Jillian Banfield


Jillian Fiona Banfield is Professor at the University of California, Berkeley with appointments in the Earth Science, Ecosystem Science and Materials Science and Engineering departments. She leads the Microbial Research initiative within the Innovative Genomics Institute, is affiliated with Lawrence Berkeley National Laboratory and has a position at the University of Melbourne, Australia. Some of her most noted work includes publications on the structure and functioning of microbial communities and the nature, properties and reactivity of nanomaterials.

Early life and education

Banfield was educated at the Australian National University where she completed her bachelor's and master's degrees both examining granite weathering. She attributes her initial interest in geomicrobiology to Dr Tony Eggleton who drew her attention to processes at the earth's surface, mineral weathering and the regolith.
Banfield graduated with a PhD in Earth and Planetary Sciences from Johns Hopkins University for high-resolution transmission electron microscopy studies of metamorphic reactions supervised by David R. Veblen.

Career and research

Banfield is an earth scientist who studies the structure, functioning and diversity of microbial communities in natural environments and the human microbiome. Her laboratory and collaborators pioneered the reconstruction of genomes from natural ecosystems and community metaproteomic analyses. Through genomics, her group has provided insights into previously unknown and little known bacterial and archaeal lineages, leading to a new rendition of the Tree of Life. She has conducted extensive research on natural and synthetic nanomaterials, exploring the impacts of particle size on their structure, properties and reactivity. Her lab described the oriented attachment-based mechanism for growth of nanoparticles and its implications for development of defect microstructures. She has also studied microorganism-mineral interactions, including those that lead to production of nanomaterials.
Banfield was a Fulbright Student in Medicine from the to in 1988, and a in 1999. She has been a professor at the University of Wisconsin-Madison from 1990 to 2001 and The University of Tokyo. Since 2001, she has been a researcher and professor at the University of California Berkeley. Here she heads their geomicrobiology program and works as a researcher under the Lawrence Berkeley National Laboratory. Her current research spans from field sites in Northern California to Australia and from subjects including astrobiology and genomics/geosciences.
The Banfield lab studies microbial communities in terrestrial ecosystems, including soils, sediments and groundwater, as well as the human environment. Topics of current interest include the process of microbial colonization, organism interdependencies, diversity and microbial evolution. This research includes consideration of microbial impacts on mineral dissolution and precipitation and the structure and reactivity of finely particulate nanomaterials and clays that are abundant and important in earth's near-surface environments.
Research exploring microbial diversity and metabolic capacities draws heavily on genome-resolved metagenomic methods coupled to tools that provide insight into function in situ. In fact, the Banfield lab led the first research that achieved reconstruction of draft genomes from shotgun sequence information as well as the first community proteomic studies of microbial communities. The combined approaches have been used to investigate many aspects of ecosystem function, including microbial impacts on the carbon, sulfur, nitrogen, iron and hydrogen cycles. Emphasis is placed on analysis of reconstructed genomes because these provide detailed information about genetic potential, with strain resolution, without reliance on laboratory isolation of the organisms or the need for sequences from related species.
Studies conducted in an underground research facility in Japan are relevant for predicting the implications of microbial activity for the safety of geological disposal of high-level radionuclide wastes. Research conducted at Crystal Geyser probes the potential for subsurface microbial communities to take up CO2 that could leak from CO2 sequestration sites, should such storage be pursued to limit CO2 contamination of the atmosphere from burning of fossil fuels. Research on the sediments and aquifer fluids at a site adjacent to the Colorado River near Rifle, Colorado, targets knowledge gaps related to how subsurface microbial communities are structured, respond to changes in environmental conditions, and influence the chemical form and reactivity of contaminants such as vanadium, selenium, arsenic and uranium. Important outcomes of this work include the first descriptions of hundreds of little known or previously unknown organisms, including those from massive groups of uncultivated bacteria and archaea.
In a study that involves collaboration with the Harrison Lab at the University of Cape Town, South Africa, the group is investigating microbial communities in bioreactors that breakdown thiocyanate, a toxic waste product of gold mining. The objective of this work is to develop understanding of how these communities function under different SCN loadings, and to provide clues as to the how to improve the effectiveness of biological decontamination of mining wastewater so that it can be recycled back into the mining process.
Research conducted at the Angelo Coast Range Reserve in northern California is comparing the membership and functioning of microbial communities involved in cycling of carbon and other compounds in soils and the vadose zone. Of particular interest is the response of soil consortia to the first fall rain event, when massive pulses of carbon and nitrogen compounds propagate through the system.
Research approaches developed initially to study mining-related sites has been adapted to investigate the human microbiome. Of particular interest has been the process of colonization of the gastrointestinal tract of premature infants during their critical first weeks of life. In parallel, the lab is studying the sources of microbes that colonize the gut and the flow of microbes between the infant and the surrounding environment. A 2017 study demonstrated low level of overlap in the strain membership of microbial communities in different infants hospitalized in the same neonatal intensive care unit at the same time.
The group continues to study nanomaterials, including the process of oriented attachment-based crystal growth that they first described in detail in the mid- to late 1990s. Also of current interest is the impact of salinity on nucleation and growth of iron oxyhydroxides and on the structure of smectite clay materials.

Honors and awards

Banfield is married to Peregrine Smith, and they have three children: Nicole Smith, Andrei Smith and Elliot Smith.