UFZ-Helmholtz Center for Environmental Research, Department of Environmental Engineering, Permoserstr 15, 04318 Leipzig, Germany.
Sci Total Environ. 2012 Jan 1;414:614-23. doi: 10.1016/j.scitotenv.2011.10.015. Epub 2011 Nov 25.
Fatty acid (FA) patterns of sediments collected from the bottom of an acidic mine pit lake (AML) at different depths (surface sediment: 0 to 1cm; deep sediment: 4 to 5 cm) were studied to characterize microbial communities and the sources of sedimentary organic matter (SOM). Studies were performed on the molecular level utilizing source-specific, diagnostic FA biomarkers. The biomarker-based approach has been used widely in marine sediment studies, but has not been applied for sediments from AMLs so far. Combined FA concentrations in the surface sediment were higher compared to those in the deep sediment (497 vs. 127 μg g(-1)d.w., respectively). This was related to deposition of autochthonous biomass and higher terrestrial plants onto the surface sediment, as well as--to lesser extent--with higher bacterial activity on the sediment-water interface. The FA distribution in both sediments was characterized by a strong even-over-odd preference and was bimodal in nature: there was a cluster at nC(14)-nC(18) characteristic of chiefly autochthonous (algal and bacterial) SOM production, and another cluster at nC(22-28) related to input from higher plants. The FA distribution in the surface sediment pointed to higher terrestrial input compared to autochthonous contribution to SOM (67%:33%) as an estimate. Fingerprinting of viable bacteria was accomplished through signature FA markers including branched C(15) and C(17) surrogates, cyclopropanoic acids, 3-hydroxy (OH) acids and monounsaturated surrogates with unusual double bond localization. The abundance of Gram-negative bacteria was higher in the surface sediment as evidenced by total diagnostic 3-OH-fatty acids (37 μg g(-1) versus 25 μg g(-1)). Potential source taxa in both sediment layers included acidophilic iron- and sulfur-oxidizing bacteria including Acidithiobacillus ferrooxidans. High abundances of terminally branched C(15) and C(17) surrogates in both sediments pointed to sulfate- and iron-reducing bacteria. Signature FAs characteristic of methanotrophs were virtually lacking in both sediments.
从酸性矿山坑湖（AML）底部不同深度（表层沉积物：0 至 1cm；深沉积物：4 至 5cm）采集的脂肪酸（FA）模式用于表征微生物群落和沉积物有机质（SOM）的来源。在分子水平上利用特定来源的、诊断性 FA 生物标志物进行了研究。基于生物标志物的方法已广泛应用于海洋沉积物研究，但迄今为止尚未应用于 AML 沉积物。与深沉积物相比，表层沉积物中的 FA 浓度更高（分别为 497 和 127μg g(-1)d.w.）。这与表层沉积物中自生生物量和更多陆地植物的沉积有关，并且在一定程度上与沉积物-水界面上更高的细菌活性有关。两种沉积物中的 FA 分布均表现出强烈的奇偶偏好，呈双峰分布：一簇在 nC(14)-nC(18)处，主要与自生（藻类和细菌）SOM 生产有关，另一簇在 nC(22-28)处，与高等植物的输入有关。与自生贡献相比，表层沉积物中的 FA 分布表明陆地输入更高（估计为 67%:33%）。通过包括支链 C(15)和 C(17)替代物、环丙烷酸、3-OH（OH）酸和具有异常双键定位的单不饱和替代物在内的特征 FA 标志物对可培养细菌进行指纹识别。通过总诊断性 3-OH 脂肪酸（37μg g(-1)与 25μg g(-1)）证明了表层沉积物中革兰氏阴性菌的丰度更高。两种沉积物层中的潜在源类群包括嗜酸铁和硫氧化细菌，包括氧化亚铁硫杆菌。两种沉积物中末端支链 C(15)和 C(17)替代物的高丰度表明硫酸盐和铁还原细菌的存在。两种沉积物中几乎没有特征性 FA 甲烷营养菌。
