Showing papers on "Lactococcus lactis published in 2022"
TL;DR: This research presents a new mesoporous composite material for propionate that has the potential to be used as a preservative in the food and animal feed industries and has shown the versatility of the material.
Abstract: Propionate is widely used as a preservative in the food and animal feed industries. Propionate is currently produced by petrochemical processes, and fermentative production of propionate remains challenging.
30 citations
TL;DR: Oral supplementation with the engineered live biotherapeutic minimized gut dysbiosis without affecting the ampicillin concentration in serum, precluded the enrichment of antimicrobial resistance genes in the gut microbiome and prevented the loss of colonization resistance against Clostridioides difficile.
28 citations
TL;DR: Results indicate that WHH2078 can alleviate rodent depressive and anxiety-like behaviors in response to CUMS, which is associated with the improvement of 5-HT metabolism and modulation of the gut microbiome composition.
Abstract: Depression is a mood disorder with a high prevalence rate globally, which is associated with abnormalities in 5-hydroxytryptamine (5-HT) metabolism. Emerging evidence suggests that certain probiotics that modulate 5-HT metabolism confer beneficial effects on depression. In this study, in vitro enterochromaffin RIN14B cells were used for screening potential antidepressant probiotic Lactococcus lactis strains. The L. lactis strain WHH2078 increased to high levels the 5-HT precursor 5-hydroxytryptophan (5-HTP) and the expression of tryptophan hydroxylase 1 (Tph1), which converts tryptophan to 5-HTP in RIN14B cells. The oral administration of WHH2078 (1 × 109 CFU mL-1) in mice with induced chronic unpredictable mild stress (CUMS) for 5 weeks significantly ameliorated depressive and anxiety-like behaviors in the tail suspension test, forced swim test, sucrose preference test, and open field test. Besides, WHH2078 significantly reduced the serum corticosterone level and restored the central levels of 5-HT, 5-HTP, and brain-derived neurotrophic factor in CUMS-induced mice. Moreover, WHH2078 also reversed the 5-HTP levels in the serum and colon, accompanied by an upregulation in colonic Tph1 gene expression. Using 16S rRNA high-throughput sequencing of feces, WHH2078 was shown to improve the CUMS-induced gut microbial dysbiosis, through restoring alpha diversity and the abundances of Firmicutes and Bacteroidetes. In summary, these results indicate that WHH2078 can alleviate rodent depressive and anxiety-like behaviors in response to CUMS, which is associated with the improvement of 5-HT metabolism and modulation of the gut microbiome composition. Therefore, supplementation of the L. lactis strain WHH2078 with antidepressant properties may serve as a promising therapeutic strategy for chronic stress-induced depression.
26 citations
TL;DR: Interestingly, the isolated strain NMCC-M2 displayed the best probiotic features including survival at pH 3 and 0.5% bile salts, complete susceptibility to the tested antibiotics, high enzymatic potential, and in vitro cholesterol reduction, and could be considered as a potential target-based probiotic in cholesterol-lowering fermented food products.
Abstract: Probiotics retrieved from animal sources have substantial health benefits for both humans and animals. The present study was designed to identify lactic acid bacteria (LAB) isolated from domestic water buffalo milk (Bubalus bubalis) and to evaluate their potential as target-based probiotics. Forty-six LAB strains were isolated and, among them, five strains (NMCC-M2, NMCC-M4, NMCC-M5, NMCC-M6, and NMCC-M7) were regarded as possible probiotics on the basis of their phenotypic and biochemical properties. These isolates were molecularly identified as Weissella confusa (NMCC-M2), Leuconostoc pseudo-mesenteroides (NMCC-M4), Lactococcus lactis Subsp. hordniae (NMCC-M5), Enterococcus faecium NMCC-M6, and Enterococcus lactis NMCC-M7. The tested bacterial strains showed significant antimicrobial activity, susceptibility to antibiotics, acid and bile tolerance, sugar fermentation, enzymatic potential, and nonhemolytic characteristics. Interestingly, NMCC-M2 displayed the best probiotic features including survival at pH 3 and 0.5% (w/v) bile salts, complete susceptibility to the tested antibiotics, high enzymatic potential, and in vitro cholesterol reduction (48.0 µg/mL for NMCC-M2) with 0.3% bile salt supplementation. Therefore, the isolated strain NMCC-M2 could be considered as a potential target-based probiotic in cholesterol-lowering fermented food products.
