Characterization and Classification of Streptococcus Thermophilus and Lactobacillus Delbrueckii Subsp. Bulgaricus Strains Isolated from Traditional Greek Yogurts

Xanthopoulos, V.; Petridis, D.; Tzanetakis, N.

doi:10.1111/j.1365-2621.2001.tb04632.x

Cited by 41 publications

(30 citation statements)

References 18 publications

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“…II), which contrasts with most reports on acetaldehyde [8,28,32]. This may have resulted from the larger final populations of S. thermophilus than of Lb.…”

Section: Effect Of the S Thermophilus/lb Bulgaricus Association On contrasting

confidence: 53%

Article

Courtin

Rul

2003

Lait

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-Yogurt is a simple ecosystem whose successful manufacture relies on interactions between two thermophilic lactic acid bacteria, Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (Lb. bulgaricus). The present work studied the impact of co-culturing S. thermophilus with Lb. bulgaricus on bacterial growth in milk. To achieve this, we considered both sides of the bacterial association, by characterising proteolysis and quantifying formic acid in pure and mixed cultures of S. thermophilus and Lb. bulgaricus. In pure cultures, S. thermophilus CNRZ385 exhibited better growth than the two Lb. bulgaricus strains (1038 and CNRZ397). The S. thermophilus/Lb. bulgaricus association was positive for S. thermophilus growth with strain 1038, contrary to the association with strain 397. These effects were correlated with the different proteolytic capacities of the two Lb. bulgaricus strains. In contrast, the bacterial association had no significant effect on Lb. bulgaricus growth, possibly because of an insufficient production of formic acid by the S. thermophilus strain. We also showed that the S. thermophilus/Lb. bulgarius association affected the production of volatile molecules involved in flavour development.Streptococcus thermophilus / Lactobacillus delbrueckii subsp. bulgaricus / milk co-cultures / proteolysis / formic acid / flavour Résumé -Interactions entre microorganismes dans un écosystème simple : les bactéries du yaourt comme modèle d'étude. Le yaourt constitue un écosystème simple dont la fabrication repose sur les interactions prenant place entre les deux espèces de bactéries lactiques Streptococcus thermophilus et Lactobacillus delbrueckii subsp. bulgaricus (Lb. bulgaricus). Au cours de ce travail, nous avons étudié l'impact de la co-culture de S. thermophilus avec Lb. bulgaricus sur la croissance bactérienne dans le lait. Pour cela, nous nous sommes intéressés aux deux aspects de l'association, en caractérisant la protéolyse et en quantifiant l'acide formique dans des cultures pures et mixtes de S. thermophilus et Lb. bulgaricus. En culture pure, S. thermophilus CNRZ385 se développait mieux que les deux souches de Lb. bulgaricus (1038 et CNRZ397). L'association S. thermophilus/Lb. bulgaricus avait un effet bénéfique sur la croissance de S. thermophilus avec la souche 1038 contrairement à l'association avec la souche CNRZ397. Ces effets étaient corrélés à des capacités protéolytiques différentes des deux souches de Lb. bulgaricus. Par ailleurs, l'association bactérienne n'avait pas d'effet significatif sur la croissance de Lb. bulgaricus possiblement en raison d'une production insuffisante d'acide formique par la souche de S. thermophilus. Nous avons également montré que l'association S. thermophilus/Lb. bulgaricus affectait la production de molecules volatiles impliquées dans le développement de la flaveur.Streptococcus thermophilus / Lactobacillus delbrueckii subsp. bulgaricus / co-culture en lait / protéolyse / acide formique / flaveur

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“…II), which contrasts with most reports on acetaldehyde [8,28,32]. This may have resulted from the larger final populations of S. thermophilus than of Lb.…”

Section: Effect Of the S Thermophilus/lb Bulgaricus Association On contrasting

confidence: 53%

Article

Courtin

Rul

2003

Lait

View full text Add to dashboard Cite

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“…The most important ingredients of cow milk required by the yoghurt starter cultures to produce acetaldehyde are lactose (mainly the glucose fraction) and the amino acids threonine and methionine. The content of acetaldehyde in yoghurt from cow milk usually ranged from 1.3-3.5 mg/kg (Xanthopoulos et al 2001) to 40 mg/kg (Ozer & Atasoy 2002). In this study, milk fermented only by the yoghurt culture contained 5.63 ± 0.36 mg/kg of acetaldehyde while in soymilk yoghurt 3.84 ± 0.30 mg/kg of acetaldehyde was found.…”

Section: Resultsmentioning

confidence: 75%

Fermentation of soymilk by yoghurt and bifidobacteria strains

Horáčková¹,

Mühlhansová²,

Sluková³

et al. 2015

Czech J. Food Sci.

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Horáčková Š., Mühlhansová A., Sluková M., Schulzová V., Plocková M. (2015): Fermentation of soymilk by yoghurt and bifidobacteria strains. Czech J. Food Sci., 33: 313-319.Soy and milk based products fermented by yoghurt culture YC-381 alone or in combination with two probiotic cultures (Bifidobacterium animalis subsp. lactis BB 12 and Bifidobacterium bifidum CCDM 94) were prepared. Bacteria growth, the amounts of lactic acid, acetic acid, and acetaldehyde were compared after 16 h of fermentation at 37°C. The changes of isoflavones concentrations were also monitored in soy products. The growth of Streptococcus thermophilus and bifidobacteria was similar in both media, but Lactobacillus delbrueckii subsp. bulgaricus showed a better growth in milk. Titratable acidity and the concentrations of acids were consistently higher in cow milk than in soymilk at the end of fermentation. Bifidobacteria, compared to the yoghurt culture, were only able to acidify the media to the half values. Comparing the bifidobacteria strains, Bifidobacterium animalis subsp. lactis BB 12 exhibited a better ability to acidify milk. The strain Bifidobacterium bifidum CCDM 94 was able to release 6.90 mg/100 ml of isoflavone aglycones in soymilk.

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“…In contrast, IMAU80846 showed a gradual increase in acetaldehyde during storage of 12-36 h. The breakdown of acetaldehyde during storage possibly resulted from the microbial enzymes driven-hydrolysis and may provide amino acids and nucleotides for maintaining the cell viability (Güler-akn, 2005). Similarly, Xanthopoulos et al (2001) observed the reduction of acetaldehyde in some S. thermophilus strains during fermented milk storage. Moreover, diacetyl, mainly produced by S. thermophilus, is another antibacterial compound potentially contributing to the yogurt aroma (Chammas et al, 2006;Kang and Fung, 1999;Routray and Mishra, 2011).…”

Section: Changes In Acetaldehyde Diacetyl Lactic Acid and Formic Acmentioning

confidence: 97%

“…Xanthopoulos et al (2001) reported that the acidification ability of S. thermophilus of 74 strains showed no obvious relation to the final amount of lactic acid produced. Formic acid is also an important metabolite of lactic acid fermentation and its production is strain-dependent (Perez et al, 1991).…”

Section: Changes In Acetaldehyde Diacetyl Lactic Acid and Formic Acmentioning

confidence: 99%