The effect of environmental factors on the dynamics of bacterial populations associated with coral colonies and the implications for holobiont health
type: CreativeWork
description: The coral holobiont is comprised of a diverse community of microbial partners, including bacteria living within microhabitats, such as the coral tissue’s and surface mucus layer (SML). However, little is known about the interactions between the bacterial communities in the various compartments of the coral holobiont. Furthermore, although we know that water flow can serve as an ameliorator of thermal stress in corals, there is a lack of information about how water flow affects the bacterial community structure during stressful times. Research described in this thesis aimed to understand, using laboratory and in situ experiments, the interaction between the coral host and bacterial communities in the tissues and SML, as well as how water flow affects the bacterial community structure when the coral is under thermal stress. The bacterial community structure in thermally-stressed individuals of the coral Acropora muricata highlighted the potential for a bacterial community shift between the coral surface mucus and tissues. Nubbins of A. muricata were subjected to increasing water temperatures of 26°C to 33°C, to explore the bacterial diversity in the SML and tissues by 16S rRNA gene amplicon sequencing. Photochemical efficiency (FV/Fm) of symbiotic dinoflagellates within the corals declined above 31°C, suggesting that the corals were under thermal stress. Both the mucus and tissues of healthy A. muricata were dominated by γ-Proteobacteria, but under thermal stress there was a shift towards bacteria from the classes Verrucomicrobiaceae and α- Proteobacteria. Members of the classes Cyanobacteria, Flavobacteria and Sphingobacteria also started to become more prominent at higher temperatures. The relative abundance of sequences affiliated with Vibrio spp. in the coral mucus increased at 29°C, but at 31°C there was a drop in the relative abundance of Vibrio spp. in the mucus, with a reciprocal increase of Vibrio spp. in the tissues. In contrast, during bleaching, the relati…
abstract: The coral holobiont is comprised of a diverse community of microbial partners, including bacteria living within microhabitats, such as the coral tissue’s and surface mucus layer (SML). However, little is known about the interactions between the bacterial communities in the various compartments of the coral holobiont. Furthermore, although we know that water flow can serve as an ameliorator of thermal stress in corals, there is a lack of information about how water flow affects the bacterial community structure during stressful times. Research described in this thesis aimed to understand, using laboratory and in situ experiments, the interaction between the coral host and bacterial communities in the tissues and SML, as well as how water flow affects the bacterial community structure when the coral is under thermal stress. The bacterial community structure in thermally-stressed individuals of the coral Acropora muricata highlighted the potential for a bacterial community shift between the coral surface mucus and tissues. Nubbins of A. muricata were subjected to increasing water temperatures of 26°C to 33°C, to explore the bacterial diversity in the SML and tissues by 16S rRNA gene amplicon sequencing. Photochemical efficiency (FV/Fm) of symbiotic dinoflagellates within the corals declined above 31°C, suggesting that the corals were under thermal stress. Both the mucus and tissues of healthy A. muricata were dominated by γ-Proteobacteria, but under thermal stress there was a shift towards bacteria from the classes Verrucomicrobiaceae and α- Proteobacteria. Members of the classes Cyanobacteria, Flavobacteria and Sphingobacteria also started to become more prominent at higher temperatures. The relative abundance of sequences affiliated with Vibrio spp. in the coral mucus increased at 29°C, but at 31°C there was a drop in the relative abundance of Vibrio spp. in the mucus, with a reciprocal increase of Vibrio spp. in the tissues. In contrast, during bleaching, the relati…
author: Lee, Tuan
license: https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm
date published: 2015
date modified: 2026-07-24T01:07:07Z
provider: University of Auckland
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: ResearchSpace@Auckland

PropertyValue
property ID: Handle
value: https://hdl.handle.net/2292/28343