A novel artificial carbon fixation pathway LATCH with 10 enzymatic steps

https://www.sciencedirect.com/science/article/pii/S2950155525000667?via%3Dihub

https://www.cas.cn/syky/202511/t20251125_5089765.shtml

A research team at the CAS Tianjin Institute of Industrial Biotechnology has proposed a novel artificial carbon fixation pathway—LATCH which comprises 10 completely known enzymatic steps. Each cycle converts two molecules of HCO₃⁻ into one molecule of acetyl-CoA, requiring only adenosine triphosphate (ATP) and reduced coenzyme II for energy. Kinetic and thermodynamic modeling analysis shows that it is a linear autocatalytic cycle structure without kinetic traps or thermodynamic barriers, possessing high feasibility and potential for continued development. It can provide insights for improving the efficiency of systems such as photosynthetic microorganisms, plants, and engineered cell factories.

Regarding the selection of parental modules, the research team referenced research on the serine cycle and designed a modified version of the serine cycle, simplifying the pathway structure and bypassing the inefficient steps involving hydroxypyruvate, thus enabling the pathway to function effectively in the heterologous host *E. coli*. Simultaneously, the team replaced the amino acid deamination and transamination steps in the serine cycle with a decarboxylation process, forming an MCG cycle free from formic acid dependence. This cycle can further convert glycerate 3-phosphate produced by processes such as the Calvin cycle and glycolysis into acetyl-CoA in a negative carbon mode. The study also referenced a series of photorespiration bypass concepts developed for recovering the Rubisco byproduct glycolate-2-phosphate, among which the TaCo module, due to its artificial carboxylation reaction, theoretically has a maximum yield of 150%. This study found that by introducing glyoxylate reductase as a key step to act as a “molecular latch,” the natural serine cycle and the artificially carboxylated module TaCo can be recombined, resulting in a functional transformation—from two parent modules dependent on organic substrates to a complete carbon-fixing cycle.

Based on the LATCH cycle formed by module integration, kinetic analysis shows that this pathway is a linear autocatalytic cycle, theoretically avoiding kinetic traps while eliminating the need to establish complex regulatory relationships. Meanwhile, eight steps in the pathway receive thermodynamic support from adenosine triphosphate (ATP), reducing power, or high-energy substrates, and the remaining two lyase-catalyzed processes do not pose thermodynamic bottlenecks. These inherent advantages at the stoichiometric, kinetic, and thermodynamic levels lay the foundation for the continued development and application of LATCH.

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https://www.sciencedirect.com/journal/green-carbon

Green Carbon has received its first Impact Factor of 14.2 in the 2025 Journal Citation Reports (JCR) released by Clarivate on June 17, 2026. This places Green Carbon in Q1 in both the “Engineering, Chemical” category (Ranked 10/183) and the “Green & Sustainable Science & Technology” category (Ranked 8/114). Achieving this in less than three years since its launch is a testament to the journal’s academic quality, rigorous publishing standards, and growing international influence.

https://english.news.cn/20260606/de8eff009a94407c8eeeb1fdab13d675/c.html

https://www.cell.com/cell/abstract/S0092-8674(26)00571-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867426005714%3Fshowall%3Dtrue

A joint research led by the CAS Institute of Oceanology in collaboration with the Hong Kong-based Chinese University of Hong Kong and Northwestern Polytechnical University in Xi’an deciphered the mechanism of ultra-long starvation tolerance in deep-sea isopods and provides an important paradigm for understanding how life balances growth and survival in extreme environments.

The deep sea is cold, dark, and almost entirely devoid of reliable nutrition, making long-term survival a remarkable evolutionary feat. To survive the abyss, the isopod possesses an enormous stomach that occupies about two-thirds of its body and acts like a deep-freeze pantry, allowing it to gorge when food is available and store the haul for months or even years. Second, it maintains an exceptionally low basal metabolic rate, essentially putting itself on permanent energy-saving mode. Together, these traits turn opportunistic binge eating into an ultra-long energy reserve.

In addition, a key gene involved in this metabolic slowdown, named ND1, is not originally part of the isopod’s own genome. The isopod “hijacks” it from an external symbiotic bacterium through horizontal gene transfer.

To verify ND1’s function, the researchers inserted the gene into zebrafish, nematodes, and human cells in the lab. Under normal temperatures, the gene recipients burned energy faster and became less tolerant of starvation. However, under cold conditions that mimic the isopod’s deep-sea home, ND1 suppressed energy metabolism, reduced mitochondrial activity, and boosted starvation endurance in zebrafish by a remarkable 37 percent.

This temperature-dependent switch solves the so-called “energy paradox” — how can a giant animal with high energy demands survive where food is extremely scarce? The ND1 acts as a metabolic thermostat, fine-tuning energy burn in response to environmental conditions. It provides a solution to the trade-off between body size and food scarcity.

http://english.cas.cn/newsroom/research-news/202606/t20260608_1161380.shtml

https://onlinelibrary.wiley.com/doi/10.1002/mlf2.70089

Researchers from the CAS Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) and Shenzhen Third People’s Hospital have developed a Ramanome-based phenotypic platform to improve the efficiency of bacteriophage evaluation for potential clinical use.

By combining Raman spectroscopy with a random forest model, the researchers introduced the Ramanome-based Phage Susceptibility Test (RPST). This phenotypic method reduces the turnaround time for host range verification to approximately one hour, compared to the 11–21 hours typically required by traditional plaque-based assays.

Bacteriophages offer a precise alternative to antibiotics in the fight against antimicrobial resistance. However, matching phages to clinical bacterial isolates remains challenging due to their narrow host ranges and the slow, qualitative nature of conventional assays.

The RPST framework monitors bacterial metabolic changes within 40 minutes of phage-host co-incubation and identifies four conserved Raman spectral biomarker regions linked to nucleic acids, proteins, and lipids. Combining these biomarkers into a Composite Infection Index (CII), the system achieved a 96.0% concordance rate across 25 phage-host pairs.

Unlike static assays, the continuous CII metric estimates the fraction of infected cells, enabling researchers to rank phage potency and determine the minimum MOI required to sustain infection.

While the method shows operational promise, the researchers acknowledge the need for large-scale, multi-center validation across different instruments to ensure long-term clinical reproducibility.

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