Propionibacterium Freudenreichii Research Articles

Surface proteins of Propionibacterium freudenreichii MJ2 inhibit RANKL-induced osteoclast differentiation by lipocalin-2 upregulation and lipocalin-2-mediated NFATc1 inhibition

Osteoclasts degrade bone and osteoclast differentiation has been implicated in bone destruction in rheumatoid arthritis. The dairy bacterium Propionibacterium freudenreichii MJ2 (MJ2) isolated from raw milk inhibits osteoclast differentiation and ameliorates collagen-induced arthritis. This study aimed to investigate the inhibitory effect of the surface proteins of MJ2 on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation and explain the underlying mechanism. The murine macrophage cell line RAW 264.7 was used to study the inhibition of osteoclast differentiation. The surface proteins significantly inhibited RANKL-induced osteoclast differentiation in a protein concentration-dependent manner by inhibiting the expression of genes and proteins related to osteoclast differentiation. RNA microarray analysis showed that the surface proteins significantly upregulated lipocalin-2 (lcn2) expression. In addition, they downregulated c-fos and NFATc1 and inhibited the expression of NFATc1-downstream genes Atp6v0d2, Calcr, and Ctsk. siRNA silencing of lcn2 decreased the extent of surface protein inhibition on osteoclast differentiation, suggesting that lcn2 plays an important role in the inhibition of RANKL-induced osteoclast differentiation. In conclusion, surface proteins of MJ2 show inhibitory effects on RANKL-induced osteoclast differentiation by upregulating lcn2 expression, in turn downregulating NFATc1, leading to the inhibition of NFATc1-downstream osteoclastogenesis-related gene expression.

Effect of the Encapsulation Process on the Viability of Probiotics in a Simulated Gastrointestinal Tract Model Medium

The primary objective of this study was to investigate the survival rate of three species of encapsulated bacteria (Propionibacterium acidipropionicici, Propionibacterium freudenreichii, and Propionibacterium thoenii) in model solutions designed to simulate the acidity levels found within the human gastrointestinal tract. The capsules were prepared by extrusion from gelatin and sodium alginate in a 1:1 ratio on a laboratory encapsulator. The use of gelatin and sodium alginate was found to provide optimum characteristics suitable for encapsulation of live bacteria. Three strains of Propionibacterium asidirgorionici, Propionibacterium freudenreichii, and Propionibacterium thoenii were subjected to in vitro assay to evaluate their probiotic potential. The final cell survival rate of P. freudenreichii was 105 CFU/mL, indicating that this probiotic is sensitive to acidic medium. The viability of encapsulated probiotics was studied in a model medium simulating the gastrointestinal tract. It was found that alginate–gelatin capsules could provide protection to P. freudenreichii from gastric acid and lead to high levels of viable bacteria released in the intestine. Practical application: Encapsulation of Propionibacterium freudenreichii into alginate–gelatin capsules produced capsules capable of delivering live probiotic bacteria into the intestine.

Fermentation of Peanut Slurry with Lactococcus lactis Species, Leuconostoc and Propionibacterium freudenreichii subsp. globosum Enhanced Protein Digestibility.

Peanuts contain nutritionally relevant levels of protein, yet are poorly digestible. Fermentation is a promising technique to boost legume protein quality, but its effect on the protein quality of raw peanuts has not been investigated. This study aimed to assess the impact of fermentation on the in vitro protein digestibility and free amino acid profile of cooked peanut slurry (peanut to water ratio 1:1). Cultures used were Propionibacterium freudenreichii subsp. globosum and a commercial fresh cheese culture that contained Lactococcus lactis subsp. cremoris, lactis, lactis biovar diacetylactis, and Leuconostoc, fermenting at 38 °C for 48 h. Samples fermented with the combination of cultures showed higher protein digestibility, as well as softer texture. Significant increases were observed only in the sample fermented with the fresh cheese culture. While the fresh cheese culture improved the free amino acid profile after fermentation, the combination of the cultures decreased all free amino acid concentrations except for glutamine, alanine, and proline. The observed increases in in vitro protein digestibility and the free amino acid profile may be attributed to the proteolytic activities of the cultures.

