"The discovery of the PyShell could also open promising avenues for biotechnological research aimed at combatting climate change ..." I wonder. Given that the oceans are already full of these diatoms, and the numbers must be gigantic, would humans be able to do anything in the same order of magnitude?
You have made a subtle misalignment of figures here. Yes, these existing diatoms fix 20% of the Earth's CO2 and are present throughout the entire ocean. However, we don't need to compete with that volume. We don't have to do the same order of magnitude to meaningfully impact the carbon cycle.
The Earth's carbon cycle manages about 750 gigatons of CO2/year and humans are emitting ~30 excess gigatons a year on top. The diatoms in the ocean are happily out there processing 150 gigatons of CO2/year, but what we need to engineer is only 30 gigatons (to completely eradicate human emissions).
If we engineered diatoms to fix, say, 0.3 gigatons/year, we'd eradicate a whole integer percent of our emissions.
Heck, if we got it in the 0.03 gigatons (30 megatons/year), we've probably built something scalable and created a useful entry in our portfolio to capture carbon, sinking about 0.1% of our carbon/year.
So, don't despair, we don't have to compete with the ocean! We only need to compete with ourselves! Or maybe do despair? Because we have to compete with ourselves... fundamentally, climate change isn't a technology problem, it's a political problem.
> "...would humans be able to do anything in the same order of magnitude?"
Good question. Answering questions is called 'research'. ;-)
I'm skeptical for the same reasons as you, too. Let's see... the ocean covers 361km^2. If we could engineer a material with "cells" that were 1000x as effective at carbon capture as diatoms, and the manufactured material was 1000x more densely packed together than diatoms are on the ocean surface, then you'd need 361 square kilometers of the magic material. Which is not out of the realm of possibility, though I have no idea what the density of diatoms is and I have a sneaking suspicion that we'd be looking at more of the 3x-4x range of efficiency improvement. And of course, you need to turn the CO2 into something and deposit it somewhere, and maybe move it around lot. Which would use energy that would produce more CO2, offsetting the gains. Oh, and manufacture the stuff.
I'm thinking releasing less of the stuff and stopping forest destruction might be much more effective for a long time here...
Extracting CO2 from the air likely requires some energy, and seafloor organisms are almost certainly energy-constrained. We could beat the seafloor simply by providing more energy, if we get within the ballpark of their efficiency. We have plenty of deserts and solar panels.
That's a standard line included in almost all photosynthesis research these days because of the global concern about fossil-fueled global warming, as a justification for continuance of one's research group funding, even if the relationship is rather minor.
The key point of this paper with respect to synthetic industrial photosynthesis:
> "Reaction-diffusion modeling of C. reinhardtii suggests that all pyrenoid-based CCMs require the following essential features: (1) aggregation of most of the chloroplast’s Rubisco enzymes, (2) a local source of high CO2 concentration at the center of this Rubisco aggregate, and (3) a diffusion barrier at the aggregate border to prevent CO2 leakage. Our data indicate that the PyShell contributes to the first two essential pyrenoid features (Figure 5A), and we wonder whether the PyShell may directly perform the third (Figure 5B)."
A big difference between oceanic diatoms and land plants is that the former's carbon source is bicarbonate, and diatoms convert bicarbonate (HCO3-) to CO2 which is utilized by Rubisco to fix CO2 onto a five carbon sugar which then splits into two 3-carbon species that are fed into carbon metabolism to generate lipids, amino acids, carbohydrates, etc. Increasing CO2 concentration around Rubisco makes the process more efficient (as this keeps out the O2, and avoids futile cycles where the O2 gets added to the target sugar). Some land plants (grasses, cacti) use alternative concentration systems not involving bicarbonate (bundle sheath and CAM).
The real takeaway for industrial-scale synthetic photosynthesis efforts is that it's always more efficient to preconcentrate CO2 into a 100% CO2 stream before feeding it into a reaction process with suitable robust catalysts in which O2 is removed and H2 is added to generate methanol or methane (somewhat analogous to ammonia synthesis) which (if you want to do real long-term storage) can be converted to materials like carbon fiber or diamond.
