Photosynthetic Cyanobacteria
have chlorophyll a and carotenoids in addition to some unusual
accessory pigments named phycobilins. The blue pigment,
phycocyanin and the red one, phycoerythrin,
absorb wavelengths of light for photosynthesis that are missed by chlorophyll
and the carotenoids. In biochemical detail, Cyanobacteria are especially
similar to the chloroplasts of red algae (Rhodophyta). Cyanobacteria
prefer a neutral to alkaline pH (6.5 to 9) and will not
grow in an acidic environment. Relative to other oxygenic
phototrophs, Cyanobacteria often grow under fairly extreme environmental
conditions such as high temperature and salinity, and will even form 3 inch
thick mats below an ice layer in the arctic. Cyanobacteria also appear
to prefer waters that have higher levels of phosphorus than ammonia, since
they can "fix atmospheric nitrogen" into water-soluble ammonia-nitrogen,
whenever nitrogen becomes limited in the environment. The other major class
of pigments present in Cyanobacteria are the carotenoids. These are
hydrocarbon-like pigments, similar in structure to vitamin A and found in
all photosynthetic organisms. The colors of the sheaths in different species,
include light gold, yellow, brown, red, green, blue, violet, and
blue-black, impart color to individual cells and colonies as well
as to "blooms" of Cyanobacteria in aquatic environments.
As true Bacteria, Cyanobacteria
contain peptidoglycan or murein in their cell walls. Most Cyanobacteria
have a Gram-negative type cell wall that consists of a deeply pigmented
outer membrane component, which is a mucilaginous sheath, even though
they show a distant phylogenetic relationship with Gram-positive bacteria.
Some of the filamentous Cyanobacteria are motile by means gliding
or rotating around a longitudinal axis. Short segments (hormogonia) may
break off from a Cyanobacterial colony and glide away from their
parent colony at rates as rapid as 10 micrometers per second. The mechanism
for this movement is unexplained but may be connected to the extrusion
of slime (mucilage) through small pores in their cell wall, together
with contractile waves in one of the surface layers of the wall. x Cyanobacteria
form filaments and may grow in large masses or "tufts"
one meter or more in length. Some strains are unicellular, a few
form branched filaments, and a few form irregular plates or irregular colonies.
Cyanobacterial cells usually divide by binary fission, and the resulting
progeny cells may separate to form new colonies. In addition, filaments
may break into fragments, called hormogonia, which separate
and develop into new colonies. Some species of Cyanobacteria form
resistant spores, called akinetes, enlarged cells around
which thickened outer walls develop. Akinetes are resistant to heat, freezing
and drought (desiccation) and thus allow the Cyanobacteria
to survive unfavorable environmental conditions. They are functionally
analogous to bacterial endospores, but they bear little resemblance and
lack the extraordinary resistance properties of endospores.
Although many species of Cyanobacteria
cause very few harmful effects on plants or animals, if they bloom
in large numbers and then die and decay in aquaculture ponds, lakes,
reservoirs, rivers, etc., they increase the BOD (biological oxygen demand),
which robs fish and other aquatic residents of their required dissolved
oxygen Related dino-flagellates have drawn a lot of public interest since
scientists discovered that runoff from CAFO's into rivers in the state of
Maryland, USA, caused these dinoflagellates to deliver the potent neurotoxin,
Saxitoxin to shell-fish found in these rivers. Death by paralytic
shellfish poisoning awaited animals and humans consuming these poisoned
bivalves. Anabaena flos-aquae,[1] Aphanizomenon flos-aquae and
Anabaena circinalis are species of the Nostocales Order of
the Cyanobacteria phyllum, reported to be responsible for producing
the highly potent neurotoxins, Saxitoxin, Microcystin LR, Nodularin
L , Anatoxin-a and Aplysiatoxin,[2], which are
contained within the cell until they are lysed, ingested by animals, or
the cells simply become old and leaky. Cell lysis usually occurs when the
water is treated with a chemical, biocide such as copper sulfate. A Brazilian
paper cites production of additional toxins by Microcystis, Planktothrix,
Lyngbya and Cylindrospermopsis raciborskii [3]. Other reports
have suggested that ALL species of Cyanobacteria produce "cyanotoxins"
and "cyanide" when killed rapidly. Geosim, a
cause of off-flavors in fish, is similarly released by
Cyanobacteria, when cells are stressed by fish/animal ingestion or
by application of a biocide to the pond, lake, reservoir or river where
they reside
Alken-Murray is only aware of one
Saxitoxin 96-well ELISA kit , manufactured by Abraxis, LLC, with a range
in water of 0.02 – 0.4 ppb (ng/mL)., which can be purchased from
Environmental Assurance
Monitoring LLC. EAM also offers kits to detect mycrocystins, nodularins,
yessotoxin, cylindrospermopsin and domoic acid. This link is also available
from our supplier links page.
