Session: Rising Stars of Mechanical Engineering Celebration & Showcase

Paper Number: 147319

147319 - Microbial Dynamics at Oil-Water Interfaces. 

Microorganisms interact with fluid interfaces in contexts relevant to health, industry and the environment. The dynamic interaction of cells with energy-rich interfaces causes them to adsorb and become trapped, eliminating a patch of the interface, and lowering the free energy of the system.  However, very little is known about the effects of interfacial tension and associated stresses at fluid interfaces on cell physiology, nor about how microbes cope with the challenging environments of the air-water or oil-water interfaces. We hypothesize that cells evolving in energy-rich confinements can exhibit unique properties and survival strategies translated by phenotypic changes. Thus, we investigate the physiological responses of microbial isolates to interfacial confinements using particle tracking, pendant drop elastometry, and metabolic profiling. Here, we will discuss the responses of Pseudomonas aeruginosa and Alcanivorax borkumensis to a hexadecane-water interface. P. aeruginosa PAO1 cells form elastic films of bacteria, excreted polysaccharides, and proteins, whereas PA14 cells move actively without forming an elastic film. Similarly, mucoid strains of P. aeruginosa and A. borkumensis isolated from the lung of cystic fibrosis patient and the Deep Horizon spill, respectively, exhibit interfacial films with strong mechanical. Cell adaptation at fluid interfaces enables them to secrete appropriate biosurfactants or metabolize the interfaces. Our data support that the formation of interfacial bacterial films provides protection, in a manner akin to biofilms, enabling cells to cope with the detrimental effects of interfacial environments. The knowledge gained through these studies opens avenues to develop new technologies to mimic and manipulate the bacteria at oil-water interfaces for applications in anti-fouling and bioremediation.

Presenting Author: Tagbo Niepa Carnegie Mellon University

Presenting Author Biography: Dr. Niepa is an Associate Professor of Chemical Engineering and Biomedical Engineering at Carnegie Mellon University, Pittsburgh PA. He started his academic journey in Côte d'Ivoire after receiving an Associate Degree in Food Science and a research experience at the Pasteur Institute. He then moved to Germany to pursue his education in bioengineering at the University of Dortmund and transferred to Syracuse University. He received his B.Sc. in Bioengineering (2009) and Ph.D. in Chemical Engineering (2014) with honors from Syracuse University. During his Ph.D. study, Dr. Niepa co-founded in 2011 Helios Innovative Technologies Inc. (now acquired by Leviant, Inc.), a medical device company that develops automated sterilization systems to fight bacterial cross-contamination. He held a Postdoctoral Fellowship for Academic Diversity at the University of Pennsylvania. In 2017, he joined the University of Pittsburgh as an assistant professor of Chemical and Petroleum Engineering. Since Fall 2023, he leads his microBiointerface Lab at CMU into multidisciplinary approaches to solve problems associated with microorganisms relevant to the environment, healthcare, and food industry. Dr. Niepa is the recipient of the 2022 NIH Director’s New Innovator, the 2022 NSF CAREER, and the 2019 NSF S-STEM Awards to promote diversity and excellence in engineering research and education. More recently, he was selected as a US Delegate by the National Academies of Sciences, Engineering, and Medicine to attend the 2nd US-Africa Frontiers Symposium (Morocco), and the 1st Connections Symposium to Sustain Science in Latin America (Colombia).

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