22 citations
TL;DR: In this article, the bacteriocin-producing strains Lactococcus lactis L3A21M1 and Lc. garvieae SJM17 isolated from artisanal Azorean cheeses were incorporated into an edible fresh-cheese coating composed of alginate, maltodextrin and glycerol.
Abstract: Edible coatings incorporated with bacteriocin-producing lactic acid bacteria (LAB) can provide an alternative natural preservation method as they can offer an additional microbiological protection to food products. The bacteriocin-producing strains Lactococcus lactis L3A21M1 and Lc. garvieae SJM17 isolated from artisanal Azorean cheeses were incorporated into an edible fresh-cheese coating composed of alginate, maltodextrin and glycerol. The immobilization of Lactococcus cells into the coating had no negative effect on their viability and antibacterial activity throughout 10 days storage at 4 °C and 10 °C. The application of coating with immobilized Lactococcus cells on cheeses reduced significantly (p
19 citations
TL;DR: The noninvasive and real-time probiotic intervention strategy makes the communiation from the gut to the host more controllable, which will enable the potential for engineered microbes accurately and effectively regulating a host's health.
Abstract: The discovery of the gut-brain axis has proven that brain functions can be affected by the gut microbiota's metabolites, so there are significant opportunities to explore new tools to regulate gut microbiota and thus work on the brain functions. Meanwhile, engineered bacteria as oral live biotherapeutic agents to regulate the host's healthy homeostasis have attracted much attention in microbial therapy. However, whether this strategy is able to remotely regulate the host's brain function in vivo has not been investigated. Here, we engineered three blue-light-responsive probiotics as oral live biotherapeutic agents. They are spatiotemporally delivered and controlled by the upconversion optogenetic micro-nano system. This micro-nano system promotes the small intestine targeting and production of the exogenous L. lactis in the intestines, which realizes precise manipulation of brain functions including anxiety behavior, Parkinson's disease, and vagal afferent. The noninvasive and real-time probiotic intervention strategy makes the communiation from the gut to the host more controllable, which will enable the potential for engineered microbes accurately and effectively regulating a host's health.
16 citations
01 Jan 2022
TL;DR: In this article , an edible fresh-cheese coating composed of alginate, maltodextrin, and glycerol was applied on Azorean cheeses to prevent the contamination by Listeria monocytogenes and prevented the growth of mesophilic bacteria.
Abstract: Edible coatings incorporated with bacteriocin-producing lactic acid bacteria (LAB) can provide an alternative natural preservation method as they can offer an additional microbiological protection to food products. The bacteriocin-producing strains Lactococcus lactis L3A21M1 and Lc. garvieae SJM17 isolated from artisanal Azorean cheeses were incorporated into an edible fresh-cheese coating composed of alginate, maltodextrin and glycerol. The immobilization of Lactococcus cells into the coating had no negative effect on their viability and antibacterial activity throughout 10 days storage at 4 °C and 10 °C. The application of coating with immobilized Lactococcus cells on cheeses reduced significantly (p < 0.05) the contamination by Listeria monocytogenes on surface and prevented the growth of mesophilic bacteria by the 6th and 8th day of storage at 4 °C. Moreover, the coating reduced moisture and weight losses of fresh cheeses during storage, without affecting the pH and titratable acidity. The coating also prevented the migration of L. monocytogenes from the surface into the cheeses. These findings indicate that alginate-maltodextrin-glycerol formulation provided an excellent matrix to support Lactococcus cells viability and bacteriocin production. This bioactive coating can act as protective antimicrobial barrier in fresh cheeses by reducing bacterial contamination after processing.
16 citations
TL;DR: LAB strains showed tolerance to pH 3.0, bile salt, resistance to lysozyme and β-galactosidase activity, and Gene mesY for bacteriocin production was detected only in Leuconostoc spp.
14 citations
TL;DR: In this article , bacteriocin was extracted from L. lactis strain CH3 and partially purified using 60 % ammonium sulphate and then completely purified by G-50 column chromatography.