A Novel Direct-Fed Microbial for Beef Cattle Has a Supportive Effect against Clostridium perfringens In Vitro and In Vivo

Two experiments were conducted to evaluate the in vitro and in vivo effects of a novel direct-fed microbial (DFM) containing Lactobacillus animalis LA-51, Propionibacterium freudenreichii PF-24, Bacillus licheniformis CH-200, and Bacillus subtilis King (BOVAMINE DEFEND® Plus) against Clostridium perfringens pathogenic strains. In Experiment 1 (in vitro), an agar diffusion assay was performed to qualitatively evaluate the in vitro inhibitory effects of the DFM against C. perfringens types A and C. Including the DFM in the tested yielded inhibition zones with greater than three ring diameters in a 96-well plate. In Experiment 2 (in vivo), twenty 1-day-old beef calves were allocated to control (n = 10) or DFM (n = 10) for 21 days. All calves were orally challenged with 1.0 × 108 colony forming units of C. perfringens type A strain S-107 per head. The procedures such as general health scores, body weight, and fecal sample collections were performed following the C. perfringens challenge. Daily feeding of DFM significantly reduced the incidence of diarrhea while improving general impression and appearance scores of calves. Overall, these results highlight the ability of the DFM containing L. animalis LA-51, P. freudenreichii PF-24, B. licheniformis CH-200, and B. subtilis (BOVAMINE DEFEND® Plus) to inhibit C. perfringens types A and C under different experimental settings.

Prevalence of Foodborne Pathogens in Pacific Northwest Beef Feedlot Cattle Fed Two Different Direct-Fed Microbials

In recent years, there has been an increased interest in beef cattle shedding of foodborne pathogens due to the potential to contaminate surrounding food crops; however, the number of studies published on this topic has declined as the majority of research has emphasized on postharvest mitigation efforts. A field study was conducted to determine the prevalence of pathogens and indicator bacteria in beef cattle fed two different direct-fed microbials (DFMs). Fecal samples from a total of 3,708 crossbred yearling cattle randomly assigned to 16 pens and two treatment groups at a commercial cattle feedlot were taken. During the study period, diets were supplemented with two different DFMs i.) Lactobacillus acidophilus (NP51) and Propionibacterium freudenreichii (NP24) (9 log10CFU/head/day), and ii.) Lactobacillus salivarius (L28) (6 log10CFU/head/day). Fecal samples from pen floors were collected on days 0, 21, 42, 63, 103, and analyzed for the presence of Salmonella and E. coli O157:H7 and concentration of E. coli O157:H7, Enterobacteriaceae, and C. perfringens. Fecal samples collected from cattle fed L28 had significantly lower concentration of C. perfringens (p < 0.05) and had a similar prevalence with no significant differences in E. coli O157:H7 as those fed NP51/NP24 through the study until day 103. On day 103, the prevalence in cattle fed L28 was 40% with a concentration of 0.95 log10MPN/g while those fed NP51/NP24 were 65% with a concentration of 1.2 log10MPN/g. Cattle supplemented with NP51/NP24 achieved a significant log reduction of EB by 2.4 log10CFU/g over the course of the 103-day supplementation period compared to L28. Salmonella prevalence was also measured, but not detected in any samples at significant amounts to draw conclusions. It is evident that E. coli O157:H7 and other foodborne pathogens are still prevalent in cattle operations and that preharvest mitigation strategies should be considered to reduce the risk to beef products.

Propionibacteria as promising tools for the production of pro-bioactive scotta: a proof-of-concept study.

