Streptococcus Thermophilus Research Articles

Gene knock-out in Mycobacterium abscessus using Streptococcus thermophilus CRISPR/Cas

The CRISPRi system using dCas9Sth1 from Streptococcus thermophilus developed for Mycobacterium tuberculosis and M. smegmatis was modified to allow gene knock-out in M. abscessus. Efficacy of the knock-out system was evaluated by applying deletions and insertions to the mps1 gene. A comparative genomic analysis of mutants and wild type validated the target specificity.

Reducing Immunoreactivity of Gluten Peptides by Probiotic Lactic Acid Bacteria for Dietary Management of Gluten-Related Diseases.

Immunoreactive gluten peptides that are not digested by peptidases produced by humans can trigger celiac disease, allergy and non-celiac gluten hypersensitivity. The aim of this study was to evaluate the ability of selected probiotic strains to hydrolyze immunoreactive gliadin peptides and to identify peptidase-encoding genes in the genomes of the most efficient strains. Residual gliadin immunoreactivity was measured after one- or two-step hydrolysis using commercial enzymes and bacterial peptidase preparations by G12 and R5 immunoenzymatic assays. Peptidase preparations from Lacticaseibacillus casei LC130, Lacticaseibacillus paracasei LPC100 and Streptococcus thermophilus ST250 strains significantly reduced the immunoreactivity of gliadin peptides, including 33-mer, and this effect was markedly higher when a mixture of these strains was used. In silico genome analyses of L. casei LC130 and L. paracasei LPC100 revealed the presence of genes encoding peptidases with the potential to hydrolyze bonds in proline-rich peptides. This suggests that L. casei LC130, L. paracasei LPC100 and S. thermophilus ST250, especially when used as a mixture, have the ability to hydrolyze immunoreactive gliadin peptides and could be administered to patients on a restricted gluten-free diet to help treat gluten-related diseases.

Investigating the Role of β-Disodium Glycerophosphate and Urea in Promoting Growth of Streptococcus thermophilus from Omics-Integrated Genome-Scale Models.

This study investigates the impact of urea and β-GP on the growth of Streptococcus thermophilus S-3, a bacterium commonly used in industrial fermentation processes. Through a series of growth experiments, transcriptome, metabolome, and omics-based analyses, the research demonstrates that both urea and β-GP can enhance the biomass of S. thermophilus, with urea showing a more significant effect. The optimal urea concentration for growth was determined to be 3 g/L in M17 medium. The study also highlights the metabolic pathways influenced by urea and β-GP, particularly the galactose metabolism pathway, which is crucial for cell growth when lactose is the substrate. The integration of omics data into the genome-scale metabolic model of S. thermophilus, iCH502, allowed for a more accurate prediction of metabolic fluxes and growth rates. The study concludes that urea can serve as a viable substitute for β-GP in the cultivation of S. thermophilus, offering potential cost and efficiency benefits in industrial fermentation processes. The findings are supported by validation experiments with 11 additional strains of S. thermophilus, which showed increased biomass in UM17 medium.

Microbial composition and viability of natural whey starters used in PDO Comté cheese-making

Natural whey starters (NWS) are cultures with undefined multiple-strains species commonly used to speed up the fermentation process of cheeses. The aim of this study was to explore the diversity and the viability of Comté cheese NWS microbiota. Culture-dependent methods, i.e. plate counting and genotypic characterization, and culture-independent methods, i.e. qPCR, viability-qPCR, fluorescence microscopy and DNA metabarcoding, were combined to analyze thirty-six NWS collected in six Comté cheese factories at two seasons. Our results highlighted that NWS were dominated by Streptococcus thermophilus (ST) and thermophilic lactobacilli. These species showed a diversity of strains based on Rep-PCR. The dominance of Lactobacillus helveticus (LH) over Lactobacillus delbrueckii (LD) varied depending on the factory and the season. This highlighted two types of NWS: the type-ST/LD (LD > LH) and the type-ST/LH (LD < LH). The microbial composition varied depending on cheese factory. One factory was distinguished by its level of culturable microbial groups (ST, enterococci and yeast) and its fungi diversity. The approaches used to estimate the viability showed that most NWS cells were viable. Further investigations are needed to understand the microbial diversity of these NWS.

