Understanding the impacts of viruses on microbial methanol utilisation in seawater

Purves, Kevin (2019) Understanding the impacts of viruses on microbial methanol utilisation in seawater. Doctoral thesis, University of East Anglia.

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Abstract

Methylotrophs are bacteria which utilise methanol and other one-carbon compounds for assimilative (growth) and dissimilative (energy) metabolism. Methylotrophy has been demonstrated by a large proportion of marine bacteria, influencing carbon cycling and is a significant sink of methanol in the marine environment. Viruses are understood to considerably influence biogeochemical cycles in the oceans, however the extent to which they influence methylotrophs and methanol cycling has remained unclear. Virus-like particles associated with a methanol-utilising methylotroph were isolated to this end and characterised using electron microscopy, indicating morphologies resembling enveloped viruses. A comprehensive seasonal survey in the Western Channel Observatory (WCO) combined virus abundance data with a taxonomic investigation of the microbial community; environmental variables; plankton abundance; bacterial production data and methanol uptake rates. The latter ranged between 0.1 – 10.6 nmol L-1 h-1 throughout the water column in the WCO with little depth variation. Seasonal trends were also consistent throughout the water column, with the highest uptake rates occurring during winter months. For the first time, seasonal virus abundance data was also determined with methanol uptake rates and bacterial production and showed a significant negative correlation with rates of methanol dissimilation. This could suggest that under high viral load bacteria are unable to utilise methanol as readily to meet their energy requirements. However, this reflects total virus abundance and not those that specifically infect methylotrophic bacteria. Furthermore, the diversity and distribution of a recently discovered alternate methanol dehydrogenase utilised by a portion of the methylotrophic community was explored. Sequencing of the xoxF5 gene was revealed to be highly conserved within the Rhodobacteraceae throughout the year in the WCO and was also the dominant associated bacterial group along a transect of the Atlantic. Future studies should focus on viruses specific to known methanol utilisers to understand their role in controlling marine methanol concentrations.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Environmental Sciences
Depositing User: Chris White
Date Deposited: 14 Apr 2021 12:23
Last Modified: 14 Apr 2021 12:23
URI: https://ueaeprints.uea.ac.uk/id/eprint/79748
DOI:

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