Dairy propionibacteria are Gram positive Actinomycetota, routinely utilized as starters in Swiss type cheese making and highly appreciated for their probiotic properties and health promoting effects. In this work, within the frame of a circular economy approach, 47 Propionibacterium and Acidipropionibacterium spp. were isolated from goat cheese and milk, and ewe rumen liquor, and characterized in view of their possible utilization for the production of novel pro-bioactive food and feed on scotta, a lactose rich substrate and one of the main by-products of the dairy industry. The evaluation of the Minimum Inhibitory Concentration (MIC) of 13 among the most common antibiotics in clinical practice revealed a general susceptibility to ampicillin, gentamycin, streptomycin, vancomycin, chloramphenicol, and clindamycin while confirming a lower susceptibility to aminoglycosides and ciprofloxacin. Twenty-five isolates, that proved capable of lactose utilization as the sole carbon source, were then characterized for functional and biotechnological properties. Four of them, ascribed to Propionibacterium freudenreichii species, and harboring resistance to bile salts (growth at 0.7-1.56 mM of unconjugated bile salts), acid stress (>80% survival after 1 h at pH 2), osmostress (growth at up to 6.5% NaCl) and lyophilization (survival rate > 80%), were selected and inoculated in scotta. On this substrate the four isolates reached cell densities ranging from 8.11 ± 0.14 to 9.45 ± 0.06 Log CFU mL-1 and proved capable of producing different vitamin B9 vitamers after 72 h incubation at 30°C. In addition, the semi-quantitative analysis following the metabolomics profiling revealed a total production of cobalamin derivatives (vitamin B12) in the range 0.49-1.31 mg L-1, thus suggesting a full activity of the corresponding biosynthetic pathways, likely involving a complex interplay between folate cycle and methylation cycle required in vitamin B12 biosynthesis. These isolates appear interesting candidates for further ad-hoc investigation regarding the production of pro-bioactive scotta.

Fat matters: Fermented whole milk potentiates the anti-colitis effect of Propionibacterium freudenreichii

Inflammatory bowel diseases (IBD) constitute a growing concern in western countries. They coincide with gut microbiota dysbiosis, including a loss of immunomodulatory bacteria. Accordingly, probiotic products containing selected immunomodulatory bacterial strains mitigate IBD. Selected strains of Propionibacterium freudenreichii display promising modulatory properties and prevent colitis in animal models. Dairy matrices protect propionibacteria immunomodulatory surface antigens during digestive transit. However, the functional role of the dairy matrix components in such fermented dairy products remains unknown. In the present workthis study, P. freudenreichii CIRM-BIA129, a probiotic strain known for its anti-inflammatory properties, was used to ferment whole milk, skim milk or skim milk ultrafiltrate. The preventive potential of fermented products was tested in DSS-induced mice colitis, in comparison with their unfermented counterparts. P. freudenreichii-fermented milk prevented colitis. Dairy fat in the fermented product potentiated the anti-colitis effects of the probiotic. This work opens new perspectives for developing immunomodulatory functional fermented foods.

Probiotics: Production, Characterization, Types, and Health Benefits

Probiotics, live microorganisms that confer health benefits to the host when administered in adequate amounts, have gained considerable attention for their potential in enhancing human health and well-being. This research paper presents a comprehensive overview of probiotics, including their production, characterization, types, and health benefits. The introduction emphasizes the significance of probiotics in maintaining a healthy human microbiota and provides a rationale for investigating their potential advantages. The production section details the processes involved in strain selection, isolation, and fermentation techniques for large-scale probiotic production. Furthermore, formulation considerations are discussed to ensure probiotic viability, stability, and functionality. The characterization section presents various methods for assessing probiotic viability, safety, and stability. The section on types of probiotics focuses on well-studied strains such as Lactobacillus and Bifidobacterium species, as well as emerging strains like Saccharomyces boulardii and Propionibacterium freudenreichii. Lastly, the health benefits section discusses the positive effects of probiotics on gut health, gastrointestinal disorders, immune system modulation, and other conditions. Further research is necessary to fully comprehend the mechanisms and potential of probiotics in promoting human health and well-being. Key Words: microbiota, metagenomics, high-throughput sequencing, cryoprotectants and encapsulation

Biochemical, structural, and kinetic characterization of PPi -dependent phosphoenolpyruvate carboxykinase from Propionibacterium freudenreichii.

