Genetically engineering koji mold to create a meat alternative

Original Article ↗ Hacker News Discussion ↗

Texture, taste, and role as meat replacement

  • Commenters note existing plant/fungal textures: lion’s mane (“monkey head”) mushrooms for chicken-like, unripe jackfruit for pulled-pork-like dishes.
  • Some vegetarians want meat-like products for ethical, environmental, religious, cost, or disease-risk reasons while still liking meat’s taste and culinary role.
  • Others dislike “meat-like” products or worry about confusing them with real meat.
  • Several point out that many cuisines already use fungi and molds (miso/koji, tempeh, soy sauce, mold-ripened cheeses).

Protein, amino acids, and satiety

  • Disagreement on whether “protein worries” are overblown:
    • One camp says normal varied diets (including vegetarian) easily meet needs; rice+beans, bread+dairy cited.
    • Another argues typical RDAs are too low, especially for active, dieting, or older people, and that hitting ~1.2–1.6 g/kg/day takes effort.
  • Mycoprotein (e.g., Quorn) is cited as relatively high in protein, with an essential amino acid profile similar to chicken.
  • Some doubt fungi-based products will feel as satiating as meat or match meat’s nutritional completeness without fortification (fat, fat-soluble vitamins).

Safety and biology of fungi

  • Clarification that koji mold (Aspergillus oryzae) is already widely used in food and can be eaten without boiling.
  • Discussion of mushroom toxins (e.g., agaritine): heat reduces them; current evidence of carcinogenicity at normal intake is deemed weak.
  • Note that fungal biomass can be high in RNA; industrial mycoprotein processes may need to reduce RNA to avoid gout risk.
  • Concerns about hyphae “penetrating” tissues are answered with cooking and normal digestion/immune defenses.

Fiber and broader health debates

  • Sharp disagreement on whether fiber is “non-essential” vs “critical”:
    • One side stresses fiber’s role in microbiome health and disease prevention.
    • Others highlight medical contexts where low- or no-fiber diets are therapeutic, arguing the picture is nuanced.

Environmental, ethical, and “natural” arguments

  • Supporters see engineered fungi as an efficient, scalable, lower-impact protein source compared to factory-farmed meat or lab-grown meat.
  • Skeptics frame this as part of a push to make people “consume less” or replace enjoyable foods, preferring “sustainable meat” over substitutes.

Soy, processing, and GM concerns

  • Debate over soy:
    • Points raised about allergies and phytoestrogens reducing androgens in some studies.
    • Others call fears exaggerated and note soy’s long culinary history.
  • Some are wary of highly processed, genetically modified fungal foods and long-term safety, asking for extensive testing.
  • Others counter that almost everything edible has some risk, and that new options don’t remove existing choices.

Lab-grown meat, Quorn, and what’s new here

  • Several compare this work to existing mycoprotein (Quorn) and ask what’s different.
  • Key claimed novelty: genetically boosting heme production in fungi to better mimic meat’s color and flavor.
  • Some argue fungal/mycoprotein routes are more realistic near-term than cultured meat, which may stay niche (e.g., exotic or endangered species), and note that legal bans in some US states currently target cultured meat, not fungal products.