A metaproteomic analysis of microbial communities of Ace Lake, Antarctica
The Vestfold Hills is an ice free oasis in East Antarctica with possibly the highest distribution of stratified lakes and marine basins in the world. Ace Lake is a meromictic lake located on the Long Peninsula in the Vestfold Hills region, and is one of the most intensively studied stratified lakes...
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
| Published: |
UNSW, Sydney
2010
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| Online Access: | http://hdl.handle.net/1959.4/50082 https://unsworks.unsw.edu.au/bitstreams/166ff9da-76ed-4f09-a1f9-1bd9a0ce036f/download https://doi.org/10.26190/unsworks/14937 |
| Summary: | The Vestfold Hills is an ice free oasis in East Antarctica with possibly the highest distribution of stratified lakes and marine basins in the world. Ace Lake is a meromictic lake located on the Long Peninsula in the Vestfold Hills region, and is one of the most intensively studied stratified lakes in Antarctica. Since its isolation from the Southern Ocean over 10,000 years ago, the marine derived community of Ace Lake have evolved with changes in the physical and chemical structure of the lake. Metaproteomics (environmental proteomics) was used to investigate the interactions and functional activity of microbial populations within the layers of Ace Lake. To achieve this, a protein extraction procedure was developed using test samples of filtered biomass from coastal marine waters (Botany Bay). The performance of two mass spectrometry analysis softwares, Mascot (spectral searching) and Peaks (de novo sequencing) were also evaluated using the metaproteomic datasets generated from Botany Bay. Although it was concluded that Mascot was a more rapid and reliable method for processing large metaproteomic datasets, the de novo sequencing capability of Peaks hold much promise for identification of proteins with novel sequences. The simulated mixed community study of Sphingopyxis alaskensis and Escherichia coli indicated that well represented organisms in terms of cell abundance resulted in higher levels of protein detection by mass spectrometry. The simulated community study provided metaproteomic datasets, which enabled the performance of Mascot database searching and protein identification validation techniques to be tested. Cross-species matching (NR database) of proteomic data derived from microbial populations at different depths of Ace Lake provided insights to th e microbial composition and functional activity of members within the lake. A SAR11 community in the surface waters of Ace Lake likely adapts to oligotrophic conditions of the lake by expressing transport proteins associated with nutrient uptake. The ... |
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