Bakteeria

Bakteeria are a diverse group of unicellular microorganisms forming a major domain of life. They are prokaryotes, lacking a membrane-bound nucleus and other organelles. Most bakteeria have cell walls made of peptidoglycan and display shapes such as cocci (spheres), bacilli (rods), and spirilla. They inhabit nearly every environment, from soil and water to living bodies, and can endure extreme conditions.

Reproduction is usually asexual, primarily by binary fission, yielding two daughter cells. Genetic diversity arises through horizontal gene transfer—transformation, transduction, and conjugation—and by mutation. Many bakteeria are motile, using flagella or pili, and some form biofilms to persist in communities.

Diversity and classification: Bakteeria are organized into numerous phyla within the domain Bacteria. They are commonly grouped by Gram staining (Gram-positive vs Gram-negative), cell wall properties, metabolism, and genetics. Archaea are a separate domain with different biochemistry.

Ecology and roles: They drive nutrient cycles, decompose organic matter, and some photosynthetic groups contribute to primary production. Bakteeria form beneficial associations with plants and animals, while others are pathogens. They are also used in industry and medicine for fermentation and biotechnological applications.

Human relevance: Bakteeria underpin microbiology, medicine, and biotechnology. They are studied via culture, genomics, and imaging to advance antibiotics, fermentation, and genetic engineering. Ongoing research seeks to map their diversity and ecological functions and to develop safer, more effective applications.