You may be asking yourself why we’re interested in this obscure cyanobacteria. Well, we have a personal interest in what gloeotrichia is, and what it is doing in our lake.
Yes, gloeotrichia is prevalent in Lake Cascade, our reservoir. Along with gloeotrichia, we have found aphanizomena, microcystis, and an unknown micro-critter. So, in order to figure out why these things are in our lake, as well as how they got there, how they’ll affect our lake and how we can get rid of them, we researched cyanobacteria, blue-green algae, and gloeotrichia.
Alas, we found information lacking greatly on gloeotrichia, so we have had to walk blindly along the path of learning when it comes to that. However, we did find abundant information on cyanobacteria and blue-green algae. This is a compilation of that information, with the few tidbits about gloeotrichia tucked in here and there where they pertain to the topic.
Following the text portion, as well as enclosed within the information, are pictures we found while researching, and pictures we the students took, in addition. I hope you benefit from this educational booklet we have worked so hard on putting together.
Cyanobacteria
The algae are the simplest members of the plant kingdom, and the blue-green algae are the simplest of the algae. They have a considerable and increasing economic importance; they have both beneficial and harmful effects on human life.
They are referred to in literature by various names, chief among which are cyanobacteria, myxophyta, cyanochloronta, cyanophyta, blue-green algae, and blue-green bacteria.
Found in almost every conceivable habitat, from oceans to fresh water to bare rock to soil, cyanobacteria produce the compounds responsible for “earthy” odors we detect in soil and some bodies of water - such as those being cyanobacterially cleaned at water treatment plants. The greenish slime on the side of your damp flower pot, the wall of your house or the trunk of that big tree is more likely to be cyanobacteria than anything else. Cyanobacteria have even been found on the fur of polar bears, to which they impart a greenish tinge!
Though cyanobacteria do not have a great diversity of form, and though they are microscopic, they are rich in chemical diversity. Cyanobacteria get their name from the bluish pigment phycocyanin, which they use to capture light for photosynthesis.
Whatever their color, cyanobacteria are photosynthetic, and so can manufacture their own food. This has caused them to be dubbed “blue-green algae”, though they have no relationship to any of the various eudayotic algae. The term “algae” merely refers to any aquatic organisms capable of photosynthesis, and so applies to several groups. Both groups are photosynthetic, but cyanobacteria lack internal organelles, a discrete nucleus and the histone proteins associated with eukaryotic chromosomes.
Physical Description
Cyanobacteria is the scientific name for blue-green algae, or “pond-scum”. The first recognized species were blue-green in color, which is how the algae got their name. Species identified since range in color from olive-green to red.
Cyanobacteria are photoautotrophs and perform plantlike photosynthesis; have chlorophyll and use two photosystems to split water yielding O2 as a by-product. Among cyanobacteria are single-celled forms, colonial species, and truly multicellular organisms with a division of labor between specialized cells.
The cell walls are often thick and gelatinous; flagella absent, motile forms glide: When viewed under the light microscope, blue-greens show a variety of movements, such as gliding, rotation, oscillation, jerking and flicking.
At the onset of adverse environmental conditions, some blue-greens can develop a modified cell, called an akinete. Akinetes contain large reserves of carbohydrates, and owing to their density and lack of gas vessels, eventually settle to the lake bottom. They can tolerate adverse conditions such as the complete drying of a pond or the cold winter temperatures, and, as a consequence, akinetes serve as “seeds” for the growth of juvenile filaments when favorable conditions return. Heterocysts and akinetes are unique to the blue-greens.
Perhaps the most important adaptation is their positive buoyancy, which is regulated by their gas vesicles. These are absent in true algae.
Once again, blue-greens are not true algae. They have no true nucleus, the structure that encloses the DNA, and no chloroplast, the structure that encloses the photosynthetic membranes. These structures are evident in photosynthetic true algae. In fact, blue-greens are more akin to bacteria which have similar biochemical and structural characteristics.
Blue-greens are bacteria, small and unicellular. They often grow in colonies large enough to see.
Colour & Identification
The blue-green color of cells (cyan means blue-green) is due to the combination of green chlorophyll pigment and a unique blue pigment (phycocyanin). However, not all blue-greens are blue-green. Their pigmentation includes yellow-green, green, grey-green, grey-black, and even red specimens.
The Red Sea derives its name from occasional blooms of a species of Oscillatoria that produces large quantities of a unique pigment called phycoerythrin.
In the arid regions of Central and East Africa, flamingos consume vast quantities of Spirulina, and their feathers derive their pink color from carotene pigments in filaments of Spirulina.
