Targeted isolation of specific marine bacterial species associated with higher organsims for the purpose of discovering new antimicrobial compounds. Specific bacterial species that are commonly found in association with marine plants and animals often produce active secondary metabolites. The aim of this project is to apply our understanding of these bacterial-host associations to the targeted isolation of novel antimicrobials from the marine environment. While these new compounds will undoubted ....Targeted isolation of specific marine bacterial species associated with higher organsims for the purpose of discovering new antimicrobial compounds. Specific bacterial species that are commonly found in association with marine plants and animals often produce active secondary metabolites. The aim of this project is to apply our understanding of these bacterial-host associations to the targeted isolation of novel antimicrobials from the marine environment. While these new compounds will undoubtedly have a number of commercial applications this project focuses on the development of products for dental hygiene in animals. Generally, the urgent need for new antimicrobial compounds to combat the growing number of microbes that are resistant to current antibiotics highlights the importance of this project.Read moreRead less
Investigating pathways of lipoglycan formation in the bacterial cell wall. This project aims to investigate how the complex cell walls of Mycobacteria and Corynebacteria are assembled. The project will utilise a combination of genetic, biochemical and advanced analytical approaches to investigate individual steps in the synthesis of key cell wall components and understand how the assembly of these components is coordinated with bacterial growth. Important outcomes of this research will be detail ....Investigating pathways of lipoglycan formation in the bacterial cell wall. This project aims to investigate how the complex cell walls of Mycobacteria and Corynebacteria are assembled. The project will utilise a combination of genetic, biochemical and advanced analytical approaches to investigate individual steps in the synthesis of key cell wall components and understand how the assembly of these components is coordinated with bacterial growth. Important outcomes of this research will be detailed information on processes that regulate the growth of bacteria with important biotechnology, veterinary and medical significance, as well as information on mechanisms of cell wall synthesis that may be conserved in all bacteria.Read moreRead less
The host specificity of bacterial pathogens. The vast majority of microorganisms that cause diseases in animals are host specific. In other words, they cause disease exclusively in a particular animal species, but are harmless for others. Despite considerable recent advances in our understanding of the mechanisms used by microorganisms in general to cause disease, in most cases the underlying basis of host-specificity is not known. In this project, we will use two animal pathogens, rabbit-spe ....The host specificity of bacterial pathogens. The vast majority of microorganisms that cause diseases in animals are host specific. In other words, they cause disease exclusively in a particular animal species, but are harmless for others. Despite considerable recent advances in our understanding of the mechanisms used by microorganisms in general to cause disease, in most cases the underlying basis of host-specificity is not known. In this project, we will use two animal pathogens, rabbit-specific enteropathogenic E. coli and the closely related bacterium, Citrobacter rodentium, which specifically infect rabbits and mice respectively, to investigate the molecular basis of host specificity.Read moreRead less
Identifying Novel Biosynthetic Pathways in Mycobacteria using DNA Microarray Technology. DNA microarrays are a powerful new bioinformatics-based technology and an ideal tool for characterising complex biosynthetic pathways since the expression of all genes in the bacterial genome can be monitored in a single experiment. In this project we aim to construct and use a DNA microarray to identify novel biosynthetic pathways in mycobacteria. Of particular interest are pathways used to create compone ....Identifying Novel Biosynthetic Pathways in Mycobacteria using DNA Microarray Technology. DNA microarrays are a powerful new bioinformatics-based technology and an ideal tool for characterising complex biosynthetic pathways since the expression of all genes in the bacterial genome can be monitored in a single experiment. In this project we aim to construct and use a DNA microarray to identify novel biosynthetic pathways in mycobacteria. Of particular interest are pathways used to create components of the highly complex and poorly characterised cell wall. Since this structure is unique in the bacterial world, we expect to identify and characterise pathways that are unique to mycobacteria.Read moreRead less
Novel mechanisms of bacterial arsenic metabolism - arsenate reduction and arsenite oxidation. Novel arsenic metabolising bacteria (i.e., arsenate respiring and arsenite oxidising), which are both phylogenetically and physiologically unique, have been isolated from arsenic-contaminated areas in Australia. The arsenate respiring bacterium, Chrysiogenes arsenatis, is of particular interest as it is the only organism reported able to respire with arsenate using the respiratory substrate acetate as t ....Novel mechanisms of bacterial arsenic metabolism - arsenate reduction and arsenite oxidation. Novel arsenic metabolising bacteria (i.e., arsenate respiring and arsenite oxidising), which are both phylogenetically and physiologically unique, have been isolated from arsenic-contaminated areas in Australia. The arsenate respiring bacterium, Chrysiogenes arsenatis, is of particular interest as it is the only organism reported able to respire with arsenate using the respiratory substrate acetate as the electron donor. It is proposed that physiological, biochemical and molecular biological studies be carried out to better understand the mechanisms by which these organisms metabolise arsenic. The knowledge gained from these studies will have worldwide application in the development of an arsenic bioremediation system.Read moreRead less
