Team:Michigan

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Project Background

Algae Bioflocculation for Biofuel Production and Bioremediation of Oil Sands Tailings Water

 Our team worked on two projects this year. Our first project aims to improve the economics of algal biofuel production by creating a cost efficient microalgae bioflocculant out of E. coli. To achieve this, we over-express Type I pili to increase the cell’s adhesiveness, and also express a chlorovirus protein on the cell surface which specifically binds Chlorella species, a promising algal feedstock for the biofuel industry.

 We are also participating in the Oil Sands Initiative and seeking to improve the biodegradation rate of naphthenic acids (NAs), a toxic by-product of the oil extraction process which can linger in the environment for decades. Two Pseudomonas strains have been found to synergistically degrade 95% of NAs. Our project focuses on engineering these Pseudomonas strains to form biofilms in the harsh tailings water environment, which can potentially increase degradation rates by two orders of magnitude, by expressing a self-associating E. coli protein.

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-Our team worked on two projects simultaneously this year: The Hy-Bi project and the Oil Sands Initiative:
+'''Algae Bioflocculation for Biofuel Production and Bioremediation of Oil Sands Tailings Water'''
-'''Hy-Bi'''
+  Our team worked on two projects this year. Our first project aims to improve the economics of algal biofuel production by creating a cost efficient microalgae bioflocculant out of E. coli. To achieve this, we over-express Type I pili to increase the cell’s adhesiveness, and also express a chlorovirus protein on the cell surface which specifically binds Chlorella species, a promising algal feedstock for the biofuel industry.
-The Hy-Bi project is in association with the Chemical Engineering department’s joint project to produce hydrocarbons from algae biomass, dubbed "Hy-Bi"[1,2]. This consists of hydrothermal processing of the algae followed by catalytic upgrading of the “bio crude” oil.  Before the hydrothermal processing can take place the algae needs to be concentrated from 1 to 10 g/L to over 250 g/L. Traditional methods that are used like centrifugation, filtration and chemical flocculation are costly.
+  We are also participating in the Oil Sands Initiative and seeking to improve the biodegradation rate of naphthenic acids (NAs), a toxic by-product of the oil extraction process which can linger in the environment for decades. Two Pseudomonas strains have been found to synergistically degrade 95% of NAs. Our project focuses on engineering these Pseudomonas strains to form biofilms in the harsh tailings water environment, which can potentially increase degradation rates by two orders of magnitude, by expressing a self-associating E. coli protein.
-For this project, we will be over-expressing type I pili and their associated adhesion protein, making a hyper-piliated, hyper-adhesive strain of E. coli. We hope that the extreme stickiness of the E. coli will turn them into an excellent bioflocculant- termed EcoGlue. In addition, we will also be expressing a virus protein which specifically binds to the algal species Chlorella vulgaris, a species of interest for harvesting algae oil. This protein will provide additional flocculation ability and specificity for this species. We hope that such a bioflocculant can provide a cheaper, safer alternative to chemical flocculants.
-'''Oil Sands'''
-Our team will also be working on the [[Oil Sands]] Initiative simultaneously. Tailings ponds have become a major ecological concern regarding oil sands operations due to the toxicity of the water. Oil sands companies are on zero discharge leases, so the tailings water must be held on site, which is done in retention ponds. The main cause of toxicity in tailings water has been identified as naphthenic acids (NAs), some of which can be very recalcitrant to degradation and persist in waters for decades. Thus, our will attempt to expedite the reclamation process. Two bacteria, ''Pseudomonas fluorescens'' and ''Pseudomonas putida'', were isolated from tailings pond sediments and found to be capable of synergistically degrading >95% of a commercial mixture of NAs resembling those found in the tailings water over a 4 week period [3]. In addition, two other bacteria have shown degradation efficiencies near 100% when in an immobilized cell reactor (ICR)[4], which functionally represents a biofilm. Following these findings, the strategy we wish to implement will be to utilize the two naturally adapted ''Pseudomonas'' species and genetically engineer them to optimize their biofilm formation abilities in tailings pond water-like conditions. This would allow for easier and improved use in an ICR. Alternatively, a more organic and aesthetically pleasing method would be to create a large 'slide' or 'washboard', where the naturally adapted ''Pseudomonas'' species would grow under a constant stream of tailings water, and function similar to an ICR.
-. http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=0937992<br>
-. http://che.engin.umich.edu/news/savagemakeoil.html<br>
-. Del Rio LF, Hadwin a KM, Pinto LJ, MacKinnon MD, Moore MM. Degradation of naphthenic acids by sediment micro-organisms. Journal of applied microbiology. 2006;101(5):1049-61. Available at: http://www.ncbi.nlm.nih.gov/pubmed/17040229.<br>
-. Paslawski J, Nemati M, Hill G, Headley J. Biodegradation kinetics of trans -4-methyl-1-cyclohexane carboxylic acid in continuously stirred tank and immobilized cell bioreactors. Journal of Chemical Technology & Biotechnology. 2009;84(7):992-1000. Available at: http://doi.wiley.com/10.1002/jctb.2122.