The BP oil spill began on April 20th, 2010 and leaked oil into the Gulf of Mexico at a rate of 35,000 to 60,000 barrels per day for a period of about three months. Various technologies have been deployed to attempt to collect or disperse the oil and to minimize damage to wildlife and property. This includes the use of about 1 million pounds of chemical dispersants to disperse the oil. The large-scale introduction of dispersants into the environment has led to an intense focus on the safety and environmental impact of these chemicals. The objective of this project is to develop "bio-dispersants" that are effective and minimally toxic to key organisms native to the Gulf of Mexico. The bio-dispersants will be produced by the natural process of fermentation. Specifically, microorganisms will be used to convert underutilized agricultural residue (for example, soybean hulls) into bio-dispersants. Gene engineering methods will be used in the laboratory to generate many different pure cultures of the microorganisms, each of which produces a different bio-dispersant. Each bio-dispersant will be purified, and the ability of each bio-dispersant to disperse oil will be measured. Bio-dispersants that are effective will be tested to determine whether they are toxic to key organisms, the benthic infauna, which are important members of the Gulf food chain and ecosystem. The objective of this research is to use iterative rounds of design, production and testing to discover bio-dispersants that are safe and effective. All significant findings from this work will be published promptly. All results and data collected as part of this research will be made available to other researchers.
Broader Impacts. The integration of computer design tools with robotic manipulation enables the use of cellular and molecular biology to produce new chemicals and materials. The field created by the convergence of computer science, robotics and biology is called "synthetic biology". There was a revolution in chemistry that occurred between 1930 and 1960, typically referred to as the "synthetic chemistry" revolution. It was during that period that scientists and engineers learned to use petrochemical feedstocks to produce the vast array of organic chemicals, polymers and plastics available to us today. We are in the early phase of a new revolution in chemistry. In particular, "synthetic biology" is enabling engineers to generate the chemicals and materials needed by our society from renewable raw materials, similar to the way "synthetic chemistry" enabled the production of organic chemicals from petroleum. Synthetic biology is enabling a "sustainable chemistry" revolution, which represents a significant opportunity for America because it depends on combining three areas of U.S. strength and excellence: agriculture, biotechnology and chemical manufacturing. According to the BIO Organization, sustainable chemistry could lead to the generation of $190 billion in domestic revenue from chemical sales, and to the creation or retention of 237,000 U.S. jobs. This research project represents a collaboration between a leading company in this important field, Modular Genetics, Inc. and scientists at three universities: Columbia University, Iowa State University and Louisiana State University. This project should simultaneously lead to the launch of new commercial products, and to the training of scientists and engineers prepared drive this industry forward.
This project investigated the production of biosurfactant, namely surfactin, and its variation fatty-acyl glutamate (FA-Glu) on biologocal substrates via fermentation. Feedstocks evaluated included glucose, and soybean hulls. Biosurfactants are amphiphilic compounds that function as emulsifiers and have dispersion activities, that would have potential benefits in oil spill applications. the following are the outcomes of this project: 1. Biosurfactants were produced by a genetically-engineered strain of Bacillus subtilis on a suitable carbon source, e.g., glucose. Aerating the medium produced foam which is enriched in surfactant. The foam was then further purified to yield a product >90% in a purity. 2. Alternative carbon sources were tested as feedstocks for FA-Glu production. Soybean hulls, and fibers were evaluated; commercial enzymes were needed to produce hydrolysates for use as feedstock. Identified blends of enzymes that produced maximum conversion of soy hull polysaccharides to fermentable sugars. 3. Determined optimum enzyme dosage and hydrolysis time for soy hulls pretreatment. Demonstrated that B. subtilis 40688-E4 produced more FA-Glu on hydrolyzed soybean hulls as on glucose. Also observed that B. subtilis 40688-E4 grew faster and to a greater extent on soy hull hydrolysates vs. glucose. 4. A red blood cell based toxicity measurement procedure, which was faster, was developed by showed that FA-Glu can cause hemolysis of red blood cells. Other pertinent information obtained were: A) FA-Glu concentrations required for hemolysis are much higher compared with surfactin, B) for both surfactants, a threshold level is required for hemolysis. Below this, no hemolysis is observed. The threshold for FA-Glu is ~50x higher than that for surfactin. C) Sensitivity to hemolysis roughly parallels sensitivity of fish in surfactant toxicity assays. Hemolysis may be a faster and more sensitive surfactant toxicity assay.
