Comparative Transcriptomic Analysis of Streptococcus thermophilus TH1436 and TH1477 Showing Different Capability in the Use of Galactose

Giaretta, Sabrina; Treu, Laura; Vendramin, Veronica; Duarte, Viní­cius da Silva; Tarrah, Armin; Campanaro, Stefano; Corich, Viviana

doi:10.3389/fmicb.2018.01765

Cited by 26 publications

(15 citation statements)

References 73 publications

(95 reference statements)

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“…The S. thermophilus strains were in the de Man, Rogosa, and Sharpe (MRS)-lactose broth with 2% lactose as the sole carbon source and were incubated at 37°C for 12 h under aerobic conditions before the analysis. After washing with a saline solution, the bacteria were transferred into the fresh MRS-lactose medium to an initial concentration of 5 × 10 6 cells/mL to record their growth, acid production, and rate of lactose utilization during incubation at 37°C for 16 h under aerobic conditions (Giaretta et al, 2018;Yang et al, 2019). After 12 h of incubation, the urease and β-galactosidase activities of the strains were determined as previously described, with 1 unit of urease activity defined as the release of 1 µmol of NH4 + per min (Mora et al, 2005;Zotta et al, 2008;Wu and Shah, 2017).…”

Section: Short Communication: Lactose Utilization Of Streptococcus Thmentioning

confidence: 99%

Short communication: Lactose utilization of Streptococcus thermophilus and correlations with β-galactosidase and urease

Li²,

Geng

et al. 2020

Journal of Dairy Science

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The ability to use lactose is critical for the application of Streptococcus thermophilus in fermented dairy products. Most studies have evaluated the use of lactose of S. thermophilus by measuring lactose utilization, but its correlation with β-galactosidase and urease has rarely been investigated. In this study, 10 strains of S. thermophilus isolated from fermented yak milk exhibited a diversity of β-galactosidase and urease activities, growth, and acid production in de Man, Rogosa, and Sharpe-lactose. Among the strains, 15G5 possessed the highest β-galactosidase activity and showed the highest cell growth, lactic acid production, and titratable acidity during fermentation. In contrast, 7G10, with the weakest β-galactosidase activity, produced the lowest lactic acid content and change in titratable acidity. Further investigation indicated that β-galactosidase activity of S. thermophilus showed significant positive correlations with the growth of cell densities, the production of lactic acid, and titratable acidity, and urease activity of S. thermophilus showed a significant correlation with the use of lactose and the production of lactic acid and acetaldehyde. These findings suggest that the differences of β-galactosidase and urease activities are essential for the performance in the lactose metabolism, growth, and acid production of S. thermophilus, providing new insights into strain selection and application.

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Section: Short Communication: Lactose Utilization Of Streptococcus Thmentioning

confidence: 99%

Short communication: Lactose utilization of Streptococcus thermophilus and correlations with β-galactosidase and urease

Li²,

Geng

et al. 2020

Journal of Dairy Science

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“…Recently, Xiong et al (2019b) demonstrated that the Gal + phenotype of S. thermophilus depends upon the expression of the gal operon, which can be widely affected by a single point mutation at the -9 box in the galK promoter. Since the accumulation of galactose in the medium by S. thermophilus may be important from a technological or nutritional perspective (Giaretta et al, 2018), we examined the presence of the mutation at the -9 box in the galK promoter in the strains analyzed. Accordingly, only B59671, CS8, EPS, and NCTC12958 T seem to be able to catabolize galactose, as they own the relevant G to A mutation in the position -9 of the -10 box related Gal + phenotype (data not shown).…”