The blue-green are microscopic life forms that exhibit several different types of organization: Some grow as single cells enclosed in a sheath of slime-like material, or mucilage. The cells of others aggregate into colonies that are either flattened, cubed, rounded, or elongated into filaments.
Actual identification of cyanobacteria (blue-greens) requires microscopic examination of cells, colonies, of filaments, although experienced aquatic biologists can usually recognize Microcystis (colonies look like tiny grey-green clumps) and Aphanizomenon (green, fingernail-like or grass like clippings).
This is one of several genera in which the trichomes consist of a basal spherical heterocyst, an enlarged, elongate akinete, then a tapered series of vegetative cells. The apical cells are the oldest, produced when the colony was young and its diameter small. Akinetes are not produced until there is food to store. They are not present in young trichomes, although heterocysts are. A colony consists of trichomes radiating from the center of a spherical mucilage ball, or sheath. The sheath may be difficult to see.
Find a colony of Gloeotrichia in a wet mount of the mixed Cyanobacteria culture. The trichomes are easy to recognize and consist of a heterocyst, an long cylindrical akinete, and a chain of spherical vegetative cells whose diameter decreases toward the apex.
Although they are truly prokaryotic, cyanobacteria have an elaborate and highly organized system of internal membranes which function in photosynthesis.
Cyanobacteria may be single-celled or colonial. Depending upon the species and environmental conditions, colonies may form filaments, sheets or even hollow balls. Some filamentous colonies show the ability to differentiate into three different cell types. Vegetative cells are the normal, photosynthetic cells formed under favorable growing conditions. Climate-resistant spores may form when environmental conditions become harsh. A third type of cell, a thick-walled heterocyst, contains the enzyme nitrogenase, vital for nitrogen fixation.
Heterocyst forming species are able to “fix” nitrogen gas, which cannot be absorbed by plants, into ammonia, nitrites or nitrates, which can be absorbed by plants and converted to protein and nucleic acids.
Cyanobacteria also form symbiotic relationships with many fungi, forming complex symbiotic organisms known as lichens.
History
The cyanobacteria have an extensive fossil record: they are among the easiest microfossils to recognize.
Many proterozic oil deposits are attributed to the activity of cyanobacteria.
Small concentrically layered structures called pisolites are also the result of fossilized bacteria. Cyanobacteria are otherwise rarely preserved in rocks other than chert, though some possible blue-green bacteria have been recovered from shale.
The blue-greens are widely distributed over land water, often in environments where no other vegetation can exist. Their fossils have been identified as over three billion years old.
They were probably the chief primary producers of organic matter and the first organisms to release oxygen, O2, into the primitive atmosphere, which was until then free from O2.
Thus blue-greens were probably responsible for a major evolutionary transformation leading to the development of aerobic metabolism and to the subsequent rise of higher plant and animal forms.
The earliest reliable account of a cyanobacterial bloom dates back to the 12th century. Cyanobacterial bloom formation seems to be linked to nutrient-rich water bodies.
Cyanbacteria: have the distinction of being the oldest known fossils, more than 3.5 billion years old.
Cyanbacteria is one of the largest and most important groups of bacterium on Earth.
It has been important in shaping the course of evolution and ecological change throughout Earth’s history.
Oxygen atmosphere that we depend on was generated by numerous cyanobacterias, bacteria during the Archean and Proterozoic eras
Many protozoic oil deposits are attributed to the activity of cyanobacteria.
The cyanobacteria have also been tremendously important in shaping the course of evolution and ecological change throughout earth’s history. The oxygen atmosphere that we depend on was generated by numerous cyanobacteria photosynthesizing during the Archean and Proterozoic Era. Before that time, the atmosphere had a very different chemistry, unsuitable for life as we know it today.
Feeding, Energy Use
Some aquatic species fix nitrogen;
Are aquatic and photosynthetic
Can manufacture their own food
Are important in the nitrogen cycle
Heterocystous blue-greens possess the unique ability to simultaneously evolve 02 in photosynthesis and H2 by nitrogenase catalyzed electron transfer to H+-ions in the absence of N2 or other substrates of nitrogenase.
This is the basis for the attempts of several workers to try to exploit the potential through the development of a “biophotolytic system” for solar energy conversion, even though to efficiency has been disappointingly low. Nevertheless, the utilization of blue greens in food production and in solar energy conversion may hold immense potential for the future, and could be exploited for the mans economy. Progress in the study of the genetics of blue-greens may enable us to manipulate the N2-fixation (nif) and associated genes, and produce strains which fix
Cyanobacteria are very important organisms for the health and growth of many plants. They are one of very few groups of organisms that can convert inert atmospheric nitrogen into an organic form, such as nitrate of ammonia. It is these “fixed” forms of nitrogen which plants need for their growth, and must obtain from the soil. Fertilizers work the way they do in part because they contain additional fixed nitrogen which plants can then absorb through their roots.
