An Exploration of Cell Death and Lysis in an Alkaliphilic Cyanobacterial Consortium using Multi-'Omics Approaches

Khot, Varada Milind

An Exploration of Cell Death and Lysis in an Alkaliphilic Cyanobacterial Consortium using Multi-'Omics Approaches

dc.contributor.advisor	Strous, Marc
dc.contributor.author	Khot, Varada Milind
dc.contributor.committeemember	Hynes, Michael Francis
dc.contributor.committeemember	de Koning, Jason
dc.contributor.committeemember	Ryan, Cathryn
dc.contributor.committeemember	Petersen, Jillian
dc.date	2024-02
dc.date.accessioned	2023-12-05T22:56:10Z
dc.date.available	2023-12-05T22:56:10Z
dc.date.issued	2023-12-01
dc.description.abstract	Cyanobacteria are important primary producers in many ecosystems, converting light into chemical energy. Their death plays a vital role in releasing organic carbon and nitrogen into the environment, supporting the life of other, heterotrophic organisms, and facilitating carbon sequestration in sediments. With warming aquatic systems, algal blooms are becoming more frequent, persistent, and larger in size, highlighting the need to understand the mechanisms of their death. Cyanobacterial death, whether via viral predation or other mechanisms such as programmed cell death, remains an underexplored topic in non-marine aquatic ecosystems. In this thesis, cell lysis and death of an alkaliphilic Cyanobacterium, Candidatus Sodalinema alkaliphilum, is explored primarily from the perspective of viral infections. Ca. Sodalinema alkaliphilum was enriched, along with its associated heterotrophic microbial community, from alkaline soda lakes on Cariboo Plateau in British Columbia, Canada. This robust cyanobacterial consortium has also been the focus of biotechnological research aimed at producing sustainable bioproducts. Robustness of this consortium can be defined as its capacity to maintain phototrophic function in spite of (a)biotic disturbances. First, bioinformatic techniques to investigate the viral ecology and dynamics of microbial communities in silico were reviewed in Chapter 2. These included identifying viral sequences, classifying their taxonomy, performing phylogenomic analyses, and predicting their hosts. Methods from Chapter 2 were subsequently applied to characterize viral populations in the alkaliphilic cyanobacterial consortium and to investigate viral dynamics by comparing bacterial defence mechanisms across multiple years. This study was the first metagenomic survey of viruses in an alkaliphilic phototrophic consortium and provided valuable insight into the viral ecology of a phototrophic enrichment culture. Finally, based on findings from Chapter 3, the same cyanobacterial consortium was challenged with threats from its natural environment, the alkaline soda lakes. In Chapter 4, the trigger and mechanism of a sudden and rapid cell lysis of the Ca. Sodalinema alkaliphilum was explored using metagenomic, metatranscriptomics analysis, and transmission electron microscopy. This work enhanced our understanding of viral dynamics within an alkaliphilic phototrophic microbial community and highlighted the complexity of cell death in the natural environment.
dc.identifier.citation	Khot, V. M. (2023). An exploration of cell death and lysis in an alkaliphilic cyanobacterial consortium using multi-'omics approaches (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	https://hdl.handle.net/1880/117616
dc.identifier.uri	https://doi.org/10.11575/PRISM/42459
dc.language.iso	en
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject.classification	Microbiology
dc.subject.classification	Bioinformatics
dc.subject.classification	Biogeochemistry
dc.subject.classification	Virology
dc.title	An Exploration of Cell Death and Lysis in an Alkaliphilic Cyanobacterial Consortium using Multi-'Omics Approaches
dc.type	doctoral thesis
thesis.degree.discipline	Geoscience
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.thesis.accesssetbystudent	I do not require a thesis withhold – my thesis will have open access and can be viewed and downloaded publicly as soon as possible.