Planktonic microbial communities in aviation fuels

Alternative fuels (biofuels) will become integral to the aviation industry, reducing the carbon footprint of air travel whilst meeting increased demand. However, there has been little consideration of the changes in the microbial communities that might occur in these new fuels. Shifts in the composition of microbial communities in fuel systems could have significant impacts upon testing and treatment of microbial contamination, needed to prevent system fouling and microbial induced corrosion. Laboratory microcosms were established, using contaminated real-world samples as inoculum, in different biofuels with current standard Jet A-1, for comparison. Microcosms were sampled after two- and four -weeks. Samples were assessed for visual contamination and total dry biomass weighed. DNA was extracted and subjected to real-time quantitative Polymerase Chain Reaction(qPCR) and Next Generation Sequencing, targeting the 16S rRNA and ITS genes. In addition, organisms were isolated on minimal media with fuel hydrocarbons as the sole carbon source. Bacterial communities were dominated by Pseudomonas sp., while Hormoconis resinae was dominant in the fungal communities, with only small variations in their relative abundance between differing fuel types. The abundance of bacterial 16S rRNA genes was higher than that of fungal ITS genes. While the types of organism that grew were similar across the fuels types, a variation in relative abundance of these organism driven by fuel type was observed. This work demonstrates the application of laboratory microcosms to simulate fuel systems and gain insights into the communities that develop in aviation biofuels, helping to inform testing and maintenance regimes.