Microalgae Overview Flashcards
Why algal biotechnology?
1. what is algal biotechnology contributing to?
2. what can it help solve?
3. what are the problems?
4. solutions?
5. Algal remediation?
- contributing to circular economy
- help to solve big issues
- problems: Linear Economy, freshwater shortage, climate change, ocean acidification, pollution, fertility decline, declining species diversity, energy supply deficit -> all lead to big problems
- solutions: circular economy, awareness, remediation, natural resources, bioprospecting, ecosystem recovery
- Algal remediation: wastewater treatment, re-use waste heat, fuel gas remediation (CO2, SOX, NOX), algal products, Nutra/Pharma -ceuticals, fertiliser, biostimulants, pesticides, good biofuels, bioplastics
what is Linear global economy?
where resources are wasted and used once -> leads to loss of resources and dumping of pollutants such as carbon dioxide in the atmosphere and sewage in waterways
-> e.g. pollution from agricultural runoff due to over application of fertilisers -> decline in habitat reduces ecosystem services which could deal with some of the pollutants -> solution is not easy but involves the concept of circular economy
every linear economy has an end-product which is dumped somewhere to detrimental effect
Carbon cycle awareness
how much gigatonnes of C accumulates annually?
4 gigatonnes of carbon (=35 of CO2) accumulates annually in the atmosphere
Linear economies
1. petroleum: fuels, plastics ->
- fishing industry: fish oil & meal ->
- fertilizer: Haber-Bosch, mining ->
- agriculture: livestock & rice, methane ->
- petroleum: fuels, plastics -> waste: CO2, plastics -> effect: climate change, pollution
- fishing industry: fish oil & meal -> aquaculture: fish feed (links to waste nutrients: denitrification, agricultural runoff) -> effect: fish & krill stock depletion
- fertilizer: Haber-Bosch, mining (link to agriculture: livestock & rice, methane) -> waste nutrients: denitrification, agricultural runoff -> effect: algal blooms, deoxygenation (can use algae to short circuit the linear economies: links to aquaculture: fish feed; agriculture: livestock & rice, methane; and circular economies)
- agriculture: livestock & rice, methane (link to waste nutrients: denitrification, agricultural runoff) -> effect: climate change
how can algae be used to combat problems with linear economies?
already growing tons of extra algae in wrong places by dumping nutrients from untreated sewage and surplus fertiliser that washes off fields and goes into water ways -> causes huge coastal algal blooms, eutrophication of lakes and deoxygenation in coastal zones
could take all those nutrients and grow the algae in the right place?
there is enough waste nutrients globally to grow tons of algae -> can make things from algae such as biodegradable bioplastics, aquafeeds, fish feeds, animal feeds and food for human consumption
this costs money so to combat high costs -> produce high value products from algae as well such as food supplements, pharmaceuticals etc
Circular economies
- algal solutions
- short circuit the linear economies using algae (effect: algal blooms, deoxygenation:
-> aquaculture: fish feed
-> agriculture: livestock & rice, methane
-> circular economies ) - feed supplements for aquaculture & agriculture
- food, industrial feed stocks
- biofuels
- polymers, pigments, pharmaceuticals
- fertilizers
- Algae?
- cyanobacteria
- macroalgae
- microalgae
- algae refers to 3 different kinds of photosynthetic organisms - unicellular = cyanobacteria and eukaryotic microalgae; multicellular = macroalgae (multi-cellularity evolved many times)
2.cyanobacteria are prokaryotes - (a gram-negative phylum), and all the rest are a polyphyletic group (many different origins) of eukaryotes - aka photosynthetic protists, protists in turn are defined by exclusion: not animals or plants
- macroalgae (3 groups) - seaweeds (red, green & brown)
- microalgae (many different groups) - their huge diversity suggest many different natural products and uses; note that cyanobacteria are usually included in the term microalgae, sometimes not
The protists - Tree of Life
how has the tree changed and example?
moved a number of phyla around so that for example Archaeplastida has Chloroplastida (green algae + land plants), Rhodophyta (red algae), and Glaucophyta
Photosynthetic protists
1. what do brown algae belong to and what are they distantly related to?
