Bonnie Laverock

University of Technology Sydney | UTS · Faculty of Science

Research into the microbiomes of natural environments is changing the way ecologists and evolutionary biologists view the importance of microorganisms in ecosystem function. This is particularly relevant in ocean environments, where microorganisms constitute the majority of biomass and control most of the major biogeochemical cycles, including thos...

This review shows that the presence of seagrass microbial community is critical for the development of seagrasses; from seed germination, through to phytohormone production and enhanced nutrient availability, and defence against pathogens and saprophytes. The tight seagrass-bacterial relationship highlighted in this review supports the existence of...

Sediment microorganisms can have profound influence on productivity and functioning of marine ecosystems through their critical roles in regulating biogeochemical processes. However, the identity of sediment microorganisms that mediate organic matter turnover and nutrient cycling in seagrass sediments is only poorly understood. Here, we used metage...

Rarefaction plot of taxonomic profiles generated from seagrass sediments across Shark Bay.

Changes in relative abundance of functional genes (annotated with SEED Subsystems database, level 2) between seagrass sediments in high salinity sites (>46‰, sites 7 and 9, white) and low salinity sites (<46‰, gray). Only putative functions that were significantly different between higher and lower salinity sites are shown, with corrected P-values...

Changes in relative abundance of putative functions related to amino acids (annotated with SEED Subsystems database, level 3) between seagrass sediments (green) and microbial communities from other ecosystems (gray, Supplementary Table S4). Only putative functions that were significantly different are shown, with corrected P-values calculated using...

Summary of metagenomic sequencing results for Shark Bay sediments. Number of base pairs, sequencing reads, annotated proteins and % predicted using the SEED subsystem database after quality control on the MG-RAST pipeline.

Summary of metagenomes used to compare microbial communities in seagrass rhizosphere sediments to other ecosystems. All metagenomes are publicly available on the MG-RAST server.

DistLM results (Stepwise selection, sequential tests using corrected Akaike’s Information Criteria as selection criteria) of taxonomic community data (class level) against nine potential predictor variables (9999 premutations).

Summary of physical and biogeochemical data at each site. Depth, temperature, and salinity all averages over 5 CTD casts. Sediment organic matter, enzyme expressions, microbial P biomass, and seagrass P content are averages (n = 3 per site). DIP = dissolved inorganic phosphorus, BD = below detection.

DistLM results (marginal tests) of taxonomic community data (class level) against nine potential predictor variables (9999 premutations).

Like both terrestrial plants and other benthic marine organisms, seagrasses host abundant and diverse communities of microorganisms. These microbes fundamentally influence seagrass physiology and health, while also regulating the biogeochemical dynamics of entire seagrass meadows. Discrete populations of bacteria, fungi, microalgae, archaea and vir...

Microorganisms play a critical role in nitrogen cycling by mineralising dissolved organic nitrogen (DON) compounds into bioavailable inorganic forms (DIN). Although DIN is crucial for seagrass growth, the hypothesis that seagrass leaf associated-microorganisms could convert DON to forms available for plant uptake has never been tested. We conducted...

The marine environment of the Kimberley is a unique area characterised by a combination of extreme physical conditions and limited anthropogenic stressors. The Kimberley is part of only 4% of the world’s oceans that are classed as “pristine”(Halpern et al. 2008) due to very low population density (1 person per 12.5 km2). However, organisms growing...

Aims Seedling establishment is a crucial life history stage in seagrasses, yet factors that affect seedling health are poorly characterized. We investigated if organic matter (OM) additions to sediments provided nutritional benefits for seagrass seedlings through microbial degradation. Methods We tested the effects of sedimentary OM additions on P...

Ocean acidification influences sediment/water nitrogen fluxes, possibly by impacting on the microbial process of ammonia oxidation. To investigate this further, undisturbed sediment cores collected from Ny Alesund harbour (Svalbard) were incubated with seawater adjusted to CO2 concentrations of 380, 540, 760, 1,120 and 3,000 A mu atm. DNA and RNA w...

Effects of ocean acidification on the composition of the active bacterial and archaeal community within Arctic surface sediment was analysed in detail using 16S rRNA 454 pyrosequencing. Intact sediment cores were collected and exposed to one of five different pCO2 concentrations [380 (present day), 540, 750, 1120 and 3000 μatm] and RNA extracted af...

In marine environments, macrofauna living in or on the sediment surface may alter the structure, diversity and function of benthic microbial communities. In particular, microbial nitrogen (N)-cycling processes may be enhanced by the activity of large bioturbating organisms. Here, we study the effect of the burrowing mud shrimp Upogebia deltaura upo...

Fig. S1. Variation in monthly pelagic nutrient concentrations in Jennycliff Bay (5.3497 N, 04.1331 W) in the Western English Channel. (A) nitrite, (B) nitrate, (C) ammonium, (D) silicate, (E) phosphate. Inset legends show water depth in metres. Data are from the PML Benthic Survey Data Inventory (Woodward et al., 2013). (F) Variation in monthly tem...

Ocean acidification (OA), caused by the dissolution of increasing concentrations of atmospheric carbon dioxide (CO2) in sea water, is projected to cause significant changes to marine ecology and biogeochemistry. Potential impacts on the microbially-driven cycling of nitrogen are of particular concern. Specifically, under seawater pH levels approxim...

Ocean acidification (OA), caused by the dissolution of increasing concentrations of atmospheric carbon dioxide (CO2) in seawater, is projected to cause significant changes to marine ecology and biogeochemistry. Potential impacts on the microbially driven cycling of nitrogen are of particular concern. Specifically, under seawater pH levels approxima...

There is an increasing need to predict the effects of global climate change on ecologically important marine organisms and a demand for proactive solutions to reduce CO2 emissions. CO2 sequestration is one such method. While this offers a practical solution, recognition should be given to the potential for considerable localised effects on marine o...

There is an increasing need to predict the effects of global climate change on ecologically-important marine organisms and demand for proactive solutions to reduce CO2 emissions. CO2 sequestration is one such method. While this offers a practical solution, recognition should be given to the potential for considerable localised impacts on marine...

Ammonia oxidation is a key microbial process within the marine N-cycle. Sediment and water column samples from two contrasting sites in the English Channel (mud and sand) were incubated (up to 14 weeks) in CO2-acidified seawater ranging from pH 8.0 to pH 6.1. Additional observations were made off the island of Ischia (Mediterranean Sea), a natural...

Metagenomics has evolved over the last 3 decades from the analysis of single genes and their apparent diversity in an ecosystem to the provision of complex genetic information relating to whole ecosystems. Metagenomics is a vast subject area in terms of methodology, which encompasses a suite of molecular technologies employed to investigate genomic...

Sediments play a key role in the marine nitrogen cycle and can act either as a source or a sink of biologically available (fixed) nitrogen. This cycling is driven by a number of microbial remineralization reactions, many of which occur across the oxic/anoxic interface near the sediment surface. The presence and activity of large burrowing macrofaun...

Ocean acidification influences sediment/water nitrogen fluxes, possibly by impacting on the microbial process of ammonia oxidation. To investigate this further, undisturbed sediment cores collected from Ny Alesund harbour (Svalbard) were incubated with seawater adjusted to CO2 concentrations of 380, 540, 760, 1,120 and 3,000 µatm. DNA and RNA were...

Bioturbation is a key process in coastal sediments, influencing microbially driven cycling of nutrients as well as the physical characteristics of the sediment. However, little is known about the distribution, diversity and function of the microbial communities that inhabit the burrows of infaunal macroorganisms. In this study, terminal-restriction...