Different carbon isotope fractionation patterns during the development of phototrophic freshwater and marine biofilms
Different carbon isotope fractionation patterns during the development of phototrophic freshwater and marine biofilms
复制标题
光养淡水和海洋生物膜发育过程中不同的碳同位素分馏模式
DOI：
--
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
J. Rijstenbil
中科院分区：
文献类型：
--
作者：
M. Staal;R. Thar;M. Kühl;M. van Loosdrecht;G. Wolf;J. D. Brouwer;J. Rijstenbil
天然光养生物膜受到多种非生物和生物因素的影响，并在时间和空间尺度上有所不同。由于生物膜的增厚，可以区分不同的发育阶段，生长速度也会有所不同，这可能会导致光或质量传输的限制。这项研究表明，二氧化碳(AQ)有效性的变化导致分馏转移，从而影响生物膜发育过程中的~(13)C特征。光养淡水生物膜的~(13)C值随生物膜厚度的增加而减小，而海洋生物膜则相反。模拟和pH分布表明，淡水系统的这种趋势是由于二氧化碳(AQ)限制的增加导致HCO3？作为C源。海洋系统中相反的趋势可以用更高的异养生物量和活性来解释，这导致了更高的碳循环，从而导致更低的13C值。我们认为~(13)C更多地与净面积光合作用速率和碳循环有关，而不是与生物膜的生长速率有关。
Natural phototrophic biofilms are influenced by a broad array of abiotic and biotic factors and vary over temporal and spatial scales. Different developmental stages can be distinguished and growth rates will vary due to the thickening of the biofilm, which is expected to lead to a limitation of light or mass transport. This study shows that variation in CO2(aq) availability leads to a fractionation shift and thereby affects ?13C signatures during biofilm development. For phototrophic freshwater biofilms it was found that the ?13C value became less negative with the thickening of the biofilm, while the opposite trend was found in marine biofilms. Modeling and pH profiling indicated that the trend in the freshwater system was caused by an increase in CO2(aq) limitation resulting in an increase of HCO3? as C-source. The opposite trend in the marine system could be explained by a higher heterotrophic biomass and activity causing a higher carbon recycling and thereby lower ?13C values. We conclude that ?13C was more related to the net areal photosynthesis rate and carbon recycling, rather than to the growth rate of the biofilms.