Cathryn O'Sullivan

The Commonwealth Scientific and Industrial Research Organisation | CSIRO · Division of Plant Industry

Membrane technologies are increasingly sought to provide solutions for processes in industrial and municipal wastewater management, manufacturing, and intensified agriculture systems that were traditionally met through natural ecosystem services provided by plants and microbes in lower-intensity systems. Services like water filtration and nutrient...

Published in 'Farm Policy Journal' ISSN: 1449-2210. Available at: https://acrobat.adobe.com/link/review?uri=urn:aaid:scds:US:fa0598de-5e83-4bf9-bd47-cff3fe3ec8d4. Circular economy (CE) and bioeconomy (BE) are overlapping concepts that are receiving attention across various levels of government, industry, and academia. Interest is driven in pursuit...

Anaerobic methanogenesis is dependent on key macronutrients (carbon, nitrogen and phosphorus) and trace metals (including iron, nickel and cobalt) to drive methane production. Reservoir derived methane emissions have correlated to eutrophication status, with elevated emissions associated with more eutrophic systems. Additionally, sediment organic m...

Streptomyces are soil-borne Actinobacteria known to produce a wide range of enzymes, phytohormones, and metabolites including antifungal compounds, making these microbes fitting for use as biocontrol agents in agriculture. In this study, a plant reporter gene construct comprising the biotic stress-responsive glutathione S-transferase promoter GSTF7...

Phytopathogenic members of the Sclerotinia genus cause widespread disease across a broad range of economically important crops. In particular, Sclerotinia sclerotiorum is considered one of the most destructive and cosmopolitan of plant pathogens. Here, were review the epidemiology of the pathogen, its economic impact on agricultural production, and...

Crown rot of wheat, caused by Fusarium pseudograminearum, results in millions of dollars of yield losses globally each year. Management strategies to control crown rot are limited and there are concerns about development of fungicide resistance so novel treatment strategies are desirable. A collection of endophytic Actinobacteria was screened for t...

Engineering perishable crops for use in indoor farms promises to expand the adoption of this high-yielding, efficient means of food production.

The FAO estimates that more than 800 million people engage in urban agriculture producing more than 15% of the world’s food. Recently, there has been a resurgence of interest in urban agriculture in many wealthy, developed cities, with new technology and agro-architecture being employed to grow food in cities at commercial scale. This has been acco...

The Food and Agriculture Organization estimates that more than 800 million people engage in urban agriculture producing more than 15% of the world's food. Recently, there has been a resurgence of interest in urban agriculture in many wealthy, developed cities, with new technology and agro-architecture being employed to grow food in cities at commer...

The efficient capture and utilisation of fertiliser nitrogen (N) by cereals has implications for crop growth, grain yield, farm profits, the environment and human nutrition. Extensive research has evaluated many innovative ways to improve the efficiency of fertiliser N recovery (N use efficiency; NUE) by wheat (Triticum aestivum). This review paper...

We report here the draft genome sequences, annotations, and predictions of secondary metabolite gene clusters of two endophytic Streptomyces species isolated from wheat plants growing in the Western Australian wheat belt. These strains, Streptomyces sp. strains MH60 and 111WW2, possess antifungal and/or plant growth-promoting activities.

Balanced applications of nitrogen (N), phosphorus (P), and potassium (K) are known to increase grain yield of wheat but the impact of the interactions among N, P, and K on root growth and nitrogen use efficiency (NUE) have not been proven. The aim of this study was to investigate the effect of balanced applications of N, P, and K on the rooting pat...

We report here the draft genome sequence and annotation of Rhodococcus sp. strain 66b isolated from the soil of southwest Western Australia. This strain exhibits a range of bioactivities, including plant growth promotion, biosurfactant production, and wax degradation. Whole-genome sequencing was conducted to uncover the underlying mechanisms.

Sclerotinia sclerotiorum is an important fungal pathogen of canola, for which limited host resistance or tolerance has been identified. Several robust seedling-based S. sclerotiorum disease assays have been developed for germplasm screening, but there is no non-destructive, reliable and routine assay for screening mature, flowering canola plants at...

