The Influence of Biosurfactants on the Rate of Oil Spill Bioremediation BIOLOGICAL RESEARCH PROJECT BY EMILY MA

Introduction  Problem: Petroleum oil is a significant source of nonrenewable energy that contributes to sustaining society; however, an oil spill can have disastrous effects on the biodiversity and productivity of a marine ecosystem.  Solution: Bioremediation is an oil spill treatment that uses naturally occurring organisms to break down toxic substances into less hazardous ones. Bacteria play a crucial role in the biodegradation of oil by producing biosurfactants.

A disastrous oil spill occurring in the Gulf of Mexico, which killed thousands of marine organisms and had lasting effects on the environment

Limiting Factors to Bioremediation Temperature Low temperatures can hinder the biodegradation process because molecules move at a slower rate, and the impact of some molecule collisions would not be strong enough to bring about a reaction. Oxygen Oxygen is also necessary because it is needed for aerobic hydrocarbon degradation reactions, one of the processes essential for bioremediation. Nitrogen and Phosphorus In addition, bacterial metabolism requires certain amounts of nitrogen and phosphorus as sources of nutrients.

Physical Status of an Oil Spill The distribution of oil in the water spreads throughout the depth of the ocean. The lighter potion of the oil normally spreads and forms a thin layer on the top of the body of water Most of the oil emulsifies and dissolves in the mid- potion of the water. Some denser potions of oil sink to the bottom of the ocean. The release and distribution of oil in the water column due to the differences in physical status and density of the oil that was released

Types of Bacterial Biosurfactants Low molecular weight  Structure -usually glycolipids, in which carbohydrates are attached to a long chain of aliphatic acid or lipopeptides  Benefits -efficiently lowers surface and interfacial tension and has a high specificity  Setbacks -Cannot bind tightly the surface molecules and less effective in preventing the combination of oil molecules High molecular weight  Structure -this kind of bacterial biosurfactant are composed of polysaccharides and other high weight molecules  Benefits -Efficient at coating oil droplets, prevents coalescence of oil, and has a high specificity  Setbacks -less effective at reducing surface tension

Design  Since high molecular weight and low molecular weight biosurfactants essentially do different tasks, creating genetically modified bacteria that would produce both types of biosurfactants would increase the rate of bioremediation.  Producing a bacteria that can synthesize and regulate the production of rhamnolipids (a low molecular weight biosurfactant) and alasan (a high molecular weight biosurfactant) would be a very effective way to treat oil spills

Types of Biosurfactants Used Alasan  Th is biosurfactant is composed of an anionic polysaccharide and a protein with a high molecular weight and is covalently bound to alanine, an enzyme  Alanine plays an important role in the structure and function of alasan  Allows this biosurfactant to become more effective in stabilizing oil emulsions and in solubilizing hydrocarbons Rhamnolipids  Rhamnolipids are a class of glycolipid produced by multiple species of Pseudomonas and it has a low molecular weight  Pseudomonas aeruginosa has the ability to metabolize an array of substrates, including n-alkanes, hexadecane and oils  The rhamnolipids are able to emulsify the oil and lower interfacial, and in turn, increase the rate of uptake in bacteria

T his system consists of the following parts  gene that enables the cell to produce rhamnolipids  gene that enables the cell to produce alasan  a sensor that would detect the presence of hydrocarbons in the oil spill (Lacl)  a regulator to transform the signal and activate the promoter (IPTG)  promoter to turn on the gene  open reading frame (Plac) that will ultimately produce alasan  a sensor that would detect the presence of alasan  a regulator to transform the signal and activate another promoter  another promoter to turn on the gene  open reading frame that will produce rhamnolipids  the terminating sequence  Pseudomonas aeruginosa

Under the Presence of Hydrocarbons: 1)The hydrocarbon sensor is stimulated 2)IPTG is activated and it transforms the signal 3)This activates the promoter 4)The Plac gene is turned on and it starts to produce alasan Hydrocarbon sensor (Lacl) Presence of hydrocarbons Regulator (IPTG) Open reading frame (Plac) on Alasan is produced

Under the Presence of Alasans: 1)The alasan sensor is stimulated 2)The regulator is activated and it transforms the signal 3)This activates the promoter 4)A certain gene is turned on and it starts to produce rhamnolipids Alasan sensor Presence of alasan Regulator Open reading frame on Rhamnolipids are produced

when there are no hydrocarbons present, then no chemical reaction would take place and neither alasan nor rhamnolipids would be produced when there are hydrocarbons present, both alasan and rhamnolipids would be produced. HydrocarbonsAlasanRhamnolipids Truth Table

Potential Problems  One of the main problems in this design is the possibility of Pseudomonas aeruginosa overpopulating and an algae bloom occurring  Overall there is a low risk factor for this design, and it is a quick and efficient way to speed up the rate of oil spill bioremediation

Testing Rhamnolipids Tests the effects of adding only rhamnolipids to an oil spill simulation Alasan Tests the effects of adding only alasan to an oil spill simulation Rhamnolipids and Alasan Tests the combined effects of adding rhamnolipids and alasan to an oil spill simulation

Bibliography  ation_of_the_biosurfactant_produced_by_Pseudomonas_aeruginosa_DAUPE_614 ation_of_the_biosurfactant_produced_by_Pseudomonas_aeruginosa_DAUPE_614      ecosystem#.VZPqbPlViko ecosystem#.VZPqbPlViko   