Actinomycetota

Tiny living things live in soil and water. They help dead things turn into food. This helps plants grow. Some even live with plant roots. They give food to the plants. The plants give food back. These tiny things also help people. Some help babies stay well. Others can make medicine. This medicine fights germs. Some have been frozen for a long time. They are very important to our world.

Actinomycetota are a large group of bacteria. They live in soil and water. These tiny life forms help the earth. In soil, they break down dead things. This lets plants take up new food. Some live with plant roots. They give nitrogen to the plants. In return, plants give them sugars.

Many of these bacteria help people. Some make antibiotics. These are medicines that fight germs. Others live inside us. For example, Bifidobacterium are common in human babies. These help keep our insides healthy.

Some of these bacteria are very old. Scientists found some frozen in ice. They were in permafrost for 640,000 years. They are among the oldest living things on Earth. This group also has very small cells. Some live in the sea. Most of these bacteria are in a group called Actinomycetia. They are very important to our world.

Actinomycetota are a huge group of bacteria. They live in many places like soil and water. These tiny living things are very important to land plants. They help the soil stay healthy for growing things. In the dirt, they break down dead organic matter. This process lets plants take up new molecules.

These bacteria work in a very special way. They grow long, thin threads called mycelia. This makes them look like fungi. For a long time, people thought they were actually fungi. Some bacteria, like Frankia, live with plant roots. They give nitrogen to the plants to help them grow. In return, the plants give them sugars.

Scientists have studied these bacteria for a long time. They used to call them Actinobacteria. Now, we use the name Actinomycetota. We group them using lists like the LPSN and NCBI. Some bacteria are very old and amazing. Scientists found some in frozen permafrost. These were frozen about 640,000 years ago.

There are many different kinds of these bacteria. The genus Streptomyces is one of the largest groups. These bacteria make many medicines called antibiotics. Examples include tetracyclines and macrolides. Other types, like Mycobacterium, can cause disease. Some bacteria, like Bifidobacterium, live in human babies. They help keep the insides of babies healthy.

We see the work of Actinomycetota everywhere. They help farmers by making things for plants. This includes insecticides and growth-promoting substances. They also make medicines for humans. These include drugs that fight viruses or tumors. Even in the ocean, they play a part. Some marine groups have the smallest cells ever found.

Actinomycetota is a massive and diverse phylum of bacteria. These organisms are classified as Gram-positive bacteria. This means they have a specific type of cell wall structure. They are also known for having high guanine-cytosine content. This is often called GC content. It refers to the amount of specific chemicals in their DNA. In some species, this GC content can reach as high as 70%.

These bacteria live in many different environments. They can be found in terrestrial habitats like soil. They can also live in aquatic environments. In the soil, they play a vital role in ecosystem health. They help decompose organic matter from dead organisms. This process breaks down matter into smaller molecules. Plants can then take up these molecules to grow. While fungi also decompose matter, actinomycetota are much smaller. This allows them to occupy a different ecological niche.

Many actinomycetota grow in a very specific way. They develop extensive networks called mycelia. These long, thin threads look very similar to fungal structures. Because of this, scientists once believed they were fungi. The order Actinomycetales, or the actinomycetes, reflects this history. Some species also form symbiotic relationships with plants. For example, the genus Frankia lives with plant roots. These bacteria fix nitrogen for the plants. In exchange, the plants provide the bacteria with saccharides, which are sugars.

Scientists have changed how they name and group these bacteria over time. They were previously known as Actinobacteria. Today, researchers use modern taxonomy systems to organize them. These systems include the List of Prokaryotic names with Standing in Nomenclature (LPSN). They also use the National Center for Biotechnology Information (NCBI). Scientists use various methods to study their relationships. This includes analyzing 16S rRNA or using whole-genome based phylogeny. They may also look at 120 marker proteins to understand their history.

Actinomycetota are incredibly important to human medicine and agriculture. The genus Streptomyces is one of the largest bacterial groups. It is a major producer of bioactive metabolites. These are natural chemicals that affect living cells. Many of these are used as antibiotics. Examples include aminoglycosides, tetracyclines, macrolides, and chloramphenicol. They also produce antifungals, antivirals, and antitumor drugs. In agriculture, they help create insecticides, herbicides, and fungicides. They can even produce substances that promote growth in plants and animals.

Other members of this phylum have different impacts on health. The genus Mycobacterium includes species that are important pathogens. Pathogens are organisms that cause disease. In the human body, some actinomycetota are very helpful. The genus Bifidobacterium is the most common in the microbiomes of human infants. In adults, intestinal bifidobacteria help maintain the mucosal barrier. They also help reduce lipopolysaccharides in the intestine. However, other groups like Gardnerella are studied for different medical reasons. The classification of Gardnerella is actually controversial among scientists.

There are also surprising facts regarding the size and age of these cells. Some actinomycetota are among the largest and most complex bacterial cells. Conversely, the marine group Actinomarinales contains some of the smallest free-living prokaryotic cells. We can even find evidence of their extreme longevity. Some actinomycetota from Siberia or Antarctica are considered very old. They were found frozen in permafrost from around 500,000 years ago. Scientists detected signs of life in samples from 640,000 years ago or younger. This shows how resilient these bacteria can be.