Dr. GUOLU ZHENG
211 Foster Hall, Lincoln University
820 Chestnut Street, Jefferson City, Missouri 65101 Phone: 573-681-5964; email: zhengG@Lincolnu.edu
EDUCATION
1993-1997 Ph.D. University of Arkansas, Fayetteville, Arkansas 1986-1989 M.S. Xiamen University, P. R. China
1979-1983 B.S. Xiamen University, P. R. China
APPOINTMENTS
2020-present Professor, Department of Agriculture and Environmental Sciences, Lincoln University, Jefferson City, Missouri
2014-2020 Associate Professor, Department of Agriculture and Environmental Sciences, Lincoln University, Jefferson City, Missouri
2009-2014 Assistant Professor, Department of Agriculture and Environmental Sciences, Lincoln University, Jefferson City, Missouri
2009-present Principal Investigator, Cooperative Research Programs, Lincoln University, Jefferson City, Missouri
2006-2009 Research Assistant Professor, Department of Veterinary Biopathology, University of Missouri-Columbia, Columbia, Missouri
2003-2005 Research Assistant Professor, University of Rochester School of Medicine and Dentistry, Rochester, New York
2000-2003 Senior Research Associate, Department of Biochemistry and Molecular biology, Oregon Graduate Institute of Science & Technology, Beaverton, Oregon
PROFESSIONAL AFFILIATIONS
- American Society for Microbiology
- International Association for Food Protection
TEACHING
- AGR 555 Food Safety: theory and practice
- AGR 507 Scientific Writing
RESEARCH INTERESTS
- Microbial safety of food and water
- Microbial source tracking
CURRENT RESEARCH
- Use of Endophytic Microorganisms to Improve the Food Safety of Fresh and Fresh-cut Produce
The number of foodborne disease outbreaks associated with fresh and fresh-cut produce has increased in recent years in the United States. However, current postharvest washing and sanitization processes do not always effectively reduce pathogen contamination in/on produce, and there is increasing concern about the chemical compounds used in postharvest sanitation. Therefore, novel control methods are critically needed. This proof-of-concept project tackles the use of endophytic microorganisms for the competitive exclusion of potential human pathogens on fresh produce. Endophytic microbes are symbiotic and able to live inside plants from farm to table. We hypothesize that produce naturally carrying single or a mixture of anti-human-pathogen endophytes can safeguard in situ fresh and fresh-cut produce against potential human pathogens from farm to table. Romaine lettuce and human pathogen E. coli O157:H7 (EcO157) were selected for this study to prove the concept of the in-situ biocontrol of human pathogens in fresh and fresh-cut produce. We will first to isolate abti-EcO157 from the internal tissues of lettuce and then evaluate their efficiencies on controlling EcO157 in lettuce pre- and post- harvest. Success of this project can lead to developing an environmentally sound, user-friendly, economic, and efficient biocontrol technique for farmers of produce at local, state, and national level.
- Assessments of the Impact of Cryptic E. coli on Current Water Quality Monitoring and Management
The presence of cryptic E. coli, including enteric- and environmental-living members, has posed a serious challenge to the current E. coli-based methods for fecal pollution monitoring and water quality management. To take steps to overcome the limitations of the current E. coli-based methods, this project seeks to obtain baseline information about cryptic E. coli. The specific objectives of this project are (1) to determine the distribution (ecological niche) and prevalence (frequency of occurrence) of cryptic E. coli in the United States, and (2) to compare the fate of cryptic E. coli versus. that of real E. coli in aquatic environments. Fecal samples from the major fecal pollution sources (including humans, livestock, and wild animals) and water samples from drainage areas of different dominant land uses will be obtained from Missouri and Virginia. The effects of three major environmental factors (temperature, pH, and UV radiation) on the fates of E. coli versus enteric cryptic E. coli will be studied in an aquatic microcosm. This is a collaborative effort of Lincoln University (Missouri), Virginia State University, and a research unit of the USDA-Agricultural Research Service (ARS) in Columbia, Missouri. The partnership is to combine the strength of the research and teaching activities of two 1890 universities with the assistance of the USDA-ARS to increase the capacity of both schools to address issues that 1890 schools commonly face and to benefit students at both schools by providing hands-on learning opportunities and the ability to interact with students of similar backgrounds.
RECENT PUBLICATIONS (* corresponding author)
- Yuan, Y., Zheng, G., Lin, M, Mustapha, A. 2018. Detection of viable Escherichia coli in environmental water using combined propidium monoazide staining and quantitative PCR. Water Res. 15 (145):398-407.
- Shen, Z., Mustapha, A., Lin. M., Zheng, G*. 2017. Biocontrol of the internalization of Salmonella enterica and Enterohaemorrhagic Escherichia coli in mung bean sprouts with an endophytic Bacillus subtilis. Int J Food Microbiol. 24(250):37-44.
- He, X., Liu, P., Zheng, G., Chen, H., Shi, W., Cui, Y., Ren, H., Zhang, X.X. 2016. Evaluation of five microbial and four mitochondrial DNA markers for tracking human and pig fecal pollution in freshwater. Sci Rep. 13(6) 6:35311
- Shen, Z., Zhang, N., Mustapha, A., Lin, M., Xu, D., Deng, D., Reed, M., Zheng, G* 2016. Identification of host-specific genetic markers within 16S rDNA intervening sequences of 73 genera of fecal bacteria. J Data Mining Genomics & Proteomics 7:1 http://dx.doi.org/10.4172/2153-0602.1000186
- Deng, D., N. Zhang, D. Xu, M. Reed, G. Zheng*. 2015. Polymorphism of the glucosyltransferase gene (ycjM) in Escherichia coli and its use for tracking human fecal pollution in water. Sci Total Environ. 15; 537:260-7.
US PATENT
US Patent 5,821,546: Xiao, Min; Zhuang, Da Kui; Zheng, Guolu; Slavik, Michael F; Method and system for fecal detection