Nitrification cannot occur in the presence of oxygen, so nitrogen is fixed in specialized cells called heterocysts. These cells have an especially thickened wall that contains an anaerobic environment.
H2O Quality
Unicellular and filamentous blue-greens are almost invariably present in freshwater lakes lakes frequently forming dense planktonic populations or water blooms in eutrophic (nutrient rich) waters.
Cyanobacteria form in shallow, warm, slow-moving or still water.
Life Requirements
Most inhabit fresh water, but there are also marine species and symbionts that live along with fungi as lichens;
The main factors which appear to determine the development of planktonic populations are light temperature, pH, nutrient concentrations and the presence of organic solutes.
An oversupply of nutrients, especially phosphorus and possible nitrogen, will often result in excessive growth of blue-greens because they possess certain adaptations that enable them to out compete true algae.
The process of nitrogen fixation and the occurrence of gas vesicles are especially important to the success of nuisance species of blue-greens.
The majority of blue-greens are aerobic photoautotrophs: their life processes require only oxygen, light and inorganic substances.
In temperate lakes there is a characteristic seasonal succession of the bloom-forming species, due apparently to their differing responses to the physical-chemical conditions created by thermal stratification.
Species of the genera Nostoc, Lyngbya, Chamaesiphon and Gloeotrichia have been occasionally encrusting submerged plants.
An oversupply of nutrients, especially phosphorus and possibly nitrogen, will often result in excessive growth of blue-greens because they possess certain adaptations that enable them to out compete true algae.
Perhaps the most important adaptation is their positive buoyancy, which is regulated by their gas vesicles which are absent in true algae.
Causes of Blooms
The formation of water blooms results from the redistribution and often rapid accumulation of buoyant planktonic populations. When such populations are subjected to suboptimal conditions, they respond by increasing their buoyancy and move upward nearer to the water surface, Water turbulence usually prevents them reaching the surface. If, however, turbulence suddenly weakens on a calm summer day, the buoyant population may ‘over-float’ and may become lodged right at the water surface. There the cells are exposed to most unfavorable and dangerous conditions, like O2 super saturations, rapidly diminishing CO2 concentrations and intense solar radiation, which are inhibitory to photosynthesis and N2-fixation, causing photo-oxidation of pigments and inflicting irreversible damage to the genetic constitution of cells.
A frequent outcome of surface bloom formation is massive cell lysis and rapid disintegration of large planktonic populations. This is closely followed by an equally rapid increase in bacterial numbers, and in turn by a fast deoxygenation of surface waters which could be detrimental to animal populations within the lake.
Water blooms are objectionable for recreational activities, and more importantly, create great nuisance in the management of water reservoirs.
Usually the filamentous forms (Anabaena species, Aphanizomenon flos-aquae and Gloeotrichia echinulata) develop first soon after the onset of stratification in late spring or early summer, while the unicellular-colonial forms (Microcystis species) typically bloom in mid-summer or in autumn.
A mass of cyanobacteria in a body of water is called a bloom.
When this mass rises to the surface of the water, it is known as surface scum, or a surface scum bloom. mostly appear in the hot summer month - quite prevalent in the prairies.
Treatments
Farm dams can be protected from blue-green algae by dosing with alum and gypsum. These chemicals work by removing phosphorus (the most important nutrient for blue green algae) from the water.
Once cyanobacteria are detected in water, chemicals can be added that to clump cells together, sink, can be filtered out easily. other ways: oxidation processes or activated charcoal - filtering?
Remove phosphorus by dosing.
Dosing is only appropriate for farm dams.
Ideally, dosing should be carried out before summer, and certainly before a bloom has developed.
Do not apply the treatment to streams or billabongs or other natural waterways.
The recommended dose is 50 kilograms of alum and 50 kilograms of gypsum for each megaliter of water.
Because of variations in water quality and algae, it is advisable to conduct a preliminary trial in a 44 gallon drum
Dosing procedure: (for dams only)
---Add the granules of alum crystals to the water and mix well. You could perhaps use a boat with an outboard motor to mix in the crystals.
---Let the water stand for a few hours, and add the gypsum granules.
---Let the water stand for at least 24 hours, or until it clears. If it does not clear within two days, add 25 to 50 per cent of the recommended dosage of alum and gypsum to promote settling.
---After dosing, check the pH of the water with a swimming pool testing kit. The pH should be in the range 6-9. If it is not, allow the water to stand two days and check again.