Cultivable microbial diversity, peptide profiles, and bio-functional properties in Parmigiano Reggiano cheese.

Lactic acid bacteria (LAB) communities shape the sensorial and functional properties of artisanal hard-cooked and long-ripened cheeses made with raw bovine milk like Parmigiano Reggiano (PR) cheese. While patterns of microbial evolution have been well studied in PR cheese, there is a lack of information about how this microbial diversity affects the metabolic and functional properties of PR cheese. To fill this information gap, we characterized the cultivable fraction of natural whey starter (NWS) and PR cheeses at different ripening times, both at the species and strain level, and investigated the possible correlation between microbial composition and the evolution of peptide profiles over cheese ripening. The results showed that NWS was a complex community of several biotypes belonging to a few species, namely, Streptococcus thermophilus, Lactobacillus helveticus, and Lactobacillus delbrueckii subsp. lactis. A new species-specific PCR assay was successful in discriminating the cheese-associated species Lacticaseibacillus casei, Lacticaseibacillus paracasei, Lacticaseibacillus rhamnosus, and Lacticaseibacillus zeae. Based on the resolved patterns of species and biotype distribution, Lcb. paracasei and Lcb. zeae were most frequently isolated after 24 and 30 months of ripening, while the number of biotypes was inversely related to the ripening time. Peptidomics analysis revealed more than 520 peptides in cheese samples. To the best of our knowledge, this is the most comprehensive survey of peptides in PR cheese. Most of them were from β-caseins, which represent the best substrate for LAB cell-envelope proteases. The abundance of peptides from β-casein 38-88 region continuously increased during ripening. Remarkably, this region contains precursors for the anti-hypertensive lactotripeptides VPP and IPP, as well as for β-casomorphins. We found that the ripening time strongly affects bioactive peptide profiles and that the occurrence of Lcb. zeae species is positively linked to the incidence of eight anti-hypertensive peptides. This result highlighted how the presence of specific LAB species is likely a pivotal factor in determining PR functional properties.

Microbiological characteristics, proximate composition and sensory properties of plant-based set yoghurt analogue produced from blends of maize-soybean

This research produced yoghurt analogue from vitamin A bio-fortified maize with or without substitution with soymilk to combat micronutrient deficiencies. Microorganisms were enumerated and isolated and pH was also determined at 7 days intervals for three weeks. Proximate composition, organoleptic properties and total sugar were also determined on the products using standard methods. The result showed that the TVC and LAB count was within the range of 4.778-8.193 log CFU.ml-1 and 6.000-8.662 log CFU.ml-1 respectively and the pH generally decreased during the period of storage at refrigeration temperature. Streptococcus thermophilus, Lactobacillus delbrueckii spp. bulgaricus, Bacillus licheniformis, Saccharomyces cerevisiae and Aspergillus niger were isolated from the samples during storage. Protein (2.23-2.86%), fat (0.43-0.61%) and ash (0.41-0.56%) contents increased while carbohydrate contents decreased with an increase in the addition of soymilk. There was no significant difference (p&gt;0.05) in the scores for colour, sourness and overall acceptability of all samples. The addition of soymilk at 50% significantly increased (p&lt;0.05) the taste and aroma of the yoghurt analogue. Thus, cereal-based yoghurt analogue can be produced from maize milk analogue substituted with up to 50% soymilk to enhance the consumption of nutrient-dense plant-based yoghurt analogue.

