Accumulated by Ken Wear commencing 8/02/07
Thoughts on a library at end of page
Most algae are water-borne, either flowing fresh water as in rivers, standing fresh water as in lakes, brackish water where fresh and sea water mix, or in the ocean. Algae have no true leaves, stems or roots; some are single-celled but some are elaborate massive plants comparable in size with flowering plants. Most are eukaryotic (cells with nuclei) as opposed to the simpler prokaryotic cell structure. For classification they are divided between fresh and salt (marine) water, where brackish water is taken as marine. As a general rule, fresh water algae are microscopic and marine algae are macroscopic and readily recognizable when found in situ or on the beach.
As with hemp, with its hundreds of strains, it is necessary to know the characteristics of a particular strain if we are to know if it can be cultivated to become a practical source of portable energy. Such things as habitat, temperature, rapidity of reproduction, attachment or free-floating, oil production, aggressiveness. Once harvested it seems likely extraction of oils and conversion to biodiesel would be nearly identical for all microscopic strains.
8-28-07 I was naive when I undertook this
page. Rather than two kingdoms of life, plant and animal, there are now recognized forms
of life that enjoy characteristics of both, numbering 5 or 8 kingdoms depending on
which school you wish to follow. The Whitaker 5-kingdom classification consists of:
1) monera (prokaryotic cells, which have poorly organized nuclei)
2) protista*
(eukaryotic cell with well organized nuclei that fits no other kingdom)
3) fungi (no
chlorophyll so they are parasitic)
4) and 5) plants and animals.
References I
have found do not clearly delineate members of the 8-kingdom classification. While I
have neither hope for nor interest in entering the controversies surrounding taxonomy, as
long as we can unambiguously assign data to a specific genus and species, we should be
able to organize data. [alga (singular), algae (plural), algal (adjective)]
*http://mclibrary.nhmccd.edu/taxonomy/protista.html lists 18 phyla of protista (eukaryotes
that do not have the distinctive characteristics of plants, animals or fungi) as:
acrasiomycota (cellular slime molds)
actinopoda
apicomplexa
bacillariophyta (diatoms) - food reserves chrysolaminarin
chlorophyta (green algae) - food reserve is starch
chrysophyta (golden algae)
chromista - includes kelp and plankton
ciliophora (ciliated protozoans - classes karyorelictea, phyllopharnygea, spiroturichea,
colopodea, prostomatea, nassophorea, litostomatea, oligohymenophorea)
dinoflagellata (dinoflagellates)
diplomonada (archezoa)
euglenophyta (euglenoids) - unicellular (1 colonial genus), food reserve is paramylon
foraminifera (forams)
myxomycota (plasmodial slime molds) - terrestrial, no cell walls, food reserve is glycogen
oomycota (water molds) - food reserve is glycogen
phaeophyta (brown algae) - colder oceans, food reserve is laminarin
rhizopoda (amoebas)
rhodophyta (red algae) - mostly marine in warm waters, food reserve is floridean starch
zoomastigophora (zooflagellates)
12-04-07 When I undertook this page my interest
was limited to biodiesel, but I have since recognized that cellulosic (carbohydrate)
conversion to fuel may be equally possible. And it's not a matter of 'either/or'; the
by-product of one may easily be the source for the other; hence accumulation of data
must respect both possibilities. Furthermore, algae will likely prove to be the
most abundant food source of the future.
1-30-08 My thoughts of the future have
undergone a transformation since first considering algae for fuel. I now see harnessing
algae as mankind's best hope for feeding a world population that seems inevitable, as
well as reducing the "greenhouse effect" of atmospheric CO2. Rather than
research on elimination of algae, which has been the dominant interest in the past, attention
must be directed to identifying and cultivating the most useful algae. In time, algae will
become our dominant source for food, both human and animal, and energy, including oil
extraction, carbohydrate conversion with fermentation to produce ethanol and anaerobic
digestion to produce methane. Economics of conversion as well as by-products will
become the realms of competition.
I surmise that research will be retarded until someone filters through available data,
selects a target (possibly a candidate for genetic modification), and reports results
showing a dramatic improvement in cultivation, harvesting and/or extraction.
A perhaps overriding interest in algae arises from its consumption of
CO2 in the process of converting sunshine into
biomass. (Canada has funded initial efforts at CO2 sequestration.)
