¿Qué son los MICROORGANISMOS? 🦠 (Bacterias, Virus, Hongos y Parásitos)

Microorganisms: Characteristics and Classification

What are Microorganisms?

• Microorganisms are tiny living beings studied in microbiology, requiring a microscope for visibility. They include beneficial species, pathogens, and others that vary by circumstances.

Types of Microorganisms

• Microorganisms can be unicellular or multicellular, encompassing both prokaryotic and eukaryotic forms. Some are ultramicroscopic, like viruses, only visible with electron microscopes.

Nutritional Needs and Environmental Conditions

• Microorganisms require nutrients (proteins or carbohydrates) for development and need water in varying amounts; bacteria need less than fungi. Most thrive at temperatures between 30°C to 50°C.

• Oxygen requirements differ among microorganisms; some need it while others tolerate its absence. pH tolerance is also narrow, leading to classifications such as acidophiles (acidic environments) and alkaliphiles (alkaline environments).

Growth Rates of Microorganisms

• The growth rate depends on the microorganism type and environmental conditions; they can be classified into slow-growing or fast-growing categories based on these factors.

Major Groups of Microorganisms

1. Bacteria:

• Unicellular organisms without organized nuclei that reproduce by binary fission; they can exchange genetic material through transformation, transduction, or conjugation. Bacterial shapes include cocci (round), spirilla (helical), and vibrios (curved).

2. Viruses:

• Acellular entities composed of a protein capsid with or without an envelope containing DNA or RNA; they are obligate parasites needing host cells for reproduction and survival. Their structure varies from spherical to cylindrical forms with complex arrangements including heads and tails.

3. Fungi:

• Eukaryotic microorganisms that can be unicellular (yeasts) or multicellular (molds); they reproduce via budding or sporulation processes where parent cells produce outgrowths that mature before separation.

4. Parasites:

• Include protozoa like amoebas and multicellular helminths/worms; while not typically classified as microorganisms, their study often overlaps with microbiology due to their biological interactions with hosts.

Beneficial vs Pathogenic Microorganisms

• Beneficial Microorganisms:

• These contribute positively to human life by forming part of the human microbiota or producing valuable products like cheese, beer, antibiotics, yogurt, and bread; most microorganisms fall into this category despite common misconceptions about their harmfulness.

• Human microbiota plays crucial roles in infection protection and digestion processes.

• Pathogenic Microorganisms:

• This group includes those capable of causing diseases in hosts—encompassing viruses, bacteria, and fungi—that infect cells to reproduce while potentially damaging them through toxin production.

• Antimicrobials such as antibiotics target bacteria specifically while antivirals focus on viruses; antifungals address fungal infections.