Microbial Life: Origin and Discovery

A living organism that requires a microscope to be seen. Most microbes consist of a single cell, but some are multicellular. However, this does not mean that they can function as individual entities.

A microbe is a microscopic one-celled organism or a group of one-celled organisms. Viruses are also considered microbes.

The genome of a microbe describes the total genetic information of that organism. This comprises all the DNA that provides instructions for the organism's growth, development, and function.

A metagenome represents a collection of sequenced DNA from various microbes collected directly from their natural environment. It offers a snapshot of the microbial communities in a specific location.

The first sequencing method that was fast enough to sequence large genomes was developed by Fred Sanger. He shared the 1980 Nobel Prize in Chemistry for this achievement.

The first genome sequence of a cellular microbe, the bacterium Haemophilus influenzae, was completed in 1995.

Microbes have had a major impact on human history, from food production to disease outbreaks. They have been involved in the development of fermented foods and beverages, the spoilage of food and wine, and even the extraction of metals from Earth's crust.

Yeasts and bacteria have been used for centuries in the production of fermented foods and beverages like bread, wine, cheese, and yogurt.

Lithotrophs are microbes specialized in breaking down rocks and minerals. These bacteria helped in the mining of metals and led to the deterioration of some ancient stone monuments.

Bubonic plague, caused by the bacterium Yersinia pestis, ravaged populations in the 14th century, causing the Black Death. This pandemic had significant consequences for human societies and demographics.

Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, is another significant disease. It caused widespread illness and death in the 19th century and continues to threaten populations worldwide.

AIDS, caused by the human immunodeficiency virus (HIV), is a modern pandemic that has deeply impacted global health and society.

Florence Nightingale (1820–1910) made groundbreaking contributions to the understanding of the importance of sanitation and hygiene in preventing disease. She pioneered the use of medical statistics to analyze mortality rates and advocate for better healthcare.

Robert Hooke (1635–1703) built the first compound microscope and used it to observe mold. He was the first person to use a microscope to observe living organisms. His work laid the foundation for the study of microorganisms.

Prokaryotes are cells that lack a membrane-bound nucleus.

Eukaryotes are cells that have a membrane-bound nucleus.

Bacteria are single-celled prokaryotes. They are found in various environments, including soil, water, and the human body

Archaea are single-celled prokaryotes that are often found in extreme environments, such as hot springs or very salty water.

Algae are eukaryotic organisms that are primarily photosynthetic, obtaining energy from sunlight.

Fungi are eukaryotic organisms that are heterotrophic, meaning they obtain their nutrition from other organisms.

Protists are a diverse group of eukaryotic organisms, often single-celled, that are not classified as animals, plants, or fungi.

Viruses are non-cellular entities made up of genetic material (DNA or RNA) surrounded by a protein coat. They can only replicate inside the cells of other organisms.

Prions are infectious proteins that can cause fatal neurological diseases. Unlike viruses, they do not contain DNA or RNA.

The three “domains” of life—bacteria, archaea, and eukaryotes—evolved from a common ancestral cell.

The theory of evolution by natural selection is based on the concept that organisms with traits that are better suited to their environment are more likely to survive and reproduce. This leads to changes in the genetic makeup of populations over time, resulting in adaptation and the evolution of new species.

The science of studying microorganisms and their interactions with other organisms and the environment.

The branch of microbiology that focuses on the study of disease-causing microorganisms, their mechanisms of infection, and the development of treatments and prevention strategies for infectious diseases.

The study of microbes and their interactions with their environment, encompassing their roles in ecosystems, biogeochemical cycles, and industrial applications.

The branch of microbiology delves into the study of the internal structure, function, and behavior of microorganisms.