Copper economy of denitrification by soil microbes
Lead Research Organisation:
Durham University
Department Name: Biosciences
Abstract
Bioavailable (fixed) nitrogen is a key limiting factor for crop production. However, a significant portion
is lost via denitrification, an essential metabolic process in major soil microbes, in which bioavailable
nitrate is reduced to inert dinitrogen gas. These reactions proceed via a conserved and copperexpensive
pathway that involves two multicopper enzymes, including a nitrite reductase (NirK). Hence
rates of denitrification correlate with copper availability. Critically, copper is a prevalent heavy metal
contaminant in topsoil, a legacy from the prolonged use of copper-derived agricultural biocides. It has
been shown that denitrification rates (hence loss of fixed nitrogen) are greater in contaminated vs. noncontaminated
soils.
We are interested in how bacteria acquire and insert nutrient copper into multicopper enzymes,
particularly NirK. Previous work in the group has shown that activation of NirK in vivo requires a
periplasmic factor called PCuC. In the absence of PCuC, NirK is produced in the metal-free form. We
hypothesise that PCuC is a metallochaperone that catalyses copper insertion into NirK. Our results may
identify strategies for improving crop production in copper-rich regions.
is lost via denitrification, an essential metabolic process in major soil microbes, in which bioavailable
nitrate is reduced to inert dinitrogen gas. These reactions proceed via a conserved and copperexpensive
pathway that involves two multicopper enzymes, including a nitrite reductase (NirK). Hence
rates of denitrification correlate with copper availability. Critically, copper is a prevalent heavy metal
contaminant in topsoil, a legacy from the prolonged use of copper-derived agricultural biocides. It has
been shown that denitrification rates (hence loss of fixed nitrogen) are greater in contaminated vs. noncontaminated
soils.
We are interested in how bacteria acquire and insert nutrient copper into multicopper enzymes,
particularly NirK. Previous work in the group has shown that activation of NirK in vivo requires a
periplasmic factor called PCuC. In the absence of PCuC, NirK is produced in the metal-free form. We
hypothesise that PCuC is a metallochaperone that catalyses copper insertion into NirK. Our results may
identify strategies for improving crop production in copper-rich regions.
Organisations
Publications
Hong Y
(2023)
Mis-regulation of Zn and Mn homeostasis is a key phenotype of Cu stress in Streptococcus pyogenes.
in Metallomics : integrated biometal science
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| BB/M011186/1 | 30/09/2015 | 31/03/2024 | |||
| 2181953 | Studentship | BB/M011186/1 | 30/09/2019 | 20/04/2024 | Jack Bolton |
| Description | Whilst the nosZ gene is expressed in the human pathogen Neisseria gonorrhoeae, the NosZ protein is rapidly degraded. As such, it is not a viable candidate for vaccine development. |
| Exploitation Route | The discovery of the rapid degredation of the nascent NosZ polypetpide in Neisseria gonorrhoeae contributes to a growing body of work which suggests the denitrification pathway in pathogenic Neisseria (gonorrhoeae, meningitidis & mucosa) have been independently inactivated. Commensal Neisseria species largely retain a functioning denitrification pathway. Determining the evolutionary drivers behind this loss-of-function in pathogenic species is an objective for future research. |
| Sectors | Healthcare Pharmaceuticals and Medical Biotechnology |
| Description | I did an industrial placement with a biotech company, Novabiotics. With them, I contributed to research on immune responses in response to cysteamine supplements in a Pseudomonas aeruginosa lung infection model. |
| First Year Of Impact | 2022 |
| Sector | Healthcare,Pharmaceuticals and Medical Biotechnology |
| Impact Types | Societal |