Acidification increases microbial polysaccharide degradation in the ocean
Acidification increases microbial polysaccharide degradation in the ocean
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DOI：
10.5194/bg-7-1615-2010
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发表时间：
2009-12
期刊：
影响因子：
4.9
通讯作者：
J. Piontek;M. Lunau;N. Händel;C. Borchard;M. Wurst;A. Engel
中科院分区：
文献类型：
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作者：
J. Piontek;M. Lunau;N. Händel;C. Borchard;M. Wurst;A. Engel
摘要。随着人为二氧化碳（CO2）的积累，海水pH值的持续下降被称为海洋酸化。海洋储存二氧化碳的能力受到生物过程的强烈影响，而生物过程的反馈潜力难以评估。海洋中二氧化碳的主要来源是异养细菌对有机分子的分解和随后的呼吸作用。然而，人们对海洋酸化对细菌降解活性的潜在影响知之甚少。本研究表明，在海洋酸化实验模拟过程中，细菌胞外酶对海洋有机物主要成分多糖的降解速度显著加快。结果通过pH扰动实验获得，其中测量了细胞外α-和β-葡萄糖苷酶的速率，并测定了浮游植物衍生多糖中中性糖和酸性糖的损失。我们的研究表明，在较低的海洋pH下，细菌对多糖的更快周转有可能减少碳出口，并增加未来海洋中呼吸性二氧化碳的产生。
Abstract. With the accumulation of anthropogenic carbon dioxide (CO2), a proceeding decline in seawater pH has been induced that is referred to as ocean acidification. The ocean's capacity for CO2 storage is strongly affected by biological processes, whose feedback potential is difficult to evaluate. The main source of CO2 in the ocean is the decomposition and subsequent respiration of organic molecules by heterotrophic bacteria. However, very little is known about potential effects of ocean acidification on bacterial degradation activity. This study reveals that the degradation of polysaccharides, a major component of marine organic matter, by bacterial extracellular enzymes was significantly accelerated during experimental simulation of ocean acidification. Results were obtained from pH perturbation experiments, where rates of extracellular α- and β-glucosidase were measured and the loss of neutral and acidic sugars from phytoplankton-derived polysaccharides was determined. Our study suggests that a faster bacterial turnover of polysaccharides at lowered ocean pH has the potential to reduce carbon export and to enhance the respiratory CO2 production in the future ocean.