Sulfate-reducing bacteria

Definition

Sulfate-reducing bacteria (SRB) are a group of microorganisms that can obtain energy by oxidizing organic compounds or molecular hydrogen while reducing sulfate to hydrogen sulfide. They play a crucial role in the sulfur cycle and are commonly found in anaerobic environments.

5 Must Know Facts For Your Next Test

1. Sulfate-reducing bacteria belong predominantly to the phylum Proteobacteria.
2. They thrive in anaerobic conditions, such as deep soil, marine sediments, and waterlogged soils.
3. Hydrogen sulfide produced by SRB can corrode metals and concrete, posing significant industrial challenges.
4. SRB use sulfate as a terminal electron acceptor during respiration, a process known as dissimilatory sulfate reduction.
5. Some SRBs can tolerate oxygen exposure for short periods, demonstrating facultative anaerobic capabilities.

Review Questions

• What phylum do most sulfate-reducing bacteria belong to?
• In what type of environmental conditions do sulfate-reducing bacteria thrive?
• What is the primary metabolic process that characterizes sulfate-reducing bacteria?

Related terms

Proteobacteria: A major phylum of Gram-negative bacteria that includes a wide variety of pathogens.

Anaerobic Respiration: A form of respiration using electron acceptors other than oxygen.

Hydrogen Sulfide: A toxic gas with the characteristic foul odor of rotten eggs, produced by SRB during sulfate reduction.