Response to substrate limitation by a marine sulfate-reducing bacterium
METADATA ONLY
Loading...
Author / Producer
Date
2022-01
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
METADATA ONLY
Data
Rights / License
Abstract
Sulfate-reducing microorganisms (SRM) in subsurface sediments live under constant substrate and energy limitation, yet little is known about how they adapt to this mode of life. We combined controlled chemostat cultivation and transcriptomics to examine how the marine sulfate reducer, Desulfobacterium autotrophicum, copes with substrate (sulfate or lactate) limitation. The half-saturation uptake constant (Km) for lactate was 1.2 µM, which is the first value reported for a marine SRM, while the Km for sulfate was 3 µM. The measured residual lactate concentration in our experiments matched values observed in situ in marine sediments, supporting a key role of SRM in the control of lactate concentrations. Lactate limitation resulted in complete lactate oxidation via the Wood–Ljungdahl pathway and differential overexpression of genes involved in uptake and metabolism of amino acids as an alternative carbon source. D. autotrophicum switched to incomplete lactate oxidation, rerouting carbon metabolism in response to sulfate limitation. The estimated free energy was significantly lower during sulfate limitation (−28 to −33 kJ mol−1 sulfate), suggesting that the observed metabolic switch is under thermodynamic control. Furthermore, we detected the upregulation of putative sulfate transporters involved in either high or low affinity uptake in response to low or high sulfate concentration.
Permanent link
Publication status
published
External links
Editor
Book title
Journal / series
Volume
16 (1)
Pages / Article No.
200 - 210
Publisher
Nature
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
Organisational unit
09496 - Lever, Mark A. (ehemalig) / Lever, Mark A. (former)