Hello,
I have been reading posts and threads in this group for years but rarely if ever have contributed, so this is a start! My name is Patrick Mellor, and I started the nonprofit Carbocene Industries (
https://carbocene.org) last year in order to extend and deploy work in open system carbon removal and metabolic integration at both organismal and biospheric scales.
A TLDR description of the state of affairs is below, but I welcome feedback and any kind of assistance (financial, help finding land to establish planting sites, spreading knowedge of our efforts) given that this is valuable work for carbon removal and an effort to salvage a promising synthetic biology project. We are based in Oakland in the SF Bay Area.
My current work derives from a project I started in late 2019, when I cofounded the company Living Carbon. Here we did the groundwork of demonstrating efficacy of a photorespiration bypass pathway in hybrid aspen, and then, in order to produce a tree legal to plant without regulation in the US, repeated the transformation using biolistics and assayed over 150 transgenic events for expression and efficacy of our synthetic pathway. We also worked on instantiating decomposition resistance in aspen, slowing the action of fungal lignin peroxidase by inducing copper accumulation from the soil with a synthetic pathway including a copper transporter from creosote bush and a metabolic system to preferentially deposit the metal in maturing xylem cell walls. Experimental work here is ongoing but wood blocks infused with copper ions at the concentration observed to accumulate in the stem tissue of our lead copper event show a halved decomposition rate. We also produced biolistic events in loblolly pine expressing the photorespiration bypass, but event selection here is still incomplete.
Our synthetic construct expresses a metabolic reroute replacing the baseline photorespiration pathway common to all C3 plants (which includes all the plants capable of significant secondary growth and therefore multiple decade carbon removal year on year), with a synthetic 3 step pathway. Photorespiration starts with the oxygenation (in place of carboxylation) of RuBisCo, which yields glycolate in place of 3-phosphoglycerate (3-PGA), and results in the loss of 25-30% of potential photosynthetic carbon fixation in C3 plants at current atmospheric oxygen concentrations. We replaced the existing photorespiration pathway, which routes glycolate to peroxisomes (where it is converted to glyoxylate releasing hydrogen peroxide), and then mitochondria, where it is converted first to glycine and then serine, releasing ammonia and CO2, with a shunt that regenerates CO2 from glycolate in the chloroplast using the pathway glycolate>glyoxylate>malate >CO2, where it can be used immediately by RuBisCo. To enable this pathway to consume the majority of the glycolate we also blocked expression of the chloroplastic glycolate transporter Plgg1 using RNA interference.
Our lead event, a tree we called Deer (we used animal names to differentiate the events), shows the highest carbon assimilation rate of any known tree and is metabolically indistinguishable from a C4 plant in terms of carbon assimilation dynamics with respect to temperature, light, and water availability. Since Living Carbon abandoned this project due to an organizational pivot induced by antiGMO sentiment in the carbon removal markets, and expelled most of the scientists who had been working on it, including myself, I have been working to salvage and extend the project, propagating and distributing trees and working at Counterculture Labs to introduce additional metabolic engineering in order to further increase their carbon assimilation rate. I am also completing experimental verification of decomposition resistance, and event selection with loblolly pine, and continuing to maintain and collect data from a planting site in Los Angeles established by Living Carbon and also abandoned as part of their reorganization.
As Living Carbon, we were the first organization to plant trees with synthetic metabolism in open system mixed forests on degraded land in an ecologically integrated manner with similar tree species composition to forests found in the local area, with our trees at around 20% density serving as an ecological analogue of aspen, poplar, or cottonwood.
As Carbocene Industries, we aim to plant up to 5 acres of trees this year in experimental short rotation coppice systems with integrated pyrolysis and enhanced weathering, to see how much carbon removal/acre is possible with optimized management practices.
If you read this far, thank you! I welcome questions!
Very Best Wishes
Patrick
