Weathering rocks naturally pull carbon dioxide from the environment, however the course of is too slow to make much of a dent in human emissions of the greenhouse fuel. Even olivine, which is taken into account a comparatively fast-weathering silicate, dissolves at charges on the order of simply micrometers per 12 months.
Researchers have now engineered marine micro organism to maintain producing siderophores, molecules that microbes use to scavenge iron from their environment, even when iron is ample, dashing up the dissolution of olivine. The examine describes how the engineered micro organism speed up olivine weathering in seawater reactors and enhance the water’s alkalinity, permitting it to soak up extra CO2 from the environment (Nat. Biotechnol. 2026, DOI: 10.1038/s41587-026-03288-w).
“These rocks rust nearly instantly,” says Neil Dalvie, a Harvard Medical College chemical engineer and the examine’s first writer. As olivine dissolves, it releases Fe(II), which oxidizes to Fe(III) in oxygenated water. Iron oxides then precipitate onto the mineral floor, inhibiting additional dissolution of the rocks, however siderophores can bind Fe(III), retaining the iron soluble and serving to forestall the buildup.
Researchers engineered Alteromonas macleodii micro organism to spice up manufacturing of siderophores, which clear rust from olivine and lead it to proceed dissolving. Credit score:
Hansjörg Wyss Institute for Biologically Impressed Engineering at Harvard College
The researchers used the marine bacterium Alteromonas macleodii, which is ample in seawater and naturally produces the siderophore petrobactin. However micro organism sometimes make siderophores solely when iron is scarce, which isn’t the case inside a reactor filled with iron-containing olivine. Dalvie and the staff genetically engineered the microbes to repeatedly produce petrobactin, which elevated olivine dissolution 2.6-fold in small seawater reactors in contrast with an abiotic management.
The researchers then scaled the system to reactors containing greater than 4 kg of construction-grade olivine and unprocessed seawater from Boston Harbor. They discovered that the engineered micro organism elevated magnesium launch, a measure of olivine dissolution, by an element of three.1 in contrast with the management. The extra alkalinity generated was equal to eradicating about 0.5 g of atmospheric CO2 per day.
The researchers envision ultimately flowing seawater by means of giant reactors containing crushed rock and engineered microbes, then returning the alkaline water to the ocean. However additional work is required: after a number of weeks, biofilms and a hardened mineral crust amassed on the olivine, doubtlessly creating new obstacles to weathering.
Dalvie says the work grew out of mixing concepts from geochemistry, microbiology, and chemical engineering, fields that strategy the identical course of at totally different scales. “A whole lot of what we’ve uncovered is simply from taking views and fields that don’t speak to one another and placing them collectively,” he says.
Ana Georgescu covers a variety of subjects in Bodily Sciences. She can also be a frequent contributor to the Enterprise desk and might be engaged on a brief video mission at any given time.