“We have now discovered that diatom pyrenoids are encased in a lattice-like protein shell,” says Dr. Manon Demulder, author on both studies. “The PyShell not only gives the pyrenoid its shape, but it helps create a high CO2 concentration in this compartment. This enables Rubisco to efficiently fix CO2 from the ocean and convert it into nutrients.”
incompatible|1 year ago
whaaaaat|1 year ago
The Earth's carbon cycle manages about 750 gigatons of CO2/year and humans are emitting ~30 excess gigatons a year on top. The diatoms in the ocean are happily out there processing 150 gigatons of CO2/year, but what we need to engineer is only 30 gigatons (to completely eradicate human emissions).
If we engineered diatoms to fix, say, 0.3 gigatons/year, we'd eradicate a whole integer percent of our emissions.
Heck, if we got it in the 0.03 gigatons (30 megatons/year), we've probably built something scalable and created a useful entry in our portfolio to capture carbon, sinking about 0.1% of our carbon/year.
So, don't despair, we don't have to compete with the ocean! We only need to compete with ourselves! Or maybe do despair? Because we have to compete with ourselves... fundamentally, climate change isn't a technology problem, it's a political problem.
sfink|1 year ago
Good question. Answering questions is called 'research'. ;-)
I'm skeptical for the same reasons as you, too. Let's see... the ocean covers 361km^2. If we could engineer a material with "cells" that were 1000x as effective at carbon capture as diatoms, and the manufactured material was 1000x more densely packed together than diatoms are on the ocean surface, then you'd need 361 square kilometers of the magic material. Which is not out of the realm of possibility, though I have no idea what the density of diatoms is and I have a sneaking suspicion that we'd be looking at more of the 3x-4x range of efficiency improvement. And of course, you need to turn the CO2 into something and deposit it somewhere, and maybe move it around lot. Which would use energy that would produce more CO2, offsetting the gains. Oh, and manufacture the stuff.
I'm thinking releasing less of the stuff and stopping forest destruction might be much more effective for a long time here...
Qwertious|1 year ago
photochemsyn|1 year ago
The key point of this paper with respect to synthetic industrial photosynthesis:
> "Reaction-diffusion modeling of C. reinhardtii suggests that all pyrenoid-based CCMs require the following essential features: (1) aggregation of most of the chloroplast’s Rubisco enzymes, (2) a local source of high CO2 concentration at the center of this Rubisco aggregate, and (3) a diffusion barrier at the aggregate border to prevent CO2 leakage. Our data indicate that the PyShell contributes to the first two essential pyrenoid features (Figure 5A), and we wonder whether the PyShell may directly perform the third (Figure 5B)."
A big difference between oceanic diatoms and land plants is that the former's carbon source is bicarbonate, and diatoms convert bicarbonate (HCO3-) to CO2 which is utilized by Rubisco to fix CO2 onto a five carbon sugar which then splits into two 3-carbon species that are fed into carbon metabolism to generate lipids, amino acids, carbohydrates, etc. Increasing CO2 concentration around Rubisco makes the process more efficient (as this keeps out the O2, and avoids futile cycles where the O2 gets added to the target sugar). Some land plants (grasses, cacti) use alternative concentration systems not involving bicarbonate (bundle sheath and CAM).
The real takeaway for industrial-scale synthetic photosynthesis efforts is that it's always more efficient to preconcentrate CO2 into a 100% CO2 stream before feeding it into a reaction process with suitable robust catalysts in which O2 is removed and H2 is added to generate methanol or methane (somewhat analogous to ammonia synthesis) which (if you want to do real long-term storage) can be converted to materials like carbon fiber or diamond.
tantalor|1 year ago
rysertio|1 year ago
We can definitely try to increase wheat production by trying to make a GMO. This could be ground breaking for food production.
bamboozled|1 year ago
phs318u|1 year ago
https://github.com/JoelGMSec/PyShell
debacle|1 year ago