Each year, plagues and vegetal illnesses evoque million of losses on world agriculture
Every year, plant pests and diseases cause losses running into millions in global agriculture. For decades, the main tool for combating them has been the use of chemical plant protection products. However, the emergence of resistance, increasing regulatory restrictions and the need to protect biodiversity are driving the development of more selective and sustainable alternatives. Among these, one technology is attracting enormous interest: biopesticides based on RNA interference (RNAi).
What is RNA interference (RNAi)?
Although the name may seem complex, the way it works is based on a simple principle. Rather than indiscriminately eliminating a pest using a chemical compound, RNAi makes it possible to ‘silence’ specific genes that are essential for the pest’s survival or its ability to cause disease. This is a natural mechanism present in virtually all eukaryotes, which regulates the expression of certain genes via small double-stranded RNA (dsRNA) molecules. When these molecules are taken up by the target organism, they block the production of essential proteins and reduce its ability to grow, feed or infect the plant.
This high specificity is one of the greatest advantages of RNAi over conventional pesticides. Whilst a chemical insecticide may also affect beneficial insects or other organisms in the ecosystem, an RNAi-based biopesticide can be designed to act solely on a specific species or even on a specific biological process. Furthermore, RNA molecules degrade naturally in the environment, reducing the persistence of residues and their environmental impact.
Another particularly interesting feature is its flexibility. Once a key gene in the target organism has been identified, it is possible to design new RNA molecules in a relatively short time, making it easier to respond quickly to new pests or to organisms that have developed resistance to traditional treatments.
SIGS: apply RNAi through spraying
Currently, this technology can be applied using two main strategies. The first involves developing plants capable of producing these RNA molecules internally, an effective approach but one associated with the use of genetically modified organisms. The second, known as Spray-Induced Gene Silencing (SIGS), simply involves spraying dsRNA onto plants, in a similar way to a conventional plant protection treatment. Once deposited on the plant’s surface, the molecules can be absorbed by the pest or pathogen and trigger the gene silencing mechanism. This strategy offers great versatility, as it can be used on different crops, allows the timing of application to be determined, and avoids the need to genetically modify the plant.
Interest in this approach has grown rapidly in recent years and has already led to significant regulatory advances. In 2023, the US Environmental Protection Agency (EPA) approved Ledprona, the first sprayable dsRNA-based biopesticide for the control of the Colorado potato beetle (Leptinotarsa decemlineata), marking a milestone in the market launch of this technology. As with any emerging technology, there are still challenges that need to be resolved before it can be widely adopted. One of the main challenges is the stability of RNA, as these molecules can degrade rapidly due to ultraviolet radiation, rain, temperature or certain enzymes present both in the environment and in the target organisms themselves. It is also essential to select the correct gene to target, ensuring high efficacy and minimising any potential effects on non-target organisms. Consequently, much of the current research focuses on developing new formulations capable of protecting dsRNA using nanoparticles, liposomes or biological vesicles, as well as on optimising its large-scale production and advancing regulatory and environmental assessment processes.
The SUPERA project: how CARTIF is developing new RNAi-based solutions
In this context, CARTIF is actively involved in developing these new strategies through the SUPERA project (Sustainable plant health through RNAi to reduce the impact of diseases on agriculture and forests), coordinated by the University of Valladolid in collaboration with the CSIC and IDAI Nature. The aim of the project has been to develop innovative RNAi-based solutions to combat diseases caused by fungi and oomycetes that affect both agricultural crops and forest species. During the project, essential genes were identified in highly significant pathogens, such as Fusarium and Phytophthora, and specific dsRNA molecules were designed to reduce the expression of these genes. At the same time, production processes using bacterial fermentation were optimised, and encapsulation strategies were developed to improve the stability of the molecules and facilitate their application via foliar and root treatments, bringing this technology closer to future real-world applications in agriculture. The results obtained demonstrate that RNAi has evolved from being merely a tool for basic research into a technological platform with enormous potential for developing a new generation of biopesticides that are more precise, sustainable and environmentally friendly. Although there are still scientific and regulatory challenges to be overcome, all the signs suggest that, over the coming years, this technology will play an increasingly important role in integrated crop protection strategies, contributing to a more efficient and resilient agricultural sector that is aligned with the sustainability goals demanded by society.
