Progress 09/01/07 to 11/30/10
Outputs OUTPUTS: I was appointed as PI on this project on August 4, 2010, after PI Dr. Katherine Taconi had left the University of Alabama in Huntsville. The bulk of the research was conducted by Dr. Taconi and her results have been published, see below. Research results obtained between August 2010 and October 2010 were presented at: UAH Bioretreat, a symposium by the UAH Biological Sciences Department on October 1, 2010; Poster title: "The effect of Fatty Acids on the Metabolism of Biodiesel-derived Crude Glycerol on Clostridium pasteurianum ATCC 6013" and at the AIChE meeting that was held in Salt Lake City from November 8-12, 2010; Poster title: "The effect of Impurities in Biodiesel-derived Crude Glycerol on the Growth and Fermentation by Clostridium pasteurianum ATCC 6013". This award supported Ph.D. student Keerthi Venkataraman, Biotechnology Ph.D. program, and it supported in part undergraduate student Judy Boatman, Department of Chemical Engineering. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Audience interested in sustainable resources PROJECT MODIFICATIONS: PI Dr. Taconi left UAH, Dr. Scholz was responsible for finishing the project and mentoring the graduate student.
Impacts My report will summarize the results achieved under my supervision. From August through November, 2010 we concentrated on the study of the impact of impurities on the butanol production by Clostridium pasteurianum. Crude glycerol contains a variety of impurities, mainly salts and residual fatty acids. We determined gravimetrically that the residual fatty acids content is approximately 10% by weight. We hypothesized that these residual fatty acids are the cause for the observed unsteady growth when the organism is grown on crude glycerol. Purifying crude glycerol by precipitating the fatty acids yielded a semi-crude glycerol on which the microbial growth rate and butanol production were identical to those of pure glycerol. The impact of other impurities (Methanol, KCl, K2SO4) was tested by adding these to pure glycerol and using the resulting mixtures in fermentation experiments. It was determined that none of these impurities impeded the growth rate or butanol production by this organism.
Publications
- Taconi, K.A., Venkataraman, K.P., Johnson, D.T. Growth and Solvent Production by Clostridium pasteurianum ATCC 6013TM Utilizing Biodiesel-Derived Crude Glycerol as the Sole Carbon Source American Institute of Chemical Engineers, Environmental Progress and Sustainable Energy, 2009, 28 (1) 100-110.
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Progress 09/01/08 to 08/31/09
Outputs OUTPUTS: The PI continues to mentor one Ph.D. student who is completing the research as part of his dissertation requirements. This student has completed multiple experiments evaluating various parameters to optimize the conversion of biodiesel-derived crude glycerol into butanol. In addition, three undergraduate students have also been mentored on a special project to evaluate the liquid-liquid extraction of butanol from fermentation broth using biodiesel. One local community college student also completed an internship working on the project in the PI's lab. The Ph.D. student was awarded 1st place in a poster presentation competition at a regional biotechnology retreat. The PI has presented the research at one national conference and several invited conferences/seminars. The PI was also a featured speaker at the 2009 Genes to Products USDA CSREES annual project directors' meeting. PARTICIPANTS: Keerthi Venkataramanan, PhD student; Lalleh Adhami, Undergraduate student; Bennie Griggs, Undergraduate student; Patrick Himebrook, Undergraduate student; Patricia Curtis, Undergraduate Student TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts The PI's research group has demonstrated significant production of butanol by Clostridium pasteurianum using biodiesel-derived crude glycerol as the sole carbon source. In addition, butanol yields on crude glycerol are comparable to those obtained when purified glycerol is used, indicating that this organism has a good tolerance to the impurities found in crude glycerol. We believe we are the first research group to have demonstrated production of butanol using crude glycerol. We have also evaluated a number of parameters, including iron concentration, pH, and crude glycerol concentration, and are quantifying the effects of these parameters on product formation.
Publications
- Taconi, K., Venkataramanan, K., and Johnson, D. "Growth and Solvent Production by Clostridium Pasteurianum ATCC 6013 Utilizing Biodiesel Derived Crude Glycerol as the Sole Carbon Source." Environmental Progress and Sustainable Energy. 2009. Vol. 28, No. 1, 100-110.
- Adhami, L., Griggs, B., Himebrook, P., and Taconi, K. "Liquid-Liquid Extraction of Butanol from Dilute Aqueous Solutions using Soybean-Derived Biodiesel." Journal of the American Oil Chemists' Society. Published on-line August 7, 2009. DOI 10.1007/s11746-009-1447-7.