2. what comprises the red seaweeds and unicellular red algae, such as Rhodella and Porphridium?
3. what do green seaweeds share a clade with?
4. what do primitive Glaucocystis still have?
5. what is Euglena believed to have captured?
6. what are the Haptophytes?
7. what are Diatoms?
8. what are Dinoflagellates?
- brown algae (e.g. kelp) belong to Phaeophyta + distantly related to microalgae (e.g. diatoms)
- Rhodophyta
- green seaweeds share clade with unicellular green algae found in freshwater and the marine environment such as this marine picoplankton Ostreococcus
- primitive Glaucocystis still has plastids that contain bacterial peptidoglycan
- Euglena is believed to have captured green algae for its plastid originally (kleptoplasty), as was the case of photosynthetic ciliates
- Haptophytes = major primary producers with calcium carbonate plates
- diatoms = major primary producers with Silica shells
- Dinoflagellates = major group which includes a lot of heterotrophs as well as primary producers
What else is a big source of genetic diversity in eukaryotic algae (not just their evolutionary diversity)?
process of endosymbiosis
what is the endosymbiosis process?
likely the main mechanism for what?
events were rare or common?
process of assimilating another organism and turning it into an organelle
likely main mechanism for acquiring new organelles, such as mitochondria and chloroplast, which were both originally gram-negative bacteria
these events were rare occurrences
what are the 3 algae lineages?
what occurred to create the first chloroplast?
- Glaucophytes, red and green algae
- there was only one original endosymbiotic event involving the capture of a cyanobacterium to create the first chloroplast
most of marine microalgae algae and brown seaweeds are what?
microalgae algae examples?
brown seaweeds are what?
all secondary endosymbiotic events where the chloroplast is really a red algal cell originally
diatoms, haptophytes, dinoflagellates and some of the picoplankton
macroalgae
what occurs everytime there is an endosymbiotic event?
there is an increase in genetic complexity because DNA from the endosymbiosed organism eventually makes its way into the genome of the host. This causes an increase in genetic diversity
Endosymbiosis
1. what is endosymbiosis?
- what occurred first?
- what did this give rise to?
- green algae…
- red algae…
- how are dinoflagellates characterised?
- what does each endosymbiotic event lead to?
- two organisms living together with one inside the other
- there was a single capture event of a photosynthetic GM-organism
- this gave rise to 3 algal lineages
- the green algae were captured a few times
- red algae were captured once but gave rise to many lineages
- dinoflagellates are characterized by further captures
- each endosymbiotic event leads to transfer of DNA from the captured organism to the nucleus of the host
Viruses
1. marine environment and viruses?
2. what do megaviruses contain?
3. what occurred with megaviruses during evolution?
4. what is this a mechanism for?
- marine environment is filled with viruses
- megaviruses contain whole biochemical pathways such as beta-oxidation which they use to adjust the energy metabolism of the host cell
- during evolution, megaviruses have transferred large amounts of DNA into the genomes of microalgae
- this is another mechanism for increasing the genetic diversity of microalgae and potentially the diversity of natural products
what can organisms such as ciliates survive by eating?
viruses (virivores)
What is algal biotechnology? - The biorefinery concept
inputs
- waste CO2
- Fuel gases
- nutrients (NPS)
- wastewater
- sewage treatment
- anaerobic digestate
- brewery wastes
- natural light
- LED light from cheap electricity
- Inorganic C
- low-value products to reduce costs
What is algal biotechnology? - The Biorefinery concept
Photobioreactor
- photosynthesis: autotrophic, heterotrophic, mixotrophic
What is algal biotechnology? - The Biorefinery concept
Outputs
High value
- pharmaceuticals
- cosmetics
- nutraceuticals
- food additives
- foods
- aquafeed
- bioplastics
- biopesticides
- animal feeds
- biofuels
- industrial feedstocks
- fertiliser
- clean water
Low value
circular economy - inputs provide high value outputs -> can be put back into inputs - e.g. reduce waste
What is algal biotechnology?
Pharmaceuticals
- recombinant proteins
- engineered vaccines
- recombinant antibodies
- Brevenal
- Eribulin (Halichondrin B)
- Phycoerythrin
- Fucoidan (sulphated polysaccharide)
- antibiotics (?)
