Researchers have identified viable, cold-adapted yeast strains within the 5,300-year-old remains of Ötzi the Iceman, facilitating preliminary experiments in food production.

研究人員在 5,300 年前的「冰人」奧茨遺骸中，發現了可生存且適應低溫的酵母菌株，並以此進行了初步的食品生產實驗。

The microbial composition of the specimen is categorized into three distinct temporal strata: indigenous microbiota present during the subject's lifetime, postmortem colonizers from the glacial environment, and contemporary contaminants introduced via conservation protocols. Analysis conducted by Mohamed S. Sarhan and colleagues at Eurac Research utilized shotgun metagenomics and culturing techniques to differentiate between degraded ancient DNA and viable organisms. The study identified four cold-tolerant yeast genera—Phenolifera, Glaciozyma, Goffeauzyma, and Mrakia—which exhibit genetic similarities to yeasts found in Arctic and Antarctic regions. These organisms appear to have infiltrated the remains postmortem and have persisted through a slow reproductive cycle, aided by the specific conditions of the South Tyrol Museum of Archaeology's storage facility.

該樣本的微生物組成被分為三個不同的時間層次：個體生存期間的原生微生物群、死後來自冰川環境的殖民菌，以及透過保存程序引入的現代污染物。Mohamed S. Sarhan 與 Eurac Research 的同事利用散彈槍元基因組學與培養技術，以分辨退化的古代 DNA 與可生存的生物。研究發現了四個耐寒酵母屬——Phenolifera, Glaciozyma, Goffeauzyma 與 Mrakia——它們與在北極及南極地區發現的酵母菌具有基因相似性。這些生物似乎是在死後滲入遺骸，並在南蒂羅爾考古博物館儲存設施的特定條件下，透過緩慢的繁殖週期得以生存。

Furthermore, the external microbiome has been modified by the introduction of Methylobacterium and Sphingomonas, likely a consequence of the UV-treated water spray used to maintain 99 percent humidity. Parallel to the biological mapping, the research team conducted experimental applications of the viable yeast strains. By introducing the yeast to a flour-based medium, the researchers successfully developed a sourdough starter. The adaptation of these strains to a dough environment suggests potential industrial utility, specifically regarding the capacity for fermentation at refrigerated temperatures, which would theoretically reduce energy expenditure during food transportation and production.

此外，由於使用經過 UV 處理的水霧以維持 99% 的濕度，導致 Methylobacterium 與 Sphingomonas 的引入，使得外部微生物組產生了改變。在進行生物製圖的同時，研究團隊亦對這些可生存的酵母菌株進行了實驗性應用。研究人員將酵母菌加入麵粉基底，成功研發出一種酸種發酵起種（sourdough starter）。這些菌株能夠適應麵團環境，顯示出潛在的工業用途，特別是在冷藏溫度下發酵的能力，理論上可減少食品運輸與生產過程中的能源消耗。

The specimen remains a dynamic biological interface, providing both insights into ancient ecosystems and potential advancements in cold-temperature fermentation.

該樣本依然是一個動態的生物界面，不僅提供了對古代生態系統的見解，還能推動低溫發酵技術的進步。