A new system of classification for
the phyllum Cyanophyte has been proposed by by Komárek and
Anagnostidis , as found on the internet by Alken-Murray President, Valerie
Anne Edwards at http://www.nessling.fi/symposiot/Symposio1/eloranta.htm
- Order Chroococcales is
assigned to ALL unicellular Cyanophytes. Seven (7) clearly distinguished
families comprise this order.
- Order Oscillatoriales is
characterised by simple filaments without branching or false branching
and without heterocytes
- Order Nostocales is characterised
by filamentous species sometimes with false branching, but always with
heterocytes
- Order Stigonematales is
characterised by filamentous species with true branching
Many of the species of Cyanobacteria
known for releasing harmful toxins into aquatic environments belong to the
order Nostocales, especially Anabaena flos-aquae, Anabaena circinalis,
Anabaenopsis, Nostocaida limicola, Aphanizomenon flos-aguae, and Cylindrospermopsis,
while other trouble-makers, including Planktothrix and Lyngbya
belong to the Order Oscillatoria. Additional filamentous species
cause serious interferences for municipal and industrial wastewater treatment
plants by producing a biosurfactant that enables them to spread in an ultra-thin
layer atop a bulking mass of foam that interferes with process control.
Cyanobacteria rarely develops into a dominant nuisance
in seriously polluted or eutrophic ponds, lakes, lagoons, rivers, canals
or streams because macro-algae and aquatic plants, including water lilies,
ferns, cat tails, duck weed, etc. grow rapidly, taking up significant physical
volume as they ingest BOTH dissolved and suspended pollution from the water
column, as they dig their roots into the rich organic sludge found at the
bottom of polluted, eutrophic water bodies. Once the water column of a lake,
pond, reservoir or river has been bioremediated by application of the correct
Alken Clear-Flo 1000 series products
(usually a combination of Alken Clear-Flo
1006 and Alken Clear-Flo 1100-50x,)
and the organic sludge layer has also been digested by application of
Alken Clear-Flo 1005, the environment
will no longer attract overgrowth of algae and plants that would otherwise
inhibit invasion by Cyanobacteria. Thus, the cleaner and more pristine
a water body becomes, the more susceptible to Cyanobacteria invasion
it becomes. Wastewater treatment system managers have learned that allowing
their system to develop a low F/M (food to biomass) ratio will favor development
of filamentous Cyanobacteria, especially when nitrogen is a growth-limiting
nutrient in the particular system. When these conditions combine, Cyanobacteria
will produce a sugary biosurfactant (Nocardia amarae is known to
produce the biosurfactant "Trehalose") that allows them to spread
out into an ultra-thin layer, floating on the surface above a cushion of
brown, sticky foam. Presenting a higher ratio of surface area to volume
allows Cyanobacteria a selective advantage for securing nutrients
in nutrient limited environments. Utilizing their ability to "fix atmospheric
dinitrogen" into "water-soluble ammonia-nitrogen" along with
their limited ability to utilize sunlight to help them "fix carbon
dioxide" into "water-soluble organic carbon compounds" changes
the rate-limiting nutrient, which they MUST obtain from the water column,
into water-soluble phosphate (also labeled ortho-phosphate). Cyanobacteria
LACK acid tolerance, thriving in a neutral to alkaline pH range(6.5
to 9). If fish and other desired species in a water-body covered in Cyanobacteria
can tolerate pH changes, it is possible to adjust the environment so that
it is less appealing to overgrowth of Cyanobacteria. Follow directions
below:
- Titrate, in the laboratory,the
amount of hydrochloric (Muriatic) acid necessary to reduce pH to the range
of 5.5 to 6.0 for a few days.
- Titrate, in the laboratory,
the amount of natural "dolomitic limestone" (calcium and magnesium
carbonate) necessary to convert all soluble phosphate into small bound
rocks of calcium and magnesium phosphate, removing this important food
source from the resident Cyanobacteria
- Adjust the actual dosage of
dolomitic limestone to the aquatic body so that final pH is NOT allowed
to increase above 6.5, while a majority of soluble phosphate has been removed
from the water column.
- If mechanical aeration is available,
increase blower speeds, so that dissolved oxygen levels remain above 5
mg/L (ppm) during the entire treatment. Maintaining high levels of DO will
inhibit bacteria from solubilizing bound phosphate and polyphosphate polymers.