In a world seeking to reduce its carbon footprint and move towards a circular economy, anaerobic microorganisms are emerging as key players in the fight against climate change. These organisms, which thrive in environments without oxygen, have been used for decades in processes such as anaerobic digestion for waste treatment and biogas production. However, their potential goes far beyond this. Thanks to advances in biotechnology, anaerobic microorganisms are emerging as key tools for industrial decarbonisation through innovative processes such as gas fermentation, where they can transform CO2 or CO into high value-added products.
Heavy industries, such as steel, concrete and petrochemicals, generate large amounts of CO2 and CO as a by-product of their processes. Traditionally, these gases have been released into the atmosphere, contributing to global warming. However, synthetic biology and biotechnology have opened up a new avenue to harness these emissions and convert them into valuable products through the action of specialised anaerobic micro-organisms.
Anaerobic bacteria, such as Clostridium, Moorella and Acetobacterium, can use CO2 and CO as a carbon source and transform them into organic compounds via specialised metabolic pathways. This process, known as gas fermentation, facilitates the conversion of industrial emissions into renewable chemicals, fuels and biomaterials, promoting a more sustainable economy. For example, Acetobacterium woodii and Moorella thermoacetica are acetogenic bacteria capable of converting CO2 in acetic acid, a key input for the chemical and food industry, while species as Clostridium Ijundahlii can produce acetate and ethanol, making them a viable alternative for the generation of biofuels and other products of industrial interest.
Image of Clostridium autoethanogenum growing from CO2/CO as a source of C.
In addition to ethanol or acetic acid, anaerobic bacteria are capable of generating other compounds of interest such as butanol, acetone and other organic acids like formic, propionic or butyric acid. These products are key in the manufacture of plastics, solvents and other chemical compounds with high industrial demand.
Biopolymers and bioplastics represent another promising avenue. Cupriavidus necator can transform CO2 into bioplastic precursors such as polyhydroxyalkanoate (PHA) and polyhydroxybutyrate (PHB), biodegradable materials that provide a sustainable alternative to conventional petroleum-based plastics.
Finally, single-cell proteins obtained from CO2 can be produced by various species of hydrogenotrophs, which convert gases such as CO2 and hydrogen into protein-rich biomass. These microbial proteins can be used as an alternative source for animal and even human food, contributing to global food security and reducing pressure on traditional agricultural resources.
“These microbial proteins can be used as an alternative source for animal and even human food”
The use of anaerobic microorganisms for the conversion of CO2 into valuable products offers multiple advantages. In first place, it reduces industrial emissions, mitigating the environmental impact of highly polluting sectors. In addition, it allows a sustainable production of chemical compounds and fuels without relying on fossil resources or agricultural crops.
Industrial gas fermentation processes already exist today and are proving their viability. For example, the company LanzaTech has developed technologies based on acetogenic bacteria to transform CO2 and CO into ethanol and other chemicals, using waste gases from the steel industry. This technology has been implemented in countries such as China and Belgium, where operational industrial plants have successfully converted emissions into biofuels and renewable materials. Another case is Carbon Recycling International (CRI), which uses microorganisms in Iceland to convert CO2 into methanol, a key compound in the chemical and transport industry.
However, despite its enormous potential, the implementation of gas fermentation on an industrial scale faces technical and economic challenges. These include optimising bioprocesses to improve CO2 conversion efficiency, reducing operating costs and developing bioreactors suitable for large-scale production. In addition, it is necessary to advance in the design of genetically modified microorganisms that can maximise the conversion of CO2 into specific products of industrial interest.
