{
  "id": 14052841,
  "title": "A conditional upper-bound design map for rhodopsin-augmented electro microbial CO2-to-biomass conversion",
  "url": "https://urgent.news/2026/10/12/a-conditional-upper-bound-design-map-for-rhodopsin-augmented-electro",
  "topic": "science",
  "section": "Science",
  "published": "2026-10-12T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.10.09.758023v1?rss=1"
  },
  "original_language": "en",
  "account": "Researchers have developed a design map to optimize the process of converting CO2 to biomass using rhodopsin-augmented electro-microbial systems. The key factors influencing the value of rhodopsin proton pumps in this conversion are molecular photophysics, pathway energetics, and reactor light delivery. They investigated the Calvin-Benson-Bassham (CBB) and reductive glycine (rGlyP) assimilation pathways in Cupriavidus necator.\n\nThe model indicates a 17.9% advantage in dark rGlyP yield compared to CBB, which aligns closely with experimental measurements in chemostats. Under ideal conditions of 568 nm light intensity at 100 PPFD and 45% membrane occupancy, light-derived ATP increases yield by 17% for rGlyP and 14% for CBB. By simultaneously charging CO2 capture and formate electrosynthesis, a retinal-only reactor achieves a 3.29% efficiency rate, surpassing the 2.56% efficiency in a dark environment.\n\nIncorporating a carotenoid antenna enhances this efficiency further, reaching 3.52% under the model's 70% transfer estimate. However, this enhancement comes at the cost of a slight decrease in efficiency by 0.04% when the thermodynamic limit is reached, as photons are diverted from photovoltaics. Notably, point-source CO2 delivery reduces the relative light benefit from 38% to 8%. Thus, rhodopsin's utility is most pronounced when upstream formate is energy-intensive, rather than providing a universal efficiency enhancement.",
  "summary": "The value of rhodopsin proton pumps as light harvesters in electro-microbial CO2-to-biomass conversion depends on molecular photophysics, pathway energetics and reactor light delivery. We couple these scales for Cupriavidus necator, comparing Calvin-Benson-Bassham (CBB) and reductive glycine (rGlyP) assimilation. The model predicts a 17.9% dark rGlyP yield advantage, close to 16.5% measured in…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}