13 citations
TL;DR: In this article , from spontaneous raw milk fermentations 14 LAB strains belonging to 6 species were isolated and their technological and nutritional characterisation led to the selection of two strains of Lactococcus lactis with a high GABA-producing capability in milk, enhanced by the addition of 5 mmol of monosodium glutamate.
13 citations
TL;DR: Understandings from this study further generalized the EV‐producing phenotype to Gram‐positive L. lactis, and provide additional insights into the EV production mechanism involving prophage‐encoded holin–lysin system.
Abstract: Gram‐positive bacterial extracellular membrane vesicles (EVs) have been drawing more attention in recent years. However, mechanistic insights are still lacking on how EVs are released through the cell walls in Gram‐positive bacteria. In this study, we characterized underlying mechanisms of EV production and provide evidence for a role of prophage activation in EV release using the Gram‐positive bacterium Lactococcus lactis as a model. By applying a standard EV isolation procedure, we observed the presence of EVs in the culture supernatant of a lysogenic L. lactis strain FM‐YL11, for which the prophage‐inducing condition led to an over 10‐fold increase in EV production in comparison with the non‐inducing condition. In contrast, the prophage‐encoded holin–lysin knockout mutant YL11ΔHLH and the prophage‐cured mutant FM‐YL12 produced constantly low levels of EVs. Under the prophage‐inducing condition, FM‐YL11 did not show massive cell lysis. Defective phage particles were found to be released in and associated with holin–lysin‐induced EVs from FM‐YL11, as demonstrated by transmission electron microscopic images, flow cytometry and proteomics analysis. Findings from this study further generalized the EV‐producing phenotype to Gram‐positive L. lactis, and provide additional insights into the EV production mechanism involving prophage‐encoded holin–lysin system. The knowledge on bacterial EV production can be applied to all Gram‐positive bacteria and other lactic acid bacteria with important roles in fermentations and probiotic formulations, to enable desired release and delivery of cellular components with nutritional values or probiotic effects.
TL;DR: Wang et al. as discussed by the authors investigated the dynamic changes in physicochemical parameters, flavor compounds, and microbiota community during the natural production of suansun, and they found that the microbial flora exhibited a dynamic change from acid-sensitive genera of Lactococcus, Leuconostoc, Weissella, and Enterobacter to an acid-resistant genus of lactic acid and acetic acid accumulation.
TL;DR: In this article , the authors compared growth and survival of individual strains during cheesemaking, and after salting and pressing, using flow cytometry with fluorescent staining by SYBR Green and propidium iodide to determine the number of live and dead cells in cheese at different salt levels.
TL;DR: In this paper , the effect of corn oil and Lactococcus lactis (L. lactis) on sourdough bread aroma and its effect on bread flavor was studied.
Abstract: Corn oil and Lactococcus lactis (L. lactis) were selected for improving the sourdough bread aroma, and their effect on bread flavor was studied. Volatile compounds (VOCs) in sourdough and bread crumbs were determined by gas chromatography−mass spectrometry. The results demonstrated that the VOC profiles appeared mainly dominated by alcohols, aldehydes, ketones, acids, esters, and heterocyclic compounds. Principal component analysis and cluster analysis showed that the formation of most alcohols were promoted by L. lactis, while corn oil addition yielded more aldehydes, ketones, and furans. Further analysis of odor-active components in bread was characterized by aroma extract dilution analysis and odor activity value (OAV). In the sourdough bread obtained with the addition of corn oil and lipase, (E,E)-2,4-decadienal, 2-pentylfuran, 1-octen-3-ol, 3-methylthio-1-propanol, and (E)-2-nonenal had higher flavor dilution factors and OAV, which were the key aroma compounds distinguished from other varieties of breads.
TL;DR: In this paper , the authors evaluated the safety and probiotic characteristics of the newly isolated Enterococcus lactis strain JDM1 by the combination of whole genome sequence information analysis and phenotypic assays, including antimicrobial susceptibility test, haemolysis assay, biogenic amine production assay, cytotoxicity assay.
TL;DR: In this article , the authors employ electron cryomicroscopy (cryoEM), functional assays, and comparative cross-linking to study in vivo assembled mesophilic Lactococcus lactis Csm (LlCsm) at the three functional states: apo, the CTR- and the NTR-bound.
