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Faculty Profile
Julia Maresca

Associate Professor

Orange horizontal rule

222 Jahn Laboratory



Welcome to the MEME lab: Maresca Environmental Microbial Engineering lab!

Our goal is to engineer environmental microbes to figure out how they do what they do in the environment, and when possible to put them to work for us. We currently have three main projects:

  1. Investigating how freshwater Actinobacteria use light, and how this helps them interact with other microbes; 
  2. Identifying the bacteria in and on concrete, and using them to tell us about concrete structural health;
  3. Investigating how microbes affect solubility and transformation of PFAS in different environments. 

For more information about individual projects, please scroll down to the RESEARCH section. For information about how to apply for a position (student or postdoc), please scroll further down to APPLY. I'm always looking for people, but currently looking for two PhD students!



Aurantimicrobium photophilum strain MWH-Mo1, isolated from a freshwater lake in Austria, with macaroni-like cell shape.

Freshwater Actinobacteria are ubiquitous and abundant in surface freshwater environments: they are found in freshwaters from bogs to lakes, eutrophic to oligotrophic, coastal to alpine. They have very small (<2 Mbp) genomes which provide very few clues to how they are so successful in such a range of environments. We have several model species available in our lab, and all grow faster in the light (Maresca 2019) -- even though they have no way to convert light energy to chemical energy (Keffer 2015). Instead, light provides them with information, and in the light they upregulate organic carbon transport and processing (Hempel 2021). To better understand how they sense light and convert that information to a change in activity, we have funding from the National Science Foundation to develop genome-editing tools in these strains. Stay tuned for a forthcoming publication demonstrating successful targeted gene inactivation!


Pink bacteria isolated from concrete, with brain-like colony morphology

Concrete hosts a small but diverse community of microbes (Maresca 2017), which come from the components that go into concrete, and change over time (Kiledal 2021, Kiledal 2023). We are developing methods to use microbes as bioindicators for concrete structural health, and engineering concrete-compatible strains such as Rhodococcus qinshengii strain CL-05 (Kiledal 2021 MRA) to add value to concrete. We've also been using metagenomic analysis to investigate how concrete microbial communities change in structural concrete on long time scales, and what kinds of microbes are present in concrete biocrusts. Stay tuned for those updates as well!




Cartoon of a microbe smashing PFAS with a hammer

PFAS is a large family of structurally related perfluorinated molecules, which have consistently been found in drinking water, groundwater, and surface waters. After a recent pilot project investigating PFAS transformation by microbes in wastewater, we are now investigating how microbes can affect solubility and transformation of PFAS in soil and plant environments.