Detection of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in Inactivated Fermented Milk Using Fluorescence Quantitative Loop-Mediated Isothermal Amplification

Currently, no effective method exists to detect and monitor fermentation probiotics and evaluate the quality of inactivated fermented milk. Therefore, in this study, a fluorescence quantitative loop-mediated isothermal amplification (FQ-LAMP) method was developed to detect Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. The specificity of LAMP primers for L. bulgaricus and S. thermophilus was verified using S-type amplification curves and a single peak at approximately 88.568°C and 83.704°C of the melting curves, respectively. The lowest quantification limits of FQ-LAMP for the two strains in inactivated fermented milk were 8.1 × 103 CFU/g (170 fg/μL) and 6.8 × 103 CFU/g (170 fg/μL), respectively. FQ-LAMP was used to analyse 40 inactivated fermented milk samples from six randomly selected brands. The logarithmic concentration of S. thermophilus in all products was between 7.482 and 8.936. The logarithmic concentration of L. bulgaricus ranged from 4.590 to 8.277, with no detectable L. bulgaricus in three samples. FQ-LAMP has the potential as a rapid, specific, and accurate method for detecting and monitoring L. bulgaricus and S. thermophilus in inactivated fermented milk during their shelf life.

Substitution of Asp29 with Asn29 in the metallochaperone UreE of Streptococcus thermophilus DSM 20617T increases the urease activity and anticipates urea hydrolysis during milk fermentation

Urease operon is highly conserved within the species Streptococcus thermophilus and urease-negative strains are rare in nature. S. thermophilus MIMO1, isolated from commercial yogurt, was previously characterized as urease-positive Ni-dependent strain. Beside a mutation in ureQ, coding for a nickel ABC transporter permease, the strain MIMO1 showed a mutation in ureE gene which code for a metallochaperone involved in Ni delivery to the urease catalytic site. The single base mutation in ureE determined a substitution of Asp29 with Asn29 in the metallochaperone in a conserved protein region not involved in the catalytic activity. With the aim to investigate the role Asp29vs Asn29 substitution in UreE on the urease activity of S. thermophilus, ureE gene of the reference strain DSM 20617T (ureEDSM20617) was replaced by ureE gene of strain MIMO1 (ureEMIMO1) to obtain the recombinant ES3. In-gel detection of urease activity revealed that the substitution of Asp29 with Asn29 in UreE resulted in a higher stability of the enzyme complexes. Moreover, the recombinant ES3 showed higher level of urease activity compared to the wildtype without any detectable increase in the expression level of ureC gene, thus highlighting the role of UreE not only in Ni assembly but also on the level of urease activity. During the growth in milk, the recombinant ES3 showed an anticipated urease activity compared to the wildtype, and analogous milk fermentation performance. The overall data obtained by comparing urease-positive and urease-negative strains/mutants confirmed that urease activity strongly impacts on the milk fermentation process and specifically on the yield of the homolactic fermentation.

Effect of biogenic exopolysaccharides in characteristics and stability of a novel Requeson-type cheese

Whey is a by-product of the dairy industry with considerable nutritional value but tends to be discarded with industrial effluents. One of the alternatives for its use is the production of whey cheeses, although they need to add extra ingredients to raise the yields, which elevates production costs. A less expensive alternative is using exopolysaccharides (EPS), carbohydrate polymers microorganisms produce. This research aimed to formulate and evaluate the stability of a Requeson-type cheese employing whey that has EPS produced biogenically by in situ fermentation with lactic acid bacteria. Two EPS-producing strains, Lactobacillus delbrueckii subsp bulgaricus NCFB 2772 and Streptococcus thermophilus SY-102, were used separately and in coculture (1:1 ratio). We found that coculture had the highest EPS production (1.49 mg/mL of whey) compared to the monocultures. This influenced the yield of the processed Requeson-type cheese (5.56%), which was higher than the produced with unfermented whey (3.77%). Similarly, the physicochemical and sensory parameters of the developed product showed differences. Furthermore, none of the Requeson-type cheeses made with fermented whey showed microbial growth after 21 days of storage (4 °C). Therefore, EPS is a potential strategy for producing Requeson-type whey cheeses with a high yield and stability.