Abstract: The small RNA-mediated immunity in bacteria depends on foreign RNA-activated and self RNA-inhibited enzymatic activities. The multi-subunit Type III-A CRISPR-Cas effector complex (Csm) exemplifies this principle and is in addition regulated by cellular metabolites such as divalent metals and ATP. Recognition of the foreign or cognate target RNA (CTR) triggers its single-stranded deoxyribonuclease (DNase) and cyclic oligoadenylate (cOA) synthesis activities. The same activities remain dormant in the presence of the self or non-cognate target RNA (NTR) that differs from CTR only in its 3'-protospacer flanking sequence (3'-PFS). Here we employ electron cryomicroscopy (cryoEM), functional assays, and comparative cross-linking to study in vivo assembled mesophilic Lactococcus lactis Csm (LlCsm) at the three functional states: apo, the CTR- and the NTR-bound. Unlike previously studied Csm complexes, we observed binding of 3'-PFS to Csm in absence of bound ATP and analyzed the structures of the four RNA cleavage sites. Interestingly, comparative crosslinking results indicate a tightening of the Csm3-Csm4 interface as a result of CTR but not NTR binding, reflecting a possible role of protein dynamics change during activation.
TL;DR: In this article , a two-step process for recombinant production of active prenisin with Corynebacterium glutamicum was proposed, and the results provided a basis for further studies to optimize product yields, transfer production to sustainable substrates and purification of pharmaceutical grade nisin.
Abstract: The bacteriocin nisin is naturally produced by Lactococcus lactis as an inactive prepeptide that is modified posttranslationally resulting in five (methyl-)lanthionine rings characteristic for class Ia bacteriocins. Export and proteolytic cleavage of the leader peptide results in release of active nisin. By targeting the universal peptidoglycan precursor lipid II, nisin has a broad target spectrum including important human pathogens such as Listeria monocytogenes and methicillin-resistant Staphylococcus aureus strains. Industrial nisin production is currently performed using natural producer strains resulting in rather low product purity and limiting its application to preservation of dairy food products.We established heterologous nisin production using the biotechnological workhorse organism Corynebacterium glutamicum in a two-step process. We demonstrate successful biosynthesis and export of fully modified prenisin and its activation to mature nisin by a purified, soluble variant of the nisin protease NisP (sNisP) produced in Escherichia coli. Active nisin was detected by a L. lactis sensor strain with strictly nisin-dependent expression of the fluorescent protein mCherry. Following activation by sNisP, supernatants of the recombinant C. glutamicum producer strain cultivated in standard batch fermentations contained at least 1.25 mg/l active nisin.We demonstrate successful implementation of a two-step process for recombinant production of active nisin with C. glutamicum. This extends the spectrum of bioactive compounds that may be produced using C. glutamicum to a bacteriocin harboring complex posttranslational modifications. Our results provide a basis for further studies to optimize product yields, transfer production to sustainable substrates and purification of pharmaceutical grade nisin.
TL;DR: Wang et al. as discussed by the authors studied the effects of bacterial community succession and core microbial reconstruction on the flavor of paocai, using HPLC and GC-MS to investigate changes in flavor compounds during the fermentation of Paocai.
TL;DR: Probiotics did not affect the microbiota composition, and none of the baseline microbiota-related features could predict therapeutic response as defined by cluster analysis, but it does not affect diversity and taxonomic composition.