A primitive discussion of algae taken from my 1957 Encyclopedia Brittanica,
where taxonomy was taken as kingdom, phylum, class, order, genus, species:
Classes of algae are: Chlorophyta, Euglenophyta, Pyrrophyta, Chrysophyta, Phaeophyta,
Rhodophyta, and Cyanophyta. Based on this, the best organization I could derive from the
encyclopedia is this: [Smithsonian indicates 300,000 species of algae]{Where 'oil', 'lipid'
or fat is mentioned, I have underscored that item.}
Phylum
Euglenophyta grass-green chromatophores; food reserves are paramylum (an insoluble carbohydrate) or fats; one class
Pyrrophyta [fire algae] yellowish to brownish chromatophores that store reserve foods as starch or starch-like compounds
Chrysophyta yellowish-green to yellowish-brown chromatophores, food
reserves are leucosin and oils [droplets]; 300 genera, 5700 species (3/4 fresh water), classes
Phaeophyta (brown algae); food reserve is the carbohydrate laminarin
dissolved in cell sap; all but 3 of 900 species are marine in colder seas. [Includes kelp, seaweed;
dismissed as source for oil]
Rhodophyta (red algae); food reserve is insoluble carbohydrate floridean starch; a single
class Rhodophyceae of 340 genera and 2500 species; about 50 species, belonging to 12
genera, are fresh water, all others marine. [Dismissed as source for oil] [Include coralline
algae whose hard carbonate shells likely contribute more to reefs than do corals] [Some
taxonomists include red algae in the plant kingdom with taxonomies in a state of flux.]
Cyanophyta (blue-green algae), 150 genera and 2000 species, 80% fresh water either
aquatic or terrestrial; only one class: Myxophyceae (Cyanophyceae), majority multicellular.
[Prokaryotes, unique among morena in that they possess photosynthetic pigments; dismissed
as source for oil][Cyanobacteria are usually unicellular although they may grow in colonies
or filaments.]
[Some people prefer to list chlorophyta, rhodophyta and phaeophyta as plants.][I am unable
to place chromista, where another source places brown algae and diatoms.]
End of discussion taken from my encyclopedia.
I spent a great deal of time with the web site www.oilgae.com. It contains a wealth of
information and links to sources of information emphasizing algae as source for petroleum
substitutes.
Algae figure prominently in many uses, including foods. For the purpose of biodiesel,
only the oil or fat content seems appropriate, although the carbohydrate content may be
of value in ethanol production. Some values are:
According to www.oilgae.com, the following strains of algae are presently being studied:
From 1978 to 1996 the U.S. Dept. of Energy (Office of Transportation Technology, under
the Assistant Secretary for Energy Efficiency and Renewable energy) in its National
Renewable Energy Laboratory (NREL), Colorado, in its Aquatic Species Program
(ASP), researched use of algae for oil production. It was an extensive program starting
with virtually no information on source for oils. Samples were collected and methods of
their analysis developed. Methods of large scale cultivation were explored. At its peak
their collection consisted of over 3000 strains, which was winnowed to aprx 300, mostly
green algae and diatoms. It had been observed that algae oil production is enhanced by
nutrient deficiency; that was a major factor studied. It was likely a poor choice to
attempt to squeeze more oil, by nutrient deficiency or genetic alteration (seeking a 'lipid
trigger' to encourage alga to produce more oil), from selected groups of strains; it proved
to be an unrewarding effort since reproduction was retarded so overall oil production was
not improved. Efforts at genetic manipulation with an enzyme did not increase production.
Control of pH, etc., allowed 90% utilization of injected CO2
in open ponds with reasonable control of algal species, but overnight low
temperatures hindered production. Concluded enclosed ponds with temperature control would
be required, and costs of biodiesel from algae would exceed petro diesel by a factor of two
(1980s). Also concluded that algal systems could provide significantly more energy than
oilseed crops [aprx 30 times more per acre]. (12-07 NREL was reported to be slated to
resume research in collaboration with Chevron.)
Their SERI (Solar Energy Research Institute) collection of microalgae was moved
in 1998 to the University of Hawaii; a NSF grant was used to form Marine Bioproduct
Engineering Center (MarBEC) at Manoa; Wikipedia lists the SERI collection.
The 328-page NREL report, providing a summary of work from 1980 to 1996, is not available
(Nov. 07) on the web site NREL.rept.pdf, but was found at
www1.eere.energy.gov/biomass/pdfs/biodiesel_from_algae.pdf. I found it very difficult to
glean useful information beyond the summary above, partly due to different experimental
conditions used by various contractors, although it describes experimental growth conditions
and rates as well as including extensive bibliographies.
From the NREL report:
Some algae grow at rates of 1.5-4 doublings per day.
