People

Dr. Mengting “Maggie” Yuan

Principal Investigator, Assistant Professor/Researcher, Pacific Biosciences Research Center, University of Hawaiʻi at Mānoa

I am interested in exploring how things work in nature. Starting off counting phytoplanktons collected from urban wetlands and figuring out how eutrophication affects freshwater life, I became fascinated by the tiny but mighty microorganisms in the soil, one of the most heterogeneous habitats on earth. Who are there? What can they do? How do they interact? How do their functions affect human-relevant soil processes in the ever-changing environment? These are my ongoing quests.

Email: myuan2@hawaii.edu

Office: 310 IAALSB, 1800 East-West Road, Honolulu, HI 96822

Phone: (808) 956-9162

Curriculum Vitae, Webpage, Lab webpage

Dr. Hans Wu Singh

Postdoctoral Researcher, Pacific Biosciences Research Center, University of Hawaiʻi at Mānoa

I seek to understand how microbial communities function and assemble. Specifically, I utilize a range of microbiological, genomic and bioinformatic techniques to query the biogeography and diversity of microbes and their functional genes across earth. Hopefully, my work will provide insight into how microbes can impact humans from a health perspective, both in terms of discovering novel specialized metabolites (as a graduate student) and mapping pathogen risk (as a postdoctoral researcher).

Email: hwsingh@hawaii.edu

Office: 314 IAALSB, 1800 East-West Road, Honolulu, HI 96822

Phone: (919) 619-8421

Dr. Nayela Zeba

Postdoc Researcher, Pacific Biosciences Research Center, University of Hawaiʻi at Mānoa

Research Affiliate, Department of Environmental Science, Policy and Management, University of California, Berkeley

After completing my PhD in Soil Science—where I investigated how microbial communities respond to pyrogenic organic matter in fire-affected soils—I began a postdoctoral research position focused on bacterial–fungal interactions in grassland soils. Building on my background in stable isotope techniques, I combine 13C labeling, flux measurements, and quantitative stable isotope probing to study the fate of plant-derived carbon and the underlying mechanisms that drive soil carbon turnover. My work merges field experiments, molecular analyses, and data analytics to deepen our understanding of how microbial communities respond to environmental change and influence soil carbon dynamics.

Email: nayela@hawaii.edu

Xiaoding Lin

Ph.D. Student, Tropical Plant and Soil Sciences, University of Hawaiʻi at Mānoa

I’m fascinated by microbial connections among soil, plant, and human health, which are much closer than previously thought. This curiosity drives my current research on Legionella in tropical agriculture. During my master’s studies, I assessed soil quality using physical, chemical, and microbial indicators to support food production. I later focused on plant-soil-microbe interactions as a research assistant, asking “how much” and “what kinds” of carbon compounds are stored in soils, and “who” processes and stabilizes them.

Email: xiaoding@hawaii.edu

Office: 305 IAALSB, 1800 East-West Road, Honolulu, HI 96822

Aaron Chew

Ph.D. Student, Tropical Plant and Soil Sciences, University of Hawaiʻi at Mānoa

Before joining the Yuan Lab, I worked as a lab technician and became fascinated by using stable isotope techniques to study plant-microbe interactions. Having contributed to several projects using these methods, I hope to build on this foundation in graduate school. My research focuses on how the plant rhizosphere forms and develops over time under varying conditions. Specifically, I want to understand if and how plants use root exudates to recruit and select microbes that provide ecosystem services. I am also interested in how root exudates and the associated microbial communities shift in response to environmental changes. To explore these questions, I plan to conduct stable isotope experiments to link microbial communities with host plants, identify root exudates, and track their changes throughout plant development and under stress conditions such as drought and extreme heat.

Email: chewa@hawaii.edu

Office: 305 IAALSB, 1800 East-West Road, Honolulu, HI 96822

Simon Lee

Undergraduate Research Assistant, Biology, University of Hawaiʻi at Mānoa

I am an undergraduate Biology student at UH Manoa, with intentions to enroll in medical school afterwards. I was given the privilege to work as a research assistant in the SMiL lab and explore the importance of microbiology, as well as its relevance to public health through Legionella research that I am currently conducting alongside Maggie and Hans. I hope to understand and uncover effective methods of culturing and observing Legionella in various environmental conditions to further future research. 

Email: simonlee@hawaii.edu

Gracie Wong

Undergraduate Research Assistant, Marine Biology, University of Hawaiʻi at Mānoa

I am an undergraduate student studying for a BA in Marine Biology from the University of Hawaiʻi at Mānoa. I aim to gain more lab experience through helping to characterize Legionella in soils and freshwater as I continue to explore career options. 

Email: graciejw@hawaii.edu

Close collaborators in the Firestone Lab at UC Berkeley

Katerina Estera-Molina

Project Manager/Researcher: Innovative Genomics Institute/Environmental Science, Policy, and Management, University of California, Berkeley

Staff Scientist: Environmental Isotope Systems Group, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory

“A nation that destroys its soil destroys itself” – Franklin D. Roosevelt. Like FDR, I believe that soils are important for the multitude of ecosystem services they provide to the world, such as food, biodiversity, and carbon storage. My research centers upon the use of 13C as 13CO2 to study belowground soil interactions among plants, soil, and different climatic events, and also use it, to an extent, as a ground truthing tool for any emerging biotechnology aimed at increasing soil C sequestration in the soil.

Email: rinaest@berkeley.edu / esteramolina1@llnl.gov

Former members

Dr. Xiongfeng Du

Xiongfeng visited the lab from the University of Chinese Academy of Sciences from 2023 to 2024. He studied soil microbial biogeography. In our lab, he developed PCR primers that target environmental Legionella.

Shea Batchelder

Shea was an undergraduate research assistant with us from 2022 to 2024. He was Environmental Science major in UC Berkeley’s ESPM department. He is interested in various organismal dynamics in our rapidly changing environments.

Zoe Woodhouse

Zoe was an undergraduate research assistant helped with the bacterial-fungal interactions field experiment at UC Berkeley . She is interested in plants, microbes, and arthropods, and all the ways they interact with each other.

Emily Savrnoch

Emily was an undergraduate research assistant in the bacterial fungal interactions project. She is Molecular Environmental Biology major and Data Science minor at UC Berkeley. Her interest is in global change biology.