Abstract: Probiotics are known to regulate host metabolism. In randomized controlled trial we aimed to assess whether interventions with probiotic containing following strains: Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Levilactobacillus brevis W63, Lacticaseibacillus casei W56, Ligilactobacillus salivarius W24, Lactococcus lactis W19, and Lactococcus lactis W58 affect gut microbiota to promote metabolic effects. By 16S rRNA sequencing we analyzed the fecal microbiota of 56 obese, postmenopausal women randomized into three groups: (1) probiotic dose 2.5 × 109 CFU/day (n = 18), (2) 1 × 1010 CFU/day (n = 18), or (3) placebo (n = 20). In the set of linear mixed-effects models, the interaction between pre- or post-treatment bacterial abundance and time on cardiometabolic parameters was significantly (FDR-adjusted) modified by type of intervention (26 and 19 three-way interactions for the pre-treatment and post-treatment abundance, respectively), indicating the modification of the bio-physiological role of microbiota by probiotics. For example, the unfavorable effects of Erysipelotrichi, Erysipelotrichales, and Erysipelotrichaceae on BMI might be reversed, but the beneficial effect of Betaproteobacteria on BMI was diminished by probiotic treatment. Proinflammatory effect of Bacteroidaceae was alleviated by probiotic administration. However, probiotics did not affect the microbiota composition, and none of the baseline microbiota-related features could predict therapeutic response as defined by cluster analysis. Conclusions: Probiotic intervention alters the influence of microbiota on biochemical, physiological and immunological parameters, but it does not affect diversity and taxonomic composition. Baseline microbiota is not a predictor of therapeutic response to a multispecies probiotic. Further multi-omic and mechanistic studies performed on the bigger cohort of patients are needed to elucidate the cardiometabolic effect of investigated probiotics in postmenopausal obesity.
TL;DR: In this article , the aim of the work was to isolate and select yeasts from spontaneous milk fermentations to be used as inoculum, together with lactic acid bacteria (LAB) for manufacturing a potentially probiotic acidic low-alcohol fermented milk.
Abstract: Probiotic milk is a class of fermented milk that possesses health-promoting effects, not only due to the lactic acid bacteria (LAB) presence but potentially also to yeast activity. Hence, the aim of this work was to isolate and select yeasts from spontaneous milk fermentations to be used as inoculum, together with LAB, for manufacturing a potentially probiotic acidic low-alcohol fermented milk. Six yeast species were detected from the spontaneous milk fermentation. A screening of 13 yeast strains and 14 previously isolated LAB strains, based on the resistance to bile salts and to acidic conditions, was carried out. The best performing strains were successively tested for in vitro gastrointestinal tolerance. A strain of Kluyveromyces marxianus and a strain of Lactococcus lactis were selected for the manufacturing of two different fermented milk. The values of the main technological and microbiological parameters (pH, organic acids, ethanol, and microbial concentrations) of the experimental milk were in the range of those reported for this category of products. The evaluation of microorganism survival in fermented milk samples subjected to simulated gastrointestinal conditions highlighted a high resistance of both strains. In conclusion, the selected microbial starter culture enabled the setting up of potential probiotic fermented milk.
TL;DR: Wang et al. as mentioned in this paper compared the flavor profile of traditional dry sausage, inoculated with lactic acid bacteria (LAB), including Lactobacillus plantarum MDJ2, Lactebacillus sakei HRB10, Lb. curvatus SYS29, Weissella hellenica HRB6, and Lactococcus lactis HRB0 using headspace solid-phase microextraction gas chromatography-mass spectrometry coupled with electronic nose (E-nose).
Abstract: The traditional dry sausage is highly appreciated in China because of its unique flavor characteristics. This study aimed to characterize and compare the flavor profile of traditional dry sausage, inoculated with lactic acid bacteria (LAB), including Lactobacillus plantarum MDJ2, Lactobacillus sakei HRB10, Lactobacillus curvatus SYS29, Weissella hellenica HRB6, and Lactococcus lactis HRB0 using headspace solid-phase microextraction gas chromatography-mass spectrometry coupled with electronic nose (E-nose). The control (non-inoculated) sausage presented higher water activity and moisture content compared to the inoculated sausages whereas, the inoculation led to decreased pH values and increased LAB counts during fermentation of dry sausages. Inoculation with LAB increased volatile compound contents and decreased total contents of free amino acids of sausages. E-nose and sensory analysis confirmed that inoculation with LAB, especially W. hellenica HRB6, Lb. sakei HRB10, and Lb. curvatus SYS29 enriched the pleasant odors of dry sausage. Correlation analysis demonstrated that sausages inoculated with W. hellenica HRB6 and Lb. sakei HRB10 showed a correlation with most of the key volatile compounds. In conclusion, W. hellenica HRB6 and Lb. sakei HRB10 are promising starter cultures to enhance the flavor characteristics of dry sausages.