Addition of glutamine to milk during fermentation by individual strains of lactic acid bacteria and the effects on pyroglutamic and butyric acid

Lactic acid bacteria fermentation generates pyroglutamic and butyric acid, two metabolites that influence the flavour of foods and could significantly benefit human health. In literature, data on the ability of lactic acid bacteria to produce these molecules is limited. Therefore, in this study, single strains were inoculated in milk to determine the quantity of butyric and pyroglutamic acid produced and the effect of glutamine enrichment substrate was evaluated. In addition to Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, which are used in traditional yoghurt, other strains (including some probiotics) isolated from different sources were studied. L. bulgaricus E1 and the probiotic L. casei ATCC393 generated the most butyric acid (110 and 108 mg 100 g−1 d.m., respectively) in media without glutamine. The highest quantity of pyroglutamic acid was produced by Lactobacillus delbruekii subsp. bulgaricus MY (700 mg 100 g−1 d.m.) and the probiotic Lacticaseibacillus casei Shirota (1786 mg 100 g−1 d.m.), respectively. Most of the inoculated strains produced a greater quantity of pyroglutamic acid in the substrate with glutamine. These results are an interesting starting point for researchers to utilize selected strains of lactic acid bacteria to develop new dairy products with functional properties due to the presence of pyroglutamic and butyric acid.

Fermentation Characteristics of Fermented Milk with Streptococcus thermophilus CICC 6063 and Lactobacillus helveticus CICC 6064 and Volatile Compound Dynamic Profiles during Fermentation and Storage.

The lactic acid bacteria Streptococcus thermophilus and Lactobacillus helveticus are commonly used as starter cultures in dairy product production. This study aimed to investigate the characteristics of fermented milk using different ratios of these strains and analyze the changes in volatile compounds during fermentation and storage. A 10:1 ratio of Streptococcus thermophilus CICC 6063 to Lactobacillus helveticus CICC 6064 showed optimal fermentation time (4.2 h), viable cell count (9.64 log10 colony-forming units/mL), and sensory evaluation score (79.1 points). In total, 56 volatile compounds were identified and quantified by solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS), including aldehydes, ketones, acids, alcohols, esters, and others. Among these, according to VIP analysis, 2,3-butanedione, acetoin, 2,3-pentanedione, hexanoic acid, acetic acid, acetaldehyde, and butanoic acid were identified as discriminatory volatile metabolites for distinguishing between different time points. Throughout the fermentation and storage process, the levels of 2,3-pentanedione and acetoin exhibited synergistic dynamics. These findings enhance our understanding of the chemical and molecular characteristics of milk fermented with Streptococcus thermophilus and Lactobacillus helveticus, providing a basis for improving the flavor and odor of dairy products during fermentation and storage.

Multistrain Probiotics Alleviate Diarrhea by Modulating Microbiome-Derived Metabolites and Serotonin Pathway.

Diarrhea, a common gastrointestinal symptom in health problems, is highly associated with gut dysbiosis. The purpose of this study is to demonstrate the effect of multistrain probiotics (Sensi-Biome) on diarrhea from the perspective of the microbiome-neuron axis. Sensi-Biome (Lactiplantibacillus plantarum, Bifidobacterium animalis subsp. lactis, Lactobacillus acidophilus, Streptococcus thermophilus, Bifidobacterium bifidum, and Lactococcus lactis) was administered in a 4% acetic acid-induced diarrhea rat model at concentrations of 1 × 108 (G1), 1 × 109 (G2), and 1 × 1010CFU/0.5mL (G3). Diarrhea-related parameters, inflammation-related cytokines, and stool microbiota analysis by 16S rRNA were evaluated. A targeted and untargeted metabolomics approach was used to analyze the cecum samples using liquid chromatography and orbitrap mass spectrometry. The stool moisture content (p < 0.001), intestinal movement rate (p < 0.05), and pH (p < 0.05) were significantly recovered in G3. Serotonin levels were decreased in the multistrain probiotics groups. The inflammatory cytokines, serotonin, and tryptophan hydroxylase expression were improved in the Sensi-Biome groups. At the phylum level, Sensi-Biome showed the highest relative abundance of Firmicutes. Short-chain fatty acids including butyrate, iso-butyrate, propionate, and iso-valeric acid were significantly modified in the Sensi-Biome groups. Equol and oleamide were significantly improved in the multistrain probiotics groups. In conclusion, Sensi-Biome effectively controls diarrhea by modulating metabolites and the serotonin pathway.

