Bactéries

Bactéries are single-celled microorganisms that are found in virtually every environment on Earth. They are prokaryotes, meaning their cells lack a nucleus and other membrane-bound organelles. Bacteria have a wide range of shapes, including spheres (cocci), rods (bacilli), and spirals (spirilla). Their cell walls are typically composed of peptidoglycan, which plays a role in their structure and protection.

Reproduction in bacteria primarily occurs through asexual binary fission, where a single cell divides into two identical daughter cells. Some bacteria can also exchange genetic material through processes like conjugation, transformation, or transduction, which contributes to their genetic diversity.

While many bacteria are known for causing diseases, the vast majority are harmless and even beneficial. Many play crucial roles in ecosystems, such as decomposition, nutrient cycling, and symbiosis with other organisms. For example, gut bacteria aid in digestion and produce essential vitamins in humans and animals. In industry, bacteria are utilized in the production of foods like yogurt and cheese, as well as in bioremediation to clean up pollution.

Bacterial pathogens can cause a variety of infections, ranging from mild to severe. However, advances in medicine, including antibiotics, have significantly reduced the impact of many bacterial diseases. Understanding bacterial biology is essential for public health, agriculture, and various industrial applications.