Section: Lactose and Galactose Metabolismmentioning

confidence: 99%

Comparative Genomics of Streptococcus thermophilus Support Important Traits Concerning the Evolution, Biology and Technological Properties of the Species

et al. 2019

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Streptococcus thermophilus is a major starter for the dairy industry with great economic importance. In this study we analyzed 23 fully sequenced genomes of S. thermophilus to highlight novel aspects of the evolution, biology and technological properties of this species. Pan/core genome analysis revealed that the species has an important number of conserved genes and that the pan genome is probably going to be closed soon. According to whole genome phylogeny and average nucleotide identity (ANI) analysis, most S. thermophilus strains were grouped in two major clusters (i.e., clusters A and B). More specifically, cluster A includes strains with chromosomes above 1.83 Mbp, while cluster B includes chromosomes below this threshold. This observation suggests that strains belonging to the two clusters may be differentiated by gene gain or gene loss events. Furthermore, certain strains of cluster A could be further subdivided in subgroups, i.e., subgroup I (ASCC 1275, DGCC 7710, KLDS SM, MN-BM-A02, and ND07), II (MN-BM-A01 and MN-ZLW-002), III (LMD-9 and SMQ-301), and IV (APC151 and ND03). In cluster B certain strains formed one distinct subgroup, i.e., subgroup I (CNRZ1066, CS8, EPS, and S9). Clusters and subgroups observed for S. thermophilus indicate the existence of lineages within the species, an observation which was further supported to a variable degree by the distribution and/or the architecture of several genomic traits. These would include exopolysaccharide (EPS) gene clusters, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs)-CRISPR associated (Cas) systems, as well as restriction-modification (R-M) systems and genomic islands (GIs). Of note, the histidine biosynthetic cluster was found present in all cluster A strains (plus strain NCTC12958 T) but was absent from all strains in cluster B. Other loci related to lactose/galactose catabolism and urea metabolism, aminopeptidases, the majority of amino acid and peptide transporters, as well as amino acid biosynthetic pathways

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“…This suggests that this single point mutation of the galK promoter may largely be responsible for the Gal + phenotype of S-3. Giaretta et al (2018) also compared the gal promoters of Gal + and Gal − strains and found mutations at various positions in the gal operon intergenic regions. These mutations result in insufficient expression of the gal operon genes in the Gal − strains.…”

Section: Sugar Uptake In Eps Biosynthesis Based On Genome Analysis Of S Thermophilus S-3mentioning

confidence: 99%

Genomic and phenotypic analyses of exopolysaccharide biosynthesis in Streptococcus thermophilus S-3

Xiong

Kong

Lai

et al. 2019

Journal of Dairy Science

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Streptococcus thermophilus, one of the most important industrial lactic acid bacteria, is widely used as a starter culture in the dairy industry. Streptococcus thermophilus S-3 isolated from Chinese traditional dairy products has shown great potential for the production of larger amounts of exopolysaccharides (EPS), which significantly affect the organoleptic properties of fermented milk products. To understand the relationship between the genotype and phenotype of S. thermophilus S-3 in terms of EPS biosynthesis, its genome of strain S-3 was sequenced and the genes related to carbohydrate utilization, nucleotide sugars synthesis, and EPS biosynthesis were investigated. The genomic analysis revealed that S. thermophilus S-3 can use sucrose, mannose, glucose, galactose, and lactose. Phenotypic analysis showed that S-3 prefers fermenting lactose to fermenting glucose or galactose. The genetic analysis of nucleotide sugars and EPS biosynthesis revealed that S-3 can synthesize uridine diphosphate (UDP)glucose, deoxythymidine diphosphate-glucose, deoxythymidine diphosphate-rhamnose, UDP-galactose, UDP-N-acetylgalactosamine, and UDP-N-acetylglucosamine. A high yield of EPS from S-3 cultivated with lactose rather than glucose as the carbon source was correlated with high transcriptional levels of the genes associated with metabolism of these nucleotide sugars and EPS biosynthesis. Our results provide a better understanding of EPS biosynthesis in S. thermophilus and can facilitate enhanced EPS production by lactic acid bacteria fermentation via genetic and metabolic engineering approaches.

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Comparative Transcriptomic Analysis of Streptococcus thermophilus TH1436 and TH1477 Showing Different Capability in the Use of Galactose

Cited by 26 publications

References 73 publications

Short communication: Lactose utilization of Streptococcus thermophilus and correlations with β-galactosidase and urease

Short communication: Lactose utilization of Streptococcus thermophilus and correlations with β-galactosidase and urease

Comparative Genomics of Streptococcus thermophilus Support Important Traits Concerning the Evolution, Biology and Technological Properties of the Species

Genomic and phenotypic analyses of exopolysaccharide biosynthesis in Streptococcus thermophilus S-3

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