TL;DR: In this paper , the first structure of a bacterial GH31 α-1,3-glucosidase was determined using X-ray crystallography and cryogenic electron microscopy and provided new insight into the substrate specificity of GH31 enzymes and physiological functions of bacterial and fungal GH31_u1 members.
TL;DR: In this article , a review of the potential immunomodulatory effects of probiotic bacteria in fermented dairy products is presented, and the authors further explore studies dealing with fermentation-containing probiotic products in a context of inflammation.
TL;DR: In this paper , Latilactobacillus sakei (29 strains), Lactococcus lactis (1 strain), Lb. plantarum MDJ2, W. hellenica HRB6, and Lc. lactis HRB0 promoted the generation of FAAs and volatile compounds.
TL;DR: In this article , the effect of Lactococcus lactis in the bacterial community of Macrobrachium rosenbergii postlarvae (PL) with initial mean weight of 0.1 g, and length 1.4 cm in biofloc, was evaluated.
Abstract: The prawns fed with Lactococcus lactis obtained 100% survival in the BFT and BFTPROB treatments compared to the CONT (80%). Regarding growth, it was observed in PROB and BFTPROB treatments, the organisms got greater weight (6.3 ± 1.6, 6.8 ± 1.3 respectively) compared to the other treatments. The effect of L. lactis in the bacterial community of Macrobrachium rosenbergii postlarvae (PL’s) with initial mean weight of 0.1 g, and length 1.4 cm in biofloc, was evaluated. A randomized experimental design was used: T1:BFT: biofloc; T2:BFTPROB:biofloc+probiotic; T3:PROB:probiotic; T4:CONT:control; all in triplicate with 60 PL's/treatment. On days 64 and 127, the weight and length of prawns were determined. 15 guts/treatment were extracted and water samples to obtain bacterial DNA. Massive sequencing of 16S rRNA gene of the samples was performed. Metagenomic analysis identified 17 bacteria classes in gut and water samples. The most abundant were Alphaproteobacteria, Gammaproteobacteria, Betaproteobacteria, Flavobacteria, Actinobacteria, and Clostridia with different benefits in the prawns' health. The bacterial community in the intermediate phase was different to the final, maybe for the colonization capacity of certain bacteria that developed in each treatment. However, L. lactis did not affect the microbial community in prawns' gut and culture water, it attributed to the displacement of the microbial community in biofloc and other probiotics, however it was observed a better prawns' growth and survival with biofloc and probiotic treatments.
TL;DR: In this article , the authors investigated the multifunctional properties of specific synthetic peptides previously identified in milk fermented with Lactococcus lactis NRRL B-50571 and NRRLB-50572 on the inhibition of enzymes involved in hypertension (ACE), type 2 diabetes (DPP-IV) and thrombosis (thrombin).
Abstract: The aim of this study was to investigate the multifunctional properties of specific synthetic peptides previously identified in milk fermented with Lactococcus lactis NRRL B-50571 and NRRL B-50572 on the inhibition of enzymes involved in hypertension (ACE), type 2 diabetes (DPP-IV) and thrombosis (thrombin). Moreover, in vitro gastrointestinal digestion was performed in order to know the stability of peptides and its effect on the biological activities. Also, in silico analysis was employed for the prediction of sequences after digestion. Results showed that peptide inhibitory activities on ACE, DPP-IV and thrombin were enhanced after digestion. After in vitro digestion, peptide NAVPITPTLN showed the best efficiency to inhibit DPP-IV. Likewise, NAVPITPTLN and QEPVLGPVRGPFIIV showed high thrombin inhibitory activities, and HPHPHLSFMAIPP and SLPQNIPPL presented high ACE inhibitory activities. In vitro and in silico studies indicated that these peptides are precursors of multifunctional peptide sequences. Therefore, this study suggests that the specific synthetic peptides previously identified in milk fermented with Lactococcus lactis NRRL B-50571 and NRRL B-50572 offer potential beneficial health effects in the management of hypertension, thrombosis and diabetes.
TL;DR: In this paper , six Lactococcus lactis and seven Lactiplantibacillus plantarum strains were evaluated for their efficacy in controlling the growth of Listeria monocytogenes during the storage of miniature fresh cheese manufactured on a laboratory scale to exploit their possible use as biopreservatives.
