The 'Dark Matter' of the Microbial World

You've probably heard about your gut bacteria—now get to know your gut archaea.

 Archaea Are More Wonderful Than You Know

The organisms he revealed -- the archaea -- are fascinating and abundant creatures, yet are hardly ever discussed in depth, even within the confines of microbiology classes. That is a shame. Archaea are everywhere -- in deep sea vents, in salt flats, in ice, in sea water, in soil, and in you. And they deserve better publicity.

 Archaea, from obscurity to superhero microbes: 40 years of surprises and critical biological insights

In what is arguably one of the most unexpected biological discoveries of the 20th century, a publication at the end of the 1970s astounded the scientific community by proposing an entirely new division of life, initially referred to as the Archaebacteria and then subsequently renamed as the Archaea (derived from the Greek word ‘archaios’ meaning ‘archetypal’, ‘primitive’ or ‘ancient’).

 What’s On Your Skin? Archaea, That’s What

It turns out your skin is crawling with single-celled microorganisms – and they’re not just bacteria.

Archaea - The Most Ancient Life

The Archaea comprise a group of single-celled microorganisms that, like bacteria, are prokaryotes that have no cell nucleus or any other organelles within their cells. Consequently, they were once considered to be an unusual group of bacteria and named archaebacteria. However, it in now known that Archaeans have an independent evolutionary history and have numerous differences in their biochemistry compared to other forms of life.

Archaea and The Discovery of the Third Domain of Life

In 1977, Carl Woese overturned one of the major dogmas of biology. Until that time, biologists had taken for granted that all life on Earth belonged to one of two primary lineages, the eukaryotes (which include animals, plants, fungi and certain unicellular organisms such as paramecium) and the prokaryotes (all remaining microscopic organisms).

Archaea and the origin of eukaryotes

The Archaea was recognized as a third domain of life 40 years ago. Molecular evidence soon suggested that the Eukarya represented a sister group to the Archaea or that eukaryotes descended from archaea.

Archaea Domain

Archaeans are extreme organisms. They can survive and even thrive under some of the most difficult conditions on planet Earth like very hot, extremely acidic, or very alkaline environments.

Archaea dominate the microbial community in an ecosystem with low-to-moderate temperature and extreme acidity

Contrary to expectation, our study showed a high abundance of archaea in this extremely acidic mine-impacted environment. Further, archaeal populations were dominated by one particular group, suggesting that they are functionally important.

Archaea vs. Bacteria: What Are the Differences?

Archaea and bacteria are two different domains of cellular life. They are both prokaryotes, as they are unicellular and lack a nucleus. They also look similar (even under a microscope). However, DNA analysis reveals that archaea are as different from bacteria as they are from human beings. Discovered during the 1970s as a unique life form, archaea play an important role in our daily lives, including as part of the human gut microbiome.

Archaea: The Third Domain of Life

The biodiversity of the Earth never ceases to astonish. One example that has radically changed the face of biology is the discovery of a group of organisms called archaea (pronounced “ar-kee-ah”). It was thought that all creatures on Earth were divided into two main evolutionary categories, but this changed in the 1990s with the discovery of archaea. Today, all known organisms belong to one of three groups, or domains: eukaryotes (which include animals like us, plants, fungi, and some single-celled organisms), bacteria, and archaea.

Diversity, ecology and evolution of Archaea

Compared to bacteria, our knowledge of archaeal biology is limited. Historically, microbiologists have mostly relied on culturing and single-gene diversity surveys to understand Archaea in nature. However, only six of the 27 currently proposed archaeal phyla have cultured representatives.

Introduction to the Archaea

The Domain Archaea wasn't recognized as a major domain of life until quite recently. Until the 20th century, most biologists considered all living things to be classifiable as either a plant or an animal. But in the 1950s and 1960s, most biologists came to the realization that this system failed to accomodate the fungi, protists, and bacteria.

Prokaryotes: Bacteria & Archaea

DNA sequence comparisons and structural and biochemical comparisons consistently categorize all living organisms into 3 primary domains: Bacteria, Archaea, and Eukarya (also called Eukaryotes; these terms can be used interchangeably).