QUT ePrints

Cystine uptake prevents production of hydrogen peroxide by Lactobacillus fermentum BR11

Hung, Jacky, Cooper, Dee, Turner, Mark S., Walsh, Terence P., & Giffard, Philip M. (2003) Cystine uptake prevents production of hydrogen peroxide by Lactobacillus fermentum BR11. FEMS Microbiology Letters, 227(1), pp. 93-99.

View at publisher

Abstract

BspA is an abundant surface protein from Lactobacillus fermentum BR11, and is required for normal cystine uptake. In previous studies, a mutant strain deficient in BspA (L. fermentum PNG201) was found to be sensitive to oxidative stress. In this study, the biochemical basis for this was explored. It was found that under aerobic batch culture conditions in de Mann–Rogosa–Sharpe medium, both L. fermentum BR11 and PNG201 entered stationary phase due to hydrogen peroxide accumulation. However, this took place at a lower optical density for PNG201 than for BR11. Measurements of hydrogen peroxide levels revealed that the BspA mutant strain overproduces this compound. Addition of 6 mM cystine to aerobic cultures was found to prevent hydrogen peroxide production by both the BR11 and PNG201 strains, but lower cystine concentrations depressed hydrogen peroxide production in BR11 more efficiently than in PNG201. Each mole of cystine was able to prevent the production of several moles of hydrogen peroxide by L. fermentum BR11, suggesting that hydrogen peroxide breakdown is dependent upon a thiol that cycles between reduced and oxidized states. It was concluded that peroxide breakdown by L. fermentum BR11 is dependent upon exogenous cystine. It is most probable that the imported l-cystine is catabolized by a cystathionine lyase and then converted into a thiol reductant for a peroxidase.

Impact and interest:

19 citations in Scopus
Search Google Scholar™
18 citations in Web of Science®

Citation countsare sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 10055
Item Type: Journal Article
Additional Information: For more information, please refer to the journal’s website (see hypertext link) or contact the author.
Keywords: Oxidative stress, Thiol, Peroxidase
DOI: 10.1016/S0378-1097(03)00653-0
ISSN: 0378-1097
Divisions: Past > QUT Faculties & Divisions > Faculty of Science and Technology
Copyright Owner: Copyright 2003 Elsevier
Deposited On: 10 Oct 2007
Last Modified: 29 Feb 2012 23:00

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page