Role of Cystathionine β-Lyase in Catabolism of Amino Acids to Sulfur Volatiles by Genetic Variants of
            <i>Lactobacillus helveticus</i>
            CNRZ 32

Lee, Won–Jae; Banavara, Dattatreya S.; Hughes, Judith M.; Christiansen, Jason K.; Steele, J. L.; Broadbent, Jeff R.; Rankin, Scott A.

doi:10.1128/aem.02290-06

Cited by 22 publications

(19 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…MetCtype cystathionine lyases of Lactobacillus spp. have been reported to occur in Lactobacillus fermentum DT41 (43), Lactobacillus helveticus CNRZ 32 (28), and Lactobacillus casei FAM18168 (20). Sequences are available for only the last two, and they have identities of 65% and 45% and similarities of 81% and 67%, respectively, to Cgl of BR11 at the amino acid level.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Cystathionine γ-Lyase Is a Component of Cystine-Mediated Oxidative Defense in Lactobacillus reuteri BR11

Turner

Barry

et al. 2009

J Bacteriol

View full text Add to dashboard Cite

Lactobacillus reuteri BR11 possesses a novel mechanism of oxidative defense involving an abundant cystine ABC transporter encoded by the cyuABC gene cluster. Large amounts of thiols, including H 2 S, are secreted upon cystine uptake by the CyuC transporter. A cystathionine ␥-lyase (cgl) gene is cotranscribed with the cyu genes in several L. reuteri strains and was hypothesized to participate in cystine-mediated oxidative defense by producing reducing equivalents. This hypothesis was tested with L. reuteri BR11 by constructing a cgl mutant (PNG901) and comparing it to a similarly constructed cyuC mutant (PNG902). Although Cgl was required for H 2 S production from cystine, it was not crucial for oxidative defense in de Mann-Rogosa-Sharpe medium, in contrast to CyuC, whose inactivation resulted in lag-phase arrest in aerated cultures. The importance of Cgl in oxidative defense was seen only in the presence of hemin, which poses severe oxidative stress. The growth defects in aerated cultures of both mutants were alleviated by supplementation with cysteine (and cystine in the cgl mutant) but not methionine, with the cyuC mutant showing a much higher concentration requirement. We conclude that L. reuteri BR11 requires a high concentration of exogenous cysteine/cystine to grow optimally under aerobic conditions. This requirement is fulfilled by the abundant CyuC transporter, which has probably arisen due to the broad substrate specificity of Cgl, resulting in a futile pathway which degrades cystine taken up by the CyuC transporter to H 2 S. Cgl plays a secondary role in oxidative defense by its well-documented function of cysteine biosynthesis.

show abstract

Section: Resultsmentioning

confidence: 99%

“…Cystathionine lyases of LAB have been widely studied in the context of cheese flavor development (4,5,20,28,43). However, there are few studies about the physiological roles of cystathionine lyases of LAB.…”

mentioning

confidence: 99%

Cystathionine γ-Lyase Is a Component of Cystine-Mediated Oxidative Defense in Lactobacillus reuteri BR11

Turner

Barry

et al. 2009

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…In addition, this study shows activity of the recombinant MGL under cheese-ripening conditions, thus establishing an alternative basis for the control and/or enhancement of VSC synthesis during the ripening process. Other promising strategies aimed at enhancing cheese flavor, such as the overproduction of cystathionine lyases (22,27) or the addition of B. linens cells to starter cultures (17), have not been developed further. In this work, the higher specificity toward L-methionine and other sulfur-containing compounds demonstrated by recombinant L. lactis strains producing MGL together with the considerable increase in VSC production point out that this strategy could represent a more efficient way to enhance cheese flavor development.…”

Section: Discussionmentioning

confidence: 99%

“…A few studies have focused on engineering lactic acid bacteria (LAB) with enhanced VSC-producing abilities by increasing cystathionine lyase activities (22,27). In this respect, a Lactococcus lactis strain engineered to overproduce cystathionine ␤-lyase was shown to produce larger quantities of VSCs with Met as a substrate compared to the wild-type strain (22).…”

mentioning

confidence: 99%

Heterologous Production of Methionine-γ-Lyase from Brevibacterium linens in Lactococcus lactis and Formation of Volatile Sulfur Compounds