An integrated approach to explore the microbial biodiversity of natural milk cultures for cheesemaking

The use of natural milk culture (NMC) represents a key factor in PDO Montasio cheeses, contributing to its distinctive sensory profile. The complex microbial ecosystem of NMCs is the result of heat treatment and incubation conditions, which can vary considerably among different production plants. In this study, the microbiota of NMCs collected from 10 PDO Montasio cheese dairies was investigated employing colony counts and metagenomic analysis. Furthermore, residual sugars, organic acids, and volatile profiles were quantitatively investigated. Results showed that Streptococcus thermophilus was the dominant species in all NMCs, and a subdominant population made of other streptococci and L. salivarius was also present. The incubation temperature appeared to be the main driver of biodiversity in NMCs. Metagenomics allowed us to evidence the presence of minor species involving safety (e.g., Staph. aureus) as well as possible functional aspects (Next Generation Probiotics). Statistical analysis based on residual sugars, organic acids, and volatiles' content allowed to correlate the presence of specific microbial groups with metabolites of great technological and sensory relevance, which can contribute to giving value to the artisanal production procedures of NMCs and clarify their role in the creation of the characteristics of PDO Montasio cheese.

Shelf-life extension of Pacific white shrimp (Litopenaeus vannamei) using sodium alginate/chitosan incorporated with cell-free supernatant of Streptococcus thermophilus FUA 329 during cold storage.

Seafood is highly perishable and has a short shelf-life. This study investigated the effect of chitosan and alginate (CH-SA) coating combined with the cell-free supernatant of Streptococcus thermophilus FUA329 (CFS) as a preservative on the quailty of white shrimp (Litopenaeus vannamei) refrigerated at 4° for 0, 3, 6, 9, 12, 15 days. Freshly shrimps were randomly divided into four groups: the CFS group (400 mL); the CH-SA group (1% chitosan/1% alginate); the CFS-CH-SA group (1% chitosan/1% alginate with 400 mL CFS) are treatment groups, and the control group (400 mL sterile water). The CFS-CH-SA coating effectively suppressed microbial growth total viable count and chemical accumulation (pH, total volatile basic nitrogen, thiobarbituric acid reactive substance) compared with the control. Additionally, the CFS-CH-SA coating improved the texture and sensory characteristics of shrimp during storage. The coated shrimp exhibited significantly reduced water loss (p<0.05). The combination of CH-SA coating with CFS treatment can extend the shelf life of shrimp. PRACTICAL APPLICATION: Recently, edible films have received more consideration as a promising method to enhance the shelf life of seafood. The presence of Lactic acid bacteria metabolites in edible films reduces spoilage and improves consumer health. Our findings encourage the application of edible coating incorporated with cell-free supernatant of Streptococcus thermophilus FUA 329 to design multifubctional foods and preserve the qualities of shrimp.

Assessment of the antioxidant and ACE-inhibitory activities and some quality characteristics of Kaşar cheese produced by probiotic Lactobacillus acidophilus

In this study, four types of Kaşar cheese were produced using raw milk (C), starter culture (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus) (S), starter culture + probiotic Lactobacillus acidophilus ATCC 4356 (SLA), and probiotic L. acidophilus ATCC 4356 (LA) were produced and ripened at 6 ± 2 °C for 150 days. The physicochemical, microbiological, proteolysis, electrophoretic (Urea-PAGE), ACE-inhibitory, and antioxidant activity analyses of vacuum-packed Kaşar cheeses were performed on 5, 30, 60, 90, 120, and 150 days of ripening. During ripening, no significant differences (p > 0.05) were detected in total solids, fat, and protein values of Kaşar cheeses. Titratable acidity, water-soluble nitrogen (WSN), ripening index (RI), and electrophoresis results of cheese samples showed an increase while pH values decreased. Also, the degradation products of αs1-casein were higher than those of β-casein. The number of probiotic L. acidophilus ATCC 4356 after scalding decreased by an average of 1.57 log cfu/g. However, probiotic bacteria count increased during ripening and maintained their viability. The addition of L. acidophilus ATCC 4356 improved the bioactivity, electrophoresis, titratable acidity, and ripening index results of Kaşar cheese. ACE-inhibitory activity of Kaşar cheeses increased during ripening and had the highest value on the 150th day of ripening. Furthermore, antioxidant activity of Kaşar cheeses increased on the 60th day of ripening and then decreased. Consequently, the combination of probiotic bacteria and starter culture had a positive effect on the physicochemical, microbiological, and proteolytic properties of Kaşar cheese.

