The biology of integrons and their role in bacterial adaptation. Bacteria evolve in ways that animals and plants do not. One of the tools available is the ability to share genes amongst individuals in a community. One example of this is the very rapid spread of antibiotic resistance genes in pathogens. Here we will be studying a genetic element that greatly contributes to this horizontal spread of genes. This will lead to a better understanding of how bacteria work, the direct benefits of whic ....The biology of integrons and their role in bacterial adaptation. Bacteria evolve in ways that animals and plants do not. One of the tools available is the ability to share genes amongst individuals in a community. One example of this is the very rapid spread of antibiotic resistance genes in pathogens. Here we will be studying a genetic element that greatly contributes to this horizontal spread of genes. This will lead to a better understanding of how bacteria work, the direct benefits of which includes the discovery of new pathways and genes for the biotechnology industry and greater understanding of how bacteria cause disease in us, other animals and in commercial crops.Read moreRead less
A functional genomic approach for understanding metal ion adaptation in marine cyanobacteria. Unicellular marine cyanobacteria constitute 20-40% of total marine chlorophyll biomass and carbon fixation, and hence significantly impact the global carbon cycle and are very relevant to combating global warming. This research will reveal some of the major mechanisms by which marine cyanobacteria have adapted to metal levels in coastal and oligotrophic environments. Thus these results will help us und ....A functional genomic approach for understanding metal ion adaptation in marine cyanobacteria. Unicellular marine cyanobacteria constitute 20-40% of total marine chlorophyll biomass and carbon fixation, and hence significantly impact the global carbon cycle and are very relevant to combating global warming. This research will reveal some of the major mechanisms by which marine cyanobacteria have adapted to metal levels in coastal and oligotrophic environments. Thus these results will help us understand the distribution and diversity of these organisms in relation to global primary productivity. They will also lead to the development of more robust biomarkers for metal stress and pollution in coastal environments.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
Safety in numbers: Bacterial aggregation and adaptation to oxidative stress. This project is a new collaboration which links two molecular microbiologists with the complementary skills required to make new insights into the molecular processes that underpin bacterial aggregation and biofilm formation. Biofilms are of immense significance in medical, industrial and environmental settings and so the fundamental information gained from this project will have wider relevance to the field of microbio ....Safety in numbers: Bacterial aggregation and adaptation to oxidative stress. This project is a new collaboration which links two molecular microbiologists with the complementary skills required to make new insights into the molecular processes that underpin bacterial aggregation and biofilm formation. Biofilms are of immense significance in medical, industrial and environmental settings and so the fundamental information gained from this project will have wider relevance to the field of microbiology. An outcome of this proposal will be fundamental knowledge about the production of surface adhesins that will form the basis for rational treatment of disease in the future. Prevention of aggregation and biofilm formation would make bacterial populations more susceptible to conventional antibiotic treatment.Read moreRead less
Competition or cooperation between marine biofilm bacteria recycling POM? Biofilms develop on any wetted surface by adhesion and subsequent growth of microorganisms. Recycling the energy, carbon and nitrogen contained in oceanic particulate organic matter (POM) is a global process essential for life on Earth. Ocean POM is degraded by its biofilm consortia, particularly bacteria secreting digestive enzymes. It is not known whether biofilm bacteria compete or cooperate in recycling POM. This proj ....Competition or cooperation between marine biofilm bacteria recycling POM? Biofilms develop on any wetted surface by adhesion and subsequent growth of microorganisms. Recycling the energy, carbon and nitrogen contained in oceanic particulate organic matter (POM) is a global process essential for life on Earth. Ocean POM is degraded by its biofilm consortia, particularly bacteria secreting digestive enzymes. It is not known whether biofilm bacteria compete or cooperate in recycling POM. This project combines microscopy image analysis, flow cytometry and molecular genetics to determine bacterial interactions quantitatively in mixed-species biofilms on natural POM. Results will increase knowledge of bacterial community functioning and biofilm recycling of POM in marine environments.Read moreRead less
