1. Biosurfactants: Let Bacteria Clean Your Dishes
Kate Jacewicz
Natural Science 2201
Winter 2015
Dr. Dinesh Mategaonkar

2. “A Typical Day of Surfactant Bacteria Hard at Work”

3. What does cleaning your dishes and cleaning up an oil spill have in common?
They are both done by with the assistance of the same microorganism
Pseudomonas aeruginosa
This bacteria…
Acts as a BIOSURFACTANT (“soap-like” substance, natural; not derived from chemicals) (1)
SUSTAINABLE and therefore NOT HARMFUL to the environment (1)
Has enzymes catalase, oxidase, peroxidase to aid in bioremediation (2)

5. What is a Biosurfactant?
An organic compound that has ampiphilic properties (3)
Has both a hydrophilic head (water-loving) and a hydrophobic tail (water-repelling)
As a result: has both soluble and insoluble water characteristics
Attaches to both oil and water to adhere them together
There is a leading practical application for sustainable cleaning which can be categorized as a “biological soap” called a BIOSURFACTANT (Medical Daily, 2013). It has been experimentally evidenced to eliminate the formation of “coffee rings” in dishes (2).
The principle is a vital step in bioremediation (3)
genetically modified petroleum hydrocarbon-degrading bacteria digest the crude oil particles
transform them into harmless carbon by-products, such as carbon dioxide and water
effectively treat water and soil that has been polluted by heavy metals and crude oil.

7. How were biosurfactants discovered?
Scientists have observed that when a bacteria- containing water particle is placed on a petri-dish in the lab, there is a proportional dispersion of the cells as the water vaporizes. After adding bacteria that has been specifically engineered to prevent production of the major biosurfactant component called a rhamnolipid, the resulting evidence was the formation of “coffee rings” (1)

8. How are biosurfactants produced?
Synthesis of biosurfactants is based on the alteration of the amino acid sequence so that it contains specific inserted DNA particles through plasmids that specialize in causing the bacteria to have specific characteristics in their genetic makeup and cell surface, which scientists use to focus on its ability to clean up an oil spill (4)
Insertion of a plasmid from other bacteria with useful qualities of enzymes (4)
Rhamnolipids, for adhesion of substrate (oil, grease) with bacteria
Ensures effective interaction between the particles and the bacteria.
Often function with supplementary microorganisms which also have important hydrocarbon-degrading enzymes, such as Bacillus subtilis (5)
Awareness of antagonism in bacteria that participates simultaneously

9. Bioengineering of a Surfactant-inducing Bacterium

10. Circular DNA plasmid being inserted into a bacteria (bottom green arrow)

11. How does this method work?
Autophagy = “digestion” upon coming in contact with the oil particles. The surface of the Pseudomonas becomes hydrophobic, which encourages the cell to adhere to the oil, which is the substrate for the bacterial enzymes (1). The bacteria acts as a “phagosome”, a digesting type of a microorganism. The rhamnolipids that have been secreted cause the substrate to emulsify and get uptaken by the Pseudomonas cell (5)

12. The Hydrocarbon-degrading Mechanism
The primary basis for this method is to utilize the enzyme activity that is imposed by these bacteria. The rhamnolipid is an important component because it metabolizes the long chains of hydrocarbons that make up crude oil.
The parallel hydrophobic/hydrophilic behavior make it effective to promote adhesiveness particles.
-stimulates interaction between the substrate (oil) and the bacteria
-assist bacteria in forming “micelles” oil-adhering particles (5)

13. A Micelle: has a hydrophobic exterior, hydrophilic interior particle, contains “captured” oil inside (4)
Adhesive “soap-like” interaction between microbes with enzymes and contaminants (oils, greases, effluents, heavy metals) (5)

14. How effective is it?
The rate of debris elimination depends on the concentration of bacteria. Usually there is a 10-15% efficiency rate per day (6)
Can take up to 2 weeks to clear an oil spill, depending on the amount and surface area covered, amount of bacteria present and any antagonism (6)
Necessary to use in combination with other microorganisms (Bacillus subtilis) for overall impact because they contain the enzymes in correct proportion to break up the hydrocarbons and degrade them into harmless carbon dioxide and water (6)

15. Pseudomonas aeruginosa in Nature
Apart from surfactant production, Pseudomonas is an opportunistic pathogen that is very resistant to antibiotics due to its sophisticated ability to evade the host cell’s phagocytosis. It infects individuals who have pre-existing infections or immune disorders; therefore, it takes the opportunity to use the host’s health compromising conditions as a way to thrive (5)
develops a parasitic relationship with the host (5)

18. How does this method relates to sustainable household cleaning?
More synthetics replaced with biodegradeable solutions (4)
Non-toxic, so the run-off would not result in negative effects of nearby habitats and ecosystems (4)
Affordable
Effective

19. Potential Future of Bioremediation

20. References
1. Bioremediation Discussion Group Retrieved from on March 28, Bioremediation of Crude Oil Polluted Soils Retrieved from on March 27, National Institute of Advanced Science and Technology. Production of biosurfactants and their functional developments Retrieved from chemmaterial_e.htm on March 28, Marti M., & Colonna W. (2013). Production and characterization of microbial biosurfactants for potential use in oil-spill remediation. Enzyme and Microbial Technology, 53(3). 5. Raheb J., & Hajipour M. (2011). The Stable Rhamnolipid Biosurfactant Production in Genetically Engineered Pseudomonas Strain Reduced Energy Consumption in Biodesulfurization. Taylor & Francis Online: Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 33(22). 6. Screening for Biosurfactant-producing Yeast: Confirmation of Biosurfactant Production (2014). Retrieved from retrieved on March 27, 2015.