Archaea Physiology & Biotechnology Group, Department of Functional and Evolutionary Ecology, Universität Wien, Vienna, Austria.
Institute for Synthetic Bioarchitectures, Department of Bionanosciences, University of Natural Resources and Life Sciences, Vienna, Austria.
mSystems. 2023 Apr 27;8(2):e0115922. doi: 10.1128/msystems.01159-22. Epub 2023 Mar 7.
Methanogenic archaea possess diverse metabolic characteristics and are an ecologically and biotechnologically important group of anaerobic microorganisms. Although the scientific and biotechnological value of methanogens is evident with regard to their methane-producing physiology, little is known about their amino acid excretion, and virtually nothing is known about the lipidome at different substrate concentrations and temperatures on a quantitative comparative basis. Here, we present the lipidome and a comprehensive quantitative analysis of proteinogenic amino acid excretion as well as methane, water, and biomass production of the three autotrophic, hydrogenotrophic methanogens Methanothermobacter marburgensis, Methanothermococcus okinawensis, and Methanocaldococcus villosus under varying temperatures and nutrient supplies. The patterns and rates of production of excreted amino acids and the lipidome are unique for each tested methanogen and can be modulated by varying the incubation temperature and substrate concentration, respectively. Furthermore, the temperature had a significant influence on the lipidomes of the different archaea. The water production rate was much higher, as anticipated from the rate of methane production for all studied methanogens. Our results demonstrate the need for quantitative comparative physiological studies connecting intracellular and extracellular constraints of organisms to holistically investigate microbial responses to environmental conditions. Biological methane production by methanogenic archaea has been well studied for biotechnological purposes. This study reveals that methanogenic archaea actively modulate their lipid inventory and proteinogenic amino acid excretion pattern in response to environmental changes and the possible utilization of methanogenic archaea as microbial cell factories for the targeted production of lipids and amino acids.
产甲烷古菌具有多样的代谢特征，是一类在生态学和生物技术上都很重要的厌氧微生物。尽管产甲烷菌在产甲烷生理学方面具有明显的科学和生物技术价值，但人们对它们的氨基酸排泄知之甚少，而且实际上也不知道在不同底物浓度和温度下，其脂类组在定量比较的基础上有何变化。在这里，我们展示了三种自养产氢型产甲烷菌 Methanothermobacter marburgensis、Methanothermococcus okinawensis 和 Methanocaldococcus villosus 的脂类组以及蛋白质氨基酸排泄的综合定量分析，以及在不同温度和养分供应下的甲烷、水和生物量的产生。排泄氨基酸和脂类组的产生模式和速率对于每种测试的产甲烷菌都是独特的，可以通过分别改变培养温度和底物浓度来调节。此外，温度对不同古菌的脂类组有显著影响。正如预期的那样，所有研究的产甲烷菌的甲烷产生速率都很高，水的产生速率也很高。我们的结果表明，需要进行定量比较生理学研究，将生物体的细胞内和细胞外限制联系起来，以全面研究微生物对环境条件的反应。生物甲烷的产生已被很好地研究用于生物技术目的。这项研究表明，产甲烷古菌会主动调节其脂类库存和蛋白质氨基酸排泄模式，以响应环境变化，并可能利用产甲烷古菌作为微生物细胞工厂，有针对性地生产脂质和氨基酸。
