Snomax is an ice nucleation inducer used to create artificial snow on ski resorts around the world, including some based in Kosciuszko National Park. The ice nucleation activity is reportedly derived from a protein purified from the fermentation of the Pseudomonas syringae bacterium. However, some strains of this bacterium carry numerous toxin and antimicrobial resistance genes. This project aims to accurately investigate the composition of this ice nucleation agent, and investigate whether it has caused any negative environmental impacts.
The first stage of the project involves detailed characterisation of the Snomax product. Amino acid compositional analysis demonstrated that it is approximately 50% protein, so further analysis of chemical composition is required in order to determine the other components. An initial proteomic characterisation using SDS-PAGE and nanoflow liquid chromatography – tandem mass spectrometry identified >1000 proteins, most of them related to P. syringae bacterium. Further proteomic characterisation will be performed in order to accurately detail the protein components involved.
The second stage of the project involves molecular analysis of field sampled soil and leaves from five different species of alpine plants. This was undertaken after the completion of the 2022 ski season, with samples collected at three different elevations from within the Thredbo ski area, and a matching set of three sites with similar geography located well outside the resort in the Dead Horse Gap area. The sites within the ski area had been exposed to the Snomax material for the previous four months, while those outside the ski area had not. Soil samples were collected, along with samples of leaves from Eucalyptus niphophila, Nematolepis ovatifolia, Tasmannia xerophila, Ozothamnus secundiflorus, and Olearia phlogopappa. The plant leaf samples will be analysed to determine whether the expressed proteome of plants exposed to Snomax is substantially different from plants collected from outside the resort area. The leaves will be analysed to determine if any significant differences in the phyllosphere (leaf microbiome) can be detected between sampling sites, and the rhizosphere bacterial communities from soil samples will be similarly analysed. The protein extraction and mass spectrometry analysis of the sampled leaves are underway, as are the DNA extraction and quantification of bacteria present in the phyllosphere and rhizosphere. Results from all these analyses will be presented in this study.