Alken-Murray uses three strains known to solubilize phosphate under anaerobic
conditions. Alken Clear-Flo 1000 used to be the primary Bacillus
treatment ordered by aquaculture hatcheries, for its ability to increase
growth of desired micro-algae. Extensive laboratory tests finally revealed
that Bacillus subtilis (strain 003) and Bacillus thuringiensis
(strain 679), in Alken Clear-Flo 1000, were responsible for solubilizing
bound phosphates into the water column, within 12 hours. Although we still
use that BT strain in a variety of other formulas, we offset its phosphate-solubilizing
activity by including one of our vegetative, gram-negative PAB (Polyphosphate
Accumulating Bacteria) to help offset their activity.
Alken-Murray has devised an aquatic
treatment product to address the most serious problems caused by overgrowth
of filamentous Cyanobacteria, a product offered to our aquatic clientele
under the name Alken Clear-Flo 1015,
which is headlined by an exceptionally talented bacterial strain, Bacillus
megaterium (strain AMC 300), which degrades cyanide, FOG (food Fats,
Oils and Greases) ,a favorite diet of Cyanobacteria, and "Trehalose"
the primary biosurfactant produced by Nocardia amarae, the best known
filamentous troublemaker found in municipal wastewater treatment facilities,
notorious for causing disruptive foaming, bulking and violation of NPDES
discharge permits. Supporting this special star are six other strains that
target "Trehalose" in our general formula, and .three in the "C"
version that is contains organisms and chemistry that comply totally with
the Canadian DSL. One of the
Trehalose-digesting strains of Bacillus also digests both long and
short-chain fatty acids, further reducing availability of food that interests
filamentous Cyanobacteria.To ensure that ALL surfactants present
in an aquatic body will be fully digested, the strains specializing in Trehalose
and other natural biosurfactants (including those based on Glucose, Fructose,
Glycine, Rhamnose & Ornithine) supported by a pair of Pseudomonas
putida (strains 151 & 483) that digest a variety of chemical surfactants,
including nonylphenols, linear and branched ethoxylated alcohols and sulfonated
surfactants. To deliver better protection of farmed crops from accidental
introduction of phenolic sanitizers and related compounds, two strains of
Pseudomonas putida (usually strains 369 & 800) were conscripted
from our industrial phenol-degrading formula, Alken
Clear-Flo 7002 into Alken Clear-Flo 1015,.
Strains selected for this
product are comfortable functioning within the same temperature and pH range
enjoyed by the filamentous species, so that competition could be encouraaged,
but we added a soil-isolated Bacillus laevolacticus (strain 494)
to digest proteins and amino acids through excursions down to pH 3, along
with a Sporosarcina pasteurii (strain 453) , formerly identified
as Bacillus pasteurii, to digest FOG up to pH 10. A dosage of 0.56 ppm of Yucca schidigera
leaf extract is included in Alken Clear-Flo®
1015 , enhancing bacterial access to the biosurfactant(s),
produced by various filamentous species, but Yucca schidigera
also inhibits activity of the urease enzyme, commonly produced by fecal
bacteria, converting urea into undesirable excesses of ammonia-nitrogen.
. Alken Clear-Flo® 1015 should
be applied in the specific SAFE dosage prescribed by your Alken-Murray distributor,
taking into account the size of your lake/pond and the oxygen level present.
Read our tutorial "Control Foaming
in Wastewater Caused by Filamentous Bacteria" [5]and then study
related microbial treatment, Alken Clear-Flo
7015. When Yucca schidigera concentration is kept at
our dosage level, 0.56 ppm, a concentration that is well below the Yucca
schidigera toxicity level of 5 ppm, fish are unlikely to suffer suffocation,
as they do when surfactants, including Yucca schidigera, Aloe vera
and other plant-based surfactants (coconut, soy, corn, etc.)prevent fish
gills from trapping oxygen bubbles, causing mechanical suffocation.
Unfortunately, it is unlikely that
a small enough dosage of Alken Clear-Flo®
1015 could be calculated for use in an aquarium. Alternative
strategies for aquarium owners include a temporary pH adjustment to 6.0
, changing all bulbs, fluorescent fixtures etc. to eliminate the undesirable
spectra that encourage Cyanobacteria. The aquarium owner can also
use Alken
Clear-Flo 1100 or Alken Clear-Flo 1100-50x to
eliminate ammonia, one form of nitrogen used by saprophytic bacteria and
Cyanobacteria.. Although most species of Cyanobacteria are
aerobic, adjusting aeration levels proves more effective in wastewater applications
than in lakes and ponds, where fish, crustaceans, protozoa, etc. all require
sufficiently high levels of dissolved oxygen for survival to classify any
attempt to control species of filamentous Cyanobacteria by controlling
the concenration of DO in the water a risky protocol with very little chance
for success and a high probability of imperiling the fish and crustaceans.
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