Response of two marine bacterial isolates to high CO2 concentration

Marine Ecology Progress Series

Cristina Sobrino¹  Eva Teira¹  Pablo Serret¹  Ana Fernández¹  Xosé Antón Álvarez-Salgado¹  Enma Elena García-Martín¹ 

关键词: Bacterial metabolism;    Flavobacteriaceae;    Ocean acidification;    Rhodobacteraceae;   

DOI  :  10.3354/meps09644

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Experimental results related to the effects of ocean acidification on planktonic marine microbes are still rather inconsistent and occasionally contradictory. Moreover, laboratory or field experiments that address the effects of changes in CO₂ concentrations on heterotrophic microbes are very scarce, despite the major role of these organisms in the marine carbon cycle. We tested the direct effect of an elevated CO₂ concentration (1000 ppmv) on the biomass and metabolic rates (leucine incorporation, CO₂ fixation and respiration) of 2 isolates belonging to 2 relevant marine bacterial families, Rhodobacteraceae (strain MED165) and Flavobacteriaceae (strain MED217). Our results demonstrate that, contrary to some expectations, high pCO₂ did not negatively affect bacterial growth but increased growth efficiency in the case of MED217. The elevated partial pressure of CO₂ (pCO₂) caused, in both cases, higher rates of CO₂ fixation in the dissolved fraction and, in the case of MED217, lower respiration rates. Both responses would tend to increase the pH of seawater acting as a negative feedback between elevated atmospheric CO₂ concentrations and ocean acidification.

【 授权许可】

Unknown