Lisa Y. Stein, PhD

Area of Study / Keywords

Canada Research Chair in Climate Change Microbiology

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Research

CLIMATE CHANGE MICROBIOLOGY

Research Interests

•   Physiology, genomics, and ecology of nitrification, denitrification, and single carbon metabolism. 

•   Influence of microbial metabolism on greenhouse gas production. 

•   Industrialization of microorganisms using single-carbon feedstocks. 

•   Increasing nitrogen use efficiency in crops by inhibiting nitrification

Work in our laboratory focuses on the numerous and diverse pathways of inorganic nitrogen and single carbon metabolism in bacteria and archaea. Using the tools of comparative genomics, molecular biology, physiology, biochemistry, and ecology we study how microorganisms process nitrogen and methane at the molecular, whole-cell, and ecosystem levels. Our goals are to track the evolution of nitrogen metabolism, predict how and when deleterious nitrogen oxide products are released to the environment, and define linkages between methane and nitrogen metabolism. The greenhouse gas nitrous oxide, the ozone depleting nitric oxide, and the groundwater polluting nitrate are the most significant of the nitrogen oxide pollutants created and released by microbial nitrogen metabolism. Single carbon metabolism, i.e. methane oxidation and carbon fixation, are intimately connected to the biogeochemical nitrogen cycle. By interrogating the linkages between single carbon and nitrogen metabolism, we can harness microorganisms to generate commercially viable bioproducts using single-carbon waste streams as feedstocks. We can also maximize microbial activities to increase productivity of vertical agriculture aquaponics systems without production of greenhouse gases.

Current Projects

Methane Oxidizing Bacteria (MOB Squad):

a) Uncovering Linkages Between Methane and the Nitrogen Cycle: Some methane-oxidizing bacteria metabolize methane and nitrate to release nitrous oxide when exposed to exceedingly low oxygen levels. Methane-dependent denitrification is an important process in permafrost, coastal oxygen minimum zones, hypoxic soils, and other ecosystems where methane, nitrate, and low oxygen co-exist. Through the collaborative Organization for Methanotroph Genome Analysis (OMeGA), we have gained access to a wealth of genome sequences and cultures of methanotrophic bacteria, allowing us to test and map functional pathways responsible for methane-dependent denitrification and nitrous oxide production.

b) Industrialization of Microorganisms using Single-Carbon Feedstocks: Using the genome-sequenced culture collection of methanotrophic bacteria, we are working with Dr. Dominic Sauvageau in Chemical and Materials Engineering and industrial partners to screen for value-added products created by bacteria as they consume methane, methanol and carbon dioxide. The resurgent interest in synthetic biology and green chemistry has placed methane-consuming microorganisms at the forefront of new bioindustrial developments. Projects in this area include screening methanotrophic bacteria for products, optimization of growth and product formation, and pathway engineering.

c) Atmosperic Methane Removal: Removal of methane from the atmosphere offers the greatest promise for slowing the rise of global temperature as this GHG has a short atmospheric lifetime with high global warming potential. In conjunction with collaborators in the US and Norway, we are exploring the use of atmospheric methane oxidizing bacteria inoculated into novel bioreactor systems for their ability to remove a meaningful amount of methane from air.

The Nitrogen Cycle (Team Nitro):

Ammonia-oxidizers & Greenhouse Gases: Specialized groups of bacteria and archaea make a living by oxidizing ammonia to nitrite as their sole energy-generating metabolism. Due to alarming increases in the greenhouse gas, nitrous oxide, to the atmosphere, there has been intensive interest in understanding how these chemolithotrophic microorganisms contribute to the nitrogen cycle and nitrous oxide release. We are using cutting-edge technologies of microrespirometry and RNAseq to show that ammonia-oxidizing bacteria and archaea have distinct mechanisms for metabolizing nitrogen and releasing nitrogen oxides. The metabolic intermediate, nitric oxide, plays a critical (albeit different) role in the pathways of both bacteria and archaea, although only the bacteria have enzymology to convert nitric oxide to nitrous oxide. This very exciting and novel line of research is changing the way we understand the microbial nitrogen cycle and makes use of one of the largest collections of genome-sequenced ammonia-oxidizing isolates in the world. Projects in the lab involve collaboration with many distinguished colleagues around the world.

Crop improvement: With colleagues at the Univ. Alberta and around the world, we are testing biological alternatives to fertilizers and pesticides that improve nitrogen use efficiency plants without greenhouse gas production. One of the main ways to improve NUE is to inhibit nitrification; thus, we are examining production of biological nitrification inhibitors by crops and their inhibitory effects on ammonia-oxidizing microorganisms. An additional aim is to ensure that these biological amendments do not have unintended consequences to other important soil processes such as methane uptake.

MICRB 606 - Microbiology Seminar

Intended for all Microbiology and Biotechnology graduate students, except those in their second year who should register for MICRB 607. Credit may be obtained more than once.

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MICRB 607 - Microbiology Seminar

Graded seminar course intended for second-year graduate students.

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Browse more courses taught by Lisa Y. Stein

Started: 2023-02-15

Over the last 50 years, over 2,600 distinguished scientists have been elected to the American Academy of Microbiology (Academy). The Academy is the honorific leadership group within the American Society for Microbiology (ASM), one of the largest life science societies in the world. The mission of the Academy is to recognize scientists for outstanding contributions to microbiology and provide microbiological expertise in the service of science and the public. It fulfills its mission by election to fellowship in the Academy, convening colloquia and oversight of ASM’s Awards Program. 

American Academy of Microbiology

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2023-04-10 to 2024-06-30

Committee of experts to research and review technologies that could enable the removal of meaningful amounts of methane from the atmosphere to reduce the pace of global warming. The report from this committee will be released to the public in October 2024.

Atmospheric Methane Removal: Development of a Research Agenda

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2022: Invited participant for the Rockefeller Philanthropy Advisor workshop on How Can Agrigenomics Help to Address Climate Change?

2021: Invited participant for the Rockefeller Philanthropy Advisors workshop on Climate Change Mitigation and Adaptation in Agriculture: 

what can biotechnology do?

2020: Editor-in-Chief for The ISME Journal

2016: Invited participant for ASM-AGU Collaborative Colloquium on the Effects of Climate Change on Microbial Ecosystems

2015: Invited chair for Nitrification section of NSF INFEWS workshop on the Nitrogen Cycle

2015: Chair and Organizer of 4th International Conference on Nitrification and Related Processes (ICoN4), Edmonton AB

Lisa Y. Stein

Cold Spring Harb Perspect Biol. 2023 October; Oct 3 10.1101/cshperspect.a041668

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Lisa Y. Stein

Proc. Natl. Acad. Sci.. 2023 September; 120

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Cavicchioli et al.

Nature Reviews Microbiology. 2019 June; 17

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Lisa Y. Stein, Martin G. Klotz

Current Biology. 26 (3):R94-R98

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Kozlowski, J.A., M. Stieglmeier, C. Schleper, M.G. Klotz and L.Y. Stein

ISME Journal. doi:10.1038/ismej.2016.2

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