Grey Anthony, Costeira Ricardo, Lorenzo Emmaline, O'Kane Sean, McCaul Margaret V, McCarthy Tim, Jordan Sean F, Allen Christopher C R, Kelleher Brian P
School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
The School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland.
Biogeochemistry. 2023;162(3):359-380. doi: 10.1007/s10533-022-01008-5. Epub 2023 Jan 10.
Coastal wetlands are highly efficient 'blue carbon' sinks which contribute to mitigating climate change through the long-term removal of atmospheric CO and capture of carbon (C). Microorganisms are integral to C sequestration in blue carbon sediments and face a myriad of natural and anthropogenic pressures yet their adaptive responses are poorly understood. One such response in bacteria is the alteration of biomass lipids, specifically through the accumulation of polyhydroxyalkanoates (PHAs) and alteration of membrane phospholipid fatty acids (PLFA). PHAs are highly reduced bacterial storage polymers that increase bacterial fitness in changing environments. In this study, we investigated the distribution of microbial PHA, PLFA profiles, community structure and response to changes in sediment geochemistry along an elevation gradient from intertidal to vegetated supratidal sediments. We found highest PHA accumulation, monomer diversity and expression of lipid stress indices in elevated and vegetated sediments where C, nitrogen (N), PAH and heavy metals increased, and pH was significantly lower. This was accompanied by a reduction in bacterial diversity and a shift to higher abundances of microbial community members favouring complex C degradation. Results presented here describe a connection between bacterial PHA accumulation, membrane lipid adaptation, microbial community composition and polluted C rich sediments.
Geochemical, microbiological and polyhydroxyalkanoate (PHA) gradient in a blue carbon zone.
The online version contains supplementary material available at 10.1007/s10533-022-01008-5.
沿海湿地是高效的“蓝碳”汇，通过长期去除大气中的二氧化碳和捕获碳（C），有助于缓解气候变化。微生物是蓝碳沉积物中碳固存不可或缺的部分，面临着众多自然和人为压力，但其适应性反应却鲜为人知。细菌的一种此类反应是生物量脂质的改变，特别是通过聚羟基脂肪酸酯（PHA）的积累和膜磷脂脂肪酸（PLFA）的改变。PHA是高度还原的细菌储存聚合物，可在不断变化的环境中提高细菌的适应性。在本研究中，我们调查了从潮间带到植被覆盖的潮上带沉积物沿海拔梯度的微生物PHA分布、PLFA谱、群落结构以及对沉积物地球化学变化的响应。我们发现，在碳、氮（N）、多环芳烃和重金属增加且pH值显著降低的高地和植被覆盖沉积物中，PHA积累、单体多样性和脂质应激指数表达最高。这伴随着细菌多样性的降低以及微生物群落成员丰度向有利于复杂碳降解的方向转变。此处呈现的结果描述了细菌PHA积累、膜脂适应、微生物群落组成与受污染的富碳沉积物之间的联系。
蓝碳区的地球化学、微生物学和聚羟基脂肪酸酯（PHA）梯度。
在线版本包含可在10.1007/s10533-022-01008-5获取的补充材料。
