Progress 04/01/10 to 12/31/12
Outputs
Target Audience: The target audience for this grant includes animal/meat producers and nearby residents who might be impacted from odor reduction technologies. Changes/Problems: The initial grant was awarded to Dr. David Parker (PI) and Dr. Mark Olsen of West Texas A&M University. Upon Dr. Olsen’s moving to Midwestern University, and Dr. Parker accepting employment with the USDA-ARS in Clay Center, Nebraska, the grant was transferred to the USDA-ARS in Nebraska. As Dr. Olsen was no longer available to work on the grant following his move to Midwestern, Dr. Parker initiated collaborative efforts with Dr. Audrey Atkin and Dr. Ken Nickerson at the University of Nebraska to work on the genetically-modified part of the grant (Objective 2 above). Collaborative efforts were also initiated with Dr. Lingshuang Cai (post-doc research formerly at Iowa State University) for completion of the project. A similar collaborative project was also conducted with Dr. Jacek Koziel (Iowa State University) to assess the efficacy of soybean peroxidase for treating swine manure on a project funded by the National Pork Board. What opportunities for training and professional development has the project provided? A post-doc researcher received training and professional development on this research project, as did a PhD student from the University of Nebraska. A new gas chromatograph and thermal desorber system was calibrated, and a small wind tunnel system was constructed. Several laboratory experiments were conducted to assess the efficacy of a commercially-available soybean peroxidase enzyme product for reducing odor in standard phenolic solutions and swine manure, and to optimize the amount of hydrogen peroxide addition. The project provided training opportunities for Dr. Lingshuang Cai (post-doc researcher) and for Krista Patefield(PhD student at the University of Nebraska). How have the results been disseminated to communities of interest? Results have been disseminated to fellow scientists and engineers through peer-reviewed publications and through oral and poster presentations at scientific conferences. Results were disseminated to animal producers at USDA field days, in one-on-one meetings, and with commodity groups. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Accomplishment 1: Odorous VOC emissions were successfully quantified using a wind tunnel system and gas chromatography instrumentation. The primary odorant from swine manure was determined to be 4-methylphenol, which accounted for 68–81% of the odor activity value. Skatole accounted for 11–13% of the odor activity value. Accomplishment 2: Two different batches of Saccharomyces cerevisiae strains were obtained: one in which the yeast display HRP on their cell surface, and one in which the yeast secrete the HRP. An enzyme assay containing a standard HRP substrate (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)—ABTS) was used to test four different variants of the secreted HRP enzyme for optimal growth conditions, enzyme activity, shelf-life, storage conditions, and thermostability. Enzyme activity was confirmed in all four variants of the secreted HRP as determined by the ABTS assay. Early testing of the secreted HRP variants using 4-methylphenol as a substrate showed promise but complete quantifying GC analysis is still pending. Accomplishment 3: The optimum application rate of soybean peroxidase for treating swine manure slurry in a totally mixed system was determined to be 50 grams per liter. At this application rate, 4-methylphenol emissions were reduced by 62 to 98 percent. Of the two peroxides evaluated, calcium peroxide was most effective. When combined with soybean peroxidase, 4-methylphenol emissions were reduced by 62 percent with hydrogen peroxide, and by 98 percent with calcium peroxide. At an estimated treatment cost of $0.33 per liter of manure treated, and more than $100 per pig, the use of soybean peroxidase/calcium peroxide would not be feasible for most commercial swine operations. Accomplishment 4: Topical application of soybean peroxidase was equally effective as the totally mixed treatment in reducing 4-methylphenol emissions for a period of about ten days. There was little difference between the 10, 50, or 100% topical application rates, suggesting that the amount of SBP required for successful treatment could be reduced when applied topically as compared to totally mixed. However, after 14 days the 4-methylphenol emissions actually increased as compared to the control and totally mixed treatments. This suggests that, as compared to the totally mixed treatments, topical treatment may be useful for short periods of time, but could possibly cause elevated odors in the long term.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Parker, D. B., L. Cai, K-H Kim, K. E. Hales, M. J. Spiehs, B. L. Woodbury, A. L. Atkin, K. W. Nickerson, K. D. Patefield. 2012. Reducing odorous VOC emissions from swine manure using soybean peroxidase and peroxides. Bioresource Technology 124:95-104.
|
Progress 04/01/10 to 03/31/11
Outputs
OUTPUTS: The PI, Dr. David Parker, accepted a position as Research Leader with the USDA-ARS on March 1, 2010. There has been minor progress during this last annual period, as the grant was being transferred from West Texas A&M University to the USDA-ARS Meat Animal Research Center. The transfer was completed in early 2011. Since then, a post-doc researcher was hired. A new gas chromatograph and thermal desorber system has been calibrated, and a small wind tunnel was constructed. Several laboratory experiments have been conducted to assess the efficacy of a commercially-available soybean peroxidase enzyme product for reducing odor in standard phenolic solutions and swine manure, and to optimize the amount of hydrogen peroxide addition. PARTICIPANTS: The following individuals worked on this project during the reporting period: Dr. David Parker (PI), Dr. Lingshuang Cai (post-doc researcher), Sue Wise (technician), Todd Boman (technician) TARGET AUDIENCES: The target audience for this grant includes animal/meat producers and nearby residents who might be impacted from odor reduction technologies. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Results of the laboratory experiments conducted in early 2011 give typical p-cresol reductions in headspace of 50-75 percent for swine manure slurry and 65-85 percent for 1 mM p-cresol standard solution. The results appear promising, and further experiments are planned for the upcoming year using the genetically modified yeast.
Publications
- No publications reported this period
|