Phosphoenolpyruvate carboxykinases (PEPCK) are a well-studied family of enzymes responsible for the regulation of TCA cycle flux, where they catalyze the interconversion of oxaloacetic acid (OAA) and phosphoenolpyruvate (PEP) using a phosphoryl donor/acceptor. These enzymes have typically been divided into two nucleotide-dependent classes, those that use ATP and those that use GTP. In the 1960's and early 1970's, a group of papers detailed biochemical properties of an enzyme named phosphoenolpyruvate carboxytransphosphorylase (later identified as a third PEPCK) from Propionibacterium freudenreichii (PPi -PfPEPCK), which instead of using a nucleotide, utilized PPi to catalyze the same interconversion of OAA and PEP. The presented work expands upon the initial biochemical experiments for PPi -PfPEPCK and interprets these data considering both the current understanding of nucleotide-dependent PEPCKs and is supplemented with a new crystal structure of PPi -PfPEPCK in complex with malate at a putative allosteric site. Most interesting, the data are consistent with PPi -PfPEPCK being a Fe2+ activated enzyme in contrast with the Mn2+ activated nucleotide-dependent enzymes which in part results in some unique kinetic properties for the enzyme when compared to the more widely distributed GTP- and ATP-dependent enzymes.

Evaluation of Sensory and Physicochemical Characteristics of Vitamin B12 Enriched Whole-Meal Sourdough Bread Fermented with Propionibacterium freudenreichii

The sustainable production of vegan or vegetarian food rich in vitamin B12 is a challenge. Propionibacterium freudenreichii fermentation has been identified as an effective method for the enhancement of vitamin B12 content in foods. However, limited studies have been conducted on the co-fermentation of P. freudenreichii with other bacteria. This study investigated the co-fermentation of P. freudenreichii with Lactic acid Bacteria (LAB) and its effects on the sensory characteristics of whole-meal sourdough bread (WMSB) in comparison to WMSB produced with LAB alone. The effects of P. freudenreichii co-fermentation on WMSB vitamin B12 content were also evaluated. Results indicated that P. freudenreichii co-fermentation with LAB significantly reduced (p &lt; 0.05) crumb hardness when compared with WMSB produced with only LAB (4532 ± 176 g and 5313 ± 846 g respectively). A significantly higher adhesiveness (p &lt; 0.05) was also observed due to the presence of P. freudenreichii. Triangle testing showed that perceptible differences were observed between the two WMSB types investigated in this study (p &lt; 0.05). Qualitative data from focus group testing indicated that WMSB produced with co-fermentation has a more homogeneous texture. However, improvement in aroma, texture, and taste was possible in both bread types. The co-fermentation of P. freudenreichii with Lactic acid Bacteria (LAB) was successful in producing bread with enriched vitamin B12 levels (ranging from 0.89 to 1.44 µg 100 g−1). Overall, the co-fermentation of P. freudenreichii presents an opportunity to improve the nutritional value of WMSB.

Investigation into the Potential Role of Propionibacterium freudenreichii in Prevention of Colorectal Cancer and Its Effects on the Diversity of Gut Microbiota in Rats.