What is algal biotechnology?
cosmetics + nutraceuticals
cosmetics:
- Astaxanthin ($500-1000/kg)
- Omega-3 FA’s (EPA, DHA)
nutraceuticals:
- Beta-carotene (pro-Vitamin A)
What is algal biotechnology?
food additives
- Phycocyanin (blue dye) (Spirulina)
What is algal biotechnology?
foods
- Saccharina japonica
- Spirulina
- Chlorella protein (chlorophyll free)
what is algal biotechnology?
bioplastics
- Chlorella (TPS – thermo plastic starch)
- Cyanobacteria (PHB polyhydroxy butyrate; PHA polyhydroxy alkanoates)
- Algal oil derived plastics
- Macroalgae polysaccharide-derived plastics
what is algal biotechnology?
biofuels
- biodiesel, jet fuels
- Chlamydomonas Biohydrogen
what is algal biotechnology?
industrial feedstocks
- Oleic acid to Nylons (plastics)
what is algal biotechnology?
fertilizer
Slow release Fertilizer (Poly Phosphate)
photosynthesis
carbon dioxide + water -(sunlight + chlorophyll)-> carbohydrate + oxygen
what do we need from algae?
- good growing species
- valuable natural products
what do we need from algae?
good growing species
- for economic cultivation & harvesting
- fast growth rate
- but able to grow on low nutrients
- resistant to predators
- edible & GRAS (Generally Regarded As Safe)
- find by screening
what do we need from algae?
valuable natural products
- interesting primary and secondary metabolites
- novel oils, carbohydrates
- novel pigments & proteins
- polyketides (often toxins)
- find by bioprospecting
- these producers may not be easy to cultivate
survival strategies and natural products - marine micro-algae
1. depending on what you are looking for…?
2. Buoyancy control & energy storage?
3. photosynthetic pigments?
4. toxins?
- look at specific habitat or niches for algal screening
- Triacylglycerol (Nannochloropsis), sulphated polysaccharides (cyanobacteria) - oligotrophic, low density, nutrient stress, open ocean, warm water, stratification
- Phycoxanthin (diatoms), Phycoerythrin (red algae) - high growth rates, out compete predators and other species - algal bloom, colder water, high nutrients, mixing - coastal, bloom, high nutrients, pollution
- Brevotoxin (Dinoflagellates) - predation, viruses, nutrient, stress - low growth rate, anti-predator & anti-competitor, defensive strategies, thick cell walls - salinity changes, salt stress, high light stress -> photoprotectants: Beta-carotene (Dunaliella)
If you want to look for valuable natural products or useful biotech organisms what is worth bearing in mind?
the survival strategies of microalgae
What is the most obvious survival strategy for microalgae and why?
what algae uses this strategy?
grow fast because that is what many of them are very good at
strategy = grow fast + to outcompete other photoautotrophs + to outgrow predators
strategy of fast algal growers is seen by algae that form algal blooms such as the haptophyte Emiliana huxleyii
What are algae that produce blooms not very good at and what does it cause?
not good at defending themselves, so blooms usually crash and this is caused by highly virulent viruses or predators
Slow growing survival strategy
some algae do not form blooms + have slower growth strategy
less vulnerable to viruses because of low cell density - in this case viruses that infect them must adopt a less virulent strategy to survive
Why is size of algae important?
middle sized algae are physically and biologically optimised for the highest growth rates
H/E, the larger the cell is the less likely you are to be eaten by a predator
Small cells can be readily hoovered up by small predators
what do picoplankton have to maximise light absorption and nutrient absorption?
what are they vulnerable to but why is it not a likely problem for them?
small cells (high surface area to volume ratio)
vulnerable to predators, but this is not a problem because they are growing at low density usually
What do defensive strategies involve and where are they adopted from?
lower growth rate - might be brought about by stress such as low nutrients, salinity changes or high light
involves growing a thicker cell wall often with projections to deter predators
another strategy is to produce toxins that are designed to deter predators
might be adopted by genetic evolution or it could be phenotypic plasticity where algae change in response to stresses - e.g. might accumulate photoprotectants such as beta-carotene if they are exposed to high salinity and cannot grow as fast
what is the evolutionary driver for a fast growth strategy?