The Biotechnology and Sustainable Chemistry area of CARTIF has developed during the last years an intense research activity around gas fermentation technology and the management of anaerobic microorganisms. Specifically, the execution of R&D projects such as BioSFerA or CO2SMOShas allowed us to position ourselves in the European panorama as an entity capable of working successfully with this peculiar class of microorganisms and to specifically optimise their growth conditions in pressurised bioreactor, in order to increase production yields of various compounds such as acetic acid, ethanol or 2,3-butanediol.
As research and development continues to advance, these microorganisms will play an even m
ore fundamental role in the transition towards a more sustainable industry and a society with less environmental impact.
When we think in agriculture, we often focus on the development of the plant, but we rarely consider the importance of proper management of the soil in which crops are grown. Soil is a vital resource that sustains our lives and provides the food that is indispensable for humanity, and its health is essential for sustainable agriculture and food security.
At first glance, soil may appear lifeless, but in reality, it is teeming with microscopic life. Healthy soils harbour a wide variety of microorganisms, including bacteria, fungi, protozoa, nematodes, etc. These organisms, which often go unnoticed, play an essential role in the functioning of terrestrial ecosystems.
Among the soil-dwelling microorganisms, many are beneficial to plant health soil quality in general. These microorganisms perform a number of vital functions:
1. Decomposition of organic matter: microorganisms break down organic matter in the soil, such as fallen leaves and plant debris. This action releases essential nutrients that can be absorbed by plants to support their growth.
2. Nitrogen fixation: nitrogen is one of the most important nutrients for plant growth. Some bacteria have the ability to fix atmospheric nitrogen in a form that plants can metabolise.
3. Protection against pests and diseases: some microorganisms act as biological control agents, helping to prevent plant diseases by competing with pathogens or producing antimicrobial compounds.
4. Improvement of soil structure: other microorganisms, such as bacteria or fungi, generate soil aggregates that improve soil structure, porosity and water holding capacity.
5. Nutrient cycling: they participate in the decomposition and release of essential nutrients, such as phosphorus, potassium and various micronutrients (zinc, iron, copper, calcium), which are essential for plant growth.
Unfortunately, modern agriculture has engaged in practices that often damage the diversity and population of beneficial microorganisms in the soil. Excessive use of chemical fertilisers and pesticides, intensive tillage and lack of crop rotation are practices that can damage or unbalance the microbial ecosystem present in the soil.
For example, chemical fertilisers may provide nutrients to plants, but they can also lead to soil acidifcation and negatively affect beneficial microorganisms. Similarly, pesticides intended to kill pests can negatively affect other microorganisms in the soil, which can trigger a cycle of dependence on agricultural chemicals.
Fortunately, there are agricultural practices that can promote soil health and the abundance of micro-organisms that play a positive role in plant development:
Organic farming
Organic farming avoids excessive use of chemical pesticides and fertilisers, which preserves the microbial ecology of the soil.
Crop rotation
Changing crops season after season encourages microbial diversity and avoids the build-up of specific pathogens.
Use of cover crops
Maintaining a vegetative cover on the soil throughout the year helps to maintain microbial activity and prevent erosion.
Composting
Adding organic compost to the soil enriches the microbial population and provides nutrients in a balanced way.
Reduced tillage
Minimising soil tillage reduces the disruption of microorganisms in their natural environment.
Use of green manures
Planting green manure crops such as legumes can increase nitrogen fixation and enrich the soil in nutrients.
Soil health is fundamental to agricultural sustainability and global food supply. Beneficial microorganisms, working in symbiosis with plants, play an essential role in preserving that health. As a society, we must recognise the importance of
these tiny creatures and adopt practices that promote their thirving in our soils.
At CARTIF, we have the experience gained through the implementation of several projects related to the proper management of microbiology applied to agriculture and especially to soils, either in the form of biofertiliser (SUSTRATEC proejct) or in the form of biopesticide (SUPERA project).
Maintaining soil health is not only essential to ensure abundant and nutritous harvests, but also to preserve biodiversity and mitigate climate change. By protecting and nurturing life in the soil, we are investing in a healthier and more sustainable future for our planet and future generations. Let us care for the land that cares for us.