Miscellaneous notes gleaned from the 328-page NREL final report:
Temporary end of information gleaned from limited search of NREL
sources. I have concluded the report provides little useful data except that its
detail provides insights into directions for research that won't be productive.
The Smithsonian Institute's Natural Museum of Natural History lists a number of
bibliographies at www.nmnh.si.edu/botany/projects/algae/biblio.htm
Ideally, we want an alga with high efficiency in conversion of sunlight and that requires
little fertilization, yields significant quantities of oil, reproduces rapidly in a pond having
little circulation at temperatures warm to the human body, free floating, easily separated.
Since algae need carbon dioxide and many strains prefer warmth, a strain that would
thrive on waste heat and flue gas from an electricity-generating facility (where aeration
ponds are now used and flue gases are discharged into the atmosphere), is my first
choice of characteristics. Aggressiveness, in their ability to resist invasion by other
strains, is also necessary unless the pond is covered to protect it from air-borne
particles.
In my view, harvesting and separation represent challenges. If benthotic (growing on
another plant or structure), they must be separated from their host; if free-floating they
must be separated from water, perhaps by gravity or centrifuging if their density allows
rising to the top of still water. Since macroalgae and emergent algae (growing in bogs
and marshes) produce few lipids, the best choices of strain seem to be microscopic;
because of size, filtering seems unlikely unless they grow in colonies, filaments or other
clusters. Once harvested, separation of oil (most expensive part of the process) may use
any of several processes that produce more energy than they spend. Several are discussed
at www.oilgae.com/algae/oil/extract/extract.html.
I lived in the research community for years, part of it funded by the Federal government
and part by private money; it is a whirling dirvish of competing motivatations. Politicians,
for whatever reason -- and I could elaborate on that to their decided embarrassment --
decided that NREL research was not yielding sufficient results and money could be directed
more to their liking elsewhere. In the fullness of time someone with be inspired to toy with
a system using a selected alga and show a profit; then the race among investors will be on
and we will get oil from algae. The oil is there, but everyone is afraid that his investment
will prove wasted because someone else will find better algae or simpler processes and his
investment will be lost to competition. What we need at this juncture is someone to
systematically explore all identifiable algae and construct a table of how each alga fares
with respect to desirable characteristics, which I detailed above.
My present intention (8-28-07) is to continue accumulating data on algae
as a casual -- not priority -- pursuit because, eventually, algae must become a primary
source for vehicle and home heating fuel. Presently, published research that I have found
seems much too primitive to offer much hope for that becoming a reality within the next
decade or two. (12-9-07) I hear Shell is building a pilot plant in Hawaii to produce
biodiesel from algae.
I am unsure of taxonomic identifications of these (from my encyclopedia):
I am unsure of taxonomic identifications of these, taken from NREL
Per http://arnica.csustan.edu/body1050/Protista/protista.htm:
http://www.algaebase.org makes available data from the unpublished Encyclopedia of
Algal Genera. Data for marine algae, particularly seasweed, are the most complete.
Tremendous amount of information but limited to what each researcher sought. There may
be taxonomic confusion.
Miscellaneous notes picked up from goodness-knows-where:
An accumulation of information on biodiesel is found by clicking here.
My printer uses 10 pages or 5 sheets of paper to print this document.
(Dec '07)Shell is reportedly building an experimental plant in
Hawaii to convert algae to fuel. Initially 2.5 hectare of water will be used, expanding to
1000 and then to 20,000 if experiments are successful. (I have been unable to learn
which green alga Shell anticipates using although it is said to be non-genetically-modified
and reproduces several times a day.)
And algae production may benefit from waste heat from electricity generation.
[Data included in brackets has been added and is not from Brittanica.]
There are some 18000 known strains of algae.
[Algae lack the stems, leaves or roots of higher plants.] Algae are highly specific in
preference for temperature and continuity of moisture.
Simplest algae are one-celled and have flagella protruding through the cell wall. Fresh
water algae may be permanently submerged and attached (benthos) or free-floating
(plankton). Benthotic algae are found mostly in flowing water, ponds & lakes,
pools and ditches, bogs & swamps. Plankton are mostly unicellular or colonial
non-filamentous found in lakes, ponds and slowly flowing streams. Soft-water lakes are
rich in species but with small number of individuals; in hard-water there are fewer species
but they may 'bloom.' Fresh water algae may exist in snow, in hot springs, in brine lakes
or in or on animals or in or on plants; some are parasitic. Aerial species may get water
from moisture in the air; terrestrial algae get water partly from air and partly from ground
water; some withstand extended drought. Zygotes of most grass-green algae secrete a
thick wall and do not germinate until they have undergone a ripening period lasting weeks
or months.