synthesis of extra photosynthetic pigments and proteins to better absorb light for photosynthesis and this has led to identification of natural products of value as well
Why must oceanic picoplankton (in this case) stay buoyant and how do they maintain buoyancy?
to avoid sinking to ocean depths (which they often have to do at night to collect nutrients)
to maintain buoyancy they prioritise the production of algal oil in some cases
what have low growth strategy algae lead to the production of?
defensive drugs of interest for pharmaceuticals
why is there a lot of interest in using marine algal strains for large scale cultivation of algae?
because they use seawater or saline water instead of freshwater that is generally in short supply globally particularly in the Global South
What are the best-growing species for cultivation?
1. what do common bloom forming algae tend to have?
2. for the best algal biotech strains, is it simply down to maximum growth rate and optimal cell size?
3. examples?
- common bloom forming algae tend to have optimal cell size
- not necessarily
3.
- Ostreococcus taurii (picoplankton)
- Phaeodactylum tricornutum (quite good) (dominates in polar waters)
- Coccolithophore bloom
- Nannochloropsis: one of the best cultivation species
what do mid-ranged algal cells appear to be optimised for, and what is the theories to explain it?
maximum growth rate based on their cell size
theories: high cell surface area to volume ratio in small cells + transport distances of metabolites, but matter has not been fully resolved
what do most algae that commonly form algal blooms seem to have?
does this make them the best species for large-scale cultivation?
optimum cell size and the fastest maximum growth rates in the lab
it is unknown - H/E fast growth rate is not everything, and with oceanic algal blooms the actual cell concentration is not that high
Screening a culture collection for the best growing marine strains
- what was looked at?
- what were the top 7 Genera and for what?
- what was the best, for what, and despite what?
- best oil or biomass (C) productivity
- Tetraselmis sp. CCAP 66/60
Rhodella violaceae CCAP 1388/6
Dunaliella polymorpha CCAP 19/14
Cylindrotheca fusiformis CCAP 1017/2
Cyclotella cryptica CCAP 1070/2
CCAP 211/21A - Chlorella vulgaris - marine Chorella
Nannochloropsis oceanica CCAP 849/10
= top 7 Genera in the screen for biomass productivity (by organic carbon)
- Nannochloropsis (40um^3) = best biomass or oil producer despite being well below the theoretical optimum cell size for bloom formation or maximum growth rate
Phycoerythrin & Phycocyanin
1. what are they?
2. what is bound to them?
3. promising treatments?
4. what else are they used for?
5. how can they be stabilised?
- photosynthetic pigments that increase spectrum of light absorption found in red algae
- protein bound to e.g. phycoerythrobilin
- promising anticancer treatment in cell-lines
- blue dye for food (phycocoyanin), anti-ageing assayed using Caenorhabditis elegans (nematode)
- can be stabilised by encapsulation in sodium alginate (another algal product)
(Suzuki et al., 2005)
Survival strategies - defensive
1. Dinoflagellate luciferase catalyses what to result in?
- what laboratory applications do luciferin and luciferase have?
- what is the blue light believed to be?
- Dinoflagellate luciferase (DL) catalyses the oxidation of dinoflagellate luciferin by molecular oxygen, resulting in an electronically excited species that emits blue light
- luciferin and luciferase have laboratory applications as reporter genes that identify changes in gene expression
- emission of blue light is believed to be a defensive mechanism triggered by motion to attract predators of the algal predators
- how can groups of algae that tend to adopt defensive strategies be identified?
- what may these algae also adopt?
- what are the best examples?
- defensive armour that in some cases could act as a defence against predators
- defensive cell wall shapes + defensive chemicals
- Dinoflagellates but also get toxic algal blooms from some diatoms and haptophyte species
Toxic Diatoms - defensive
- what also exists that can be harmful for marine life and humans?
- what is domoic acid?
- who are the real target of the toxin based of some experimental evidence?
- what receptors does it target?
- what are glutamate analog? and what do they produce?