AimA simple, rapid, colourimetric method for screening biological nitrification inhibitors in plants is presented. Methods Our approach combines the use of the Griess assay to track the rate of nitrite (NO2−) production by pure cultures of ammonia oxidising bacteria in the presence and absence of nitrification inhibitors with a simple method for co...

This study investigated the ability of several plant species commonly occurring as weeds in Australian cropping systems to produce root exudates that inhibit nitrification via biological nitrification inhibition (BNI). Seedlings of wild radish (Raphanus raphanistrum), great brome grass (Bromus diandrus), wild oats (Avena fatua), annual ryegrass (Lo...

Nitrification inhibitors (NIs) such as 3,4,-dimethylpyrazole phosphate (DMPP), are used to suppress the abundance of ammonia-oxidising micro-organisms responsible for nitrification. In agriculture, NIs are used to retain soil mineral nitrogen (N) as ammonium to minimise the risk of losses of N from agricultural soils. It is currently unclear whethe...

Improving the nitrogen (N) uptake efficiency (NUpE) of wheat has the potential to offer significant economic gains to growers and improvement in environmental quality. One way to improve NUpE may be by matching wheat genotypes which have greater uptake efficiency for NH 4 + or NO 3-to soil types that favour the production of one of these N forms ov...

This study investigated whether applying dicyandiamide (DCD) and guanyl thiourea (GTU) in conjunction with urea improves the efficacy of nitrification inhibition relative to traditional fertiliser application of urea or urea + DCD. Urea at a rate of 100 mg N kg−1 soil was applied to soil microcosms (high nutrient tenosol and low nutrient hydrosol)...

This study investigated whether selenium species in wheat grains could be altered by exposure to different combinations of nitrogen (N) and sulphur (S) fertilisers in an agronomic biofortification experiment. Four Australian wheat cultivars (Mace, Janz, Emu Rock and Magenta) were grown in a glasshouse experiment and exposed to 3 mg Se kg−1 soil as...

Background and aims Nitrification is the first step in several pathways that lead to losses of nitrogen from agricultural systems. Biological nitrification inhibition (BNI) refers to the ability of some plant species to release chemicals from their roots that inhibit microbial ammonia oxidation thereby decreasing nitrification rates. BNI has been f...

Bio-hydrogen production from mixed culture fermentation (MCF) of glucose was studied by conducting a comprehensive product measurement and detailed mass balance analysis of their contributions to the final H2 yield. The culture used in this study was enriched on glucose at 60 °C through a sequential batch operation consisting of daily glucose feeds...

Eight wheat cultivars were grown in soil amended with arsenate (AsV) at a concentration of 15 mg As kg−1 soil, with or without a triple super phosphate amendment of 40 mg P kg−1 soil. All eight wheat cultivars accumulated higher As in stems/leaves (9–23 μg As g−1) and chaff (9–22 μg As g−1) compared with the grain (0.6–1.6 μg As g−1). The As presen...

The effectiveness of the nitrification inhibitor 3,4,-dimethylpyrazole phosphate (DMPP) on sandy soils containing low nitrifying microbial abundance has not been established. Two coarse-grained soils, representative of Western Australia's agricultural zones, were incubated with 100mgNkg-1 soil, added as either urea, urea+DMPP or urea+nitrapyrin as...

It is well established that metabolic pathways in the fermentation of organic waste are primarily controlled by dissolved H2 concentrations, but there is no reported study that compares observed and predicted shifts in fermentation pathways induced by manipulating the dissolved H2 concentration. A perfusion system is presented that was developed to...

Aims Identification of soil, environmental, or microbial properties linked with efficacy of the nitrification inhibitor dicyandiamide (DCD) in high and low-input pastoral farming system soils. Methods Soils were collected from under 25 pastures. Potential nitrification rate (PRN) was quantified in the presence and absence of DCD, and percentage ef...

Sampling locations and soil groups of samples collected for the DCD inhibition assay. Samples in blue are taken from dairy farms, samples in red are from sheep, sheep & beef or beef farms (i.e. ‘other’ land-use). Soil groups are given

Ammonia-oxidising archaea (AOA) have recently been described as having an important role in soil nitrification. However, published data on factors which influence their distribution and their impact on a soil's potential nitrification rates (PNR) are sparse, particularly compared with the amount of information available regarding ammonia-oxidising...

