Awarded to: Jill Banfield
Abstract: Microbial Mediation of Watershed Biogeochemical Cycles
Medal lecture in:
Session 10f in Room 3, Goldschmidt2020 - Virtual Venue on Friday 26th June 05:30 - 05:33

Citation: It is my distinct pleasure and honor to introduce Jillian Banfield, the 2020 recipient of the Harold Urey award from the European Association of Geochemistry (EAG). Our paths first crossed in Wisconsin in the early 1990s, when I was a Professor at the Center for Great Lakes Studies in Milwaukee and she was a recently hired assistant Professor at UW-Madison. From the beginning it was clear she was a fine scientist, and much different from any of my microbiology colleagues. Since these early days, I have enjoyed many interactions with her (and her students and postdocs): as a colleague, collaborator, and friend for nearly thirty years. We have served on student committees, written proposals, edited books, run workshops, and published papers, while all the time searching for a common ground in the growing field of geobiology. With this perspective in hand, I feel at ease talking about the accomplishments, and the transformative work that Jill has produced, as well as the immense impact that she has had in areas of geochemistry, geology, geobiology, and as of late, environmental molecular biology.
In the early Wisconsin days, Jill’s interests were in mineral transformation and weathering, and her approaches were both ultrastructural (transmission electron microscopy) and geochemical, with no hints of the importance of biology. This excellent work provided a baseline for abiotic reactions: something that is not easy for a non-geologist to comprehend. By the mid-1990s, Jill had become immersed in the microbial world, using her analytical and observational expertise to assess the impact of microbes on the dissolution and formation of minerals in ways that had not been previously done. One of her great assets is that she finds good colleagues and interacts with them, as in 1997, when she co-organized a workshop entitled: Geomicrobiology: Interactions between Microbes and Minerals, Reviews in Mineralogy Volume 35. It introduced the world of geomicrobiology to the geological world via a legitimate and visible publication, and it put many of the leaders in the field in touch with each other. I mention this because it has been one of the very strong features of Jill Banfield – utilizing a truly interdisciplinary approach that has yielded substantial success for a field that was virtually unknown to anyone except the practitioners at the time of the workshop. A few years later, when the impact of molecular biology was being felt, Jill co-organized another workshop entitled Molecular Geobiology: Reviews in Mineralogy, Volume 59. It should be obvious from this discussion that Jill has an almost uncanny ability to attract, train, stimulate, and support students, graduate students, postdoctoral fellows and colleagues. Not only does she have a cadre of postdocs who keep her at the forefront of fast-moving fields, but she takes care to help both students and postdocs in their careers. She is already, at a comparatively young age, one of the leaders in the area of geobiology, but I expect her impact to be far greater in another decade, when the many good people she has trained will be seen as a “who’s who” in the field.
Another of Jill’s special abilities is the identification of important problems that are “ready” to be investigated using new methods. For example, when she began her work on the Iron Mountain (acid-mine drainage) site, it became clear that the microbial diversity was so low that the molecular approaches could be brought to bear on the entire system, leading to major breakthroughs in the application of molecular genetics to field studies of environmental microbiology. This pioneering work pointed the way for many other groups working in more complex systems. The same can be said of her recent work on the subsurface Rifle site, from which extremely interesting data are emerging. But her impact is not on geobiology alone – as these extreme environments have been studied, it has been possible to move from identifying the organisms and their genomes, to transcriptomics (identifying the genes that are activated), to proteomics (identifying the gene products that are produced) and recently, inroads into metabolomics (identification of the metabolites that are produced by the gene products). This groundbreaking work has led the way in many aspects of environmental microbiology, and morphed rather quickly into the study of microbiomes of all kinds, from lakes to oceans, to humans: a remarkable achievement. Through all of this, Jill has maintained a focus on nanoparticles and mineral transformations, never forgetting the questions that brought her into this field. We now see the “Banfield brand” on topics as diverse as “The Tree of Life”, the “Human Microbiome”, “Biofilm Formation and Activity”, and “cryogenic TEM of clay and oxyhydroxide minerals”.
These examples reveal an almost magical mixture of abilities that allows her to think at different levels and from different perspectives – these include both intellectual abilities (a strong knowledge of both geology, microbiology, and molecular biology), and technical abilities (a background in imaging (electron microscopy) and field geology). I can think of no one else who so successfully brings such a combination of talents and skills to the table. I know of no one else who thinks and acts so broadly with such energy, enthusiasm and warmth.
In summary, Jill Banfield is one of the best scientists in the world in the area of environmental geochemistry/geomicrobiology. Her great success comes from seeing which problems are amenable to solution by a clever combination of the latest approaches in microbiology/molecular biology and geochemistry, and combining these insights with a keen eye for the techniques needed to solve them. This has been true for more than 25 years, and I expect it to continue (unabated) for another 20 years with equal success and aplomb. Her contributions are at the basic science level, the teaching level, and the outreach level – making geobiology come alive for everyone.
As I said at the start, I am honored to make this introduction, she is a friend, a colleague, and a great teacher and scientist – a perfect choice for the Urey Award.

