seaweed resources is ZDC’s real-world effort to implement its corporate philosophy ″to promote highly efficient agriculture and food safety around the world.″

Figure: An Example of Dry Kelp Analysis: Durvillaea Potatorum 

ZDC’s Global Selection of Optimal Seaweed Raw Materials

There is a large variety of seaweed in the world, which grow in different marine environments. Therefore, the active substances contained in different seaweed species can vary greatly in terms of composition, content and activity. ZDC has analyzed and compared major seaweed species used in agricultural production around the world and selected two kinds of brown algae, which are Ecklonia Maxima and Durvillaea Potatorum. ZDC has focused its research and development on these two seaweed species, which are used as the raw materials for ZDC’s innovative pesticide formulations, special fertilizers and seaweed extract series.

Nutritive Indicators of 5 Types of Typical Brown Seaweed

Raw Material No.1: Ecklonia Maxima

Ecklonia Maxima exists on the Atlantic coast of Africa from South Africa to Namibia. The body of Ecklonia Maxima is differentiated in a manner like stems and leaves, with stems being thick and tall like tree trunks with a strong reproductive ability and fast growth rate, forming a huge undersea forest nearshore. Ecklonia Maxima grows in harsh environments with low water temperatures, limited sunlight and large waves. It contains extremely high levels of betaine and endogenous hormones, with strong stress resistance. Authorized by the South African Ministry of Agriculture, the local community can lawfully harvest wild Ecklonia Maxima that wash up on the shore.

Signing of Seaweed Resource Cooperation Agreement in South Africa

Raw Material No.2: Durvillaea Potatorum

Durvillaea Potatorum is distributed along the cold coastal waters near Antarctica in the southern hemisphere, and has a large holdfast and contains plenty of biomass, growing in a dispersed manner. It is capable of growing rapidly via different parts of the thallus with continuous cell division, unlike other seaweeds that grow from top or bottom. 

Among species of brown seaweed, Durvillaea Potatorum has the highest concentration of sodium alginate, where its high content structural polysaccharide in the cell wall provides strength and tenacity. Durvillaea Potatorum has a strong reproductive ability and is capable of sexual reproduction through spores during cold winters, being able to release millions of gametes from a single plant, Durvillaea Potatorum has high hormone content in the plant body.

The centralized commercial harvesting of Durvillaea Potatorum takes place on the west coast of Tasmania, Australia, where the local government only licensing its collection if it is washed up on the shore.

Signing of Seaweed Resource Development Agreement in Australia

Extraction of Active Ingredients from Seaweed

The key step to the full utilization of active ingredients in seaweed is based on extracting active substances by breaking down their cell wall to cause the flow-out of substances, while degrading macromolecules into micromolecules with high solubility that can be absorbed and utilized by plants. Current seaweed extraction methods include physical, chemical, biological and combined methods.

Physical method

Physical method involves physical means, such as high-pressure homogenization, freeze-thaw crushing and ultrasound, to directly break down cell walls, therefore, causing the flow-out of substances. This method has high demand on equipment, with crushing efficiency being low and energy consumption being high. It is used less in mass production.

Chemical method

Chemical method involves crushes dried seaweed into granules, which is placed into water with an acid-based solution and then hydrolyzed. After hydrolysis, the solid residue is filtered through plate pressure filtration/centrifuge and the supernatant is extracted, which is the seaweed extract. This method is simple, with less demand on reaction materials, being easy to use for scale-up production. However, the high temperature, high pressure and high concentration of the acid-base environment required for the full reaction of seaweed cells could cause the inactivation of some active ingredients. Also, the molecular weight of the acid-hydrolyzed fragments is hard to be made even and uniform.

Chemical Sensitivity of Different Seaweed  Active Substances

Biological method

The surface layer of seaweed cell wall contains arrangements of cellulose and alginate as its main structure. The biological method uses enzymes or microorganisms to hydrolyze specific glycosidic bonds to break down the seaweed cell wall and release cellular contents at room temperature. This process does not involve excess acids or alkali and high temperature or high pressure. It can also maximize the preservation of biological actives and nutritional contents inside seaweed cells, which produces a fertilizing effect. 

However, the preparation of enzymes/microorganisms limits the biological method from being used on a mass production scale.

Different species of seaweed have different cell wall structures. Preparing the correct type of enzyme/microorganism is a critical factor to hydrolysis efficiency, due to their affinity to the cell wall surface. 

ZDC enzymatic hydrolysis process

Through research cooperation with the Ocean University of China, ZDC has separated and cultivated wild-type enzyme producing strains. ZDC’s research team identified and introduced enzyme-producing sequences into its engineering expression system for industrial fermentation. 

As a result, ZDC obtained the high-efficiency brown algae, alginate lyase CP-045.

By using alginate lyase CP-045, ZDC has upgraded the enzyme hydrolysis of Ecklonia Maxima and Durvillaea Potatorum on an industrial level.

ZDC purification process

ZDC conducts the fluidized nanofilm treatment of seaweed to extract mother liquor. This process filters solids and large molecule impurities, as well as salts that affect corps growth. It retains algal oligosaccharides (degree of polymerization of 2-5), soluble small peptides, amino acids and chelated nutrients. 

The enzymatic hydrolysate after treatment presents a true solution state, which has a clear and transparent appearance with good mixability, being highly compatible with pesticides or fertilizers.

The benefit of this purification process to the application of seaweed extracts is best reflected by the algal active substance, alginate.

Alginate is a natural polysaccharide that exist at high levels in the cell wall of brown algae. It is  a high molecular weight substance composed of guluronic acid (G) linked to beta 1,4 glycosidic bond, providing flexibility support for the cell wall of seaweeds.

In the soil, alginate, as a macromolecular carboxylic acid, can form alginate by chelating with different metals, where the salt formed with divalent metal after touching water can be gelated, which conserves soil and water, promotes the formation of a granular structure, activates mineral elements and regulates soil pH.

However, as a macromolecular polysaccharide, its relative molecular weight is above 10,000, which is hard for plants to absorb. ZDC uses modern technology to degrade alginate, which forms a micromolecular weight oligosaccharide with molecular weight of 2-5.

Brown algae oligosaccharides can directly act on plants to promote nutrient absorption, activate enzymes related to growth and development, facilitate chloroplast absorption and the conversion of light energy, to accelerate the process of carbon and nitrogen metabolism. In addition, it regulates the level and the balance of endogenous hormones to accelerate plant cell division and elongation, which can promote root growth and nutrient absorption, ultimately leading to yield increases and quality improvement.

Effect of Application of ZDC Seaweed Extracts

Video presentation of effect of ZDC kelp enzyme hydrolysate on root growth:

Effect of ZDC brown seaweed kelp oligosaccharide 15% solution on rice root growth

Effect of ZDC pesticide product: Dingcan (Trifloxystrobin + Tebuconazole 40% SC + kelp extract) applied to various crops:

For more information about ZDC and our products, please visit: www.zdcagri.com