MICromycete tarGeted bIotechnological Valorizations for Environmental bioRemediation – MicGIVER
The benefits of fungi for sites and soil natural decontamination
The Mic GIVER project aims to explore the bioremediation potential of microscopic fungi on 4 groups of pollutants emblematic of human activities. After screening for biodegradation activities and/or production of metabolites of interest, the decontamination potential of these fungi will be assessed using in situ biostimulation and bioaugmentation tests.
Evaluation of the ability of fungal strains to degrade organic pollutants
The objective of the Mic GIVER project is to explore the biotechnological potential of micromycetes for the in-situ bioremediation of 4 groups of various but emblematic HNS (Hazardous and Noxious Substances): Glyphosate and AMPA, Picric acid, crude oil, waxes. These HNS represent a persistent threat to the environment either directly or through their degradation byproducts. A pollutant requires specific depollution methods which depend on the individual lifetime, inherent physicochemical properties and their behavior within the impacted environment. Bioremediation is a green depollution method using natural or biotechnologically engineered living organisms selected for their ability to degrade, transform and/or accumulate HNS in situ. These organisms are able to thrive by using the toxic compounds as carbon and energy sources, through co-metabolism or through changing their organic or oxidative state to a less hazardous and more bioavailable state (e.g. water solubility, metal speciation…). Bioremediation can be used when the rate of natural attenuation of pollutants is too weak or slow. Plants, fungi, and bacteria have proven to be able to partially or totally decontaminate strongly impacted environments (e.g. by heavy metals, oil spills). Bioremediation can be achieved according to two strategies: in situ directly on the polluted site or ex situ by harvesting the polluted matrix (e.g. sands) and decontaminating for example using a slurry bioreactor. Ex situ bioremediation is generally much more efficient than in situ bioremediation. However, due to the cost, the use of ex situ bioremediation is limited to cases where the polluted matrix can be easily extracted from the impacted environment
The approach adopted for this project integrates 4 successive phases:
- WP1:Screening for biodegradation activities and surfactant production: Screening of HNS biodegradation activities and mycosurfactant production from 500 fungal strains from the UBOCC and LUBEM collection with the final aim of 2 positive hits by HNS. Discovery of new mycosurfactants and/or biodegradation activities specific to 4 emblematic HNS (TRL3).
-WP2: Structural chemistry: Extraction, purification & structural characterization of fungal secondary metabolites identified during WP1.
-WP3: Innovation optimization and industrial transfer: The biodegradation of the 4 selected compounds (Picric acid, glyphosate, diesel and waxes) was already reported in literature and some biodegradation pathways elucidated. The aim of the project is to characterize the efficacy of a set of strains able to be used for waters and/or soils contamination, a sort of turnkey approach from the producer to the user
-WP4: Operational assessment: Design and optimization of field protocols suitable for an operational context
The first results of the project consisted in the selection of 11 fungal strains out of 250 tested, which showed biodegradation activity on the pollutants tested. At 18 months into the project, the metabolites produced by these strains are in the process of being indexed. Pilot-scale cultivation of these strains is also at the initiation stage.
At the end of the project, we propose two main deliverables (TRL 8):
o A screened biological collection of fungi immediately available on an industrial scale for pollution control activities on the four reference HNS. This screening includes confirmed direct biodegradation activities or indirect biodegradation activities by improving the bioavailability of pollutants (e.g. mycosurfactant production).
o An in situ mycoremediation operational guide on the four reference HNS according to specificities of potentially different impacted environments.
A review on the identification of biosurfactant was submitted. Several publications are in progress: screening of fungal strains, analysis of rhamnolipids.
Since the beginning of the industrial age, humanity has been able to exponentially increase its productivity and access to resources, and this, to levels unimaginable only 200 years ago. If this inexorable technological progress has made it possible to multiply the human population sevenfold in a century, to free ourselves from many formely fatal and now benign diseases, to curb, albeit unequally, famine or to push the okumene beyond the very limits of the planet, this has also had an irreversible impact on the biosphere. In its irrepressible march towards progress, humanity has destroyed and anthropized its environment to levels not reached since the start of the cognitive revolution 50,000 years ago. One of the consequences of this forced progress has been the release into the environment of various pollutants (or HNS: Hazardous and Noxious Substances), some of which are extremely persistent, even beyond human generations. Since the end of the 20th century, a worldwide awareness has emerged of the dangers incurred by present and future generations because of this pollution. More and more, the laws tend, always in a very unequal manner across the world, to limit these emissions and to prohibit their use for the more dangerous forms. While encouraging, these initiatives are nonetheless insufficient to address the damage already done and stem its long-term effects. With its genius, humanity has therefore developed various methods to clean up the impacted environments. These methods can be physicochemical and use protocols initially obtained from industry (e.g. use of resins, surfactants, excavation, pyrolysis, etc.). Other methods, more gentle and specific, exploit bioremediation. Bioremediation is a biological phenomenon during which living organisms either directly metabolize HNS (bioaugmentation), immobilize them in their biomass or increase their bioavailability (biostimulation) for other trophic links. Bioremediation, when mastered, demonstrates an attractive biotechnological potential by the possibility of treating pollution in situ or ex situ on an almost unlimited set of HNS (from hydrocarbons to radionuclides) while avoiding an additional degree of anthropogenic disturbance compared to physicochemical methods. In this sense, fungi (filamentous fungi or yeasts) present a substantial biotechnological resource due to their ability to degrade HNS, which are particularly recalcitrant. The Mic GIVER project intends to exploit this potential for fungal bioremediation on four HNS, chemically diverse and as diverse emblematic of human activities: picric acid, glyphosate, diesel and waxes (C10 to C20). This fungal bioremediation will focus on native HNS but also on their potentially ecotoxic degradation products. Firstly, 500 fungal strains will be screened for their ability to degrade HNS or to synthesize biosurfactants that may increase their bioavailability. Next, the culture conditions will be optimized on 16 of the most promising strains (8 for the degradation of HNS and 8 for synthesizing biosurfactants). A metabolomics approach will also be deployed in order to finely characterize these biosurfactants. From the four most promising strains, production and extraction on an industrial pilot will be carried out in order to increase the degree of TRL from 3 to 5 (Technology Readiness Level). Finally, a bioremediation test bench will be developed in order to be able to test and optimize in situ (bioaugmentation and biostimulation) these bioremediation solutions in relevant operational conditions (TRL8). Ultimately, Mic GIVER will allow the development of new fungal bioremediation bioprocesses for industrial stakeholders in the field of pollution control.
Monsieur Stéphane Le Floch (Centre de documentation de recherche et d'expérimentations sur les pollutions accidentelles des eaux)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
ICOA Institut de Chimie Organique et Analytique
CEDRE Centre de documentation de recherche et d'expérimentations sur les pollutions accidentelles des eaux
URN-COBRA Université de Rouen Normandie (URN), Laboratoire CHIMIE ORGANIQUE, BIOORGANIQUE : RÉACTIVITÉ ET ANALYSE
UBO-LEMAR Université de Bretagne Ocidentale (UBO), Laboratoire des sciences de l'Environnement Marin (LEMAR)
UBO-LUBEM Université de Bretagne Occidentale (UBO), Laboratoire Universitaire de Biodiversité et Ecologie Microbienne (LUBEM)
UBO-SGPLAT Université de Bretagne Occidentale (UBO), Service Général des Plateformes Technologiques (SGPLAT)
CNRS-ICSN Centre National de la Recherche Scientifique (CNRS), Institut de Chimie des Substances Naturelles (ICSN)
Help of the ANR 637,540 euros
Beginning and duration of the scientific project: January 2022 - 48 Months