Chlorophyta: [includes green seaweed; energy storage is starches]
Order
Species
Volvocales (most primitive order) with motile vegetative cells genera mostly are fresh-water as
Chalmydomonas reinhardii [NREL studied extensivelsy]
Tetrasporales up to 100 species, mostly fresh water
Ulotrichales 80 genera, mostly fresh-water, 450 species.
Ulvales 100 species, mostly marine, cells joined in flat sheets or hollow tubes
Schizogoniales 3 genera
Cladophorales have multinucleate cells joined end to end in branched or unbranched filaments, 12 genera
Oedogoniales, 3 genera, 350 species;
Zygnematales 40 genera, 3000 species, all fresh water and acquatic
Chlorococcales mostly fresh water, reproduction by spores or gametes
Siphanoles are unicellular, multinucleate branched tubes; 50 genera, mostly marine in tropics & sub-tropics
Siphonocladiales marine, 120 species, tropical waters
Acetabularia is known as mermaid's wineglass
Charales 6 genera, 200 species, all submerged in fresh or brackish water.
Euglenales includes all genera with motile cells
Colaciales has only one genus
[Dinoflagellates = red tides (result from excess nutrients in the water)
Karenia (Gymnodinium) brevis generates brevetoxin in Gulf of Mexico
Alexandrium fundyense generates saxitoxin in Gulf of Maine
Alexandrium (Gonyaulax) tamarense from Canadian E coast]
Gymnodiniales (without a wall)
Peridiniales
Dinophysidales
Dinocapsales
Dinotrichales
Dinococcales
Heterochloridales, 9 unicellular genera
Rhizochloridales, 7 genera; very rare, fresh water
Heterocapsales, rare, fresh water, are colonial similar to Tetrasporales
Heterotrichale cells joined end to end
Heterococcales: largest order, 45 genera, nearly all fresh water, unicellular & colonial
Heterosiphonales have only one genus
Chrysomonadales (half of order)
Rhizochrysidales (12 genera) are fresh water
Chrysocapsales are colonial (10 genera)
Chrysotrichales (5 genera, rare, fresh water) cells unite end to end in branched or unbranched filaments
Chrysococcales (6 genera, all fresh water)
muelleri
Centrales (100 genera & 2400 species) mostly marine
Pennales 70 genera, 2900 species, somewhat more marine than fresh water.
Algae strain %lipids... %carbohy- %protein... %nucleic
drates acid Anabaena cylindrica 4-7 25-30 43-56 Chlamydomonas rheinhardii 21 17 48
Chlorella pyrenoidosa 2 26 57 Chlorella vulgaris 14-22 12-17 51-58 4-5 Dunaliella bioculata 8 4 49 Dunaliella salina 6 32 57 Euglena gracilis 14-20 14-18 39-61 Porphyridium cruentum 9-14 40-57 28-39 Prymnesium parvum 22-38 25-33 28-45 1-2 Scenedesmus dimorphus 16-40 21-52 8-18 Scenedesmus obliquus 12-14 10-17 50-56 3-6 Scenedesmus quadricauda 1-9 47 Spirogyra sp. 11-21 33-64 6-20 Spirulina maxima 6-7 13-16 60-71 3-4.5 Spirulina platensis 2-5 8-14 46-63 2-5 Synechoccus sp. 5 15 63 5 Tetraselmis maculata 3 15 52 per Becker, 1994
neochloris oleoabundans, a green algae
schenedesmus dimorphus, a unicellular green algae, is heavy and forms thick sediments if not
kept in constant agitation.
euglena gracilis
phaeodactylum tricornutum, a diatom
pleurochrysis carterae, a unicellular coccolithophorid alga (class haptophyta or
prymnesiophyceae) calcerous scales surround cell wall
prymnesium parvum is toxic
tetraselmis chui
isochrysis galbanais micro
nannochloropsis (strain of eustigmatophyte) salina (nannochloris oculata - N. oculata) same group as N. atomus Butcher,
N. maculata Butcher, N. gaditaa Lubian, N. oculata (Droop)
botryococcus braunii strains (a green algae) can produce long chain hydrocarbons (86% dry
weight) are unique in quality and quantity of liquid hydrocarbons it produces
dunaliella tertiolecta is fast-growing with oil yield aprx 37%
nannochloris sp.
spirulina species
Diatoms were most favored by NREL researchers but require narrow temperature range and
need silicon in the water to grow; green algae need nitrogen to grow and tolerate temperature
fluctuations.
