Progress 09/01/13 to 08/31/17
Outputs
Target Audience:1. Scientific and industrial community in bio-energy 2. Scientific and industrial community in water and environmental quality 3. Owners of concentrated animal feedingfarmers and owners of concentrated animal feeding operations operations Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?1. Three graduate students were supported and trained through this project. 2. One postdoctoral scientist was trained through this project 3. One technician was trained through this project How have the results been disseminated to communities of interest?1. The results have been presented in professional conferences and meetings. 2. The scientific findings have been presented in research papers that are submitted or to be submitted to the peer-review journals in environmental science. What do you plan to do during the next reporting period to accomplish the goals?We will continue to publish and present our findings to the professional community and industry.
Impacts
What was accomplished under these goals?
The goal of this project Confined animal feeding operations in the United States have led to a buildup of enormous volumes of animal waste that require special treatment to reduce their adverse effects on the health of humans and environment. Untreated animal waste may carry human pathogens and antibiotic resistance genes. Human pathogens are disease-causing bacteria and antibiotic resistance genes in pathogens can make the diseases untreatable by antibiotics. The goal of this project was to use animal waste as a source of organic materials to generate energy (biogas) and at the same time, to control the potential pollution caused by animal waste, pig manure in this study. The technology under investigation to treat animal waste in this project was the "anaerobic digestion". The specific aims of this project were: 1) to maximize the yield of biogas from the anaerobic digestion and minimize the outputs of potential human pathogens and antibiotic resistance genes carried in pig manure; and 2) to identify and use key microbial indicators for monitoring and control of the performance of anaerobic digestion in preventing it from failure. What was accomplished under the goal? Animal waste is a large reservoir of human pathogens and antibiotic resistance genes, which pose a risk to human health. Thus, animal waste must be properly treated before disposal. A common collection and disposal system in the United States has been an anaerobic lagoon/spray irrigation system, but the anaerobic digestion technology is believed to be superior both environmentally and financially. Unfortunately, problems such as low biogas yield and process instability are often encountered in anaerobic digestion, preventing this technology from being widely applied. In addition, the conclusion on the effectiveness of this technology to remove potential human pathogens and antibiotic resistance genes has been controversial in some cases. This project, using pig manure as the organic materials, has determined the key elements of anaerobic digestion processes at 22 ºC, 37 ºC, and 55 ºC. The key elements are chemical, physical, and microbiological factors that play the important roles in the biogas yield and in the removal of human pathogens and antibiotic resistance genes. Unlike the previous studies, this project investigated not only the chemical and physical factors, but also the microbial factor, as the anaerobic digestion process is a process depending heavily on the activities of microorganisms carried in the seed slurry and animal manure. This project was a joint effort of scientists from Lincoln University of Missouri (LU) and University of Missouri-Columbia (UMC). Overall, the proposed two aims of this project have been achieved: to maximize the yield of biogas from the anaerobic digestion and minimize the outputs of potential human pathogens and antibiotic resistance genes carried in pig manure: The biogas production appeared increase with the concentration of pig manure and with the temperature of anaerobic digestion. In addition, a higher temperature showed a generally higher effectiveness to remove human pathogens and antibiotic resistance genes, but some heat-tolerant pathogens such as Camylobacter jejuni could survive and even grew under the anaerobic digestions at all the three temperatures tested. This observation is in contradictory to the results of the studies of others, where the pathogen was reportedly inactivated by the anaerobic digestion. However, unlike in our study where the change of low number of the pathogen naturally carried by the manure during the anaerobic digestions was investigated, in the studies of others, a relatively high concentration (rarely found in animal wastes) of the pathogen were artificially spiked and therefore, the results of the others might not have reflected the change of the pathogen naturally carried in animal manure during the anaerobic digestions. The resistance of the pathogen against the anaerobic digestion seen in our study is a serious health concern, because Campylobacter jejuni has been recognized as the main causative agent of campylobacteriosis, the number one bacterial diarrhea in the United States and one of the most widespread diseases in the world. Based on the results of this study, we suggest that that effluent of the anaerobic digestion needs additional treatment before disposed to the environment. Similar to the results of others, the major antibiotic resistance genes in pig manure were found to be the genes against antibiotics tetracycline, sulfonamide, and macrolide. This finding was in line with the industry practice of using these antibiotics for the treatment and prevention of pig diseases, and for promoting the pig's growth. Based on the results of this study, we also suggest that development of a novel strategy to reduce using of antibiotics in food animal industry is urgently needed. to identify and use key microbial indicators for monitoring and control of the performance of anaerobic digestion in preventing it from failure: This study found that the key microbes for a successful anaerobic digestion at 22 ºC and 37 ºC were bacterium Candidatus Cloacimonas acidaminovorans (the dominant) andarchaea of the genus Methanoculleus (the sub-dominant), while those for the anaerobic digestion at 55 ºC were heat resistance bacteria Coprothermobacter proteolyticus (the dominant) and Anaerobaculum mobile (the sub-dominant). In addition to the key microbes, the pH value of the anaerobic digestion was determined to be critical for the stability of the anaerobic digestions and the microbes of seed slurry might play a critical role in the process of anaerobic digestion. Based on the results of this study, we recommend to keep the pH of the anaerobic digestion at between 7 and 8 and to maintain the key microbes as the dominant microbes during the digestion.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
H. Chen, M. Reed, and G. Zheng. Fate of camplobacter jejuni in pig manure during anaerobic digestion. 2017 Missouri Academy of Science Annual Meeting.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2017
Citation:
Hang Chen. Fate of antibiotic resistance genes in pig manure during the anaerobic digestions. M.S. Thesis. Lincoln University of Missouri, Jefferson City, MO 65102
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Hang Chen, Mary Reed, Guolu Zheng, Ning Zhang, Dong Xu, Liyuan Hou, Zhiqiang Hu.Fate of antibiotic resistance genes in pig manure during the mesophilic anaerobic digestion. The 17th Biennial 1890 Research Symposium, Atlanta, Georgia
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Guolu Zheng, Dong Xu, and Zhiqiang Hu. Prediction and control of the performance of anaerobic digestion of animal manure through metagenomics for rRenewable energy and a sustainable environment. The Program Project Director Meeting, Virginia Beach, VA
- Type:
Journal Articles
Status:
Other
Year Published:
2018
Citation:
Hang Chen, Ning Zhang, Chuanren Duan, Liyuan Hou, Daiyong Deng, Dong Xu, Zhiqiang Hu, Mary Reed, Guolu Zheng. Fates and relationships of microbiome, resistome, and mobilome during the anaerobic digestions of pig manure at different temperatures
- Type:
Journal Articles
Status:
Submitted
Year Published:
2018
Citation:
Hang Chen, Chuanren Duan, Liyuan Hou, Daiyong Deng, Zhiqiang Hu, and Guolu Zheng. Anaerobic digestions may be ineffective to remove Campylobacter jejuni. Science of the Total Environment.