Colorectal cancer (CRC) accounts for 10% of all cancer diagnoses and cancer-related deaths worldwide. Over the past two decades, several studies have demonstrated the clinical benefits of probiotic supplementation and some studies have shown that certain probiotics can modulate immunity and strengthen gut microbiota diversity. This study aims to assess the impact of the Propionibacterium freudenreichii (PF) probiotic against CRC induced by azoxymethane (AOM), and to investigate its effects on gut microbiota diversity in rats, as well as to evaluate the anti-proliferative activities of PF in HCT116 CRC cells. This experiment was performed using four groups of SD rats: normal control, AOM group, PF group (1 × 109 CFU/mL), and standard drug control (5-fluorouracil, 35 mg/kg). Methylene blue staining of colon tissues showed that the administration of PF significantly reduced the formation of colonic aberrant crypt foci (ACF) compared to the AOM control group. In addition, treated rats had lower levels of malondialdehyde in their colon tissue homogenates, indicating that lipid peroxidation was suppressed by PF supplementation. Furthermore, 16S rRNA gene analysis revealed that probiotic treatment enhanced the diversity of gut microbiota in rats. In vitro study showed that the viability of HCT116 cells was inhibited by the probiotic cell-free supernatant with an IC50 value of 13.3 ± 0.133. In conclusion, these results reveal that consuming PF as probiotic supplements modulates gut microbiota, inhibits the carcinogenic effects of AOM, and exerts anti-proliferative activity against CRC cells. Further studies are required to elucidate the role of PF on the immune response during the development and growth of CRC.

The total eye volume of cheese is influenced by different fat-levels

The impact of fat content in cheese on eye formation was investigated. Observations in practice have shown that fat-reduced cheeses tend to have more eyes than equivalent full-fat counterparts. A semi-hard cheese with CO2 production through citrate catabolism by Lacticaseibacillus paracasei and a hard Swiss-type cheese with CO2 production by Propionibacterium freudenreichii were produced with different fat content. Four different fat-in-dry-matter levels (∼100 to ∼480 g kg−1) were applied to the semi-hard cheeses and three (∼330 to ∼560 g kg−1) to the hard cheeses. The direct influence of the fat content on eye formation was distinguished from the consequentially altered cheese composition on bacterial fermentation (i.e., on CO2-production). An increasing fat content had a significant (p <0.05) inhibitory effect on relative eye volume in semi-hard and hard cheeses by increasing the capacity of the cheese matrix to solubilise more CO2.

The Effect of Direct-Fed Microbials on In-Vitro Rumen Fermentation of Grass or Maize Silage

Direct-fed microbial products (DFM) are probiotics that can be used advantageously in ruminant production. The in vitro gas production technique (IVGPT) is a method to simulate rumen fermentation and can be used to measure degradation, gas production, and products of fermentation of such additives. However, inter-laboratory differences have been reported. Therefore, tests using the same material were used to validate laboratory reproducibility. The objective of this study was to assess the effect of adding two DFM formulations on fermentation kinetics, methane (CH4) production, and feed degradation in two different basal feeds while validating a newly established IVGPT laboratory. Six treatments, with three replicates each, were tested simultaneously at the established IVGPT lab at the University of Copenhagen, and the new IVGPT lab at Chr. Hansen Laboratories. Maize silage (MS) and grass silage (GS) were fermented with and without the following DFM: P1: Ligilactobacillus animalis and Propionibacterium freudenreichii (total 1.5 × 107 CFU/mL), P2: P1 with added Bacillus subtilis and B. licheniformis (total 5.9 × 107 CFU/mL). The DFM were anaerobically incubated in rumen fluid and buffer with freeze-dried silage samples for 48 h. Total gas production (TGP: mL at Standard Temperature and Pressure/gram of organic matter), pH, organic matter degradability (dOM), CH4concentration (MC) and yield (MY), and volatile fatty acid (VFA) production and profiles were measured after fermentation. No significant differences between the laboratories were detected for any response variables. The dOM of MS (78.3%) was significantly less than GS (81.4%), regardless of the DFM added (P1 and P2). There were no significant differences between the effects of the DFM within the feed type. MS produced significantly more gas than GS after 48 h, but GS with DFM produced significantly more gas at 3 and 9 h and a similar gas volume at 12 h. Both DFM increased TGP significantly in GS at 48 h. There was no difference in total VFA production. However, GS with and without probiotics produced significantly more propionic acid and less butyric acid than MS with and without probiotics. Adding P2 numerically reduced the total methane yield by 4–6% in both MS and GS. The fermentation duration of 48 h, used to determine maximum potential dOM, may give misleading results. This study showed that it is possible to standardize the methodology to achieve reproducibility of IVGPT results. Furthermore, the results suggest that the P2 DFM may have the potential to reduce CH4 production without affecting organic matter degradation.