Measures to control the growth of blue-greens
Chemicals are widely used to prevent the growth of nuisance algae, and the commonest one being copper sulphate. A number of other algicides are phenolic compounds, amide derivatives, quaternary ammonium compounds and quinone derivatives. Dichloron- aphthoquinone is selectively toxic to blue-greens. The hazards of using toxic chemicals indiscriminately in the natural environment are will documented.
Biological control is in principle possible, though not always practical and as effective. In vertebrates like cladocerans, copepods, ostracods and snails are known to graze on green algae and diatoms. Daphnia pulex has been reported to feed on Aphanizomenon flos- aquae while present in the form of single filaments or small colonies but avoid large raft-like colonies. The copepod Diaptomus has been implicated in the grazing of Anabaena populations in Severson Lake, Minnesota.
The long-term approach is no doubt the systematic removal of major nutrients.
Predation
Micro-organisms (fungi, bacteria and viruses) appear to play an important part in regulating growth of blue-greens in freshwater. Certain chytrids ( fungal pathogens) specifically infest akinetes, other heterocysts. Bacterial pathogens belonging to the group of myxobacterials can effect rapid lysis of a wide range of unicellular and filiamentous blue-greens, though heterocysts and akinetes remain generally unaffected. Viral pathogens belonging to the group of cyanophages exhibit some degree of host specifity. Phage AR-1 attacks Anabaenopsis, phages SM-1 and AS-1 are effective against the unicellular forms, Synechococcus and Microcystis, OHage C-1 lyses Cylindropermum, and the LPP-1 virus is effective against strains of Lyngbya, Phormidium and Plectonema.
Toxicology
Many others species of cyanobacteria produce populations that are toxic to humans and animals.
Blue-green pond scums have been linked to the poisoning of cattle and dogs, and occasionally people.
Nuisance/Noxious Conditions
Most of these conditions are produced by just three blue-greens, informally referred to as Annie (Anabaena flos-aquae), Fannie (Aphanisomenon flos-aquae), and Mike (Microcystis aeroginosa).
Poisonous Conditions
Poisonous blue-greens occur in ponds and lakes throughout the world. In Canada, they primarily occur in the prairie provinces.
Poisoning has caused the death of cows, dogs, and other animals. Although humans ordinarily avoid drinking water that displays a blue-green bloom or scum, they may be affected by toxic strains when they swim or ski in recreational water bodies during a bloom.
Typical symptoms include redness of the skin and itching around the eyes; sore, red throat; headache; diarrhea; vomiting; and nausea. The frequently occurring ‘swimmers itch’ is attributed to contact with Lyngba majuscula, Schizothrix calciola and Oscillatoria nigroviridis, which are commonly found in tropical and subtropical seawater. The toxins responsible are lipid-soluble phenolic compounds.
Since the same or similar symptoms can be produced by bacteria or viruses, one should not necessarily conclude that blue-greens are responsible for a human illness simply because the sick individual recently swam in a lake or pond that has suffered a bloom.
Human death has not been documented. Reported cases affecting humans list Anabaena as the main culprit.
Most of the recorded toxic blooms are caused by Microcystis aeruginosa, which manufactures “microcystin,” which yields 7 (or 14) amino acids upon hydrolisys. It causes enlargement and congestion of the liver followed by necrosis and hemorrhage, and may also exhibit neurotoxic activity.
they are made up of cells, which can house poisons called cyanobacterial toxins.
Cyanobacterial toxins are the naturally produced poisons stored in the cells of certain species of cyanobacteria. Some are known to attack the liver - hepatoxins, or the nervous system - neurotoxins, or irritate the skin. These toxins are usually released into the water when the cells rupture and die.
Hepatoxins - mostly produced and released by cyanobacteria called microcystis - first isolated from Microcystis aeruginosa.
Microcystins most common of cyanobacterial toxins, and most responsible for poisoning animals and humans who come in contact with toxic blooms. Can survive in both warm and cold water, can tolerate radical changes, including pH. 50 diff kinds of microcystins.
30 to 50 percent of cyanobacterial blooms are harmless, contain only non-toxic species of freshwater cyano. Blooms containing even one species of toxic cyanobacteria will be poisonous and potentially dangerous. No obvious way to tell if a bloom is toxic - must be analyzed in lab.
Many species of cyanobacteria produce populations that are toxic to humans and animals
Many toxic blooms are also produced by either Anabaena flos-aquae (manufactures “anatoxins”)
Alkaloid toxins act on the nervous system leading to paralysis of muscles needing to breathing.
