首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Enhanced Calcite Dissolution in the Presence of the Aerobic Methanotroph Methylosinus trichosporium
Authors:Stefan Krause  Giovanni Aloisi  Anja Engel  Volker Liebetrau  Tina Treude
Institution:1. GEOMAR Helmholtz Centre of Ocean Research, Department of Marine Biogeochemistry , Kiel , Germany;2. GEOMAR Helmholtz Centre of Ocean Research, Department of Marine Biogeochemistry , Kiel , Germany;3. Laboratoire d’Océanographie et du Climat , Expérimentations et Approches Numériques , Paris , France
Abstract:Microbial aerobic methane oxidation (MOx) is intrinsically coupled to the production of carbon dioxide, favoring carbonate dissolution. Recently, microbial organic polymers were shown to be able to induce carbonate dissolution. To discriminate between different mechanisms causing calcite dissolution, experiments were conducted in the presence of solid calcite with (1) actively growing cells (2) starving cells, and (3) dead cells of the methanotrophic bacterium Methylosinus trichosporium under brackish conditions (salinity 10) near calcite saturation (saturation state (Ω) 1.76 to 2.22). Total alkalinity and the amount of dissolved calcium markedly increased in all experiments containing M. trichosporium cells. After initial system equilibration, similar calcite dissolution rates, ranging between 20.16 (dead cells) and 25.68 μmol L?1 d?1 (actively growing cells), were observed. Although concentrations of transparent exopolymer particles declined with time in the presence of actively growing and starving cells, they increased in experiments with dead cells. Scanning electron microscopy images of calcite crystals revealed visible surface corrosion after exposure to live and dead M. trichosporium cells. The results of this study indicate a strong potential for microbial MOx to affect calcite stability negatively, facilitating calcite dissolution. In addition to CO2 production by methanotrophically active cells, we suggest that the release of acidic or Ca2+-chelating organic carbon compounds from dead cells could also enhance calcite dissolution.
Keywords:carbonate  cold seep  methane  ocean acidification  saturation rate
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号