The proteolytic systems of lactic acid bacteria

Kunji, Edmund R. S.; Mierau, Igor; Hagting, Anja; Poolman, Bert; Konings, Wil N.

doi:10.1007/978-94-009-1774-3_7

Cited by 132 publications

(215 citation statements)

References 160 publications

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“…The protease-negative genetic lineage populations had the highest relative abundance in cheese until the ripening period (0.1-35%), consistent with the previous observations (Hugenholtz et al, 1987), indicating a peptide cross feeding for the acquisition of essential amino acids during their growth in milk (Kunji et al, 1996). The protease-positive cells were stably maintained in the starter community, which is generally not observed in single-strain populations (Bachmann et al, 2011).…”

Section: Community Dynamics In Cheesesupporting

confidence: 88%

Multifactorial diversity sustains microbial community stability

et al. 2013

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Maintenance of a high degree of biodiversity in homogeneous environments is poorly understood. A complex cheese starter culture with a long history of use was characterized as a model system to study simple microbial communities. Eight distinct genetic lineages were identified, encompassing two species: Lactococcus lactis and Leuconostoc mesenteroides. The genetic lineages were found to be collections of strains with variable plasmid content and phage sensitivities. Kill-the-winner hypothesis explaining the suppression of the fittest strains by density-dependent phage predation was operational at the strain level. This prevents the eradication of entire genetic lineages from the community during propagation regimes (back-slopping), stabilizing the genetic heterogeneity in the starter culture against environmental uncertainty.

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Section: Community Dynamics In Cheesesupporting

confidence: 88%

Multifactorial diversity sustains microbial community stability

et al. 2013

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“…Endogenous tyrosine transporters of L. lactis were most likely responsible for loading in the latter case. The low level of tyramine uptake without tyrosine preloading probably results from exchange with an internal pool of tyrosine, as reported by Kunji et al (1996).…”

Section: Discussionsupporting

confidence: 64%

Characterization of the tyramine-producing pathway in Sporolactobacillus sp. P3J

Coton¹,

Fernández

Trip

et al. 2011

Microbiology

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A sporulated lactic acid bacterium (LAB) isolated from cider must was shown to harbour the tdc gene encoding tyrosine decarboxylase. The isolate belonged to the Sporolactobacillus genus and may correspond to a novel species. The ability of the tdc-positive strain, Sporolactobacillus sp. strain P3J, to produce tyramine in vitro was demonstrated by using HPLC. A 7535 bp nucleotide sequence harbouring the putative tdc gene was determined. Analysis of the obtained sequence showed that four tyramine production-associated genes [tyrosyl-tRNA synthetase (tyrS), tyrosine decarboxylase (tdc), tyrosine permease (tyrP) and Na + /H + antiporter (nhaC)] were present and were organized as already described in other tyramine-producing LAB. This operon was surrounded by genes showing the highest identities with mobile elements: a putative phage terminase and a putative transposase (downstream and upstream, respectively), suggesting that the tyramine-forming trait was acquired through horizontal gene transfer. Transcription analyses of the tdc gene cluster suggested that tyrS and nhaC are expressed as monocistronic genes while tdc would be part of a polycistronic mRNA together with tyrP. The presence of tyrosine in the culture medium induced the expression of all genes except for tyrS. A clear correlation was observed between initial tyrosine concentration and tyramine production combined with an increase in the final pH reached by the culture. Finally, cloning and expression of the tyrP gene in Lactococcus lactis demonstrated that its product catalyses the exchange of tyrosine and tyramine.

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“…lactocepin, which mainly releases peptides of large molecular mass from caseins (Juillard et al, 1995b;Kunji et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

The specificity of oligopeptide transport by Streptococcus thermophilus resembles that of Lactococcus lactis and not that of pathogenic streptococci

2005

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Peptide transport is a crucial step in the growth of Streptococcus thermophilus in protein-or peptide-containing media. The objective of the present work was to determine the specificity of peptide utilization by this widely used lactic acid bacterium. To reach that goal, complementary approaches were employed. The capability of a proteinase-negative S. thermophilus strain to grow in a chemically defined medium containing a mixture of peptides isolated from milk as the source of amino acids was analysed. Peptides were separated into three size classes by ultrafiltration. The strain was able to use peptides up to 3?5 kDa during growth, as revealed by liquid chromatography and mass spectrometry analyses. The same strain was grown in chemically defined medium containing a tryptic digest of casein, and the respective time-course consumption of the peptides during growth was estimated. The ability to consume large peptides (up to 23 residues) was confirmed, as long as they are cationic and hydrophobic. These results were confirmed by peptide transport studies. Extension of the study to 11 other strains revealed that they all shared these preferences.

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The proteolytic systems of lactic acid bacteria

Cited by 132 publications

References 160 publications

Multifactorial diversity sustains microbial community stability

Multifactorial diversity sustains microbial community stability

Characterization of the tyramine-producing pathway in Sporolactobacillus sp. P3J

The specificity of oligopeptide transport by Streptococcus thermophilus resembles that of Lactococcus lactis and not that of pathogenic streptococci

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