Microbial consortium

A microbial consortium or microbial community is a group of two or more bacterial or microbial groups that live together in a helpful way, called symbiotically. These groups can live inside each other or on each other's surfaces, or sometimes both. One interesting example is a tiny organism called Mixotricha paradoxa, which lives inside a type of termite called Mastotermes darwiniensis. This organism is always made up of several different types of bacteria working together.

The idea of a consortium was first suggested by Johannes Reinke in 1872, and the word symbiosis was introduced in 1877. Scientists believe that this kind of close working together among tiny organisms was very important for the development of land plants. It likely helped plants move from living in the water, like algae, to living on land.

Overview

Microbial consortia naturally formedon the roots of Arabidopsis thalianaScanning electron microscopy pictures of root surfaces from natural A. thaliana populations showing the complex microbial networks formed on roots.a) Overview of an A. thaliana root (primary root) with numerous root hairs. b) Biofilm-forming bacteria. c) Fungal or oomycete hyphae surrounding the root surface. d) Primary root densely covered by spores and protists. e, f) Protists, most likely belonging to the Bacillariophyceae class. g) Bacteria and bacterial filaments. h, i) Different bacterial individuals showing great varieties of shapes and morphological features.

Microbes can help make useful products from materials that are hard to break down. Scientists have found groups of tiny living things, called microbes, that work together better than single microbes. For example, some special groups of microbes can break down certain materials found in nature.

There are two ways to create these groups of microbes. One way is to mix together different microbes in a lab. Another way is to take samples from nature and encourage the right microbes to grow. Even with these steps, these groups can still be very diverse, which can make them harder to use in practical ways. By finding simpler groups that still work well, scientists can create better and more controlled processes for using microbes in industry.

Examples

Microbialites

Microbialites are layers formed by tiny living things in freshwater and ocean environments. They are the oldest known proof of life on Earth, dating back 3.7 billion years. Today, they are rare and are mainly made by certain types of bacteria, blue-green algae, sulphate-reducing bacteria, diatoms, and microalgae. These tiny organisms create sticky substances that stick sand and rocks together, forming layers that grow over time.

Rhizosphere microbial consortia

Rhizosphere

Studies show that when two or more tiny living things work together, they can help plants grow better than one alone. This happens in the soil around plant roots, called the rhizosphere. These tiny helpers can make nutrients easier for plants to use, change plant hormones, protect plants from harmful germs, and help plants survive tough conditions. Different types of helpful bacteria and fungi, like Trichoderma and Mycorrhizae, work together to give plants extra benefits.

Workflow of enrichment and dilution-to-extinction cultures to select simplified microbial consortia (SMC) for keratin degradation.

Keratin degradation

Tiny living things can break down tough materials, which is useful for cleaning the environment and making products. While single types of these organisms have been studied, scientists are now looking at groups of them because they work better together. Keratins are strong proteins found in skin and hair. In 2020, scientists created a smaller group of these tiny helpers from a soil sample that could break down keratins just as well as the larger group.

Human health

Groups of tiny living things are common in humans, like those on the skin and in the intestines, where they help protect us and support our nutrition. Scientists have also found bacteria in the brain, which was once thought to have no living things. These bacteria seem to be part of a helpful group, similar to those found in the gut, and they do not harm health.

Synthetic microbial consortia

Main article: Synthetic microbial consortia

Synthetic microbial consortia, also known as co-cultures, are systems made up of many different types of tiny living things working together. These groups can be adjusted to help with many different jobs in factories and nature. In science, these groups help researchers study and create new behaviors in cells by working together. These kinds of groups are very common in nature and are often stronger than groups with just one type of tiny living thing. Scientists have been able to grow and study just over 7,000 types of bacteria so far, but there are probably around 1.2 million more that we haven’t discovered yet. When scientists create these groups or change natural ones, they watch things like the amount of acid or alkali, temperature, and how fast the tiny living things grow.