Bacteria, gold in our hands

Have you ever wondered how a living thing that is invisible to you can have such an impact on your life? So small and yet bacteria have the power to offer immense possibilities to humanity…. Hassina Ait-Abdherrahim, Director of the MicroOrganismS Centre of Excellence at the Lesaffre Institute of Science & Technology, never ceases to be amazed by their infinite potential.

Bacteria are simple prokaryotes, i.e. they have no nucleus and only one chromosome, whereas yeast has 16 and man 46. Yet despite their simplicity, they are considered to be the cradle of life. Bacteria appeared 3.8 billion years ago, whereas humans only appeared 200,000 years ago! Champions of adaptation, bacteria have survived and thrived in a wide variety of environments, from the depths of the ocean to the highest mountain peaks, in the desert… Imagine their superpowers… They can survive in extreme environments, very cold, very hot, very acidic and very salty. Indispensable to the survival of plants and animals, they maintain a symbiotic relationship with them. In fact, they have largely colonised us and learned to live with us throughout our bodies – both inside and out – forming a unique and specific microbiota for each and every one of us. In fact, our health is closely linked to our intestinal microbiota: billions of bacteria that help us digest food, produce vitamins and other essential nutrients, protect us against dangerous pathogens, train and control our immune system (70% of our immunity depends on our intestinal microbiota) and even impact our mood, since our intestine is considered to be our second brain – incredible, isn’t it?

Bacteria, genius communicators

In the modern world, networked communication has become an essential part of our daily lives. The ability to connect with others around the world, communicate instantly and share information has transformed the way we work, learn and socialise. What if we told you that bacteria are masters of communication, that they have developed a vast communication network to coordinate their activities and thrive in their environment. Bacterial communication is known as quorum sensing, a process in which bacteria release small signalling molecules or peptides into their environment to coordinate specific activities. When these molecules accumulate and reach a certain threshold, they trigger a change in behaviour, such as the formation of a biofilm or the expression of a visrulence factor. Bacteria have developed various secretion systems that can be useful for communication, but also for other surprising uses. Why not use them tomorrow to transport medicines? The ability of anaerobic bacteria to colonise oxygen-free environments, for example, has inspired researchers in the fight against certain cancers. Anaerobic bacteria transformed into drug ‘taxis’ could deliver toxic agents to solid tumours(1) . They would support conventional treatments such as chemotherapy or immunotherapy.

Innovating for life

When it comes to innovation and creativity, it’s sometimes useful to draw inspiration from nature. Man still has a lot to learn from bacteria. And do you know why? Quite simply because the genius of bacteria lies in their incredible ability to constantly evolve and innovate. They have been perfecting their skills for billions of years, so they can efficiently create new solutions for survival! In other words: innovation is a matter of life and death for bacteria! For example, they have developed the ability to create biofilms composed of biopolymer-based materials with fascinating properties, capable of protecting colonies from a hostile environment. Motivated by the versatility and robustness of bacterial biofilms, researchers are exploring ways of taking advantage of these characteristics to develop innovative living materials, using bacteria, for various industrial applications.

Also surprising is the kit devised by researchers to restore bioluminescent bacteria at any time, a natural source of light energy (visible even to satellites(2) !). This biological light solution could replace certain products with a short life cycle, such as illuminated beacons, night-time decorations and boat signage.

Bacteria at the service of sustainable food

Eating is vital, but it’s also a pleasure. The first known uses of bacteria by humans were in food preservation. Fermented foods such as yoghurt, cheese, kefir, kimchi and sauerkraut have been part of the human diet for thousands of years. It is only recently that interest has been shown in the bacterial biodiversity of these fermented products. Today, they are adorned with numerous nutritional and health benefits, thanks in particular to the probiotic activity of certain bacteria, but also to the molecules of interest produced during fermentation. This simple, sustainable process can also be used to transform vegetables and legumes, diversifying their tastes and textures and making them more digestible. It is even possible today to produce bacterial biomass that consumes CO2 and hydrogen to recover valuable proteins (up to 70%) as an alternative to animal proteins(3) . Nutritional enhancement of our food and decarbonisation, two future assets for mankind…

Our food is of course inextricably linked to agriculture. Some provocative articles mention that to feed the estimated 9 billion human beings in 2050, we would need two planets! Against a backdrop of climate change, how can we increase crop yields and combat plant diseases while preserving the environment? It’s a complex equation, but among the solutions, bacteria have shown that they can play a role in biocontrol and bionutrition. They can help increase crop yields and reduce the need for harmful pesticides and fertilisers. They can also help plants to absorb nutrients from the soil more efficiently and modulate its microbiota to increase plant resistance to stress and improve immunity.

Genius pollution cleaners

Wastewater treatment has become a crucial issue due to the increase in human population and the demand for clean water. Bacteria have the natural ability to break down and metabolise waste and pollutants, providing an effective and sustainable means of treating wastewater. That’s why bacteria are at the heart of our wastewater treatment plants.

They are also used to decontaminate polluted soil or groundwater, a process known as bioremediation. Depending on the type and complexity of the pollutants (hydrocarbons, heavy metals, pesticides, etc.), specific bacteria are used to transform the toxic chemicals into less toxic substances. During an oil spill, bacteria were able to swallow up 200,000 tonnes of dissolved oil and gas! And did you know that bacteria can be used to detect harmful substances? Known as “bioreporters”, these bacteria are often modified to emit a rapidly identifiable signal, such as colouration, fluorescence or bioluminiscence, as soon as they come into contact with the chemical molecule(4) .

The story doesn’t end there, because recent advances in science and technology, such as omics, new genome-editing techniques and new-generation sequencing methods, are making it possible to better understand the complexity of living organisms and to create bacteria with unprecedented properties to meet current and future challenges.  In addition, numerous emerging applications such as the capture and recovery of CO2 or the degradation of plastics using bacteria will contribute to a more sustainable world.

As you can see, bacteria that are sometimes overlooked or even disliked as pathogens can do a great deal for humanity, and these few examples are just a brief glimpse of their infinite potential.