Kenneth H. Nealson
University of Southern California, USA

Response: Thank you, Ken Nealson, for leading the effort to nominate me for the Urey award, to others who supported it, and to the committee that made the selection. As a relatively early career scientist who decided to jump into biology with essentially no prior training, Ken was one of my informal tutors. I think there were plenty of times I drove him up the wall with questions – yet he was always patient. He also co-convened two MSA short courses on geomicrobiology with me and played the pivotal role of identifying whom to bring together from the microbiology perspective.
The Urey award is a huge honor, though I must say I do not think it well deserved by me. If there is any credit to be had, it should go to the amazing group of students, postdocs, other lab members and an outstanding set of long-term collaborators, the list for which is too long to include here.
I have been extraordinarily fortunate to have worked in many research fields that are fascinating to me, studying topics ranging from mechanisms of reactions in minerals to microbial evolution and diversity to the assembly of the human microbiome during infant development. I was tremendously lucky early on to have had the mentorship of Tony Eggleton at the Australian National University and subsequently, David Veblen at Johns Hopkins University. These scientists introduced me to the wonders of mineral structure and microstructure and the ways to study them – primarily through high-resolution transmission electron microscopy. It was approaches to understanding atomic structure and microstructure, as well as structure – properties – reactivity interconnections, that led logically (at least in my mind) to study environmental biogeochemical processes by methods founded on genomics. My lab has continued to work on minerals, but with the transition into biology the focus of inorganic research shifted to nanomaterials – including the products of microbial biomineralization, and clay minerals. In this regard, I’d like to acknowledge central contributions of my first Ph.D. student, Lee Penn, my one time lab members and long term collaborators HengZhang and Ben Gilbert, as well as Mike Whitaker, a brilliant current postdoc and early career scientist who is using cryogenic high-resolution electron tomography to provide new insights into the behavior of clays in aqueous solutions.
My lab’s biological research has focused almost entirely on microbial communities in natural environments. We joined the microbiology field as molecular methods, developed for example, by Norm Pace, were growing in prominence and as genomes of isolated microorganisms began to appear. In adoption and development of biological methods in my lab,I’d like to mention the contributions of Phil Bond, who was a postdoc and brought key molecularexpertise, Gene Tyson, a Ph.D. student who was the lead author of the first paper to report genomes reconstructed from microbial community samples (an approach that is now referred to as genome-resolved metagenomics), and Bob Hettich and his lab at Oak Ridge National Laboratory, with whom we took the first steps into community (meta)proteomics.
The geological foundation for our lab led us to study microbial communities of the near-subsurface, such as in aquifers and sediments and ultimately, in soils. Some of this work has been propelled forward by one-time Ph.D. student Ken Williams, who now co-leads a major program related to biogeochemical and physical processes in watersheds (and is now one of my bosses at LBNL!). Aquifers and soils had been little investigated using molecular methods, so we had the delightful experience of discovering group after group of new bacteria and archaea and exploring their lifestyles. Clearly, luck played a tremendous role in our research. Overall, my hope is that by working across many different environments with interdisciplinary approaches, we will uncover general principles related to how microbial consortia function together to modulate Earth’s biogeochemical cycles. We have just taken the first steps and the horizon is broad.
Jillian Banfield
University of California, Berkeley, USA