Definition

1. Noun:
   • An organism that lives without free oxygen: An anaerobe is a living thing, especially a type of bacterium, that grows and lives in environments that lack air or free oxygen (O₂). Some anaerobes are harmed by the presence of oxygen.

Usage and Examples

• Noun:
  • Clostridium botulinum, the bacterium that causes botulism, is a dangerous anaerobe.
  • The scientist studied how the anaerobe produced energy through fermentation.
  • Anaerobic digesters use various anaerobes to break down organic waste and produce biogas.

Advanced Usage

• Obligate (strict) anaerobe: An organism that cannot survive in the presence of oxygen. Oxygen is toxic to it.
  • The obligate anaerobe Bacteroides fragilis is a common part of the human gut flora.
• Facultative anaerobe: An organism that can grow with or without oxygen. It uses oxygen if available but can switch to anaerobic methods.
  • Escherichia coli is a facultative anaerobe; it can live in your intestines (low oxygen) or on a lab plate (with oxygen).
• Aerotolerant anaerobe: An organism that does not use oxygen for growth but can tolerate its presence.
  • Lactobacillus, used in making yogurt, is an aerotolerant anaerobe.

Variants and Related Words

• Anaerobic (adjective): Relating to, involving, or being an organism that lives without oxygen, or a process that occurs without oxygen.
  • Anaerobic respiration is a way cells generate energy without oxygen.
  • He does anaerobic exercises like weightlifting.
• Anaerobiosis (noun): The state or mode of life of an organism in an oxygen-free environment.

Synonyms

• Anaerobic organism: A direct synonym.
• Non-aerobic organism: A descriptive synonym emphasizing the lack of oxygen requirement.

Antonyms

• Aerobe: An organism that requires free oxygen to live.
• Obligate aerobe: An organism that must have oxygen to survive.

Noun

1. an organism (especially a bacterium) that does not require air or free oxygen to live