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Dr. J.E. Hallsworth

Dr. John Hallsworth
Dr. John Hallsworth
Lecturer in Environmental Microbiology
BSc (Hons) Plant Biotechnology, 1990;
Imperial College Wye, University of London
PhD Fungal Stress Metabolism, 1995,
Cranfield University.

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Contact Information
Tel:  +44 (0)28 9097 2314 (Direct line)
Fax:  +44 (0)28 9097 5877
Email:  j.hallsworth@qub.ac.uk
Room:  Medical Biology Centre - 0B.453

Research Interests

Life is based on water: my research interests relate to the structure and function of cellular systems, biological macromolecules and ecosystems in relation to their dependence on the availability and behaviour of water:

Pure

  • Microbial stress mechanisms and responses
  • Metabolic, proteomic and genomic adaptations to solute activities
  • Physiology of compatible solute synthesis and activities in microbial cells
  • Water: biological macromolecule interactions

Environmental

  • Tenacity of microbes in deep-sea hypersaline basins and Arctic sea-ice
  • Diversity and ecology of fungi in arid regions of sub-Saharan Africa
  • Non-osmotic water stress in soil bacteria induced by pollutants
  • Ecophysiology of xerophilic fungi: limits of the functional biosphere

Applied / Industrial

  • Stress metabolism of insect-pathogenic fungi used for biological control
  • Solvent stress in Pseudomonas putida during industrial biocatalysis
  • Stress phenomena in food and beverage fermentations
  • Ethanol-induced water stress in Saccharomyces cerevisiae

Research Details

Cellular life is based on water, and any dissolved substance or change in environmental conditions can potentially affect the behaviour of water molecules and thereby impact on water:biological macromolecule interactions.  My research focuses on microbial responses and adaptations to stress and toxic solutes, in both environmental microbes and those used in biotechnologies.  Recently, we studied the stress effects of low molecular weight solutes that decrease water:water and water:macromolecule interactions, but readily penetrate lipid bilayers and do not affect cell turgor.  We found that chaotropic compounds, including common environmental pollutants and agrochemicals, induce a novel class of cellular stress: non-osmotic water stress, and destabilization of cellular macromolecules.  Characterization of genomic responses to such compounds revealed the up-regulation of diverse macromolecule protection systems.  These results challenge the idea that cellular water stress necessarily involves osmotic (turgor) changes.  This work has been applied to a number of microbial studies, including bioremediation of soil pollutants (MIFRIEND and LINDANE), salt stress and ecology of microbes in hypersaline deep-sea basins (BIODEEP), solvent stress during biocatalysis (Kluyver Centre), and (PSYSMO)."  We use various techniques to study in vivo responses including DNA microarrays, proteomics, analytical methods (e.g. HPLC, GC, GC-MS, NMR), analysis of growth kinetics, and macromolecule model systems.

Vacancies and opportunities to join Environmental Microbiology at Queen's

We welcome any enquiries from research students or staff who are interested in working in the area of environmental microbiology.  Possible areas for future projects include:

  • Microbial ecology of deep-sea hypersaline environments
  • Genomic and proteomic microbial responses to environment and solute activities
  • Fungal ecology of sub-Saharan Africa (and biotechnological exploitation)
  • Function of biological macromolecules and metabolomics of microbes under stress
  • Bacterial stress metabolism during bioremediation and biocatalysis
  • The limits of stress tolerance for food-spoilage and fermenting microorganisms