Fuel-biofilms - Deep (meta)genomics and (meta)transcriptomic analyses of fungi and bacteria consortia from aircraft tanks and kerosene containing habitats

Microbial contamination of fuels, associated with a wide variety of bacteria and fungi, leads to decreased product quality, can compromise equipment performance by biofouling, and microbiologically influenced corrosion. Detection and quantification of microorganisms are critical in monitoring fuel systems for an early detection of microbial contaminations. The aims of this study are (i) to analyze the diversity of fuel-contaminating microorganisms with the purpose to identify key-mechanisms and microorganisms for fungi and bacteria lifestyle in fuel containing habitats and (ii) to quantify bacterial and fungal contamination in samples from aircraft tanks, using culture independent (qPCR) approaches. Deep metagenome sequencing and binning approaches in combination with RNA-seq data implied a metabolic symbiosis between fungi and bacteria. Based on criteria of abundance, the most relevant microorganisms were identified as bacteria of the genera of a-, ß-, and ?-Proteobacteria, and the filamentous fungi Amorphotheka. The most active microorganisms are Methylobacteria sp., Pseudomonas sp., Kocuria sp., Amorpotheka sp., and Aspergillus sp., Fusarium sp., Penicillium sp. as well uncultured and unknown bacteria and fungi, who are potential effectors for kerosene degradation, biofilmformation and so far for biofouling/bio-corrosion. We identified highly active genes, encoding for alcohol- and aldehyde dehydrogenases, alkane monooxygenase, Cytochrome P450, exopolysaccharide production, attachment and pili/flagellar associated proteins, efflux pumps and secretion systems. We were able to verify the abundance of fungi and bacteria, by the use of qPCR- methods and primers that amplify regions of the ITS-region and 16S rRNA genes as well as specific genes of interests, respectively.