Premium
Anaerobic microbial biogeochemistry in a northern bog: Acetate as a dominant metabolic end product
Author(s) -
Duddleston Khrystyne N.,
Kinney Monica A.,
Kiene Ronald P.,
Hines Mark E.
Publication year - 2002
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/2001gb001402
Subject(s) - methanogenesis , acetogenesis , chemistry , fermentation , environmental chemistry , peat , anaerobic exercise , biogeochemistry , ethyl acetate , incubation , methane , ecology , food science , biology , biochemistry , organic chemistry , physiology
Field measurements and incubation techniques were used to determine the dynamics of acetate formation, iron reduction, and methanogenesis in surficial peat of an Alaskan bog. Acetate concentrations were ∼100 μ M early in the season and decreased to ∼20 μ M in July when the water table decreased. Acetate levels increased rapidly to ∼1000 μ M when the water table rose to the surface in August. Acetate production in anaerobic slurries occurred at rates of 2.8–420 nmol carbon mL −1 day −1 , which was 7–120 times more rapid than CH 4 production. Experiments utilizing 14 C‐acetate confirmed that methanogenesis was not acetoclastic although acetate was converted very slowly to CO 2 . Peat incubated anaerobically for 4.5 months at 24°C never produced methane from acetate, suggesting that anaerobic acetate accumulation would have occurred all season if the water table had remained high. CO 2 production was the most rapid process measured in laboratory incubations (up to 750 nmol mL −1 day −1 ) and appeared to be due primarily to fermentation. Acetate was the primary organic terminal product of anaerobic decomposition in the bog, and acetate was ultimately oxidized to CO 2 via aerobic respiration and to a much lesser extent anaerobically by Fe reduction.