高温热泉铁同位素的组成特征及生物分馏机制研究

Terrestrial hot springs are rich in iron, the transport and transformation of iron being affected by Fe-metabolism related microbes in the hot spring. Fe isotope fractionation signals for these processes may be recorded in hot spring geological bodies. However, the knowledge of Fe isotope biological fractionation mechanism and its controlling factors in high-temperature hot spring environments has been lacking. Therefore, we chose Tengchong high-temperature hotsprings as our study area to carry out the following research aspects: firstly, investigating the compositional characteristics of Fe isotope in water and sediments from the hot spring, establishing the relationship between Fe isotope composition and iron metabolism related microbes and geological environmental parameters; secondly, constructing an in situ micro-cosmic environment, to explore the effect of sulfur on iron isotope fractionation produced during dissimilatory Fe(III) reduction by hyperthermophilic iron-reducing bacteria , and reveal the mechanisms of iron isotope fractionation in high-temperature hot spring environments. This research has important significance for further understanding the iron biogeochemical cycle in extreme high temperature environments and the synergistic evolutionary relationship between extreme life and environments.

陆地热泉富含丰富的铁元素，它的迁移转化过程受热泉铁代谢微生物的影响，并以铁同位素分馏信号的形式记录在各种热泉地质体中。然而，目前国内外对高温热泉环境中铁同位素生物分馏机制及控制因素的认知十分匮乏。本项目以腾冲高温热泉水体和沉积物为研究对象，主要从以下两个方面展开工作：1. 查明高温热泉环境中铁同位素的组成特征，建立铁同位素组成与铁代谢相关微生物和地质环境指标之间的联系；2. 开展室内模拟实验，探讨元素硫对超嗜热铁还原菌的铁同位素分馏过程的影响，揭示高温热泉环境铁同位素的分馏机制。该研究的开展对深入理解极端高温环境中铁的生物地球化学循环以及极端生命与环境的协同演化关系具有重要的科学意义。

陆地热泉富含丰富的铁元素，它的迁移转化过程受热泉铁代谢微生物的影响，并以铁同位素分馏信号的形式记录在各种热泉地质体中。然而，目前国内外对高温热泉环境中铁同位素生物分馏机制及控制因素的认知十分匮乏。通过本项目的实施，基本查明了腾冲高温热泉的矿物学及地球化学特征及铁同位素的组成特征，丰富了表生环境下铁同位素储库，揭示了Si及微生物(蓝细菌和嗜热的铁还原菌)是影响高温热泉环境铁同位素分馏的主要机制。该研究的开展对深入理解极端高温环境中铁的生物地球化学循环以及极端生命与环境的协同演化关系具有重要的科学意义。