In partial fulfillment of the requirements for the degree of

Master of Science in Biology

in the

School of Biological Sciences

Jiong Wang

Will defend her thesis

“THE EFFECT OF COPPER OXIDE NANOPARTICLES ON BACTERIAL COMMUNITY ASSEMBLY”

19th, November 2021

11 AM

https://bluejeans.com/878478642/0893

Thesis Advisor:

Dr. Lin Jiang

School of Biological Sciences

Georgia Institute of Technology

Committee Members:

Dr. William Ratcliff

School of Biological Sciences

Georgia Institute of Technology

 Dr. Yongsheng Chen

School of Civil and Environmental Engineering

Georgia Institute of Technology

Abstract: A growing amount of copper oxide nanoparticles (CuO NPs) has been released into the environment. CuO NPs are known to be toxic to various organisms, but their impacts on the assembly of ecological communities are poorly understood. We examined the role of CuO NPs in influencing the assembly of laboratory bacterial assemblages consisting of three bacterial species. CuO NPs had significant negative effects on the growth rate and carrying capacity of all three species. Alpha diversity was significantly reduced by CuO NPs, regardless of assembly history. CuO NPs enhanced the inhibitive priority effects of early arriving species on later arriving species during community assembly. By so doing, CuO NPs promoted the importance of assembly history in shaping bacterial community structure, resulting in greater beta diversity between communities subjected to different histories. Moreover, communities in the copper ion treatment tended to have similar alpha and beta diversity as those in the controls, suggesting that copper ions may not be responsible for the effect of CuO NPs on community assembly. Our results indicate that CuO NPs could modify bacterial community structure by changing the importance of community assembly history and thus the strength of priority effects.