Inactivation of an Iron Transporter in Lactococcus lactis Results in Resistance to Tellurite and Oxidative Stress
Article
Article Title | Inactivation of an Iron Transporter in Lactococcus lactis Results in Resistance to Tellurite and Oxidative Stress |
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ERA Journal ID | 2456 |
Article Category | Article |
Authors | Turner, Mark S., Tan, Yu Pei and Giffard, Philip M. |
Journal Title | Applied and Environmental Microbiology |
Journal Citation | 73 (19), pp. 6144-6149 |
Number of Pages | 6 |
Year | Oct 2007 |
Publisher | American Society for Microbiology |
Place of Publication | United States |
ISSN | 0099-2240 |
1098-5336 | |
Digital Object Identifier (DOI) | https://doi.org/10.1128/AEM.00413-07 |
Web Address (URL) | https://journals.asm.org/doi/10.1128/AEM.00413-07 |
Abstract | In Lactococcus lactis, the interactions between oxidative defense, metal metabolism, and respiratory metabolism are not fully understood. To provide an insight into these processes, we isolated and characterized mutants of L. lactis resistant to the oxidizing agent tellurite (TeO32-), which generates superoxide radicals intracellularly. A collection of tellurite-resistant mutants was obtained using random transposon mutagenesis of L. lactis. These contained insertions in genes encoding a proton-coupled Mn 2+/Fe2+ transport homolog (mntH), the high-affinity phosphate transport system (pstABCDEF), a putative osmoprotectant uptake system (choQ), and a homolog of the oxidative defense regulator spx (trmA). The tellurite-resistant mutants all had better survival than the wild type following aerated growth. The mntH mutant was found to be impaired in Fe2+ uptake, suggesting that MntH is a Fe2+ transporter in L. lactis. This mutant is capable of carrying out respiration but does not generate as high a final pH and does not exhibit the long lag phase in the presence of hemin and oxygen that is characteristic of wild-type L. lactis. This study suggests that tellurite-resistant mutants also have increased resistance to oxidative stress and that intracellular Fe2+ can heighten tellurite and oxygen toxicity. |
Keywords | Genes; Iron; Metabolism; Mutagenesis; Oxidative stress; pH |
Contains Sensitive Content | Does not contain sensitive content |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Byline Affiliations | Queensland University of Technology |
University of Queensland |
https://research.usq.edu.au/item/yywxz/inactivation-of-an-iron-transporter-in-lactococcus-lactis-results-in-resistance-to-tellurite-and-oxidative-stress
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