Molecular characterization and functional analysis of the manganese-containing superoxide dismutase gene (sodA) from Streptococcus thermophilus AO54

Andrus, Jason M.; Bowen, Steven W.; Klaenhammer, Todd R.; Hassan, Hosni M.

doi:10.1016/j.abb.2003.09.007

Cited by 19 publications

(30 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Instead of using SOD, Lactobacillus plantarum developed an alternative nonenzymatic defense system that involves the accumulation of high intracellular concentrations of manganese ions, which can scavenge O 2 Ϫ (4). Previous work has shown that S. thermophilus possesses only one type of SOD, the Mn-containing enzyme (MnSOD) (3,15,44). The gene encoding MnSOD (sodA) from S. thermophilus AO54 has been characterized, cloned, and heterologously expressed in other bacteria (3,13,14).…”

mentioning

confidence: 99%

Role of Antioxidant Enzymes in Bacterial Resistance to Organic Acids

Bruno-Bárcena

Azcarate‐Peril

Hassan³

2010

Appl Environ Microbiol

View full text Add to dashboard Cite

Growth in aerobic environments has been shown to generate reactive oxygen species (ROS) and to cause oxidative stress in most organisms. Antioxidant enzymes (i.e., superoxide dismutases and hydroperoxidases) and DNA repair mechanisms provide protection against ROS. Acid stress has been shown to be associated with the induction of Mn superoxide dismutase (MnSOD) in Lactococcus lactis and Staphylococcus aureus. However, the relationship between acid stress and oxidative stress is not well understood. In the present study, we showed that mutations in the gene coding for MnSOD (sodA) increased the toxicity of lactic acid at pH 3.5 in Streptococcus thermophilus. The inclusion of the iron chelators 2,2-dipyridyl (DIP), diethienetriamine-pentaacetic acid (DTPA), and O-phenanthroline (O-Phe) provided partial protection against 330 mM lactic acid at pH 3.5. The results suggested that acid stress triggers an iron-mediated oxidative stress that can be ameliorated by MnSOD and iron chelators. These findings were further validated in Escherichia coli strains lacking both MnSOD and iron SOD (FeSOD) but expressing a heterologous MnSOD from S. thermophilus. We also found that, in E. coli, FeSOD did not provide the same protection afforded by MnSOD and that hydroperoxidases are equally important in protecting the cells against acid stress. These findings may explain the ability of some microorganisms to survive better in acidified environments, as in acid foods, during fermentation and accumulation of lactic acid or during passage through the low pH of the stomach.

show abstract

mentioning

confidence: 99%

Role of Antioxidant Enzymes in Bacterial Resistance to Organic Acids

Bruno-Bárcena

Azcarate‐Peril

Hassan³

2010

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Studies of gram-positive bacteria suggested that paraquat and quinones may not be actively transported. Thus, S. thermophilus was shown to be resistant to paraquat and to other redox cycling compounds (1,11), and in L. fermentum, paraquat can be internalized only when the membrane is modified (57). We concluded, therefore, that we cannot use paraquat or quinones as superoxide generators (i.e., oxidative stress agents) in the organisms used in this study.…”

Section: Resultsmentioning

confidence: 99%

“…The sodA from this organism has proven to be more suited for expression in other LAB because S. thermophilus is a grampositive, non-spore-forming organism and has a low GϩC content that is more close to the Lactobacillus group than is E. coli. Furthermore, the sodA of S. thermophilus is constitutively expressed (12) and does not appear to have a complex promoter region (1). This appears to promote recognition by the Lactobacillus transcription and translation machinery and allows constitutive production of the enzyme in the different hosts.…”

Section: Discussionmentioning

confidence: 99%

“…Unlike most sodA genes, S. thermophilus sodA is expressed under both anaerobic and aerobic conditions and is not induced by the redox cycling compound, paraquat (12). This antioxidant enzyme was shown to be essential for the growth of S. thermophilus under aerobic conditions (1). However, most lactobacilli lack this general defense system (SODs).…”

mentioning

confidence: 99%

“…In most Streptococcus and Lactococcus spp., elimination of ROS conform to this general antioxidant defense system since they both possess MnSOD (46,52). Previously, our group has identified, characterized, and cloned the gene (sodA) encoding the manganese-containing SOD from Streptococcus thermophilus AO54 (1,12). Unlike most sodA genes, S. thermophilus sodA is expressed under both anaerobic and aerobic conditions and is not induced by the redox cycling compound, paraquat (12).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Expression of a Heterologous Manganese Superoxide Dismutase Gene in Intestinal Lactobacilli Provides Protection against Hydrogen Peroxide Toxicity

Bruno-Bárcena¹,

Andrus²,

Libby³

et al. 2004

Appl Environ Microbiol

100

View full text Add to dashboard Cite

In living organisms, exposure to oxygen provokes oxidative stress. A widespread mechanism for protection against oxidative stress is provided by the antioxidant enzymes: superoxide dismutases (SODs) and hydroperoxidases. Generally, these enzymes are not present in Lactobacillus spp. In this study, we examined the potential advantages of providing a heterologous SOD to some of the intestinal lactobacilli. Thus, the gene encoding the manganese-containing SOD (sodA) was cloned from Streptococcus thermophilus AO54 and expressed in four intestinal lactobacilli. A 1.2-kb PCR product containing the sodA gene was cloned into the shuttle vector pTRK563, to yield pSodA, which was functionally expressed and complemented an Escherichia coli strain deficient in Mn and FeSODs. The plasmid, pSodA, was subsequently introduced and expressed in Lactobacillus gasseri NCK334, Lactobacillus johnsonii NCK89, Lactobacillus acidophilus NCK56, and Lactobacillus reuteri NCK932. Molecular and biochemical analyses confirmed the presence of the gene (sodA) and the expression of an active gene product (MnSOD) in these strains of lactobacilli. The specific activities of MnSOD were 6.7, 3.8, 5.8, and 60.7 U/mg of protein for L. gasseri, L. johnsonii, L. acidophilus, and L. reuteri, respectively. The expression of S. thermophilus MnSOD in L. gasseri and L. acidophilus provided protection against hydrogen peroxide stress. The data show that MnSOD protects cells against hydrogen peroxide by removing O 2 ·؊ and preventing the redox cycling of iron. To our best knowledge, this is the first report of a sodA from S. thermophilus being expressed in other lactic acid bacteria.

show abstract