- Toxic diatoms such as Pseudo-nitzschia
- Domoic acids is a neurotoxin causing Amnesic shellfish poisoning which can harm the predators of shellfish (including us)
- there is some experimental evidence that the real target of the toxin is Copepod grazers
- target glutamate receptors
- include amino acids, neurotoxins, and other compounds that mimic glutamate; Glutamate analog produced from glutamate and an isoprenoid product
Haptophyte - Prymnesin-1
- what do several haptophyte algal species produce?
- what are Prymnesium parvum blooms responsible for?
- what does some evidence suggest that the toxins are really targeting?
- when do toxins tend to be produced?
- complex toxins that damage fish gills by allowing ions to leak out of the plasma membrane
- Prymnesium parvum blooms are responsible for many fish kills in e.g. the Norfolk Broads in the UK
- targeting algal predators such as Ciliated and Copepods
- toxins tend to be produced when local conditions prevent growth such as changes in salinity, loss of nutrients etc.
Prymnesium parvum
giant enzymes in tiny organism synthesize giant toxin
- polycyclic polyether toxins
- 239 enzymatic steps carried out by only 2 huge enzymes: PKZILLA-1 & 2
- PKZILLA-1 is the worlds largest protein at 4,700 kDaltons
- polyketide synthases
Cyanobacteria - microcystins
1. what is the most toxic one?
2. what are they?
3. how are they synthesised?
4. what is the target?
5. what can it cause?
- Microcystin-LR most toxic
- short non-ribosomal peptides
- synthesised by proteins with polyketide synthase activity and peptide synthase activity
- target is signal transduction phosphatases leading to increased phosphorylation in liver cells
- hepatotoxicity - liver damage caused by exposure to harmful substances
what do dinoflagellates frequently produce?
toxic algal blooms (red)
what are the toxic compounds that dinoflagellates produce, and what do they principally target?
are dinoflagellates easy to cultivate?
complex polyketides
targeted at zooplankton predators - can also impact shellfish, fish and humans
dinoflagellates are not easily cultivated
Defence strategies to drug leads: Brevenal
1. what can dinoflagellate red tides often release, what is it produced by, and where can it accumulate?
2. what do the toxins target?
3. what does the dinoflagellate also produce, what is it and what is it a candidate drug for?
- what is interesting about Karenia Brevis (red bloom)?
- dinoflagellate red tides often release toxins, such as BREVETOXIN, which is produced by the dinoflagellate Karenia brevis and can accumulate in shellfish and fish
- toxins target voltage-gated sodium channels in the nervous system
- this dinoflagellate also produces BREVENAL, a brevetoxin antagonist and candidate drug for Cystic Fibrosis and other respiratory diseases to free up airways of mucous
- currently under trial - Karenia Brevis (red bloom) produces its own antidote to Brevotoxin called Brevenal. Brevenal became of interest as an anti-inflammatory agent that could reduce lung inflammation
Defence strategies to drug leads: Erubilin
1. where was it originally isolated from, and in what year?
2. what property was identified in mice at this time?
3. what is the mechanism?
4. what was it prioritised as and in what year?
5. what was achieved and in what year, that led to the production in simplified form as Erubilin?
6. who approved Erubilin and in what year, to treat what?
7. how many years did it take from discovery to approval?
- originally isolated from marine sponge - 1986 - most likely from an unknown dinoflagellate (structure indicated likely produced from symbiotic dinoflagellate)
- anticancer properties in mice identified at this time
- mechanism: tubulin-targeted mitotic inhibitor
- prioritised as an anti-cancer therapeutic in 1991
- chemical synthesis of Halichondrin B achieved in 1992 leading to production in simplified form as Erubilin
- Erubilin approved by USDA in 2010 to treat metastatic breast cancer (late-stage disease)
- took 24 years from discovery to approval
why are recent experiments on dinoflagellates interesting, and why does it seem they are not trying to poison us?
cast light on the toxin synthesising strategies of dinoflagellates, providing answers on why they produce them
seems they are not trying to poison us but appears that the Copepod predator can detect that the Dinoflagellate is toxic possibly by taste or other cue
what could be caused due to the toxins produced by dinoflagellates, in terms of Copepod predators?
instead of ingesting and dying the Copepod targets other algae, such as diatoms that are faster growing competitors of Dinoflagellates
could be a mechanism for Dinoflagellate algal bloom replacing a diatom bloom through activity of Copepod predators - could be mechanism for red tides and how an algal species that is not fast growing can produce an algal bloom
Brief history of microalgal biotech
Before 2000:
1. where was Spirulina traditionally harvested and sold?