Abstract: In the present study, six Lactococcus lactis and seven Lactiplantibacillus plantarum strains isolated from artisanal Sardinian dairy products were evaluated for their efficacy in controlling the growth of Listeria monocytogenes during the storage of miniature fresh cheese manufactured on a laboratory scale to exploit their possible use as biopreservatives. The strains were tested for antimicrobial activity and some technological characteristics before using them in miniature fresh cheese to evaluate their in situ antilisterial effect. Our results showed that five strains (L. lactis 16FS16-9/20234-11FS16 and Lpb. plantarum 1/14537-4A/20045) could be considered suitable candidates for use as protective cultures in fresh cheese manufacture since they significantly lowered the pathogen counts by 3–4 log units compared to the control; however, all strains tested were capable of decreasing L. monocytogenes numbers. Our results suggest that the single and combined action of the acidifying power and the production of bacteriocin of these strains was capable of controlling and/or reducing the growth of L. monocytogenes. Considering their technological characteristics, they might be used as starter/adjunct cultures to increase the safety of the products, perhaps in association with other antimicrobial hurdles.
TL;DR: In this paper, the authors investigated the multifunctional properties of specific synthetic peptides previously identified in milk fermented with Lactococcus lactis NRRL B-50571 and NRRLB-50572 on the inhibition of enzymes involved in hypertension (ACE), type 2 diabetes (DPP-IV) and thrombosis (thrombin).
Abstract: The aim of this study was to investigate the multifunctional properties of specific synthetic peptides previously identified in milk fermented with Lactococcus lactis NRRL B-50571 and NRRL B-50572 on the inhibition of enzymes involved in hypertension (ACE), type 2 diabetes (DPP-IV) and thrombosis (thrombin). Moreover, in vitro gastrointestinal digestion was performed in order to know the stability of peptides and its effect on the biological activities. Also, in silico analysis was employed for the prediction of sequences after digestion. Results showed that peptide inhibitory activities on ACE, DPP-IV and thrombin were enhanced after digestion. After in vitro digestion, peptide NAVPITPTLN showed the best efficiency to inhibit DPP-IV. Likewise, NAVPITPTLN and QEPVLGPVRGPFIIV showed high thrombin inhibitory activities, and HPHPHLSFMAIPP and SLPQNIPPL presented high ACE inhibitory activities. In vitro and in silico studies indicated that these peptides are precursors of multifunctional peptide sequences. Therefore, this study suggests that the specific synthetic peptides previously identified in milk fermented with Lactococcus lactis NRRL B-50571 and NRRL B-50572 offer potential beneficial health effects in the management of hypertension, thrombosis and diabetes.
TL;DR: In this paper , the authors evaluated the impact of lactic acid bacteria (LAB) cocultures and formulation on the physico-chemical and sensory properties of YAs by emulsifying anhydrous milk fat (AMF) or coconut oil in milk and lupin protein suspensions.
Abstract: Food transition requires incorporating more plant-based ingredients in our diet, thus leading to the development of new plant-based products, such as yogurt alternatives (YAs). This study aimed at evaluating the impact of lactic acid bacteria (LAB) cocultures and formulation on the physico-chemical and sensory properties of YAs. YAs were made by emulsifying anhydrous milk fat (AMF) or coconut oil in milk and lupin protein suspensions. The starters used, in mono- and cocultures, were the strains Lactococcus lactis NCDO2125, Enteroccocus faecalis CIRM-BIA2412 and Lactiplantibacillus plantarum CIRM-BIA1524. Textural properties and metabolites of YAs were evaluated and their sensory properties compared using a sorting task. Some cocultures led to higher firmness, viscosity, and water holding capacity of YAs, compared to monocultures. AMF and a milk:lupin protein ratio of 67:33 gave firmer and more viscous YAs. YAs were sensorially discriminated on the basis of protein ratio and fat type, but not of starters. The cocultures exhibited more diverse functional outputs, such as texturing, production of flavour compounds, proteolysis, when the strains associated in coculture had distinct capacities. Appropriate associations of LAB and formulation offer interesting solutions to improve the perception of YAs, and ultimately, encourage their consumption.