Pyrmnisophytes (haptophytes), marine, 500 species
Eustigmatophytes, includes genus nannochloropsis
Cyanobacteria are prokaryotic with no significant lipids, 2000 species
Microalgae produce more oil than macroalgae, which produce almost none.
Algae may be subdivided into microalgae, macroalglae (which grow mostly in marine
environments), and emergents (which grow partially submerged); since macroalgae and
emergents produce few lipids, ASP concentrated on microalgae.
Researchers isolated the enzyme Acetyl CoA Carboxylase (ACCase) and isolated the
gene that encodes for ACCase. They demonstrated over-expression of the ACCase
gene, but it did not yield higher oil production.
Diatoms dominate the phytoplankton in the ocean and are also found in fresh and brackish
water. They contain polymerized silica in their cell walls.
Green algae are abundant in fresh water as single cells or colonies.
Blue-green algae are closer to bacteria in structure and organization; they play an
important role in fixing nitrogen in the atmosphere.
Golden algae are similar to diatoms; they may be yellow, brown or orange in color. They
produce oils and hydrocarbons.
Algae growth was undertaken in shallow open ponds of raceway design with paddles to
provide circulation and waste CO2 intoduced into
the water. Coal-fired generating plants emit flue gas containing up to 13%
CO2.
ASP considered 1) production of methane, 2) production of ethanol via fermentation and
3) production of biodiesel. Of course algal biomass may be burned as a fuel.
Biodiesel results from reacting a simple alcohol with the triacetylglycerols (TAGs) from
algae to produce an alkyl ester (transesterification) that is very similar to petro diesel.
Detailed examination of reports by various investigators shows results to be severely
compromised by effort to increase lipid production using deficient culture media.
Moreover, the open ponds used for field studies were subject to invasion by wind-borne
strains. In consequence I have undertaken neither an alphabetical listing of species
included in studies nor tabular data of research results.
aquatic fresh water: trentepohlia - tropic & temperate
cephaleuros - parasitic - never in cold regions
compsopogon - so. U.S., W Indies, Central America
pithophora - tropic & temperate
golenkinia - cell bears bristles
merispodia - colonial in a flat plate
pediastrum - colonial in a flat plate
Caulerpa -unicellular macroscopic with leaf, stem and root-like branches
Chondrus - red algae with filaments compacted to form a plant body - macroscopic
Ectocarpus - branched filaments free of one another
Gloeocapsa - cells have no definite orientation with respect to one another
Kelp - brown with rootlike holdfast, stemlike stalk, leaflike blades
Macrocystis - kelp
Nereocystis - kelp
Spirulina grows under high pH
Urothrix - cells joined end-to-end in unbranched filament
Ankistrodesmus & Chlorococcum: genus or sp.?
Monoraphidium minutum
Boekelovia: genus or sp.
Phyla of kingdom Protista (characterized as heterogeneous assemblage of unicellular,
colonial and multicellular eukaryotes that do not have the distinctive characters of plants,
animals or fungi; locotion by flagella; sexual reproduction; carbohydrate food reserves);
12 classes including unicellular plankton, photosynthetic phytoplankton, heterotrophic
zooplankton:
Euglenophyta: aprx 900 species, mostly freshwater; unicellulalr except one
colonial genus; chlorophylls A and B in 1/3 of genera; pellicle cell wall; reproduction
by cell division.
Myxomycota: aprx 700 species; terrestrial; lack cell walls (naked protoplasm
creeps over lawns, plants, rotting materials; sexual reproduction
Rhodophyta: 4000-6000 species, mostly warm or tropical marine; grow attached to
rocks or other algae (few free floating, few unicellular or colonial); calcium carbonate in
cellulose cell walls important in building coral reefs; food for corals
Oomycota: aprx 700 species; unicellular to highly branched; cellulose cell walls;
species saprolegnia is common water mold
Bacillariophyta: (diatoms) aprx 100,000 extant species, mostly unicellular w/few
colonials; reproduction mainly asexual
Phaeophyta: aprx 1500 species (brown algae and/or kelps) include most seaweeds
of temperate regions; mostly marine in colder oceans
Chlorophyta: green algae, aprx 17000 species, precursor of true plants; mostly
multicellular in free floating colonies in gelatinous matrix
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caulerpa taxifolia: noxious seaweed "killer algae" spreading along the Mediterranean coasts
gonyaulax tamarensis: "red tide" in Canadian and New England waters
Kingdom protista Phylum dinoflagellates
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