2. this continues as a what industry?
3. what comprises Spirulina?
4. what was investigated after WWII?
5. what was designed, by who and in what year to benefit this industry?
- In Africa Spirulina was harvested from alkaline lake Chad and sold in local markets
- continues as a cottage industry
- Spirulina comprises a long chain of cells in spiral form (cyanobacteria)
- after WWII Chlorella was investigated as a food sources
- Open raceway ponds were designed by Oswald in 1957
Brief history of microalgal biotech
Before 2000:
1. By what year was what substance investigated, and what was it investigated for?
2. by what year did what crisis lead to the investigation of?
3. In what years was the commercial production of what began?
4. what type of cultivation and why?
5. about this time the USDA began what?
6. during what years did the production of what begin?
- 1960’s use of CO2 from power stations was investigated for biogas, aquafeed etc. for waste grown algae
- 1970’s oil crisis led to investigation of algal oil for biofuels and Spirulina started to be produced commercially for food
- 1980’s Commercial production of Dunaliella salina for beta-carotene began in very large unmixed ponds in South-western Australia at Hutt Lagoon (where a natural pink lake exists)
- algae flow continuously through the different ponds growing as they do so (continuous flow cultivation)
- about this time the USDA “Aquatic Species Program” began to look for strains suitable for cultivation in saline conditions (for algal biofuels)
- during 1990’s production of DHA (an omega-3) by heterotrophic dinoflagellate Crypthecodinium cohnii began in fermenters by Martek (USA)
Brief history of microalgal biotech
After 2000:
1. what was produced early 2000’s?
2. what is Haematococcus pluvialis?
3. what occurs under stress (and what stress)?
4. where are the highest levels found?
- By the early 2000’s Astaxanthin was produced commercially in open raceway ponds or in tubes from Haematococcus pluvialis
- flagellated green algae (quite a large cell)
- under conditions of high light, nutrient stress, high salinity it will accumulate the valuable Carotenoid Astaxanthin
- highest levels are found in protective cysts
Brief history of microalgal biotech
Boom and bust: the algal biofuels revival & survival
1. from the 2000s what was there renewed interest for?
who invested and how much was invested into it?
2. what did the successful company Cyanotech produce?
3. by 2009, what happened to GreenFuel Technologies and Sapphire Energy?
4. what did Exxon announce in what year?
5. what transition occurred?
6. what does Solazyme bought by Corbion make?
7. what do Sapphire energy plant now owned by Qualitas health produce?
8. what is Algenol (Florida) using and producing?
9. in what year did what company renew what?
10. in what year did what industries, operate what?
11. what is algae for biofuels mostly pushed by?
- renewed interest in algal biofuels using CO2 from power stations with major investments form Exxon Mobil/Synthetic genomics
Bill Gates invested $200 million in Sapphire to build the largest raceway pond facility for Biofuel in New Mexico
- produced Spirulina and later Astaxanthin (Haematococcus) because they were using large outdoor raceway ponds
- GreenFuel Technologies went bust with a loss of $50 million - at this time Sapphire Energy provided Algal Oil for a couple of test flights
- in 2013 Exxon announced that algal biofuels was 25 year in the future and cut back most of the funding although research continued
- most surviving algal biofuel entities made the transition to higher value products such as omega-3 oil and food supplements
- Solazyme bought by Corbion and makes algae cooking oil in Walmart
- Sapphire energy plant now owned by Qualitas health and produce omega-oil supplements
- Algenol (Florida) is using its bioreactors to produce food colouring products
- 2017 - Exxon Mobil/Synthetic genomics (now Viridos) renewed their agreement for research into algal biofuels
- 2018 - Reliance Industries (big oil refinery, in India), was operating nearly 25 acres of ponds in an algal biofuels pilot plant
- algae for biofuels continues but mostly pushed by the Oil Industry (e.g. Shell Oil in Hawaii, Petrobas in Brazil, Exxon…)
Algae production 2019
1. what algae?
