CAREER: Microorganisms swimming around microstructural heterogeneity

Board Of Regents, Nshe, Obo University Of Nevada, Reno, Reno NV

Investigators

Abstract

1252182 Fu The goal of the proposed work is to obtain a fundamental understanding of how motile microorganisms, such as bacteria, are able to move through complex biological environments, such as bodily tissues or mucus, which often have microstructural features of similar size as the microorganisms. To properly study the effect of these microstructural features on swimming microorganisms, numerical computations capable of calculating the flows around complex geometries will be employed. These computations will also be able to study the flexibility of the microstructures and the swimming microorganisms and the effects of this flexibility on swimming. In the past, most theoretical investigations into swimming in such complex environments have only treated the microstructure in an average sense; these studies have not been able to determine what environmental properties control swimming behavior. It is expected that treating the microstructure explicitly as moving objects will give insight into what features promote or hinder movement through these environments. The results obtained through the numerical computations will expose the physical mechanisms of microstructural influence on swimming and be compared to results from investigations that do not treat the microstructure explicitly. Microorganism locomotion and propulsion in environments with microstructure affects infection, healthcare, and ecology. As examples, the microstructure of mucus can act as a barrier in infection; the research may lead to ways to alter the microstructure to hinder infection. Understanding tissue penetration is needed to design microrobots capable of precise delivery of drugs to targeted tissues such as cancer tumors, avoiding side effects in other tissues. Ecologically, the secretions of marine organisms can form a microstructural network; understanding the effects of this network on swimming microorganisms may alter estimates of microbial foraging efficiency, which affects carbon recycling rates and hence the global climate. Environmentally, bacterial dispersion in porous soils can be hindered to prevent water contamination or enhanced to promote bioremediation of pollutants. Finally, the proposed work also contains an educational component which aims to create "Move Like a Microbe," a force-feedback simulation of microscale microbial locomotion. It will bring the proposed research to life for the public and K-12 students by providing a hands-on demonstration of how microorganisms are able to swim, and explain the consequences of microbial locomotion to everyday life.