Uses of Phaeophyceae Flashcards
What is the scientific name of Kombu and where is it commonly found?
- Saccharina japonica syn. Laminaria japonica;
- it is commonly found in the intertidal-subtidal belt of temperate-cold waters, primarily in Korea and Japan areas.
What are the characteristics of Saccharina japonica (Kombu)?
- Large brown blades (fronds up to 2-5 m in length)
- Found in the intertidal-subtidal belt, up to 10-15 m of depth
- Intolerant of temperatures above 23°C
- Native to areas around Korea and Japan
How did L. japonica end up in China?
In 1927 L. japonica was accidentally introduced into China from Japan (by navigation) and naturalized on the shores of the Yellow Sea
What happened in 1951?
A cultivation program of L. japonica started in China:
- Cultivation techniques were experimented to reduce its life cycle from 2 years to 1 year
- Lines with more expanded surfaces and higher iodine content were selected
What are the current uses of L. japonica in China, and what challenges does its cultivation face?
Current uses in China:
- 50% as food
- 50% as a source of Alginates, Mannitol, Iodine
Challenges in cultivation:
Grazers (gastropod snails, amphipods) and diseases (some fungi) can cause significant harm to cultivated kelps, with biomass lowering by up to 85%.
What do the highlighted countries have in common in relation to S. japonica?
Main producer countries of Saccharina japonica
What do we see in the graph?
Global aquaculture production of S. japonica from 1959 to 2016
How long is the life cycle of S. japonica?
24 months
What is the first phase in the life cycle and when does it occur?
It starts in late autumn and lasts for 24 hours.
Events in this phase:
- Production and release of meiospores by sporophyte
- Meiospores settle down on the substrate
- Male and female gametophyte development
What is the second phase of the life cycle?
Takes place from December - February and lasts 2 months.
Events in this phase:
- Release of gametes - Fusion of gametes and growth of small sporophytes (~6mm)
What is the third phase of the life cycle?
This phase lasts for 20 months
Events in this phase:
- Development and maturation of sporophyte
What happens in the first and second year of the life cycle?
- 1st year: growth of the vegetative thallus
- 2nd year: growth of the thallus and production of sporangial sori
After the release of meiospores the old blade dies
How does the plant know when to switch from the 1st year to the 2nd year in the life cycle?
In the autumn – winter between 1st and 2nd year the seaweed perceives the “cold signal” ( = signal of transfer from 1st to 2nd year) and moves on to reproductive phase
How did researchers in China reduce the cultivation period of S. japonica to 11 months?
Through a technique called: forced cultivation
What are the 4 phases of this forced cultivation?
- Collection and settlement of zoospores on seed substrates
- Production of seedlings
- Growing of seedlings and transplantation
- Harvesting
What is the key to the rearing system (kweek systeem) of kelps?
Seedling production
How are seedlings produced in China during the summer?
Seedlings are produced in greenhouses during summer in China by controlling the water temperature and light.
How many seedlings can seedling production facilities in China produce yearly?
800 million seedlings
Where do the collected zoospores settle, and what occurs there?
The collected zoospores settle on substrates arranged in greenhouses (hatcheries), where the production of gametophytes occurs.
What steps are involved in breeding kelp gametophytes in greenhouses?
Breeding involves:
- Control of light intensity and photoperiod adjustment using black and white roof-curtains
- Control of seawater temperature adjusted by coolers
- Fertilization with chemicals, typically nitrate and phosphate
During which months are all steps of kelp breeding typically carried out in greenhouses?
All steps of kelp breeding are typically carried out in greenhouses from July to the end of October.
What happens when the seawater temperature in the greenhouse declines to 20°C?
When the seawater temperature in the greenhouse declines to 20°C, the young seedlings, attached to substrates, are moved to nursing sites for further rearing into large seedlings before transplantation into the sea.
Overview of cultivation phases
3 methods of growing Japanese kelp in different countries
- Vertical culture method
- Horizontal culture method
- Mixed culture method
Vertical culture method
Horizontal culture method
Mixed culture method
Cultivation process
What is presented in the pictures?
Top picture:
Harvesting of S. japonica from the ropes
Lower pictures:
Harvested mature thalli are sun-dried
What is the harvesting season dependent on?
The harvesting season depends on the seawater temperature.
When the seawater temperature reaches 21 °C, the kelp must be harvested; otherwise, it will rot, due to poor-tolerance to higher temperatures.
Why is S. japonica called the best “bioconcentrator” of iodine from the sea?
It can concentrate iodine up to values 100,000 times higher than those of sea water
Laminaria has been used for millennia in Eastern Asian medicine to heal…
- Hypothyroidism
- Glandular imbalances
- Obesity
- Arthritis
- Pulmonary and cardiovascular diseases
- Colitis
- Liver disease
It was recently found that Laminaria has antitumor and antiviral activity, including against the AIDS virus
How is Kombu harvested in Japan?
Kombu in Japan consists of different species of Laminaria collected in the field and harvested at the end of the 2nd year of growth by tearing them from the substrate.
What cultivation system was introduced in Japan in the 1970s?
Forced cultivation was introduced in Japan in the 1970s, with a system similar to the Chinese one.
What is the current production breakdown of Kombu in Japan?
Currently, the production of Kombu in Japan derives from:
Cultivated seaweeds (1/3)
Spontaneous seaweeds (2/3)
What are the main uses of Kombu in Japan?
Japan has sufficient production for its internal needs, mainly consisting of the use of Kombu as food.
How does the production of Kombu differ in Korea compared to Japan?