2. how much wet tonnes of global algae production?
3. what is the global microalgal share of this?
4. where is virtually all seaweed produced?
5. how much of seaweed is wild-harvested?
6. how much is the European share for both micro and macroalgae?
- macro and microalgae
- global algae production is 36 million wet tonnes
- global microalgal share of this is only 1% : 56,000 tonnes microalgae
- virtually all seaweed is produced in Asia
- about 2/3 of seaweed is wild-harvested
- The European share for both micro and macroalgae is only 1%
Relative value of Algal products in Europe
1. in Europe what was microalgae products dominated by?
2. how much of macroalgal productions are not high value?
- in Europe, microalgae products are dominated by high value products
- more than half of macroalgal products (60%) are not high value
How much microalgae can we produce in future?
1. how much microalgae is produced currently?
2. NREL report indicated how much is possible to be made per year in the USA?
3. this has been predicted using what?
- currently only 56,000 tonnes AFDW (Ash-free dry weight)
- a recent NREL report indicated 150 million tons AFDW per year is possible in the USA
- using today’s CO2 sources, unused land and saline groundwater
What is it worth? Global Algae market value estimates
1. what is the microalgae market value?
2. what is the macroalgae market value?
3. even taking into account?
4. market value of macro vs micro?
5. what does this reflect?
- 4-12 billion USD (2023)
- 9 billion USD
- even taking into consideration the uncertainty for the microalgae prediction
- market values are similar for macro and micro despite huge difference in production levels
- this probably reflects the higher value of microalgae products
algae company distribution in Europe
1. what is the distribution of macroalgae, microalgae and spirulina in Europe?
much macroalgae in UK
more microalgae produced in mainland Europe
lots of spirulina made in mainland Europe, especially France
Microalgae cultivation in Arctic circle, uses what?
uses red and blue lights to benefit photosynthesis
Global seaweed production and uses
1. in 2020
2. example of Gracilaria
3. example of Saccharina
4. example of Eucheuma / Kappaphycus
5. uses
- 2020 - most = Saccharina, 2nd = Eucheuma / Kappaphycus, 3rd = Gracilaria
- Irish moss or Ogonori
-> Agarose: n = Agarbiose disaccharide (D-galactose and 3,6-anhydro-L-galactopyranose)
-> Agaropectin: alternating D-galactose and L-galactose with modified side chains such as glucorate, sulphate & pyruvate - Alginic acid: blocks of (1→4)-linked β-D-mannuronate (M) and α-L-guluronate (G) residues or alternating MG blocks
- Carrageenan: repeating sulphated disaccharides alternating 3-linked β-D-galactopyranose (G-units) and 4-linked α-D-galactopyranose (D-units) or 4-linked 3,6-anhydro-α-D-galactopyranose (DA-unitsn = Agarbiose disaccharide (D-galactose and 3,6-anhydro-L-galactopyranose)
- uses: food rich in antioxidants and dietary fibre, food additives, gelling agents, lab products (electrophoresis), animal feed, pharmaceuticals, dentistry moulds (alginic a.), cosmetics, fertilizers
Local history of seaweed cultivation
1. what continent dominates seaweed market?
2. what areas have potential for the seaweed market?
3. where is there a neglected history of seaweed use?
4. where is seaweed fertilizer used?
5. what seaweed product is made in Wales?
6. what seaweed is used in flavouring?
7. Seaweed food example?
- Asia
- Europe & the USA with local strains
- neglected history of seaweed use in coastal communities
- fertilizer: on the Hebrides
- Laverbread (Wales)
- Dulse (flavouring) Palmeria palmata
- Irish Moss Pannacotta
Structural polysaccharides: given structural roles
1. what is cellulose?
2. what do cellulose molecules form?
3. what is the most abundant organic molecule on Earth?
4. what is starch?
5. leaf building blocks?
- cellulose = glucose polysaccharides
- cellulose molecules form microfibrils
- cellulose is the most abundant organic molecule on Earth
- starch (spiral molecule)
- B glucose monomer -> cellulose molecules -> microfibril -> cellulose microfibrils in a plant cell wall -> cell wall
Storage polysaccharides: animals and plants’ stores of fuel
1. what stores glucose-based polysaccharides and what for?
