Nanaerobe

Nanaerobes are organisms that cannot grow in the presence of micromolar concentrations of oxygen, but can grow with and benefit from the presence of nanomolar concentrations of oxygen (e.g. Bacteroides fragilis). Like other anaerobes, these organisms do not require oxygen for growth. This growth benefit requires the expression of an oxygen respiratory chain that is typically associated with microaerophilic respiration. Recent studies suggest that respiration in low concentrations of oxygen is an ancient process which predates the emergence of oxygenic photosynthesis.

Microbiology: Bacteria

Pathogenic
bacteria

Human flora

Substrate
preference

Oxygen
preference

Structures

Cell envelope	Cell membrane Cell wall: Peptidoglycan NAM NAG DAP Gram-positive bacteria only: Teichoic acid Lipoteichoic acid Endospore Gram-negative bacteria only: Bacterial outer membrane Porin Lipopolysaccharide Periplasmic space Mycobacteria only: Arabinogalactan Mycolic acid

Outside envelope	Bacterial capsule Slime layer S-layer Glycocalyx Pilus Fimbria

Composite	Biofilm

Shapes

Index of bacterial disease

Description	Bacteria classification Growth media

Disease	Gram-positive firmicutes Gram-positive actinobacteria Gram-negative proteobacteria Gram-negative non-proteobacteria Cholera Tuberculosis

Treatment	Antibiotics cell wall nucleic acid mycobacteria protein synthesis other Antibodies Vaccines