Institute of Environment & Biogeochemistry (eBig), School of Earth Science, Zhejiang University, Hangzhou, 310027, China.
Marine Science Program and Southeast Environmental Research Center, Florida International University, Miami, FL, 33199, USA.
Sci Rep. 2018 Jun 5;8(1):8626. doi: 10.1038/s41598-018-26900-9.
Here we report the molecular biomarker co-occurrence of three different races of Botryococcus braunii (B. braunii) in the freshwater wetland ecosystem of the Florida Everglades, USA. Thespecific biomarkers include C-C botryococcenes for race B, C-C n-alkadienes and n-alkatrienes for race A, and lycopadiene for race L. The n-alkadienes and n-alkatrienes were present up to 3.1 and 69.5 µg/g dry weight (dw), while lycopadiene was detected in lower amounts up to 3.0 and 1.5 µg/g dw in periphyton and floc samples, respectively. Nutrient concentrations (P and N) did not significantly correlate with the abundances of these compounds. In contrast, n-alkadienes and n-alkatrienes were present in wider diversity and higher abundance in the floc from slough (deeper water and longer hydroperiod) than ridge (shallower water and shorter hydroperiod) locations. n-Alkadienes, n-alkatrienes, and lycopadiene, showed lower δC values from -40.0 to -35.5‰, suggesting that the source organisms B. braunii at least partially utilize recycled CO (C depleted) produced from OM respiration rather than atmospheric CO (C enriched) as the major carbon sources.
在这里，我们报告了美国佛罗里达州大沼泽地淡水湿地生态系统中三种不同品系的 Botryococcus braunii（B. braunii）的分子生物标志物共同出现情况。具体的生物标志物包括品系 B 的 C-C 角鲨烯、品系 A 的 C-C 正构烯和正构三烯以及品系 L 的番茄红素。正构烯和正构三烯的含量高达 3.1 和 69.5μg/g 干重（dw），而番茄红素的含量较低，分别为 3.0 和 1.5μg/g dw，存在于周丛和絮体样品中。营养物浓度（P 和 N）与这些化合物的丰度没有显著相关性。相比之下，在沼泽（水深和水力停留时间较长）的絮体中，正构烯和正构三烯的多样性更广泛，丰度更高，而在脊（水深较浅和水力停留时间较短）的位置则较少。正构烯、正构三烯和番茄红素的δC 值在-40.0 到-35.5‰之间，表明至少部分来源生物 B. braunii 利用了由 OM 呼吸产生的再循环 CO（C 耗尽）作为主要碳源，而不是大气 CO（C 富集）。
