About This Project
The oceans are a sink for CO2. Rocks such as olivine could be dissolved into ocean water, which would increase the pH and precipitate bicarbonate with magnesium to irreversible withdraw CO2 from the atmosphere and ocean. The natural weathering of olivine takes >10,000 years. Rapid solubilization olivine could neutralize human-produced CO2 and reverse global warming. We propose to create an enzyme that will catalyze and accelerate the solubilization of olivine.
Ask the ScientistsJoin The Discussion
What is the context of this research?
The oceans have capacity to store CO2 as bicarbonate ions, with residence times >50,000 years. Soils and oceans already uptake and store nearly half of anthropogenic CO2 emitted each year. The capacity of the ocean to store CO2 is governed by its alkalinity, which is generated by natural weathering of silicate minerals. Mineral weathering occurs on geologic time scales. Moreover, CO2 uptake has already acidified the oceans, which slows further sequestration and damages ecosystems. “Enhanced weathering” of silicate minerals would increase ocean buffering and accelerate CO2 sequestration. Olivine is an abundant mineral that can theoretically sequester 1 Gt CO2 per Gt dissolved olivine: Mg1.8Fe0.2SiO4 + 4CO2 + 4H2O --> 1.8Mg2+ + 0.2Fe2+ + 4HCO3- + H4SiO4
What is the significance of this project?
Sequestration of 1000 Gt of anthropogenic CO2 by 2100 (the goal to limit average temperature increase to <1.5 degrees) might be achieved by dissolution of <50 Gt olivine/year, (less than the throughput of the global construction industry, indicating we could move this much rock). The natural weathering rate of olivine is only ~5 µm/year. Processing of 500-5000 Gt of olivine/year would be needed, because its dissolution rate is so slow.
Microbes accelerate dissolution of silicate minerals. This effect occurs only during microbial growth, however, suggesting that the weathering rate would scale linearly with the number of cultivated microbial cells. Catalytic molecules or processes are needed to accelerate the weathering of >50 Gt olivine.
What are the goals of the project?
Aim 1: De novo design of candidate olivine-degrading enzymes
Aim 2: Evaluation of olivinase activity at lab scale
The ultimate goal is to develop an enzyme that will be part of a scaled-up system that will solubilize olivine, a very abundant mineral, and allow its component ions to capture human-generated CO2 in the ocean. To neutralize excess CO2 at the rate it is currently produced, we estimate that we need to increase olivine solubilization rates by about 10-fold relative to natural weathering.
Pamela Silver will oversee the whole project.
Jeffrey Way will design the proteins and perform hands-on direction of the research assistant, and will help with experiments as needed.
The research assistant (Colin Molloy) will create DNA constructs, express secreted artificial enzymes in yeast, purify the proteins, and test them.
Neil Dalvie, a HIVE fellow, will assist in the project but is supported by a fellowship.
Completion of olivinase designs: Month 1. (after funding) We have already started.
Expression of candidate olivinase enzymes: Month 2-4.
Testing of partially purified candidate enzymes for enhancement of olivine solubilization rate: Month 5-6.
Dec 01, 2023
Completion of olivinase designs:
Dec 15, 2023
Feb 01, 2024
Construct yeast that express candidate enzymes
Mar 01, 2024
Obtain partially purified proteins
Apr 15, 2024
Test proteins for catalysis of olivine solubilization
Meet the Team
Pamela Silver – Full professor and team leader.
Jeffrey Way – Lecturer. Expert in protein design and synthetic biology.
Neil Dalvie – Post-doc/HIVE Fellow. Expert on microbial solubilization of olivine (current work). Expert in expression of proteins in Pichia pastoris (Ph.D. work).
Colin Molloy – Research assistant. Expert in DNA constructions.
Jan-Tobias Boehnke – Visiting scientist. Expert on assays for olivine solubilization.
Principal Investigator: Pamela Silver, PhD is an endowed Professor of Systems Biology at Harvard Medical School, the lead founder of the Synthetic Biology HIVE at HMS, and a founding Member of Harvard’s Wyss Institute. She is a leader in the fields of Synthetic and Systems Biology and was elected to the American Academy of Arts and Sciences. Dr. Silver is a founder of the greentech companies Kula Bio and Circe Bio, which use carbon-capturing bacteria to generate fertilizer and foodstuffs, respectively. These companies spun out of her lab based on sustainability research analogous to that proposed here. She also developed high throughput screening to discover new molecules now in successful clinical trials that form the basis for the publicly traded company KPTI. In addition, she has founded and served on the SAB of numerous startups.
- $0Total Donations
- $0Average Donation