Site of infusion of a commercially available direct-fed microbial on performance and digestibility in lactating Holstein cows

The objective of this research was to evalu ate site of infusion of a commercially available direct-fed microbial (DFM) containing 109 cfu/g of Lactobacillus acidophilus and 109 cfu/g Propionibacterium freudenreichii on DMI, rumen kinetics, ruminal VFA, digestibility, milk production, milk components, and blood metabolites in lactating dairy cows. Four Holstein cows equipped with ruminal cannulas were used in a Latin square design experiment with 4 periods. Each 37-d period consisted of 14 d of no treatment to prevent crossover contamination, 14 d of adaptation to treatments, 8 d of sampling, and 1 d for ruminal evacuations. Within each period, cows were assigned to 1 of 4 treatments: (1) cows were fed a TMR formulated to meet or exceed nutrient requirements plus 5 g of lactose twice daily without the addition of DFM (control); (2) cows were fed the TMR with a daily dose of DFM top dressed on the feed twice daily (TD); (3) cows were fed the TMR with ruminal infusion of the DFM administered twice daily (RuI); or (4) cows were fed the TMR plus abomasal infusion of the DFM twice daily (AbI). During the sampling period within each period, DMI and milk production were measured daily with set days for blood and rumen fluid collection. Data were analyzed using the MIXED procedure of SAS with animal within period as a random effect. Dry matter intake was not different among treatments. No differences were detected in rumen kinetics, pH, individual VFA or VFA ratios, ammonia, or digestibility. There were no differences in kilograms of milk production (P > 0.87); SCC (P > 0.54); or percentage of butter fat (P > 0.21), milk protein (P > 0.83), lactose (P > 0.91), SNF (P > 0.88), and MUN (P > 0.49). No difference existed in most of the milk fatty acids except for 8:0, which had a greater concentration (P > 0.01) in AbI versus control, TD, and RuI. Route of administering DFM overall had no effects on DMI, rumen kinetics, ruminal VFA, digestibility, milk production, or milk components in the present experiment.

Nutritional and protective environmental factors for microbial consortium cultivation

Currently, the use of highly active probiotic strains for obtaining consortia with high biochemical and technological potential is relevant and promising in the dairy industry. Such probiotic microorganisms include propionic acid bacteria and Acidophilus bacillus. The creation of a consortium based on Propionibacterium freudenreichii Sh 85 and L. acidophilus makes it possible to develop specialized food products and biologically active additives with high probiotic properties. An inoculate was obtained based on pure cultures of Propionibacterium freudenreichii Sh 85 and L. acidophilus in a ratio of 2:1, which has a high biochemical activity and can provide a high level of enzymatic processes when co-cultured on a dairy medium. The nutrient medium based on whey has been optimized for obtaining the biomass of a consortium of propionic acid bacteria and Acidophilus bacillus. The optimal temperature range for biomass growth is (30±2) °C. The article shows the results of the selection of the optimal amount of cobalt ions in the nutrient medium. For normal biomass growth, high yield of viable cells of Propionibacterium freudenreichii Sh 85 and L. acidophilus cultures and vitamin B12 biosynthesis, a dose of 0.0025 g/l cobalt chloride was selected. The resulting biomass is characterized by a high titer of viable cells of propionic acid bacteria and Acidophilus bacillus 1012 k.f.u./cm3. The accumulation of vitamin B12 is active in the biomass. Cellular biomass is applicable as a biologically active additive for direct consumption and in the dairy industry as a bacterial concentrate.

