Bakterieens

Bakterieens refers to bacteria, a vast and diverse group of unicellular microorganisms. Most bacteria are prokaryotes, lacking a defined nucleus. They range from 0.2 to 100 micrometers and have a cell membrane and wall, often with peptidoglycan that helps distinguish Gram-positive from Gram-negative species.

Bacteria exhibit shapes such as cocci (spherical), bacilli (rod-shaped), and spirilla or spirochetes (spiral). They live in nearly every habitat, from soil and water to extreme environments. Reproduction is usually by binary fission, an asexual division. Genetic diversity arises through mutations and horizontal gene transfer, including transformation, transduction, and conjugation.

Their metabolism is diverse. Some are phototrophs that harvest light; others are chemotrophs that derive energy from chemical reactions. They can be autotrophic, fixing carbon dioxide, or heterotrophic, relying on organic matter. Oxygen requirements vary: aerobes, anaerobes, and facultative species.

Bacteria play essential roles in ecosystems and human life. They drive decomposition and nutrient cycling, fix nitrogen in some plant partnerships, form biofilms, and participate in fermentation. They contribute to foods, medicines, and industrial enzymes. Many species are harmless or beneficial, while others are pathogens.

Studying bacteria involves microscopy, culturing on selective media, biochemical tests, and genetic sequencing. Understanding bacterial diversity and evolution supports medicine, agriculture, and biotechnology, and informs strategies to combat antibiotic resistance.