Ghiotto G, De Bernardini N, Orellana E, Fiorito G, Cenci L, Kougias P G, Campanaro S, Treu L
Department of Biology, University of Padua, via U. Bassi 58/b, 35131, Padova, Italy.
BTS Biogas s.r.l., Via Vento 9, 37010, Affi, VR, Italy.
NPJ Biofilms Microbiomes. 2025 Jan 8;11(1):7. doi: 10.1038/s41522-025-00649-2.
Biomethanation is a crucial process occurring in natural and engineered systems which can reduce carbon dioxide to methane impacting the global carbon cycle. However, little is known about the effect of on-and-off gaseous provision and micronutrients on bioconversion. Here, anaerobic microbiomes underwent intermittent feeding with incremental starvations and selective metal supplementation to assess the impact of hydrogen and carbon dioxide availability on microbial physiology. Resilience was tested under differential cultivations in basal medium supplemented with either nickel or cobalt. Nickel-augmented cultures exhibited faster recovery upon starvation, suggesting a beneficial effect. Dominant Methanothermobacter thermautotrophicus demonstrated robust growth, genetic stability and transcriptional downregulation when starved. Conversely, bacteria were plastic and prone to genetic fluctuations, accumulating mutations on genes encoding for ABC-transporters and C-metabolism enzymes. This study pioneers cellular resilience and response to micronutrient supplementation in anaerobic carbon dioxide-fixating microbiomes, offering valuable insights into microbial activity recovery after carbon and electron donor deprivation.
生物甲烷化是自然和工程系统中发生的一个关键过程，它可以将二氧化碳还原为甲烷，从而影响全球碳循环。然而，关于间歇性供气和微量营养素对生物转化的影响，人们所知甚少。在这里，厌氧微生物群落经历了间歇性投喂，并伴有逐渐增加的饥饿期和选择性金属补充，以评估氢气和二氧化碳的可利用性对微生物生理学的影响。在补充了镍或钴的基础培养基中，在不同培养条件下测试了恢复力。添加镍的培养物在饥饿后表现出更快的恢复，表明有有益效果。占主导地位的嗜热自养甲烷杆菌在饥饿时表现出强劲的生长、遗传稳定性和转录下调。相反，细菌具有可塑性，容易发生遗传波动，在编码ABC转运蛋白和C代谢酶的基因上积累突变。本研究开创了厌氧二氧化碳固定微生物群落中细胞恢复力和对微量营养素补充的反应，为碳和电子供体剥夺后微生物活性的恢复提供了有价值的见解。
