A selective differential medium for Lactobacillus plantarum

Comparative genome analysis of the immunomodulatory ability of Lactiplantibacillus plantarum and Lactiplantibacillus pentosus from Japanese pickles

Lactic acid bacteria (LAB) are pivotal in food preservation and exhibit immunomodulatory effects on interleukin-10 (IL-10) and interleukin-12 (IL-12) production. Lactiplantibacillus plantarum (L. plantarum) and Lactiplantibacillus pentosus (L. pentosus) from fermented food are known for their effect; however, a comprehensive comparative genome analysis is needed to identify the linked genes. Here, we investigated the immunomodulatory capability at the genome level of L. plantarum and L. pentosus strains isolated from Japanese pickles at the genome level, and we further identified their immunomodulation-associated genes using the potential-gene (PG) index derived from the Calinski-Harabasz (CH) index. The results revealed an immunostimulatory clade with strain-specific IL-10 and IL-12 induction and identified key genes via the PG index. Both genes across two species were shown to encode the enzyme TagF2, which is crucial for synthesizing poly-glycerol-3-phosphate type wall teichoic acid (poly-GroP WTA), indicating that TagF2 plays a potential role as an effective microbe-associated-molecular-pattern. In vivo analyses confirmed the IL-10-inducing ability of one strain, reinforcing the IL-10-stimulating capacity of its poly-GroP WTA. Subpotential genes in L. plantarum TagF2-possessing strains were linked to host‒cell interactions, suggesting that such strains play potential probiotic roles. Collectively, the PG index effectively identified immunomodulation-related genes, thus paving the way for the use of the PG index to detect potential health benefit-associated genes in other LAB species.

IMPORTANCE

Lactic acid bacteria are pivotal in food preservation and exhibit immunomodulatory effects on interleukin-10 (IL-10) and interleukin-12 (IL-12) production. Lactiplantibacillus plantarum and Lactiplantibacillus pentosus from fermented food are known for such effect, yet comprehensive comparative genome analysis is needed to elucidate the linked genes of the two species. The significance of our research is in observing the immunostimulatory clade with strain-specific cytokine induction and identifying key immunostimulation-related genes encoding enzymes that are crucial for synthesizing a potentially effective microbe-associated-molecular-pattern using the potential-gene index across two species. The further in vivo validation reinforced the interleukin-10-stimulating capacity of the identified pattern, and the detected sub-potential genes in Lactiplantibacillus plantarum key-gene possessing strains implied the utility of potential-gene index in detecting potential health-benefit-associated genes in other lactic acid bacteria species.

Application of Lactiplantibacillus plantarum LP5 for the bioremediation of wastewater effluent from a dairy product manufacturing plant

The objective was to evaluate the capacity of Lactiplantibacillus plantarum LP5r to improve the microbiological and physicochemical quality of wastewater from a dairy company. Lactiplantibacillus plantarum LP5r was inoculated (8.8 log10 CFU g-1 mL-1) into 50 L containers of wastewater, 10 mL was added to T1, 10 mL to T2 with monthly replenishment, 50 mL to T3, and 50 mL to T4 with monthly replenishment. The CT was kept without inoculum. Initially, L. plantarum LP5r showed values ​​above 6 log10 CFU g-1. In T1 and T3 decreased to undetectable values, but in T2 and T4 remained above 4 log10 CFU g-1. Enterobacteriaceae were initially 5.46 log10 CFU g-1 and decreased to 4.88 and 4.73 log10 CFU g-1 for T2 and T4 and increased to 7.31 log10 CFU g-1 in CT. Coliforms were reduced from 7.38 log10 CFU g-1 to 2.95 and 2.11 log10 CFU g-1 in T2 and T4. Initial suspended solids were 19 997 mg L-1, which decreased to 6058.3 mg L-1 and 4118.9 mg L-1 for CT and T4. The pH did not differ between samples. An initial BOD5 of 7680 mg L-1 was detected in all samples, which decreased to 2385 mg L-1 for CT and 820 mg L-1 for T4, and the COD decreased from 17 827 mg L-1 to 4839 mg L-1 and 1649 mg L-1 for the CT and T4 samples. Lactiplantibacillus plantarum LP5 positively influences the microbiological quality and COD and BOD5 of the dairy's wastewater.