2. what is it in plants?
3. what are the plants glucose-based polysaccharides composed of?
4. what is starch stored in?
5. what is it in animals?
6. what is the glucose-based polysaccharide in animals?
7. where is glycogen stored?
8. spiral molecule?
- plants, animals, and other organisms store glucose-based polysaccharides for fuel
- in plants = starch
- composed of two distinct glucose polymers - amylose and amylopectin
- starch is stored in plastids
- in animals = glycogen
- multibranched polysaccharide of glucose (also in fungi and bacteria)
- in animals, glycogen is stored in muscle and liver cells
- spiral molecule - starch is a gelling agent
What is one example of a pharmaceutical drug from seaweeds?
what part is important?
is it designated as a drug?
how does it work?
what does the inclusion of seaweed in the diet suggest?
Fucoidan: anticancer drug
sulphated cell wall polysaccharide component that has been tested in low molecular weight form (shorter chains)
it is not designated as a drug yet so cannot undergo large scale-trials
mode of action is through glycoprotein receptors which is understandable given that it comprises a carbohydrate chain so it could mimic the glycoproteins which consist of short carbohydrate chains attached to proteins. This binding triggers signal transduction cascade that triggers Natural Killer cell activation or apoptosis of tumour cells and so on
link to cancer of the colon is interesting because it suggests that inclusion of seaweeds in the diet could be lowering the incidence of disease and contributing to longevity reported in countries where a lot of seaweed is consumed such as Japan
Fucoidan: anticancer drug
properties and trials
1. what is it a component of?
2. what does it contain?
3. what is it?
4. what is it shown to have?
5. what does it appear to bind to?
6. what is it trial testing for?
7. what is the disease control rate and the control (%)?
- cell wall component of brown macroalgae
- contains unusual 1, 3 linkage of monomers
- sulphated polysaccharide (R)
- shown to have anti-tumour effects in cancer cell lines and mouse models
- appears to bind to glycoprotein receptors to trigger effects
- metastatic colorectal cancer (mCRC) patients trial testing it as a supplement to chemotherapy
- 93% Disease Control Rate, c.f. 69% control
Red algae and cattle methane release
1. what does the fermentation of carbohydrates in ruminants into volatile fatty acids (VFA) produce?
2. what converts it to methane?
3. what can reduce methane production when fed to cattle?
4. what is the active ingredient?
- fermentation of carbohydrates in ruminants into volatile fatty acids (VFA) produces dihydrogen (H2) and carbon dioxide (CO2)
- methanogenic archaea can convert these to methane
- the red algae Asparagopsis when fed to cattle reduces methane production
- active ingredient is bromoform which inhibits methane synthesis
Summary
Microalgae
PRODUCTION LEVELS:
- 56,000 tons per year (AFDW) - underestimated
- 30,000 tons in 2015 so doubling every 10 years
- USA could theoretically produce 150 million tons (AFDW)
- this is 1% of seaweed production (DW for DW)
- does not include the aquafeed contribution (because this is never directly harvested)
- most production is in Chine, USA, Australia
GLOBAL VALUE:
- market value: $4-12 billion (an uncertain estimate)
USES:
- food supplements & cosmetics (high-value); aquafeed
- variety of secondary products
ADVANTAGES:
- high species diversity; some are GRAS (many are toxic); economically viable is product is high value
DISADVANTAGES:
- costs often impact the economics; often technically challenging to cultivate
- production limitations/costs minimises impact for biofuel or animal feeds
- disease pathology an issue but there is very high species diversity
Summary
macroalgae
PRODUCTION LEVELS:
- 36 million tons wet (4 million tons DW) - accurate
- medium to high value products (food)
- most production is in Asia, but unused coastlines are available in the West
GLOBAL VALUE:
- market value: $9 billion (reliable estimate)
USES:
- food & food additives (mid-value)
- variety of secondary products
ADVANTAGES:
- moderate species diversity; virtually all species GRAS; economic to cultivate; can reduce methane emissions in cattle
DISADVANTAGES:
- regulatory issues for wild-harvesting/cultivation (could hamper expansion)
- cultivation hampered by disease pathologies
