EXPO 40 years BCCM: Microorganisms

Did you know that about two-thirds of life on Earth is invisible?

All organisms that we cannot see with the naked eye are called microorganisms. There are an estimated 1 billion species of microorganisms and new ones are being discovered every day. Most are indispensable for life on earth and necessary for both our health and many applications of our daily lives. 

Their small size is about the only thing that the different types of micro-organisms have in common, otherwise they are very diverse, both in terms of their way of life and metabolism, and of the functions they can perform.

Be amazed by their beauty!




By the end of 2022, the entire patrimony of the BCCM consortium comprised about 300,000 different biological materials, belonging to different types of organisms:


BCCM holds more than 25 000 bacterial strains from over 7000 species.



Bacteria are single-celled microorganisms that play a crucial role in our lives, both for us as individuals and for the entire planet. At their core, bacteria are simple, but incredibly diverse organisms. They are prokaryotic, meaning they do not have a true nucleus or membrane organelles, which distinguishes them from more complex eukaryotic cells. But don't let their simplicity fool you: bacteria are masters of adaptation and survival. They live in a wide range of environments, from deep ocean trenches to the human gut, demonstrating their adaptability and ubiquity.

Bacteria help digest food, synthesize vital nutrients and even protect our bodies against pathogens. In the field of biotechnology, they serve as workhorses for the production of drugs, enzymes and other valuable compounds. Additionally, bacteria play an essential role in nutrient cycling, decomposition and soil enrichment, which are vital for agriculture and the maintenance of ecosystems.



BCCM holds more than 700 cyanobacterial strains from over 90 species.



The Cyanobacteria (blue-green algae) are a group of photosynthetic bacteria that have typically a blue-green color, but they can also be purple, red, yellow, brown, blackish. Cyanobacteria gets its common name from the blue-green pigment, phycocyanin, which along with chlorophyll a gives cyanobacteria a blue-green appearance. Species within this group are non-motile and range from single-celled, to colonial, or filamentous.

They were instrumental in the metamorphosis of the primitive earth, which lacked oxygen, into the green planet we know today know. The oldest fossils of cyanobacteria were found in sedimentary rocks that were formed 3,500 million years ago. From then on, they provided the supply of oxygen in the Earth's atmosphere, allowing algae, plants, fungi and animals (including humans) could develop. Moreover, they are the ancestors of the plastids, having merged with a primitive eukaryote.

Cyanobacteria have a wide variety of habitats that range from frozen lakes, to acidic bogs, to deserts and volcanoes. They are most commonly found in alkaline aquatic environments, they can also be found in soil, on rocks, and even in the atmosphere.

Species of Cyanobacteria are commonly responsible for the outbreak of freshwater toxic algal blooms.



BCCM holds more than 1000 mycobacterial strains from over 110 species.



The genus Mycobacterium, part of the Actinobacteria, has about 165 species and subspecies. Some of them are found just about everywhere, both in water (including drinking water and swimming pools) and in soil. Most species are harmless and useful because they break down organic components in soil break down. A few are used for industrial applications. However, there are several species that cause diseases in animals and humans. The main disease-causing species for humans are Mycobacterium tuberculosis (the main causative agent of the disease tuberculosis), M. leprae (causative agent of leprosy) and M. ulcerans (pathogen of Buruli ulcus). In addition, there are a number of species that occur in water and soil that cause non-tuberculous mycobacterial (NTM) diseases. These mainly cause problems in persons with immunodeficiency (people infected with HIV, for example).



Les BCCM hébergent plus de 620 microalgal strains from over 90 species.

Diatoms and microalgae


Bacillariophytes, or diatoms, are an extremely diverse group of organisms, and are the most species rich group of algae. Diatoms are single-celled and golden-brown in color with motile and non-motile species.  The cell walls of diatoms are composed of silica, which fits together in two halves like a box.  The lid and base of the box are known as valves, which are connected by a girdle, and the whole structure is known as a frustule.  Frustules occur in two basic forms, cylindrical (centric, circular in valve view) and elongated (pennate, roughly boat-shaped in valve view, although there are many variations on the theme).

Diatoms are one of the most common forms of phytoplankton and are an important food source for aquatic life, living in both fresh- and saltwater environments. Diatomaceous earth is mined deposits of fossilized diatoms; due to diatom's hollow and silica frustules, diatomaceous earth has a wide selection of commercial uses, such as in “natural” pest control, cosmetic abrasives, and water filtration.



BCCM holds more than 40 000 fungal strains from over 6500 species.

Fungi and yeasts


The realm of fungi consists of single-celled yeasts, filamentous fungi and mushroom-forming species. Currently, about 100,000 species are known, but recent estimates speak of a diversity of 5.1 million fungal species.  Quite a few species play an important ecological role as saprophytes that break down plant residues or other organic matter, thus reintroducing nutrients into the ecosystem into the ecosystem. Other species are essential symbionts for plants or animals. A minority live as parasites at the expense of other organisms.

Yeasts are microscopic, single-celled fungi found in many natural and artificial environments. The morphologically simple yeasts have physiologically adapted to survive and thrive in a wide variety of environments, ranging from terrestrial and thrive, ranging from terrestrial, atmospheric to aquatic and extreme environments with low temperatures and little oxygen or water. 

Arbuscular mycorrhizal fungi (AMF) are important root symbionts. They are considered key players for plant nutrition and resistance/tolerance to abiotic/biotic stresses.


BCCM holds more than 221 000 plasmides and more than 220 plasmid host strains.

Plasmids and plasmid host strains


Recombinant plasmids are of important scientific interest for basic and biotechnology research.

Empty plasmids, useful for the recombinant (over)expression of proteins of interest in bacteria, yeasts, fungi, cells of insects cells of plants and animals such as (but not exclusively): plasmids with broad host specificity belonging to different incompatible groups, gateway clones, dicistrone expression plasmids, adenoviral and retroviral expression plasmids, yeast two-hybrid and three-hybrid expression plasmids, reporter plasmids, etc.

Expression plasmids carry genes or sequences of interest such as (but not exclusively): genes for all kinds of cytokines and growth factors receptors, intracellular signalling proteins, enzymes (kinases, proteases, genes related to related to glycosylation, ubiquitin ligases, etc.), bacterially virulent genes, microRNA sequences, promoter sequences, etc.