Construction of green fluorescent protein plasmids for labeling of herbicide-degrading Delftia acidovorans MC1071

Green Fluorescent Protein (GFP);Delftia acidovorans;2,4-Dichlorophenoxyacetic Acid;2,4-Dichlorophenoxypropanoic Acid;tfdC Promoter;Micromodels;Herbicide Degradation

Ng, Kenneth Siu Hin ; Werth ; Charles J. ; Zilles ; Julie L.

关键词: Green Fluorescent Protein (GFP);    Delftia acidovorans;    2,4-Dichlorophenoxyacetic Acid;    2,4-Dichlorophenoxypropanoic Acid;    tfdC Promoter;    Micromodels;    Herbicide Degradation;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/26268/Ng_KennethSiuHin.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Each year, approximately 46 million pounds of 2,4-dichlorophenoxyacetate (2,4-D) (EPA, 2005) and 4 million pounds of 2,4-dichlorophenoxypropionate (2,4-DP) (EPA, 2007) herbicides are applied for commercial or residential usage in the US. Accidental runoff of herbicides such as 2,4-D and 2,4-DP from human applications is toxic to non-target organisms and harmful to the environment. The main mode of removal for most herbicides in nature is biodegradation. In natural environments, herbicides and substrates are non-uniformly distributed, and microorganisms compete to degrade thesecompounds.The favorability of one microbe over another depends on many factors, including the herbicide and substrate concentrations.The objective of my research is to construct two green-fluorescent protein (GFP) plasmids to tag a specific strain of D. acidovorans (MC1071) for visual distinction from one or more competing microbes in a microfluidic pore structure that contains spatially varying concentrations of 2,4-DP, 2,4-D, and/or oxygen. Two GFP plasmids, designated pKNlacgfp and pKNtfdgfp, were constructed and successfully transformed into MC1071. One resultant strain, MC1071/pKNlacgfp, constitutively expressed GFP, while the strain MC1071/pKNtfdgfp expressed GFP only when herbicide degradation was induced. The MC1071/pKNlacgfp strain will now be visually distinct from other D. acidovorans strains when grown in micromodels, allowing for monitoring of competition between MC1071 and other strains. The MC1071/pKNtfdgfp strain will allow distinction of active and inactive MC1071 biomass in micromodels, thus facilitating the study of bacteria adaptation in micromodels.