Organic biomarkers in marine sedimentary rocks hold important clues about the early history of Earth’s surface environment. The chemical relicts of carotenoids from anoxygenic sulfur bacteria are of particular interest to geoscientists because of their potential to signal episodes of marine photic‐zone euxinia such as those proposed for extended periods in the Proterozoic as well as brief intervals during the Phanerozoic. It is therefore critical to constrain the environmental and physiological factors that influence carotenoid production and preservation in modern environments. Here, we present the results of coupled pigment and nucleic acid clone library analyses from planktonic and benthic samples collected from a microbially dominated meromictic lake, Fayetteville Green Lake (New York). Purple sulfur bacteria (PSB) are abundant and diverse both in the water column at the chemocline and in benthic mats below oxygenated shallow waters, with different PSB species inhabiting the two environments. Okenone (from PSB) is an abundant carotenoid in both the chemocline waters and in benthic mats. Green sulfur bacteria and their primary pigment Bchl e are also represented in and below the chemocline. However, the water column and sediments are devoid of the green sulfur bacteria carotenoid isorenieratene. The unexpected absence of isorenieratene and apparent benthic production of okenone provide strong rationale for continued exploration of the microbial ecology of biomarker production in modern euxinic environments.

中文翻译：

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类胡萝卜素生物标志物是淡色的费耶特维尔绿湖中产氧养分群落的不完美反映。

海洋沉积岩中的有机生物标记物提供了有关地球表面环境早期历史的重要线索。产氧学家认为，来自产氧硫细菌的类胡萝卜素的化学残留物特别受关注，因为它们具有发信号通知海洋光合带富营养化事件的潜力，例如在元古生代建议延长时期，在古生代建议短暂间隔。因此，限制影响现代环境中类胡萝卜素生产和保存的环境和生理因素至关重要。在这里，我们介绍了从微生物占主导地位的淡紫色湖泊Fayetteville Green Lake（纽约）收集的浮游和底栖样本中的色素和核酸克隆文库耦合分析的结果。紫色的硫细菌（PSB）在趋化菌的水柱中和在氧化的浅水以下的底栖垫中都丰富多样，其中有不同的PSB物种居住在两种环境中。烯酮（来自PSB）在趋化霉素水域和底栖动物垫中都是丰富的类胡萝卜素。绿硫细菌及其主要色素Bchle也表示在趋化环中和下方。但是，水柱和沉积物不含绿色的硫细菌类胡萝卜素异戊二烯。异戊烯烯酮的出乎意料的缺乏和酮的明显底栖生产为现代探空环境中继续探索生物标志物生产的微生物生态学提供了强有力的理由。