Comparing the antioxidant effects of single and binary combinations of Lactiplantibacillus plantarum in vitro and in vivo and their application in yogurt

Lactiplantibacillus plantarum have been studied for their antioxidant properties, which can mitigate oxidative stress and improve health outcomes. The study aimed to compare the antioxidant properties of single and binary L. plantarum and their impact on yogurt. Lactiplantibacillus plantarum 847 (Lp-C), L. plantarum 8014 (Lp-G), and their combination were chosen for their in vitro antioxidant potential. In vivo experiments were performed in Drosophila melanogaster and results showed that binary L. plantarum notably improved the survival time, weight, catalase activity and intestinal integrity in H2O2-induced flies. As compared with single L. plantarum treated flies, binary strains improved the survival curve, superoxide dismutase and catalase activities in females, prolonged the average survival time in males, and increased the expression level of keap1, Nrf2, and SOD genes in all sexes. To explore the effect of single and binary L. plantarum on milk fermentation, the physicochemical properties and antioxidant activity of yogurt were detected, and results presented that yogurt fermented with L. plantarum exhibited the improved antioxidant capacity, with the binary strain combination demonstrating superior effects in rheological properties and the later period of yogurt storage. This research offers a foundation for choosing the combinations of lactic acid bacteria with antioxidant properties.

Probiotic Lactiplantibacillus plantarum subsp. plantarum Dad-13 Alleviates 2,4,6-Trinitrobenzene Sulfonic Acid-Induced Colitis Through Short-Chain Fatty Acid Production and Inflammatory Cytokine Regulation

The development of inflammatory bowel disease (IBD) is closely linked to inflammatory damage and dysbiosis. Recently, probiotics are being increasingly used to improve intestinal health. Probiotic-based therapies can prevent IBD by restoring the balance of gastrointestinal microbiota, reducing gut inflammation, and increasing the concentration of short-chain fatty acids (SCFAs). The present study aimed to investigate the protective effects of Lactiplantibacillus plantarum subsp. plantarum Dad-13, a novel probiotic strain derived from dadih (Indonesian curd from buffalo milk), on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in BALB/c mice. The results showed that probiotic Dad-13 supplementation at a dose of 107 or 109 CFU/mL improved the clinical symptoms of IBD and enhanced the production of SCFAs, particularly propionate and butyrate. Moreover, probiotic Dad-13 supplementation significantly decreased the levels of pro-inflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-6, and IL-1β] and significantly increased the levels of anti-inflammatory cytokines (IL-10). These findings show that L. plantarum Dad-13 can effectively prevent TNBS-induced colitis by modulating SCFA production and inflammatory cytokines.

Molecular Detection and Identification of Plant-Associated Lactiplantibacillus plantarum

Lactiplantibacillus plantarum is a lactic acid bacterium often isolated from a wide variety of niches. Its ubiquity can be explained by a large, flexible genome that helps it adapt to different habitats. The consequence of this is great strain diversity, which may make their identification difficult. Accordingly, this review provides an overview of molecular techniques, both culture-dependent, and culture-independent, currently used to detect and identify L. plantarum. Some of the techniques described can also be applied to the analysis of other lactic acid bacteria.

Applicability of the probiotic Lactiplantibacillus plantarum BFL as an adjunct culture in a dry fermented sausage

The addition of probiotic bacteria to a meat batter allows the development of functional fermented sausages. The aim of this work was to study the effect of microencapsulated Lactiplantibacillus plantarum BFL (EP) and as free cells (FP) on microbiological, physicochemical, and sensory parameters of fermented sausages during the drying stage and on the product ready for consumption. The microencapsulation of L. plantarum BFL did not improve its viability during the drying stage. In addition, sausages inoculated with L. plantarum BFL (FP and EP) caused lower residual nitrites values, pH values and Escherichia coli counts than the Control (C). However, only the presence of free cells of L. plantarum BFL (FP) caused a decrease in the Enterobacteriaceae and mannitol salt-positive Staphylococcus counts. In the sensory analysis, no significant differences were found in the acceptability of the different sausages. However, the acidity in probiotic sausages (FP and EP) was an attribute that consumers highlighted. The probiotic L. plantarum BFL could adapt and survive at high doses in the matrix of an industrial fermented sausage. Therefore, its use could represent a strategy both for biocontrol of pathogens and for the development of functional meat products.

Storage stability of texture, organoleptic, and biological properties of goat milk yogurt fermented with probiotic bacteria

Introduction

Goat milk is an attractive food due to its high nutritional values, easy digestibility and hypoallergenicity, but has an undesirable "goaty" flavor.

Methods

In this study, goat yogurt was fermented with four probiotics, respectively, including Lactobacillus acidophilus (GYA), Bifidobacterium animalis (GYB), Lactobacillus casei (GYC) and Lactobacillus plantarum (GYP), and tested for texture, organoleptic, and biological properties during a 4-week storage period at the refrigerated temperature.