Developing a single-stage continuous process strategy for vitamin B12 production with Propionibacterium freudenreichii

BackgroundVitamin B12 is a widely used compound in the feed and food, healthcare and medical industries that can only be produced by fermentation because of the complexity of its chemical synthesis. Besides, the use of Generally Recognized as Safe (GRAS) and Qualified Presumption of Safety (QPS) microorganisms, like Propionibacterium freudenreichii, especially non-GMO wild-type producers, are becoming an interesting alternative in markets where many final consumers have high health and ecological awareness. In this study, the production of vitamin B12 using the Propionibacterium freudenreichii NBRC 12391 wild-type strain was characterized and optimized in shake flasks before assessing several scale-up strategies.ResultsInitial results established that: (i) agitation during the early stages of the culture had an inhibitory effect on the volumetric production, (ii) 5,6-dimethylbenzimidazole (DMBI) addition was necessary for vitamin B12 production, and (iii) kinetics of vitamin B12 accumulation were dependent on the induction time when DMBI was added. When scaling up in a bioreactor, both batch and fed-batch bioprocesses proved unsuitable for obtaining high volumetric productivities mainly due to carbon source limitation and propionic acid inhibition, respectively. To overcome these drawbacks, an anaerobic single-phase continuous bioprocess strategy was developed. This culture strategy was maintained stable during more than 5 residence times in two independent cultures, resulting in 5.7-fold increase in terms of volumetric productivity compared to other scale-up strategies.ConclusionOverall, compared to previously reported strategies aimed to reduce propionic acid inhibition, a less complex anaerobic single-phase continuous and more scalable bioprocess was achieved.

Propionic acid production via two-step sequential repeated batch fermentations on whey and flour

In this study, two-stage process was developed for propionic acid production via repeated batch and fed-batch fermentations. In the first step, either whey lactose or flour hydrolysate was used as carbon source to produce lactic acid using Lactobacillus plantarum in repeated batch and fed-batch fermentations. Then, produced lactic acid was used as a carbon source for propionic acid fermentation using Propionibacterium freudenreichii in repeated batch fermentations. Maximum lactic acid concentrations were achieved as 100 g/L at 250th hour of incubation (corresponding to 6th cycle of repeated batch fermentation) on whey lactose and 97 g/L at 500th hour (1st cycle) on flour hydrolysate as substrate. For propionic acid production, maximum propionic acid concentrations were obtained as 28 g/L at 700th hour (13th cycle) on lactic acid obtained from whey and 35 g/L at 3600th hour (10th cycle) on lactic acid obtained from flour hydrolysate. Lactic acid and propionic acid productivities were 0.80 g/Lh and 0.050 g/Lh on whey lactose higher than the values 0.12 g/Lh and 0.025 g/Lh obtained on flour hydrolysate respectively.

Different culture media and purification methods unveil the core proteome of Propionibacterium freudenreichii-derived extracellular vesicles.

Bacterial extracellular vesicles (EVs) are natural lipidic nanoparticles implicated in intercellular communication. Although EV research focused mainly on pathogens, the interest in probiotic-derived EVs is now rising. One example is Propionibacterium freudenreichii, which produces EVs with anti-inflammatory effects on human epithelial cells. Our previous study with P. freudenreichii showed that EVs purified by size exclusion chromatography (SEC) displayed variations in protein content according to bacterial growth conditions. Considering these content variations, we hypothesized that a comparative proteomic analysis of EVs recovered in different conditions would elucidate whether a representative vesicular proteome existed, possibly providing a robust proteome dataset for further analysis. Therefore, P. freudenreichii was grown in two culture media, and EVs were purified by sucrose density gradient ultracentrifugation (UC). Microscopic and size characterization confirmed EV purification, while shotgun proteomics unveiled that they carried a diverse set of proteins. A comparative analysis of the protein content of UC- and SEC-derived EVs, isolated from cultures either in UF (cow milk ultrafiltrate medium) or YEL (laboratory yeast extract lactate medium), showed that EVs from all these conditions shared 308 proteins. This EV core proteome was notably enriched in proteins related to immunomodulation. Moreover, it showed distinctive features, including highly interacting proteins, compositional biases for some specific amino acids, and other biochemical parameters. Overall, this work broadens the toolset for the purification of P. freudenreichii-derived EVs, identifies a representative vesicular proteome, and enumerates conserved features in vesicular proteins. These results hold the potential for providing candidate biomarkers of purification quality, and insights into the mechanisms of EV biogenesis and cargo sorting.

