Amplicon pyrosequencing reveals spatial and temporal consistency in diazotroph assemblages of the Acropora millepora microbiome. (28th January 2014)

• Record Type: Journal Article
• Authors: Lema, Kimberley A.; Willis, Bette L.; Bourne, David G.
• Is Part Of: Environmental microbiology. Volume 16:Number 10(2014:Oct.)
• Page Start: 3345
• Page End: 3359
• Publication Date: 2014-01-28
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; 579.17
• DOI: 10.1111/1462-2920.12366
• Languages: English
• ISSNs: 1462-2912

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Diazotrophic bacteria potentially play an important functional role in supplying fixed nitrogen to the coral holobiont, but the value of such a partnership depends on the stability of the association. Here we evaluate the composition of diazotroph assemblages associated with the coral <italic>A</italic><italic>cropora</italic><italic> millepora</italic> throughout four seasons and at two reefs, an inshore and an offshore (mid‐shelf) reef on the Great Barrier Reef, Australia. Amplicon pyrosequencing of the <italic>nifH</italic> gene revealed that diazotrophs are ubiquitous members of the bacterial community associated with <italic>A</italic><italic>. millepora</italic>. Rhizobia (65% of the overall <italic>nifH</italic> sequences retrieved) and particularly <italic>B</italic><italic>radyrhizobia</italic> sp<italic>.‐</italic>affiliated sequences (> 50% of rhizobia sequences) dominated diazotrophic assemblages across all coral samples from the two sites throughout the year. In contrast to this consistency in the spatial and temporal patterns of occurrence of diazotroph assemblages, the overall coral‐associated bacterial community, assessed through amplicon sequencing of the general bacterial 16S ribosomal RNA gene, differed between inshore and mid‐shelf reef locations. Sequences associated with the <italic>O</italic><italic>ceanospirillales</italic> family, particularly with <italic>E</italic><italic>ndozoicomonas</italic> sp., dominated bacterial communities associated with inshore corals. Although rhizobia represented a variable and generally small fraction of the overall bacterial community associated with <italic>A</italic>. <italic>millepora</italic>, consistency in the structure of these diazotrophic assemblages suggests that they have a functional role in the coral holobiont.</p> </abstract>