Biocontamination survey for Microbially Influenced Corrosion exposure TEST

Project Information

MICTEST

Grant agreement ID: 831976

DOI

10.3030/831976

Project closed

EC signature date 7 March 2019

Start date 1 April 2019

End date 31 March 2022

Funded under

• SOCIETAL CHALLENGES - Smart, Green And Integrated Transport

Total cost

€ 497 933,75

EU contribution

€ 497 933,75

Coordinated by

ACONDICIONAMIENTO TARRASENSE ASSOCIACION
Spain

Periodic Reporting for period 2 - MICTEST (Biocontamination survey for Microbially Influenced Corrosion exposure TEST)

Reporting period: 2020-10-01 to 2022-03-31

Summary of the context and overall objectives of the project

Bio-contamination is one of the main sources of contamination of jet fuel and aircraft fuel systems, causing plugging, clogging of flow in fluids systems and, particularly, microbiologically influenced corrosion (MIC) of fuel tanks. Antimicrobial and/or antibiofilm coatings and materials are a highly promising tool to anticipate and mitigate bio-contamination. These materials and coatings should be robust to severe bio-contamination while at the same time have no reverse effect on the fuel itself.
Therefore, there is an urgent need to update protocols enabling the development, testing and validation of antimicrobial in simulated environment representative of real aircraft conditions.
The MICTEST project has as main goal to develop new exposure protocols for testing and validation of coatings, materials and components of aircraft fuel systems at laboratory environment, validate the different protocols for microbial growth inhibition and material and coating performance in pilot fuel tanks.
Conclusions:
Firstly, a microbial strain collection (142 strains) was obtained from fuel tanks sample (CLH facility). From those, ten strains have been selected following two criteria: i) belonging to OTUs from the core microbiome and ii) belonging to genera defined in literature as problematic for fuel systems. Finally, a three-strain consortium comprehended by a fungal strain (genus Hormoconis), and two bacterial strains (genera Pseudomonas and Escherichia) has been selected. The ability to form a synergistic multispecies biofilm on the surface of a representative material of aircraft fuel tanks was optimized and tested at lab-scale, simulating real environmental conditions, and monitored through plate count and Scanning Electron Microscope (SEM). All the obtained information allowed the creation of a protocol design in guideline format with the aim of standardized antimicrobial/antibiofilm material properties studies. In conclusion, different methodologies described in this project can contribute to validate new materials, coatings, fuels and components for aviation systems.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The MIC-TEST project started its implementation phase by performing an exhaustive sampling of fuels and materials, to select representative samples of bio-contamination in aircraft fuel systems.
The entire CLH network in Spain has been sampled for this task (approx. 1500 samples).Thirteen samples were selected for a more in-depth microbiological characterization. The core microbiome from those thirteen samples was defined through bacterial and fungal biodiversity analysis based on next generation DNA sequencing.
After the characterization of the bacterial and fungal biodiversity present in the fuel tanks, an isolation process of bacterial and fungal strains from the same samples was carried out. Ten of the isolated strains were selected as candidates to simulate biocontamination. From those ten isolates, three different consortia (composed by two or three strains each) were stablished. A state of the art of current and innovative antimicrobial/antibiofilm coating materials is being produced. Materials/coatings will be pre-selected as feedback for setting up the new protocol. Specific groups (SGs) of material, fuel, conditions, and their corresponding representative microorganisms will be obtained.
After the identification of the core microbiome of real fuel tanks through bacterial and fungal biodiversity analyses (Illumina sequencing of ribosomal markers), the same samples were used to create a microbial strain collection (142 strains). From those, ten strains were selected following two criteria: i) belonging to OTUs from the core microbiome and ii) belonging to genera defined in literature as problematic for fuel systems. A three-strain consortium comprehended by a fungal strain (genus Hormoconis, MIC 177), and two bacterial strains (genera Pseudomonas, MIC 212 and Escherichia, MIC 49) was defined and used as model for multispecies-biofilm development. Once defined the biofilm-formation protocol, several methodologies were established for the measurement of fuel biodeterioration and the biocontamination and subsequent biocorrosion on different materials and coatings with potential for becoming good candidate for the aircraft industry.
In future, the know-how obtained in MICTEST project could be considered to correctly select materials and coatings involved not only in the Dassault facility, but also in others aviation related companies. These knowledges will contribute to find a solution in the biocontamination and the posterior biocorrosion of fuel tanks.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Until the end of the project, MICTEST will go beyond the state of the art by: i) defining the best growing conditions to form biofilms simulating biocontamination on relevant materials for the aircraft industry, ii) select the consortia with best growth and viability on relevant materials for the aircraft industry, iii) define the final protocol for tailor-made exposure tests for assessing antimicrobial and antibiofilm properties of materials.
Until the end of the project is expected the following potential impacts:
• A contribution to greener aircraft with higher fuel efficiency and lower emissions, because of the new exposure protocol for assessing antimicrobial and antibiofilm properties of materials will contribute to the eco-design of the aircraft fuel systems.
• A strengthening of EU knowledge- base, industry and competitiveness. The availability of robust protocols simulating real biocontamination will increase the transferability and replicability of the results obtained at laboratory to real scale, increasing the competitiveness of EU material and coating developers. More effective materials for preventing biocontamination in fuel systems will contribute to reduce fuel and components deterioration and therefore increase the competitiveness of industries along the full value chain. That is an important socio-economic impact allowing a high-quality antimicrobial materials and coatings to reach EU markets and reduce time-to-market for new product innovation through faster development cycles.
In MICTEST project has been created a specific biofilm-formation protocol starting from microorganisms inhabiting the aviation context. This methodology has been standardized and validated to fill the lack of knowledge in this field, contributing in testing and selecting new materials, coatings, fuels and components for aviation systems.

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