Two other genera, Oscillatoria and Nodularia are also known to produce toxic populations. Whether the animal survives the poisoning depends primarily upon the concentration of the toxin ingested.
Blue-green toxins may act on zooplankton and might be an effective mechanism of protection against grazing pressures.
Little is known about the percent of blooms that are toxic, and also why a toxic bloom is considered a nuisance in recreational lakes and water supply reservoirs of North America, the near continuous blooms of blue greens in some tropical lakes are a valuable source of food for humans.
A complicating factor is that part of bloom can be toxic and another part nontoxic within the same lake. It has been suggested that toxic strains may develop only under a particular set of environmental conditions, or that toxin production may be associated with plasmid-mediated gene transfer.
Many other species of cyanobacteria produce populations that are toxic to humans and animals. Blue-green pond scums have been linked to the poisoning of cattle and dogs, and occasionally people. It is therefore not recommended that wild populations be gathered and eaten without some knowledge of the organisms involved.
Cyanobacteria may cause other problems as well; a species of Lyngbya is responsible for one of the skin irritations commonly known as “swimmer’s itch.”
Benefits
Their reputation as “nuisance” or “noxious” is totally undeserved. While periodic blooms are considered a nuisance in recreational lakes and water supply reservoirs in North America, the near continuous blooms of blue-greens in some tropical lakes are a valuable source of food for humans.
Some blue-green species make major contributions to the world food supply by naturally fertilizing soils and rice paddies.
R. N. Singh of the Banares Hindu University in India has shown that the introduction of blue-green algae to saline and alkaline soils in the state of Uttar Pradesh increases the soil’s content of nitrogen and organic matter and also their capacity for holding water. This treatment has enabled formerly barren soils to grow crops.
Astushi Watanabe of the University of Tokyo found the introduction of Tolypothrix tenuis resulted in a 20% increase of rice crop.
W. E. Booth of the University of Kansas showed through experiments in Kansas, Oklahoma, and Texas, that a coating of blue-greens on prairie soil binds the particles to the soil to their mucilage coating, maintains a high water content and reduces erosion.
The utilization of blue-greens in food production and in solar energy conversion may hold immense potential for the future, and could be exploited for man’s economy. Progress in the study of genetics of blue-greens may enable us to manipulate the N2-fixation (nif) and associated genes, and produce strains which fix N2, evolve H2 or release ammonia with great efficiency.
Some blue-green species make major contributions to the world food supply by naturally fertilizing soils and rice patties. Tokyo found the introduction of Tolypothrix tenuis resulted in a 20% increase of rice crop.
Humans also consume Spirulina. It contains all of the amino acids essential for humans and its protein content is high. It is a staple food in parts of Africa and Mexico. In China, Taiwan and Japan, several blue greens are served as a side dish and a delicacy.
Several areas in North America culture and commercially process certain blue-greens for various food and medicinal products such as vitamins, drug compounds and growth factors.
Classification
The principal groups of the blue-greens (with comparison of modern and early systems of classification) are as follows per the following sequence:
Section (Rippka et al. 1979)
Basic morphology
Reproduction
Plane of division
Order (family) Fritsch (1945)
Representatice general
Unicellular or colonial
I
Binary fission
Single
Gloeobacter
Chroococcales
Gloeothece, Synechococcus, (Anacystis, Agmenellum)
Two of more
Gloeocapsa, Chroococcus, Synechocysitis, Microcystis, Merismopedia
II
Unicellular of colonial
Budding
Chamaesiphonales
Chamaesiphon
Multiple fission
Dermocarpa, Dermocarpella, Chroococcidiopsis
Pleurocapsales
Xenococcus, Myxosarcina, Pleurocapsa, Hyella
III
Filamentous, non-differentiated
Trichome fragmentation, hormogonia
Single
Nostocales (oscillatoriaceae)
Oscillatoria, Microcoleus, Spirulina, Pseudanabaena,
Plectonema, Lyngbya, Phormidium, Schizothrix
IV
Filamentous, heterocystous
Trichome fragmentation, hormogonia, akinetes
Single
(Nostocaceae)
Anabaena, Aphanizomenon, Nostoc, Nodularia,
Anabaenopisis, Cylindrospermum
(Rivulariaceae)
Calothrix, Dichothrix, Gloeotrichia, Rivularia
(scytonemataceae)
Scytonema, Tolypothrix
V
Branched filamentous, heterocystous
Trichome Fragmentation, hormogonia, akinetes
Two or more
stigonematales
Masstigocoleus, Nostochopsis, Mastigocladus, Westiella,
Fischerella, Hapalosiphon, Stigonema, Chlorogloeopsis
(Chlorogloea)
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