Probiotics in Industrial Poultry Farming

In the conditions of industrial production, the problem of growing poultry with increased resistance to various diseases is relevant because the birds are exposed to various stress conditions. Traditionally, disease prevention is carried out through the use of vaccines, chemical pharmaceuticals, and antibiotics. The global use of therapeutic drugs contributes to the emergence of resistant strains of microorganisms and a decrease in the effectiveness of treatment; some of them have an immunosuppressive effect. The article presents the results of research on the effect of the preparation "Lactobacillus plantarum, Enterococcus faecalis, and Propionibacterium freudenreichii ssp." on the immune status, growth rate, and safety of experimental stock in broiler chickens. Studies were carried out on 150 one-day-old Ross-308 broiler chicks that were divided into three groups of 50 birds. The control Group (G3) was fed a standard ration based on the phases of growth, while the experimental Groups (G1 and G2) were supplemented with probiotics at different doses in the feed. The experiment was designed to last for 41 days. In the 3rd week, the average live weights of G1 and G2 broiler chickens exceeded those of G3 by 5.5 and 4.1%, respectively. In the 6th week, G1 and G2 broiler chicks had average live weights that exceeded those of G3 by 7.7 and 7.4%, respectively. The survival rates of the flocks in G1 and G2 were 4 and 2% higher, respectively than in G3. The average titers for Newcastle Disease and infectious bronchitis viruses in G1 were 314.9 and 53.5% higher, respectively than in G3, while in G2 they were 3.7 and 21.8% lower, respectively. For infectious bursal disease, G1 and G2 exceeded the control group by 74.2 and 6.4%, respectively. The meat yield of G1 and G2 was higher at 17.2 and 9.1%, respectively, compared to G3. Probiotics have shown many beneficial properties, including the ability to improve immunity, gut structure, and gut barrier function in broilers. These factors can improve digestion and absorption, ultimately increasing the quality and safety of products.

Propionic Acid Fermentation—Study of Substrates, Strains, and Antimicrobial Properties

Since milk whey is an abundant dairy by-product and a significant threat to the environment, its utilization is of great interest. The study compares valorization of lactose and lactates—the main carbon sources of whey—by fermentation—an environmentally friendly process. Antimicrobials released during fermentation by food-grade bacteria can help increase the microbiological safety of food. Propionic acid—a strong antimicrobial—is obtained mainly by the petrochemical route, yet there is increasing interest in its synthesis in biotechnological pathway. Five strains of propionic acid bacteria (Acidipropionibacterium acidipropionici, Propionibacterium cyclohexanicum, Propionibacterium freudenreichii, Acidipropionibacterium jensenii and Acidipropionibacterium thoenii) were investigated for their ability to produce organic acids and biomass using Na lactate or lactose as carbon sources. Selected fermentates were investigated for their antimicrobial efficacy during in vitro studies with foodborne pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. Results confirm that the production of acids and biomass is considerably influenced by the added carbon source. The tested fermentates have strong and specific antimicrobial activity against Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. In addition, inhibition of Staphylococcus aureus and Klebsiella pneumonia depends on the activity of produced bacteriocins. The article also discusses the possibility of increasing the antimicrobial activity of fermentates by acidification.