Synthesis and assembly of bacterial repeat unit polysaccharides. Bacteria make an enormous range of surface polysaccharides. The complexity was first appreciated as antigenic diversity, but we now have hundreds of chemical structures and perhaps a hundred sequences of their gene clusters, but the number in nature must be many thousands. Our knowledge of gene function is growing but is not keeping up with the discovery of new sequences and structures. The aim is to determine structure and functio ....Synthesis and assembly of bacterial repeat unit polysaccharides. Bacteria make an enormous range of surface polysaccharides. The complexity was first appreciated as antigenic diversity, but we now have hundreds of chemical structures and perhaps a hundred sequences of their gene clusters, but the number in nature must be many thousands. Our knowledge of gene function is growing but is not keeping up with the discovery of new sequences and structures. The aim is to determine structure and function of key O antigen processing genes and the functions of a range of glycosyl transferases, and to use the information to generate novel gene clusters to synthesise novel polysaccharidesRead moreRead less
Elucidation of bacterial glycosylytransferase specificity. The benefits are involvement in the growth area of polysaccharide research, with potential for major industrial spin off. Polysaccharides are critical in all organisms as signalling, structural and storage compounds. Bacteria make a wide variety with extensive use of unusual sugars, some with uses from oil emulsifiers to food thickeners. The project is on the enzymes that assemble bacterial polysaccharides. We are world leaders in genet ....Elucidation of bacterial glycosylytransferase specificity. The benefits are involvement in the growth area of polysaccharide research, with potential for major industrial spin off. Polysaccharides are critical in all organisms as signalling, structural and storage compounds. Bacteria make a wide variety with extensive use of unusual sugars, some with uses from oil emulsifiers to food thickeners. The project is on the enzymes that assemble bacterial polysaccharides. We are world leaders in genetics of the gene clusters especially synthesis of the unusual sugars. We now aim to fill a major gap by determining which enzymes make which bonds, leading to options for new gene combinations and novel structures. We have a lead in research in this area and Australia gains if we maintain that lead.Read moreRead less
Bacterial innovation and evolution: Molecular prospecting by targeting integrons and gene cassettes. Bacteria can respond rapidly to environmental change by acquiring new genes via lateral gene transfer. A DNA element called the integron can capture, mobilise and express genes, thereby playing a role in the transfer process. We have discovered that integrons are surprisingly abundant in the environment and are associated with a hitherto unsuspected diversity of novel genes. In this study we will ....Bacterial innovation and evolution: Molecular prospecting by targeting integrons and gene cassettes. Bacteria can respond rapidly to environmental change by acquiring new genes via lateral gene transfer. A DNA element called the integron can capture, mobilise and express genes, thereby playing a role in the transfer process. We have discovered that integrons are surprisingly abundant in the environment and are associated with a hitherto unsuspected diversity of novel genes. In this study we will assess the diversity of environmental integrons and examine their contribution to bacterial evolution. Further, we aim to use integron systems to prospect for novel genes and contract new enzyme pathways by directed evolution.
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Enhanced biocatalysis in organic solvents for pharmaceutical biotransformation. Enzymes such as hydrolases play an important role in biotechnology because of their extreme versatility with respect to substrate specificity and stereoselectivity. The use of lipases as catalysts for optical isomer-specific organic reactions is often limited by unacceptably low enantioselectivities. We will investigate recombinant enzymes cloned from thermophilic lipolytic bacteria for synthetic reactions in orga ....Enhanced biocatalysis in organic solvents for pharmaceutical biotransformation. Enzymes such as hydrolases play an important role in biotechnology because of their extreme versatility with respect to substrate specificity and stereoselectivity. The use of lipases as catalysts for optical isomer-specific organic reactions is often limited by unacceptably low enantioselectivities. We will investigate recombinant enzymes cloned from thermophilic lipolytic bacteria for synthetic reactions in organic solvents, especially chiral resolution of mixtures in the production of pharmaceutical intermediates. Genetic improvement of lipase enantiospecificity and regioselectivity will be achieved using in vitro evolution by recombination and screening. The outcome will be cost-effective production superior biocatalysts with specifically enhanced regiospecific, enantioselective and hydrolytic characteristics.
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In vitro evolution of more thermostable dextranases for the Australian sugar industry. Dextrans are polysaccharides that adversely affect the productivity of sugarcane mills. The Australian sugar industry currently imports dextranases to deal with this problem but they are not heat stable so the mills have run at lower temperatures than optimal. We have isolated dextranases from thermophilic microorganisms and aim to improve their performance by generating superior heat-stable dextranases using ....In vitro evolution of more thermostable dextranases for the Australian sugar industry. Dextrans are polysaccharides that adversely affect the productivity of sugarcane mills. The Australian sugar industry currently imports dextranases to deal with this problem but they are not heat stable so the mills have run at lower temperatures than optimal. We have isolated dextranases from thermophilic microorganisms and aim to improve their performance by generating superior heat-stable dextranases using in vitro evolution, creating new activity levels by random mutation and recombination. The research will be significant in providing novel enzymes for domestic use, allowing import substitution and an outcome will be the development of a product with export potential.
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