Hanniffy

Philo

Peláez

et al. 2009

Appl Environ Microbiol

View full text Add to dashboard Cite

The conversion of methionine to volatile sulfur compounds (VSCs) is of great importance in flavor formation during cheese ripening and is the focus of biotechnological approaches toward flavor improvement. A synthetic mgl gene encoding methionine-␥-lyase (MGL) from Brevibacterium linens BL2 was cloned into a Lactococcus lactis expression plasmid under the control of the nisin-inducible promoter PnisA. When expressed in L. lactis and purified as a recombinant protein, MGL was shown to degrade L-methionine as well as other sulfurcontaining compounds such as L-cysteine, L-cystathionine, and L-cystine. Overproduction of MGL in recombinant L. lactis also resulted in an increase in the degradation of these compounds compared to the wild-type strain. Importantly, gas chromatography-mass spectrometry analysis identified considerably higher formation of methanethiol (and its oxidized derivatives dimethyl disulfide and dimethyl trisulfide) in reactions containing either purified protein, whole cells, or cell extracts from the heterologous L. lactis strain. This is the first report of production of MGL from B. linens in L. lactis. Given their significance in cheese flavor development, the use of lactic acid bacteria with enhanced VSC-producing abilities could be an efficient way to enhance cheese flavor development.

show abstract

“…Thus, the CBL from Lactococcus lactis subsp. cremoris and L. helveticus have been shown to catalyze ␣,␤-and ␣,␥-elimination reactions and degrade methionine to methanethiol (1,17,21). A CGL has been identified in Lactobacillus fermentum, Lactobacillus reuteri, and L. lactis subsp.…”

mentioning

confidence: 99%

Cloning and Characterization of Two Lactobacillus casei Genes Encoding a Cystathionine Lyase

Irmler

Raboud

Beisert

et al. 2008

Appl Environ Microbiol

View full text Add to dashboard Cite

Volatile sulfur compounds are key flavor compounds in several cheese types. To better understand the metabolism of sulfur-containing amino acids, which certainly plays a key role in the release of volatile sulfur compounds, we searched the genome database of Lactobacillus casei ATCC 334 for genes encoding putative homologs of enzymes known to degrade cysteine, cystathionine, and methionine. The search revealed that L. casei possesses two genes that putatively encode a cystathionine ␤-lyase (CBL; EC 4.4.1.8). The enzyme has been implicated in the degradation of not only cystathionine but also cysteine and methionine. Recombinant CBL proteins catalyzed the degradation of L-cystathionine, O-succinyl-L-homoserine, L-cysteine, L-serine, and L-methionine to form ␣-keto acid, hydrogen sulfide, or methanethiol. The two enzymes showed notable differences in substrate specificity and pH optimum.Volatile sulfur compounds (VSC) are found in many cheese varieties and are important components of flavor (10). The sulfur compounds methanethiol, methional, and dimethyl trisulfide (DMTS) are key odorants of Swiss Gruyère cheese flavor and are presumably derived from the bacterial metabolism of methionine, which is present in caseins at higher concentrations than cysteine. Swiss Gruyère (place of designated origin) cheese is produced with thermophilic mixed-strain starters which usually contain Streptococcus thermophilus and Lactobacillus delbrueckii subsp. lactis. In addition, depending on the cheese factory, Lactobacillus helveticus can also be present. However, after ripening, Lactobacillus casei and Lactobacillus rhamnosus bacteria are found in high numbers (8). Interestingly, L. casei is also a constituent of the nonstarter lactic acid bacteria of many other cheese varieties (6). Therefore, this species is considered to play an important role during ripening and may be a key player in the formation of flavor compounds.The catabolic pathway(s) of methionine and cysteine in lactobacilli is not well characterized. Possible pathways involve transaminases, methionine ␥-lyases, cystathionine ␤-lyases (CBL), and cystathionine ␥-lyases (CGL) (13). The transamination of methionine by aminotransferases has been studied in lactococci (18,27,34). The results of these studies suggested that methionine is converted to 2-oxo-4-methylthiobutyric acid, which is then converted, either enzymatically or chemically, to methanethiol. In Brevibacterium linens, a methionine ␥-lyases which catalyzes the deamination of methionine and releases methanethiol has been identified and the corresponding gene has been cloned (2,14).CBL, which is encoded by the gene metC in Escherichia coli, is involved in the ␣,␤-elimination of cystathionine to form homocysteine, pyruvate, and ammonia. In comparison, CGL catalyzes the ␣,␥-elimination reaction of cystathionine, producing cysteine, ammonia, and ␣-ketobutyrate. CBL and CGL generally show catalytic promiscuity, which means that they catalyze different reactions. Thus, the CBL from Lactococcus lactis subsp. cremor...

show abstract

Role of Cystathionine β-Lyase in Catabolism of Amino Acids to Sulfur Volatiles by Genetic Variants of Lactobacillus helveticus CNRZ 32

Cited by 22 publications

References 25 publications

Cystathionine γ-Lyase Is a Component of Cystine-Mediated Oxidative Defense in Lactobacillus reuteri BR11

Cystathionine γ-Lyase Is a Component of Cystine-Mediated Oxidative Defense in Lactobacillus reuteri BR11

Heterologous Production of Methionine-γ-Lyase from Brevibacterium linens in Lactococcus lactis and Formation of Volatile Sulfur Compounds

Cloning and Characterization of Two Lactobacillus casei Genes Encoding a Cystathionine Lyase

Contact Info

Product

Resources

About