Rewiring a geological pace
As olivine slowly dissolves, it can move atmospheric carbon dioxide into a form that lasts. Siderophores speed that process by binding iron, but natural bacteria stop making them once iron becomes plentiful. Researchers rewired the marine bacterium Alteromonas macleodii around that feedback and increased the olivine dissolution rate by 2.6 times.[1]
The pilot fits this large idea into a small vessel: 4 kg of olivine, unprocessed seawater and a renewable acetate feedstock. With the engineered cells present, the system removed 0.50 g of carbon dioxide from the air each day through alkalinity generation. The quantity is still small. Its significance lies in directly measuring the chain from a living intervention to atmospheric carbon.[1]
The carbon balance is also a design
The life-cycle analysis places two conditions beside the faster chemistry: renewable feedstock and minimal replenishment of modified cells. Net carbon removal at scale depends on them. The bacterium creates an option; the carbon burden of sustaining the living system determines the climate value of that option.[1]
The next meaningful signal will be a longer continuous run that reports net removal after feedstock production and cell replenishment are counted. Such a measurement could give the institutions funding, operating and verifying these reactors common ground for a decision. The faster rock reaction has opened a door; collective choices will determine whether the whole system passes through it.[1]