Comparison of microbial contaminants in conventional, synthetic and sustainable aviation fuels

Microbial contamination in aviation fuel systems can foul sensors, blocking filters, degrade fuel and cause corrosion, requiring regular testing. The shift from fossil fuel sources to synthetic fuels may influence the composition of contaminating microbial communities. This study examines how different aviation fuels influence the microbiome, including sustainable aviation fuels (SAFs), which have been proposed as means of reducing aviation’s carbon footprint, as well as diversifying the fuel supply chain. In this study we examined changes in the microbiomes of two communities when cultured with different fuels (conventional kerosene, synthetic and sustainable fuel blends). Microbial growth and community composition was determined by weighing microbial biomass, quantitative PCR and high-throughput DNA sequencing. Microbial communities grew in all fuels tested, but was somewhat reduced in microcosms supplied with Farnesane or Gevo. Although there were numerical differences in the relative abundance of community members, there was no major change in community membership or in the dominant contaminants across the studied fuels. This indicates that culturing with synthetic aviation fuels did not result in significant alterations in the fuel microbiome. However, contaminating microbiomes are known to be highly diverse and this potential issue should be monitored closely by the fuel industry.