In Korea, the production of Kombu mainly derives from crops obtained through the Chinese system. The demand is scarce because Undaria (Wakame) is preferred.
Which region has recently emerged as a producer of Kombu?
Russia is a recent producer in its Far Eastern region. L. japonica is a major commercially important species in this area, ranking among the top culture organisms.
Distribution of the “forests” of Laminaria (Kelp)
Where do Laminaria species (Kelps) primarily grow?
Laminaria species (Kelps) grow on most of the rocky coasts of the Pacific and North Atlantic.
How have Laminaria species been historically used in Northern Europe?
They have been used for a very long time as food in the countries of Northern Europe, where they are harvested from the sea.
Which species of Laminaria is of the greatest interest?
The species of greatest interest is L. digitata (Atlantic Kelp).
Where does L. digitata primarily grow, and where is it abundant?
L. digitata grows along the coasts of the North Seas and the Atlantic Ocean and is abundant along the coasts of England.
What are the uses of L. digitata?
L. digitata is used:
- as food
- for the preparation of food supplements and pharmaceutical products
- for the extraction of phycolloids (alginates).
Laminaria digitata (Atlantic kelp)
Chemical composition of food supplements made with L. digitata
Dried thalli of L. digitata used as a food product
What is another name for Laminaria ochroleuca, and where is it used in the cosmetics industry?
Laminaria ochroleuca, also known as yellow algae, is used in the cosmetics industry by companies like Biotherm and L’Oréal group.
What is the peculiarity of Laminaria ochroleuca?
The peculiarity of Laminaria ochroleuca is its ability to contract and then relax within a few seconds to resist the destructive force of waves.
How did biologists extract an active ingredient from Laminaria ochroleuca, and what does it do?
By simulating the stress phase experienced by Laminaria ochroleuca, biologists extracted an active ingredient that appears to stimulate the production of collagen and protect the fibroblasts, which are the producers of collagen itself.
Where did biologists conduct their research on Laminaria ochroleuca?
Biologists conducted their research on Laminaria ochroleuca at the Roscoff Marine Biology Station in Brittany.
Undaria pinnatifida (Wakame)
- Brown seaweed up to 1-3 m in length
- It lives in the intertidal and subtidal belt (up to 15-20 m of depth) in temperate-cold waters (optimal temperature 5 -15° C)
Undaria pinnatifida (Wakame) is native to…
Japan.
But it has spread to regions all over the world, especially around New Zealand, Australia, and Europe.
Why is this seaweed opportunistic, colonizing and highly invasive?
Due to its high growth potential
How long has Undaria pinnatifida (Wakame) been used as food in Japan?
Undaria pinnatifida (Wakame) has been used as food in Japan for more than 700 years.
How was Undaria pinnatifida traditionally harvested in Japan?
Undaria pinnatifida was traditionally harvested by hand from natural habitats in Japan for centuries.
When did cultivation of Undaria pinnatifida begin in Japan, and why?
Cultivation of Undaria pinnatifida began in the early 1900s when the demand exceeded the quantity obtainable from the sea.
What is the current rank of Undaria pinnatifida in production and consumption in Japan?
- Undaria pinnatifida is currently the third alga in order of production and consumption in Japan, after Porphyra (Nori) and Laminaria (Kombu)
- With approximately 80,000 tons (wet) produced yearly.
Which country is the largest producer of Undaria pinnatifida, and what percentage of edible seaweeds does it represent?
Korea is the largest producer of Undaria pinnatifida, representing 50% of the edible seaweeds produced yearly by the country, with approximately 800,000 tons (wet) produced yearly.
What is the primary source of world production of Wakame?
Most of the world production of Wakame comes from cultivation, with only a small part deriving from sea harvesting.
Where is Undaria pinnatifida also cultivated besides Japan and Korea?
Undaria pinnatifida is also cultivated in France and along the coasts of Western Europe, known as Atlantic Wakame.
What concerns have been raised about the increase in Undaria pinnatifida cultivation?
Ecologists are concerned about the possible “escape” of Undaria pinnatifida from cultivation areas, leading to competition with native kelp populations and ecosystem alteration.
Annual life cycle of Undaria pinnatifida
Production cycle of Undaria pinnatifida
Which 2 algae species are in the picture?
Long one on the right: Laminaria japonica
Short one on the left: Undaria pinnatifida
Chemical composition of Undaria pinnatifida
Composition of Undaria pinnatifida (in wet weight)
Other than food, in what way is Undaria pinnatifida very useful?
Undaria pinnatifida is considered the most useful alga for improving the condition of the skin, nails and hair
It is used as a remedy against…
- hair loss
- weak nails
- Acne
- Psoriasis
- Gastritis
- Ulcer
- Hypothyroidism
- Liver disease
- Hypercholesterolemia
- Hypertension
- Cardiovascular diseases
Alaria esculenta
- Large brown alga known as “Winged Kelp”
- It has a wide distribution in cold waters (<16 ° C) of the sub-littoral zone
- Present in:
»_space; Ireland – Iceland – Scotland – France-Norway
»_space; Russia
»_space; Canada (New Scotland)
»_space; North Japan (Hokkaido)
In which countries is Alaria esculenta used as food?
It is used ad food in Ireland – Scotland – Iceland
(Wild Atlantic Wakame)
Usually collected from the sea and eaten by local populations
Alaria esculenta contains a large amount of…
Proteins.
Alaria esculenta is, among the Kelps, the species containing the greatest amount of proteins
It is also very rich in minerals and vitamins, especially niacin (vitamin PP)
