Intellectual merit: Microbes that use minerals as energy sources are frequently found colonizing appropriate mineral surfaces. How these microbes access the surfaces of these minerals is a fundamental question that remains unanswered. Results of a recent study by the principle investigator (PI) suggested that chemotactic responses to metals (i.e. the ability of bacteria to move up gradients of metal ions) could facilitate mineral surfaces colonization. However, this research has called into question the experimental approach used in this study. Here, investigators propose to readdress the role of chemotaxis in mineral surface accessibility using the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 as the model organism. Specifically, they will use a more suitable chemotaxis assay for analyzing behavioral responses to Fe(II) and Fe(III). In addition, because Fe(III) (hydr)oxides are highly insoluble, they will investigate the role of chelating agents on chemotactic responses to Fe(III). The results of this study will answer a fundamental question relating to the biogeochemistry of microbe-mineral interactions. Their results will be shared with members of the Shewanella Federation at biannual meetings, with members of the bacterial chemotaxis community at the Bacterial Locomotion and Signal Transduction (BLAST) conference, and with geochemists at the annual AGU meeting. The rapid dissemination of these results will stimulate discussion and maximize the impact of our research. Broader impacts: The interdisciplinary nature of the microbiological sciences encourages a life-long commitment to learning that is central to the PIs research and educational plans. The PI promotes scholarly excellence by teaching microbiology and molecular biology as rapidly evolving and cross-disciplinary topics to engineering students. The PI?s interest in how microbes locate optimal environments for growth fits particularly well with this plan, allowing the incorporation of the PI?s research into many class lectures and laboratory sessions. As part of a combined research and educational plan, the PI has set up molecular biology facilities in the Engineering School at Johns Hopkins University. These facilities are made available to faculty, post-doctoral fellows, graduate students and undergraduate students who wish to perform research, or participate in the Molecular Biology for Engineering Applications class, which the PI offers each year. Educating engineers in aspects of modern molecular biology is essential for a society interested in improving public health and protecting the environment. The PI?s research and educational plans have consequently improved the infrastructure at Johns Hopkins University in a way that will benefit society. The PI is also involved in an outreach program, Women in Science and Engineering (WISE), which involves collaboration with the local Garrison Forest High School, and introduces female high school students to science and engineering research, with the intention of engaging their interest and impacting their future career decisions. Encouraging more women to consider becoming engineers is essential for increasing the diversity of talent that will be required by future generations.