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Progress 09/01/07 to 08/31/08
Outputs OUTPUTS: Experiments evaluating the anaerobic fermentation of biodiesel-derived crude have been performed using both wild-type mixed cultures and pure cultures of Clostridium pasteurianum. Early results indicated that wilde-type cultures were able to produce 1,3-propanediol (PDO) and ethanol using crude glycerol; however, a disruption in graduate student personel resulted in the loss of these cultures. Efforts are now focusing on the utilization of pure cultures of C. pasteurianum for glycerol fermentation. Experiments have compared the growth of C. pasteurianum on purified glycerol and biodiesel-derived crude glycerol in batch culture at initial glycerol concentrations of 5, 10, and 25 g/L. Results indicated no significant differences in growth (as measured by optical density) between cultures grown on purified and crude glycerol. Our results have also produced a maximum butanol yield of 0.36 g/g glycerol, a maximum ethanol yield of 0.36 g/g glycerol, and a maximum PDO yield of 0.41 g/g glycerol. These yields are higher than those reported previously for the fermentation of purified glycerol by C. pasteurianum. The butanol yield is also higher than what is typically achieved by C. acetobutylicum or C. beijerinckii during glucose fermentation. Additionally, our results indicate that cultures can produce solvents, including butanol, using biodiesel-derived crude glycerol as the sole carbon source. This is believed to be the first demonstration of solvent production from crude glycerol. Although cultures can produce solvents from crude glycerol, the product yields have not been as high as those achieved using purified glycerol. Crude glycerol contains significant amounts of methanol and salts. In order to determine how methanol affects solvent production, future experiments will compare growth and solvent production using purified glycerol spiked with methanol. Experiments will continue to evaluate the effect of initial glycerol concentration on growth and solvent production, as experiments containing 50 g/L purified and crude glycerol are currently in progress. Efforts will also focus on determining the effect of pH and undissociated acid (specifically acetic and butyric) concentration on growth and solvent production. Finally, solvent producing cultures will be transferred to a semi-continuous fermentation system in an effort to maintain a stable, solvent-producing culture. PARTICIPANTS: Keerthi Venkataramanan - Ph.D. student, Biotechnology Science and Engineering Program, UA Huntsville Received an Alabama EPSCoR Graduate Research Fellowship to continue work on this project. Received 1st place in the Research Poster Competition at the 10th Annual Biotech Retreat, Huntsville, AL. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: The original research plan was to utilize mixed wild-type anaerobic cultures for glycerol fermentation. However, due to a problem with graduate student personnel, the wild-type cultures were lost. Subsequently, research efforts have focused on utilizing pure cultures of Clostridium pasteurianum for glycerol fermentation.
Impacts In addition to the results described above, this research project is currently supporting one student, Keerthi Venkataramanan, who is pursuing a Ph.D. in Biotechnology Science and Engineering as well as one undergraduate research assistant. In previous semesters, one additional undergraduate research assistant was supported using grant funds. Ph.D. student Keerthi Venkataramanan as recently awarded an Alabama EPSCoR Graduate Research Fellowship from the Alabama EPSCoR office. This is a competitive fellowship program that provides a 1-year stipend to recipients. Ph.D. student Keerthi Venkataramanan also received a 1st place award in the research poster competition at the 10th Annual Bioretreat, hosted by the Partnership for Biotechnology Research, UA Huntsville, and the Hudson-Alpha Institute. Conference Presentations Taconi, Katherine; Venkataramanan, Keerthi. Production of Butanol from Biodiesel Derived Crude Glycerol Using Pure Cultures of C. Pasteurianum (ATCC 6013). American Institute of Chemical Engineers Annual National Meeting, Philadelphia, PA (November 2008). Taconi, Katherine; Johnson, Duane T. Fermentation of Biodiesel-Derived Crude Glycerol to Produce Value-Added Chemicals. American Institute of Chemical Engineers Annual National Meeting, Salt Lake City, UT (November 2007). Poster Presentations Venkataramanan, Keerthi; Taconi, Katherine. The Anaerobic Fermentation of Crude Glycerol from Biodiesel Plant into Butanol using Clostridium Pasteurianum ATCC 6013. Partnership for Biotechnology Research, UA Huntsville, Hudson-Alpha Institute 10th Annual Bioretreat. Huntsville, Al (September 2008). Taconi, Katherine; Venkataramanan, Keerthi. Production of Butanol from Biodiesel-Derived Crude Glycerol using Pure Cultures of C. Pasteurianum (ATCC 6013). 2008 Annual Alabama EPSCoR Conference. Montgomery, AL (July 2008). Taconi, Katherine; Venkataramanan, Keerthi. Fermentation of Biodiesel-Derived Crude Glycerol to Produce Value-Added Chemicals. Best of UAH Research Expo. Huntsville, AL (April 2008).
Publications
- Taconi, K.A., Venkataramanan, K. P., and Johnson, D.T. "Growth and Solvent Production by Clostridium Pasteurianum ATCC 6013 Utilizing Biodiesel Derived Crude Glycerol as the Sole Carbon Source." Manuscript Submitted to Environmental Progress, September 2008.
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