- Type:
Theses/Dissertations
Status:
Other
Year Published:
2018
Citation:
Liyuan Hou. Effects of solids reaction time and other important parameters in anaerobic membrane bioreactor operation treating municipal wastewater
Ph.D Dissertation. University of Missouri, Columbia, MO 65203
|
Progress 09/01/15 to 08/31/16
Outputs
Target Audience:1. Scientific and industrial community in bio-energy 2. Scientific and industrial community in water and environmental quality 3. Owners of concentrated animal feedingfarmers and owners of concentrated animal feeding operations operations Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project has provided training opportunities for three graduate students and one post-doc. The three graduate students include one in Environmental Science, one in Environmental Enginerring, and one in Bioinformatics. The post-doc is in environmental science. The students and post-doc are expanding their skills and kownledge beyond their disciplines. How have the results been disseminated to communities of interest?The findings of this study have been presented in twoprofesssional conferences and in oneseminar for LU faculty and students. What do you plan to do during the next reporting period to accomplish the goals?Comprehensive experiments wiil be carried out to achieve the goal of the objective 2:Identify and use key microbial indicators for monitoring and control of the performance of anaerobic digestion to prevent its failure.
Impacts
What was accomplished under these goals?
The objective 1 has been fulfullied. Onditions to maximize the yield of methane and biogas, the stability of the anaerobic digestion, and the mitigation of pathogens and antibiotic resistance genes (ARGs) have been studied and identified.Our preliminary data demonstrated that over twenty ARGs were commonly found in pig manure and that the tetracycline resistance genes, such as tetQ and tetW, were the most abundant, in line with the industry practice using tetracycline to promote pig's growth. This study also showed that removal of ARGs varied widely during both mesophilic and thermophilic AD, and some ARGs were even increased over some AD process. The increase of certain ARGs during some AD could lead to a serious human and animal health issue, as it may facilitate the spread of the ARGs among microorganisms including human and animal pathogens. In general, thermophilic AD appeared to be more effective in removal of ARGs and higer yield of methane and biogasthan mesophilic AD, although the former showed less stable during the anaerobic digestion.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2016
Citation:
Hang Chen, Mary Reed, Guolu Zheng, Ning Zhang, Dong Xu, Liyuan Hou, Zhiqiang Hu.Fate of Antibiotic Resistance Genes in Pig Manure during the Mesophilic Anaerobic Digestion. Poster Presentation. the 17th Biennial 1890 Research Symposium, Atlanta, Georgia
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Guolu Zheng, Dong Xu, and Zhiqiang Hu. Prediction and Control of the Performance of Anaerobic Digestion of Animal Manure through Metagenomics for Renewable Energy and a Sustainable Environment. the Program
Project Director Meeting, Virginia Beach, VA
|
Progress 09/01/14 to 08/31/15
Outputs
Target Audience:1. Scientific and industrial community in bio-energy 2. Scientific and industrial community in water quality 3. Owners of concentrated animal feedingfarmers and owners of concentrated animal feeding operations operations Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project has provided training opportunities for three graduate students and one post-doc. The three graduate students includeone in Environmental Science, one in Environmental Enginerring, and one in Bioinformatics. The post-doc is in environmental science. The students and post-doc areexpanding their skills and kownledge beyond their disciplines. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?More studies are planned to determine the biogas production and methane yield from anaerobic digestion of swine waste at different temperatures. DNA samples for metagenomics analyses will be collected before, during, and after digestion under the ambient (22°C) and thermophilic (55°C) conditions, respectively. The dynamics of microbial populations, pathogenic genes, and antibiotic resistance genes will be analyzed for the anaerobic digestion under the ambient and themophilic conditions. Based on the data to obtain and those that we have had, the condition for maximal production of methane and mitigation of pathogens and antibiotic resistance genes will be determined and the key microbial for the success of the anaerobic digestion will be identified.
Impacts
What was accomplished under these goals?
Objective 1 has been partially achieved. It has been determined that themethane yield and cumulative methane volume are positively correlated with theswine manure concentrations (from 400 to 8,000 mg COD/L) under the mesophilic (37 C) anaerobic digestion processes. Metagenomics analyses have been conducted to understand the dynamics of microbial populations, pathogenic genes, and antibiotic resistance genesduring themesophilic anaerobic digestionprocess.
Publications
|