Date of Award

Summer 2022

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

Committee Chairperson

John M. Pisciotta, Ph.D.

Committee Member

Oné R. Pagán, Ph.D.

Committee Member

Benjamin S. Chambers, Ph.D.

Abstract

Anthropogenically-produced nanoparticles are a form of nanotechnology being used in industries including food and textiles. Humans and livestock are frequently exposed to metal-containing nanoparticles (MCNPs), that have been washed into streams and rivers, have been deliberately used in food packaging as antimicrobials, preservatives or for supplementation. The animal microbiome, which consists of a diverse community of microorganisms, provides a number of benefits to the host in terms of nutrition availability, immune support, and can influence behavior. Biofilms of diverse microbes may cause detrimental effects, for instance by causing dental diseases in humans. However, the scientific community has not reached consensus on if direct contact with MCNPs is harmful to animals and or the microbiomes. This study exposed the microbiota of the planarian flatworm Girardia tigrine and developing microbial biofilms to MCNPs to investigate their effect on biofilms and the microbiome of this model organism. Zinc oxide (ZnO), copper silicon (CuSi), and tribasic copper chloride (TBCC) nanoparticles were used at 6 different concentrations. ZnO NPs, CuSi NPs, and TBCC NPs, inhibited the formation of a mixed community plastic-adherent biofilm as determined by plate assay. The pure culture Staphylococcus aureus F-182 biofilm was inhibited by ZnO NPs and CuSi NPs but was not inhibited when exposed to TBCC NPs. The planarian microbiome experienced a pronounced shift from Betaproteobacteria to Gammaproteobacteria when exposed to ZnO NPs, and CuSi NPs. Of the MCNPs CuSi NPs increased the diversity of the microbiome while TBCC treatment induced minimal microbiome disruption as compared to untreated control.

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