Molecular mechanisms of pilin glycosylation in Neisseria: a model system for protein glycosylation in bacteria. The disease causing bacteria Neisseria meningitidis and Neisseria gonorrhoeae are important human pathogens. Cell surface structures, called pili, are known to be important in allowing the bacteria to stick to host cells. Genetic and structural studies have identified that the protein subunits, which make up pili, are glycosylated - modified by the addition of sugars. Until recently ....Molecular mechanisms of pilin glycosylation in Neisseria: a model system for protein glycosylation in bacteria. The disease causing bacteria Neisseria meningitidis and Neisseria gonorrhoeae are important human pathogens. Cell surface structures, called pili, are known to be important in allowing the bacteria to stick to host cells. Genetic and structural studies have identified that the protein subunits, which make up pili, are glycosylated - modified by the addition of sugars. Until recently glycosylation of Gram-negative bacterial proteins was not thought to occur, however our recent work with these bacteria, and other groups studying Pseudomonas and Campylobacter, have shown that this process may be widespread. In our previous studies, we have identified and analysed a number of genes involved in pili glycosylation, in bacteria, which make known sugar structures. We have used this information to developed models for how the biochemistry and physiology of the glycosylation system may work. With a well-established structure and many genes already identified, glycosylation in Neisseria represents the best available model system to study this novel and important process. In the proposed study we describe experiments planned to test our models and reveal the molecular detail of this process. This study could lead to major advances in our understanding of this process and, when understood, may have future applications in biotechnology.Read moreRead less
Bacterial filamentation as a survival strategy: a goldmine for the discovery of new cell division regulators. The increasing emergence of untreatable bacterial infections is a serious threat to the health of Australians. Medical advances (organ transplants, chemotherapy), increases in diabetes, and an aging population increase the risk of infections caused by bacteria that are now resistant to most available antibiotics. New classes of antibiotics are urgently needed to treat these infections. T ....Bacterial filamentation as a survival strategy: a goldmine for the discovery of new cell division regulators. The increasing emergence of untreatable bacterial infections is a serious threat to the health of Australians. Medical advances (organ transplants, chemotherapy), increases in diabetes, and an aging population increase the risk of infections caused by bacteria that are now resistant to most available antibiotics. New classes of antibiotics are urgently needed to treat these infections. This project uses a novel approach to identify the mechanisms bacterial cells use to control their growth and avoid attack by our immune system. The research will identify potential targets for the development of new, effective antibiotics to kill multi-resistant bacteria, and ensure Australia's position at the forefront of infection control.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
Nuclear structure and function in the nucleated planctomycete bacterium Gemmata obscuriglobus: a third cell plan for living organisms? The project will contribute knowledge of how cells such as those of animals and plants evolved from bacterial components. Origins of cell nuclei and pores in nuclear membranes will be studied via the simple eukaryote-like nucleus of the planctomycete Gemmata obscuriglobus, from Australian freshwater. Simple nuclear pore-like structures of G. obscuriglobus will he ....Nuclear structure and function in the nucleated planctomycete bacterium Gemmata obscuriglobus: a third cell plan for living organisms? The project will contribute knowledge of how cells such as those of animals and plants evolved from bacterial components. Origins of cell nuclei and pores in nuclear membranes will be studied via the simple eukaryote-like nucleus of the planctomycete Gemmata obscuriglobus, from Australian freshwater. Simple nuclear pore-like structures of G. obscuriglobus will help understanding nucleus function in animal cells, and such pores will give insight into 'minimal' composition needed for cell nuclei, and allow design of biological nanopores. The origin of the nucleus is a major problem in biology, and an Australian contribution to its solution will achieve international recognition. Read moreRead less
Biology and evolution of intracellular parasitism. This project will investigate the development of intracellular parasitism in environmental amoebae. The outcomes of this work will help to understand the mechanisms by which bacteria have evolved to survive inside cells and in some cases cause disease.