CHEM409: Natural organisms, a mean to Eradicating
Zebra Mussel from freshwater bodies
Bacteria, a food source of Zebra Mussels.
Zebra mussels naturally feed by filtering food off water column. As a result, it consumes bacteria and
other microorganisms including phytoplankton as its food (Vaughn et al 2008). To verify that zebra
mussel utilize bacteria as its sole food source, a group of researchers conducted an experiment by
collecting a sample of zebra mussels and isolated them in an artificial river water for three months
without feeding. During these three (3) months periods, mussels’ physiological responses were recorded.
On monthly intervals, 10 animals were removed and analyzed for physical signs of starvation. By the end
of three months when starvation was evidence, zebra mussels were fed with bacteria and their starvation
recovery responses recorded. Subsequently; results shown starvation recovery, which confirmed
hypothesis that zebra mussels feed on bacteria (Fisher et al 2000). Figure (1) shows mussel filter-feeding
on microorganisms by inhaling and exhaling water.
Figure (1): Mussel filter-feeding
Bacteria toxins may eradicate Zebra Mussels.
A promising method of eradicating zebra mussel is Zequanox. Developed by Marrone Bio Innovation,
Zequanox is a commercial name for a biological control product that kills zebra mussels (Moore et al
2009). It is derived from a naturally occurring pseudomonas fluorescens bacterium (Marrone Bio
Innovation, 2012). Researchers gained interest in this breed of bacteria when it was hypothesized that
bacteria in nature, have toxins that may be used to eradicate aquatic pests. In identifying the “North
American isolate”, strain (breed) pseudomonas fluorescens CL145A (pf-CL145A), researchers screened
over 700 bacterial strains. Subsequently, they identified 10 strains of pseudomonas fluorescens that are
lethal to zebra mussel. When laboratory tested, only pf-CL145A was found to be highly toxic to zebra
mussels. Although pf-CL145A is toxic to zebra mussel, it shows no sign of toxicity to it when filterfeeding (Molloy 2007). The figure below shows mussel’s digestive system, a part that is highly
susceptible to bacteria toxins (pf-CL145A).
Figure (2): Mussel’s digestive system
Pseudomonas Fluorescens CL145A (pf-CL145A) destroys Zebra Mussel’s Digestive System
When zebra mussel consume high dosage of strain pf-CL145A bacteria, toxic substance contained in
bacterial cells cause damage to its digestive system and dies (Mayer 2008). This bacterial strain destroys
zebra mussel’s digestive system, even when its cells are dead (Moore et al 2009). Moreover, Mayer
(2008) describes that this bacterial product is highly effective under appropriate environmental factors.
These factors include water temperature, oxygenation, turbidity and chemistry, to name a few. The
technique are laboratory developed and shows significant success rate in eradicating zebra mussels
greater than 90%, while causing no harm to non-targeted microorganism (Molloy & Mayer 2007).
“The toxicity of the bacterial product is highly specific to quagga and zebra mussels. At dosages
that produce high mussel mortality, no bacteria-induced mortality has been observed among any
of the non-target species tested, including fish, ciliates, daphnids and native bivalves. Mammalian
toxicological studies predict human safety when working with this product ” Mayer 2008..
Molloy also explains that this technique is better in controlling zebra mussels, as opposed to the use
chlorine which cause adverse effect to ecosystem. Figure (3a) shows normal blood cells, figure (3b)
shows mussel’s affected blood cells.
Figure (3): Image showing mussel’s digestive system destroyed.
(3a)
Figure (4): graph showing mussels’ percent (%) mortality rate.
(3b)
How does it’s chemistry work in killing zebra mussels? (subject to more research) later!!!
+
Zebra
mussel
digestive
enzyme
The compound consist of 2,4-Diacetylphloroglucinol (IUPAC name: 1-(3-acetyl-2,4,6trihydroxyphenyl)ethanone, which is found in pf 145a.
2,4-Diacetylphloroglucinol (IUPAC name: 1-(3-acetyl-2,4,6-trihydroxyphenyl)ethanone) is a natural
phenol found in specific strains of the Gram-negative bacterium Pseudomonas fluorescens. This
compound is found to be responsible for the antiphytopathogenic[1] and biocontrol[2] properties in these
strains.
http://en.wikipedia.org/wiki/2,4-diacetylphloroglucinol
Reference
Denise A. Mayer, D., A., (2008). US House of Representatives Committee on Natural Resources
Subcommittee on Water and Power. Retrieved October 6, 2012 from
http://naturalresources.house.gov/uploadedfiles/mayertestimony06.24.08.pdf
Digestive System (2012) Diversity of animal system. Image retrieved October 9, 2012, from
http://diversityofanimalsystems.wikispaces.com/Digestive+System
Ficher, M. E.,Nierzwicki-Bauer, S. A., Parsons, R.H., Vathanodorn, K., Waitkus, K. R., (2000).
Interaction between zebra mussels (Dreissena polymorpha) and microbial communities.
Canadian Journal of Fisheries and Aquatic Science. Retrieved October 7, 2012 from
http://search.proquest.com.ezproxy.lib.ucalgary.ca/docview/219322225/fulltextPDF?accountid=9
838
Molloy, D. P., Mayer, D. A., (2007). Overview of a Novel Green Technology: Biological Control of
Zebra and Quagga Mussels with Pseudomona fluorescens. New York State Museum. Retrieved
October 6, 2012 from http://www.aquaticnuisance.org/wordpress/wpcontent/uploads/2009/01/Dreissena%20 Novel%20Green%20Technology%20
for%20Dreissena%20Control%20%284%29%20Malloy.pdf
Moore, R.,Wiers, A., Phillips, S., Williams, G., (2009). Paradise Lake Management Plan. Biological
Stations, University of Michigan. Retrieved October 7, 2012 from
http://141.213.232.243/handle/2027.
42/64840?mode=full&submit_simple=Show+full+item+record
Mussels and Clams (Bivalvia) (2012). The living world of Molluscs. Image retieved October 9, 2012,
from http://molluscs.at/bivalvia/index.html?/bivalvia/main.html
Vaughn, C. C., Nichols, S. J., Spooner, E. D., (2008). Community and food web ecology of freshwater
mussels. Journal of North American Benthological Society. Retrieved October 6, 2012 from
http://www.jnabs.org/doi/abs/10.1899/07-058.1
Zequanox Overview (2012). Zequanox Invasive Mussel Control. Marrone Bio Innovation Website,
Retrieved October 7, 2012 from http://marronebioinnovations.com/products/zequanox/
Good one
(http://www.minnesotawaters.org/group/whitefish/zebra-mussel-control-experiments )