Cultivating numerically significant soil bacteria. The vast majority of soil bacteria have not been able to be studied in the laboratory because they cannot be grown outside the soil. They are therefore termed unculturable. Most of these belong to groups that are completely unstudied. Advances made in the Janssen lab have overcome this impediment to laboratory cultivation of numerically abundant and globally distributed soil bacteria. This project will develop these advances to generate simple a ....Cultivating numerically significant soil bacteria. The vast majority of soil bacteria have not been able to be studied in the laboratory because they cannot be grown outside the soil. They are therefore termed unculturable. Most of these belong to groups that are completely unstudied. Advances made in the Janssen lab have overcome this impediment to laboratory cultivation of numerically abundant and globally distributed soil bacteria. This project will develop these advances to generate simple and widely applicable methods to enable many of the previously unculturable soil bacteria to be studied. This will allow assessments of their ecological roles and biotechnological potentials to be made.Read moreRead less
Unravelling small RNA regulatory networks to target and control bacteria. Small RNA (sRNA) molecules are critical regulators of bacterial gene expression. These molecules control important phenotypes in the Gram-negative veterinary pathogen Pasteurella multocida. This project aims to identify the range of P. multocida sRNAs and to show how expression of these molecules changes under various growth conditions. Specifically, this project endeavours: to identify the mRNA targets of the sRNAs; to id ....Unravelling small RNA regulatory networks to target and control bacteria. Small RNA (sRNA) molecules are critical regulators of bacterial gene expression. These molecules control important phenotypes in the Gram-negative veterinary pathogen Pasteurella multocida. This project aims to identify the range of P. multocida sRNAs and to show how expression of these molecules changes under various growth conditions. Specifically, this project endeavours: to identify the mRNA targets of the sRNAs; to identify the mechanisms of sRNA-mRNA interaction; to build systems-biology models that describe the sRNA regulatory circuits; to design inhibitors capable of disrupting critical sRNA-mRNA interactions; and to use the new inhibitors to modulate specific phenotypes. The ability to precisely manipulate sRNA regulatory circuits could allow fine control of bacterial phenotypes and could be widely applicable.Read moreRead less
Host cell targets of bacterial virulence effectors. The research described in this proposal will result in a better understanding of the cell biology of host-pathogen interactions. We are in a unique position to analyze the importance of protein/protein interactions between bacterial virulence determinants and host cell proteins using a range of cell biology techniques to address the fundamental, molecular basis of the host-pathogen interaction. In addition we will construct a new genetic tool ....Host cell targets of bacterial virulence effectors. The research described in this proposal will result in a better understanding of the cell biology of host-pathogen interactions. We are in a unique position to analyze the importance of protein/protein interactions between bacterial virulence determinants and host cell proteins using a range of cell biology techniques to address the fundamental, molecular basis of the host-pathogen interaction. In addition we will construct a new genetic tool to identify novel bacterial virulence determinants. We anticipate that a greater knowledge of the factors that contribute to the host-pathogen interaction will provide new insights into the subversion of host cell processes by bacterial pathogens of animals, plants and humans.
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Disulfide catalysis and protein folding in bacterial virulence. The molecular mechanisms that underpin disulfide bond formation have had a major impact on our understanding of protein folding and function. This project will make a major contribution to fundamental areas of disulfide catalysis pathways in bacterial pathogens and thus help maintain a strong international profile for Australian research in this field. The work will lead to training of research scientists and students in techniques ....Disulfide catalysis and protein folding in bacterial virulence. The molecular mechanisms that underpin disulfide bond formation have had a major impact on our understanding of protein folding and function. This project will make a major contribution to fundamental areas of disulfide catalysis pathways in bacterial pathogens and thus help maintain a strong international profile for Australian research in this field. The work will lead to training of research scientists and students in techniques that include molecular genetics, protein biochemistry and structural biology. Our findings may impact future directions for vaccine research on pathogens that cause life threatening infections in humans and therefore lead to improved health and reduced health care expenditure.Read moreRead less
A microscopical examination of curdlan production by an Agrobacterium sp. We will investigate the secretion of the insoluble polysaccharide curdlan, a (1,3)-beta-glucan, from the surfaces of Agrobacterium cells and the assembly of the individual polysaccharide chains into microfibrils. Using state-of-the-art techniques in time lapse and electron microscopy we will compare the images of wild type curdlan-producing cells with those of mutants impaired in the production of curdlan. The outputs will ....A microscopical examination of curdlan production by an Agrobacterium sp. We will investigate the secretion of the insoluble polysaccharide curdlan, a (1,3)-beta-glucan, from the surfaces of Agrobacterium cells and the assembly of the individual polysaccharide chains into microfibrils. Using state-of-the-art techniques in time lapse and electron microscopy we will compare the images of wild type curdlan-producing cells with those of mutants impaired in the production of curdlan. The outputs will be information on the mechanics of curdlan production that will complement that emerging from our molecular biological and biochemical studies. These will have implications for understanding bacterial polysaccharide production in general and may have a commercial outcome in enhanced curdlan production.Read moreRead less