Results

All goat yogurt with probiotics showed an increase on titratable acidity and a corresponding downward trend on pH value. Viable counts of L. acidophilus and L. casei were above 6 log cfu/mL at the end of the storage, which met the minimum standards for viable probiotic bacteria in yogurt specified by the Food and Agriculture Organization of United Nation (FAO). The texture and organoleptic characteristics of fermented goat milk depended on the strain and the storage period. DPPH free radical scavenging rate and ferric reducing antioxidant power activity gradually increased in all goat yogurts during the storage and yogurt with probiotic bacteria showed higher values than those of GY0.

Discussion

Among all probiotic containing goat yogurts, GYC exhibited the desirable characteristics of hardness, adhesiveness, water holding capacity, antioxidant activity during the whole storage. Furthermore, the addition of L. casei effectively weakened the goaty flavor and enhanced the overall acceptability. Thus, fermented goat milk with L. casei is optional for the development of goat milk product with satisfactory texture properties, pleasant sensory quality and high bioactivity.

Safety assessment of the indigenous probiotic strain Lactiplantibacillus plantarum subsp. plantarum Kita-3 using Sprague-Dawley rats as a model

Lactiplantibacillus plantarum subsp. plantarum Kita-3 is a candidate probiotic from Halloumi cheese produced by Mazaraat Artisan Cheese, Yogyakarta, Indonesia. This study evaluated the safety of consuming a high dose of L. plantarum subsp. plantarum Kita-3 in Sprague-Dawley rats for 28 days. Eighteen male rats were randomly divided into three groups, such as the control group, the skim milk group, and the probiotic group. Feed intake and body weight were monitored, and blood samples, organs (kidneys, spleen, and liver), and the colon were dissected. Organ weight, hematological parameters, serum glutamic oxaloacetic transaminase (SGOT), and serum glutamic pyruvic transaminase (SGPT) concentrations, as well as intestinal morphology of the rats, were measured. Microbial analyses were carried out on the digesta, feces, blood, organs, and colon. The results showed that consumption of L. plantarum did not negatively affect general health, organ weight, hematological parameters, SGOT and SGPT activities, or intestinal morphology. The number of L. plantarum in the feces of rats increased significantly, indicating survival of the bacterium in the gastrointestinal tract. The bacteria in the blood, organs, and colon of all groups were identified using repetitive-polymerase chain reaction with the BOXA1R primers and further by 16S rRNA gene sequencing analysis, which revealed that they were not identical to L. plantarum subsp. plantarum Kita-3. Thus, this strain did not translocate to the blood or organs of rats. Therefore, L. plantarum subsp. plantarum Kita-3 is likely to be safe for human consumption.

The role of probiotics in the treatment of adult atopic dermatitis: a meta-analysis of randomized controlled trials

Background

Atopic dermatitis (AD) is chronic inflammatory skin disease that is relapsing and a serious condition that disrupts the quality of life of affected individuals. Probiotics are an immunomodulator that can enhance the immune control of atopic dermatitis.

Methods

All randomized controlled trials of probiotics for the treatment of adult AD published before December 2020 were included in this study from the PubMed databases and manual searching.

Results

Six randomized controlled trials (n = 241) were selected for this meta-analysis study. Probiotics were effective in treating adult patients with AD, indicated by the decrease in Scoring Atopic Dermatitis/SCORAD (Mean Difference (MD)  − 7.90, 95% CI − 7.25 to − 6.92; p < 0.00001; I² = 96%) and improved quality of life (MD − 7.68, 95% CI − 14.08 to − 1.29; p = 0.02; I² = 47%) which were statistically significant. However, skin severity, itch severity, Dermatology Life Quality Index (DLQI), IL-4, TFN-γ, and IgE showed no significant difference in this meta-analysis study (p > 0.05).

Limitations

The study found no available data for side effects of probiotics.

Strength

This meta-analysis analyzed a total of 241 AD patients of Asian and European origin.

Conclusion

The use of probiotics decreased SCORAD significantly in adult patients with AD. Probiotics can improve the quality of life of patients with AD.

Capsule summary

The use of probiotics in atopic dermatitis has been widely studied, with controversial results. This meta-analysis suggests that the use of probiotics can improve SCORAD and the quality of life of patients with atopic dermatitis.

