Department of Biology, University of Crete, Voutes University Campus, GR-70013 Heraklion, Crete, Greece.
Department of Biology, University of Crete, Voutes University Campus, GR-70013 Heraklion, Crete, Greece; Botanical Garden, University of Crete, Gallos University Campus, GR-74100 Rethymnon, Crete, Greece.
J Biotechnol. 2021 Dec 10;342:128-138. doi: 10.1016/j.jbiotec.2021.10.011. Epub 2021 Nov 4.
The present study demonstrates biotechnological applications of the lichen Pleurosticta acetabulum, specifically the production of large amounts of hydrogen even after the lichen exposure to extreme conditions such as a) extreme UVB radiation (1.7 mW/cm = 1000 J m min) over different time periods (4, 20 & 70 h) and b) combined exposure of the lichen to high intensity UVB radiation and extreme low (-196 °C) or extreme high temperatures (+70 °C). The results highlight that the extremophilic and polyextremophilic behavior of lichens both in dehydrated and in regenerated form, under extreme conditions not necessarily recorded on earth, is compatible with their biotechnological uses. The lichen viability was measured using fluorescence induction techniques (OJIP-test), which record changes in the molecular structure and function of the photosynthetic mechanism, while its ability to produce molecular hydrogen was measured through thermal conductivity gas chromatography (GC-TCD) analysis. Hydrogen is a promising fuel for the future. The exciting result of a lichen micro-ecosystem is its ability to expel its moisture and remain in an inactive state, protecting itself from extreme conditions and maintaining its ability to high yield hydrogen production in a closed system, with the sole addition of water and without the need for additional energy. Our results expand the potential use of lichens for future biotechnological applications in extreme Earth environments, but also in environments on other planets, such as Mars, thus paving the way for astrobiotechnological applications.
本研究展示了地衣 Pleurosticta acetabulum 的生物技术应用，特别是在地衣暴露于极端条件下，如 a）不同时间段（4、20 和 70 小时）的极端 UVB 辐射（1.7 mW/cm = 1000 J m min）和 b）地衣同时暴露于高强度 UVB 辐射和极低温（-196°C）或极高温（+70°C）下，仍能大量产生氢气。这些结果突出表明，地衣在脱水和再生形式下的极端嗜热和多极端适应能力，在地球上不一定记录到的极端条件下，与它们的生物技术用途兼容。地衣的生存能力通过荧光诱导技术（OJIP 测试）进行测量，该技术记录了光合作用机制的分子结构和功能变化，而其产生分子氢的能力则通过热导气相色谱（GC-TCD）分析进行测量。氢气是未来有前途的燃料。地衣微生态系统令人兴奋的结果是，它能够排出水分并保持非活动状态，从而保护自己免受极端条件的影响，并在封闭系统中保持高产氢气的能力，只需添加水，无需额外的能量。我们的研究结果扩大了地衣在未来极端地球环境以及其他行星环境（如火星）中的生物技术应用潜力，为天体生物技术应用铺平了道路。