Anaerobic digestion is a viable on-site treatment technology for rich organic waste streams such as food waste and blackwater. In contrast to large-scale municipal wastewater treatment plants which are typically located away from the community, the effluent from any type of on-site system is a potential pathogenic hazard because of the intimacy of...

The abundances of ammonia-oxidising archaea (AOA) and ammonia-oxidising bacteria (AOB) in soils underlying pastures in the south-west of Western Australia (WA) were investigated. Samples were collected from irrigated pastures and one unmanaged (driveway) area during December 2009. Archaeal and bacterial ammonia monooxygenase (amoA) genes were quant...

Export Date: 18 May 2013, Source: Scopus

The aim of this study was to explore the potential of three aquatic weeds, water hyacinth, cabomba, and salvinia, as substrates for anaerobic digestion. A set of four pilot-scale, batch digestions were undertaken to assess the yield and quality (% methane) of biogas from each plant species, and the rate of degradation. A set of 56 small-scale (100...

This paper explores the potential for advanced membranes to act as a sink for hydrogen generated during anaerobic digestion thereby maintaining very low hydrogen concentrations and more favorable conditions for fermentative and possibly acetate oxidative pathways. This necessitates that the membranes function when submerged in water.Permeation of h...

A systematic study on the anaerobic degradability of a series of starch:polyvinyl alcohol (TPS:PVOH) blends was performed to determine their fate upon disposal in either anaerobic digesters or bioreactor landfills. The aims of the study were to measure the rate and extent of solubilisation of the plastics. The extent of substrate solubilisation on...

In this study, a flat plate flowcell was modified to provide a reactor system that could maintain anaerobic, cellulolytic biofilms while providing the data needed to carry out a chemical oxygen demand mass balance to determine the cellulose digestion rates. The results showed that biofilms could be observed to grow and develop on cellulose particle...

The aim of this work was to compare the impact of inoculation density on the rate of cellulose hydrolysis by a rumen derived culture with that of a microbial enrichment from an organic waste anaerobic digester. The results showed a linear relationship between the mass of biomass at the start of the first order degradation phase (Xo) and the first o...

The utility of fluorescence in situ hybridization (FISH) for detecting uncultured micro-organisms in environmental samples has been shown in numerous habitats. In this study a suite of three FISH probes for cellulolytic bacteria is described and their efficacy is demonstrated by quantifying the relative abundance of the target micro-organisms in a...

The aim of this study was to investigate the effect of rumen fluid and leachate-based media on the ability of rumen and anaerobic digester derived microorganisms to degrade cellulose. The results demonstrated that rumen microorganisms are not capable of solubilising cellulose, or generating biomass, at an optimal rate when grown in leachate-based m...

The aim of this study was to conduct a number of controlled digestions to obtain easily comparable cellulose solubilisation rates and to compare these rates to those found in the literature to see which operational differences were significant in affecting cellulose degradation during anaerobic digestion. The results suggested that differences in v...

It is widely accepted that cellulose is the rate-limiting substrate in the anaerobic digestion of organic solid wastes and that cellulose solubilisation is largely mediated by surface attached bacteria. However, little is known about the identity or the ecophysiology of cellulolytic microorganisms from landfills and anaerobic digesters. The aim of...

Fisherman Islands is an area of reclaimed land at the mouth of the Brisbane River in Queensland, Australia. Ongoing groundwater monitoring has found elevated concentrations of hydrogen sulfide (H2S) in the groundwater on the island. The presence of H2S on Fisherman Islands is of concern because of its toxic nature, the potential for acid sulfate so...

An anaerobic landfill leachate bioreactor was operated with crystalline cellulose and sterile landfill leachate until a steady state was reached. Cellulose hydrolysis, acidogenesis, and methanogenesis were measured. Microorganisms attached to the cellulose surfaces were hypothesized to be the cellulose hydrolyzers. 16S rRNA gene clone libraries wer...

Hydrogen is a renewable pollution-free energy carrier, but its production is relying heavily on technologies such as coal gasification and steam reforming of non-renewable resources. Anaerobic digestion of organic wastes can produce hydrogen without renewable resources. In order to maximise the hydrogen yield during digestion, hydrogen must be remo...