Influence of Hesperidin on the Physico-Chemical, Microbiological and Sensory Characteristics of Frozen Yogurt.

Frozen yogurts contain yogurt culture bacteria, which might impart health benefits to their consumers. Global frozen yogurt market sales are expected to grow by 4.8% by 2028, which represents an important opportunity for the industry, consumers and researchers. Polyphenols are metabolites found in plants which have antioxidant and anti-inflammatory properties and might prevent chronic diseases such as cancer, diabetes and cardiovascular diseases. The objective of this study was to elucidate the effect of the polyphenol hesperidin on the physico-chemical, microbiological and sensory characteristics of frozen yogurts. Hesperidin was incorporated into frozen yogurt at three concentrations (125, 250 and 500 mg/90 g of product), while yogurt with no hesperidin was used as a control. The viscosity and overrun of the frozen yogurt were analyzed on day 0. The hardness, pH, color and Lactobacillus bulgaricus and Streptococcus thermophilus counts were determined after 0, 30 and 60 d. The melting rate was determined at 60 and 90 min after 0, 30 and 60 d. The bile and acid tolerances of both S. thermophilus and L. bulgaricus were measured after 7 and 60 d. A hedonic scale of nine points was used to measure sensory attributes. Data were analyzed at α = 0.05 with an ANOVA with Tukey's adjustment, and McNemar's test was used to analyze purchase intent. Hesperidin did not influence the pH, overrun or microbial characteristics. Polyphenol addition compared to the control decreased the melting rate but increased the hardness and bile tolerance of L. bulgaricus, as well as the L* and b* values. The sensory characteristics were not influenced by the lowest concentration of hesperidin, as it was not statistically different from the control. Moreover, consumers were interested in purchasing frozen yogurt with added hesperidin after learning about the health claim. This study can assist in the development of a healthier frozen yogurt in an increasingly competitive market.

Synergistic Effect of B-Type Lotus Seedpod Oligomeric Procyanidin and Probiotics against Adhesion of Enterotoxigenic Escherichia coli In Vitro

Enterotoxigenic Escherichia coli (ETEC) adhesion to gut epithelial cells is a prerequisite for diarrhea. Here, we studied the synergistic effect and potential mechanism of B-type lotus seedpod oligomeric procyanidin (LSPC) combined with probiotics against adhesion of ETEC. The results indicated that LSPC exhibited an effective anti-ETEC adhesion effect. LSPC showed signally synergistic effects with probiotics, e.g., Streptococcus thermophilus (ST) and Lactobacillus rhamnosus (LGG) in response to ETEC adhesion, with the combination of LSPC and LGG being the most efficacious. This may be attributed to the restoration of transmembrane resistance of cells, the increased expression of anti-inflammatory factors (IL-10, 1.89-fold), and the reduction of cellular inflammatory factor levels (TNF-α and IL-8), regulated by LGG-LSPC, resulting in a better enhancement of cellular immune defense and barrier function. In addition, the results of gas chromatography showed that LSPC, as a prebiotic, could significantly increase the total amount of short-chain fatty acids (especially, butyric acid) produced by probiotics (e.g., LGG), thus better maintaining intestinal health against ETEC infection. In conclusion, the synergistic effect of LSPC and probiotics (represented by LGG) against ETEC adhesion in epithelial cells may be achieved through the enhancement of cellular immune defense, cellular barrier function, and maintenance of homeostasis in the gut.

БИОПРОДУКТ ДЛЯ ПРОФИЛАКТИЧЕСКОГО ПИТАНИЯ

The purpose of the study is to develop technology for a preventive bioproduct based on raw milk, enriched with plant components and probiotic cultures. Objectives: creating a biological product with a good mutual combination of ingredients of plant and animal origin, allowing to obtain high nutritional and biological value in the final product; determination of quality indicators and sanitary-significant indicators of the finished enriched bioproduct. Research was carried out at the Siberian Cossack Institute of Technology and Management (branch of the FSBEI HE Moscow State University of Technology and Management named after K.G. Razumovsky) using the production and laboratory facilities of VNIMI-Sibir LLC (Omsk). The main characteristics of the enriched product are planned: high protein-energy index, high content of macro- and microelements and probiotic microorganisms. In order to comply with all the declared characteristics of the product with preventive properties, it was decided to use curd cheese obtained by the acid method using the enrichment of probiotic microflora as the basis for the dessert bioproduct. In the course of research, the composition of a combined starter was experimentally selected, consisting of a monospecies lyophilized concentrate of thermophilic streptococci of the species Streptococcus thermophilus “BK-Uglich-TNV” and a complex probiotic culture AiBi B6.10MIX (Bifidobacterium sp., Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus rhamnosus ). The study investigated the feasibility of using natural frozen cranberry puree, pine nut seeds and apple pectin in the recipe as functional plant ingredients, which were introduced into dairy raw materials to enrich the dessert bioproduct with biologically active nutrients. A dessert bioproduct was developed with a high protein content (animal and vegetable) and high probiotic properties (Lg number of cells, CFU/1 cm3: lactic acid bacteria – 10.14 ± 0.1, bifidobacteria – 7.15 ± 0.1) and organoleptic characteristics, enriched with macro- and microelements, vitamins and dietary fiber, which is recommended for use in preventive nutrition.

Analysis of metabolic differences between Jiaosu fermented from dendrobium flowers and stems based on untargeted metabolomics

Dendrobium officinale is an important traditional Chinese medicinal herb containing bioactive polysaccharides and alkaloids. This study characterized metabolite differences between jiaosu (fermented plant product) from Dendrobium flowers versus stems using untargeted metabolomics. The jiaosu was fermented by mixed fermentation of Saccharomyces cerevisiae, Lactobacillus bulgaricus and Streptococcus thermophilus. Liquid chromatography-mass spectrometry analysis identified 476 differentially expressed metabolites between the two Jiaosu products. Key results showed downregulation of flavonoid metabolism in Dendrobium Stems Edible Plant Jiaosu (SEP) but increased flavonoid synthesis in Dendrobium Flowers Edible Plant Jiaosu (FEP), likely an antioxidant response. SEP displayed upregulation of lignin metabolites with potential antioxidant properties. The findings demonstrate significant metabolite profile differences between SEP and FEP, providing the basis for developing functional jiaosu products targeting specific health benefits.

Fermentation Practices Select for Thermostable Endolysins in Phages.

Endolysins are produced by (bacterio)phages and play a crucial role in degrading the bacterial cell wall and the subsequent release of new phage progeny. These lytic enzymes exhibit a remarkable diversity, often occurring in a multimodular form that combines different catalytic and cell wall-binding domains, even in phages infecting the same species. Yet, our current understanding lacks insight into how environmental factors and ecological niches may have influenced the evolution of these enzymes. In this study, we focused on phages infecting Streptococcus thermophilus, as this bacterial species has a well-defined and narrow ecological niche, namely, dairy fermentation. Among the endolysins found in phages targeting this species, we observed limited diversity, with a singular structural type dominating in most of identified S. thermophilus phages. Within this prevailing endolysin type, we discovered a novel and highly conserved calcium-binding motif. This motif proved to be crucial for the stability and activity of the enzyme at elevated temperatures. Ultimately, we demonstrated its positive selection within the host's environmental conditions, particularly under the temperature profiles encountered in the production of yogurt, mozzarella, and hard cheeses that rely on S. thermophilus.