Improvement of Sourdough and Bread Qualities by Fermented Water of Asian Pears and Assam Tea Leaves with Co-Cultures of Lactiplantibacillus plantarum and Saccharomyces cerevisiae

Qualities of sourdough and sourdough bread using fermented water from Asian pears and Assam tea leaves with Lactiplantibacillus plantarum 299v and Saccharomyces cerevisiae TISTR 5059 as starter cultures were evaluated. Changes in the growth of lactic acid bacteria and yeast, pH, sourdough height, total phenolic contents (TPCs) and antioxidant activities detected by ORAC, FRAP and DPPH radical scavenging assays were monitored during sourdough production. Mature sourdough was achieved within 4 h after 18 h retard fermentation and used for bread production. The bread was then analyzed to determine chemical and physical properties, nutritional compositions, TPCs, antioxidant activities and sensory properties as well as shelf-life stability. Results showed that fermented water significantly promoted the growth of yeast and increased TPCs and antioxidant activities of sourdough. Compared to common sourdough bread, fermented water sourdough bread resulted in 10% lower sugar and 12% higher dietary fiber with improved consumer acceptability; TPCs and antioxidant activities also increased by 2–3 times. The fermented water sourdough bread maintained microbial quality within the standard range, with adequate TPCs after storage at room temperature for 7 days. Fermented water from Asian pears and Assam tea leaves with L. plantarum 299v and S. cerevisiae TISTR 5059 as starter cultures improved dough fermentation and bread quality.

New sources of lactic acid bacteria with potential antibacterial properties

In the face of the growing demand for functional food, the search for new sources of lactic acid bacteria (LAB) becomes a priority. In our research, we used multiplied culture conditions followed by identification via the matrix-assisted laser desorption ionization-time of flight mass spectrometry for seeking LAB strains in plant- and animal-derived sources. Furthermore, the selected LAB isolates were examined for their proteolytic activity as well as antimicrobial action against different bacterial pathogens. The applied method appeared to be useful tool for searching LAB strains within different types of the biological matrices. The best source of the LABs was from calf. Comparing properties of the two selected LABs, those isolated from calf demonstrated the greatest proteolytic and antibacterial properties suggesting that gastrointestinal microbiota are the most valuable LAB source. Nevertheless, second selected strain derived from pickled cucumber juice may be also treated as a promising source of potential probiotic strains.

Effect of probiotic Lactiplantibacillus plantarum and chestnut flour (Castanea sativa mill) on microbiological and physicochemical characteristics of dry-cured sausages during storage

The effect of chestnut flour (Castanea sativa Mill) on L. plantarum viability and physicochemical characteristics in a dry-cured sausage (Longaniza de Pascua) during storage is discussed. Four batches were prepared: CL with 3% chestnut flour added; CPL with 3% chestnut flour and 8.5 log CFU/g L. plantarum added; PL with 8.5 log CFU/g L. plantarum added and L, the batch control. The sausages were stored at 4 °C and 20 °C, and vacuum packed for 43 d. L. plantarum viability was affected by storage time (P < 0.001). However, higher L. plantarum counts at the final of storage were reached due to chestnut flour addition (P < 0.001). At room storage, chestnut flour caused a higher increase in TBARS values (P = 0.022). Nevertheless, all lipid oxidation treatments were in the range of accepted values at the sensory detection level. In conclusion, Longaniza de Pascua can be kept at 4 °C or 20 °C for 43 d without causing any rancidity problems.

Metabolomic profile of milk fermented with Streptococcus thermophilus cocultured with Bifidobacterium animalis ssp. lactis, Lactiplantibacillus plantarum, or both during storage

In this study, the microbial interactions among cocultures of Streptococcus thermophilus (St) with potential probiotics of Bifidobacterium animalis ssp. lactis (Ba) and Lactiplantibacillus plantarum (Lp) in fermented milk were investigated during a storage period of 21 d at 4°C, in terms of acidifying activity (pH and titratable acidity), viable counts, and metabolites. A nontargeted metabolomics approach based on ultra-high-performance liquid chromatography coupled with mass spectrometry was employed for mapping the global metabolite profiles of fermented milk. Probiotic strains cocultured with St accelerated milk acidification, and improved the microbial viability compared with the single culture of St. The St-Ba/Lp treatment manifested a higher bacteria viability and acidification ability in comparison with the St-Ba or the St-Lp treatment. Relative quantitation of 179 significant metabolites was identified, including nucleosides, AA, short peptides, organic acids, lipid derivatives, carbohydrates, carbonyl compounds, and compounds related to energy metabolism. The principal component analysis indicated that St treatment and coculture treatments displayed a complete distinction in metabolite profiles, and Lp had a larger effect than Ba on metabolic profiles of fermented milk produced by cofermentation with St during storage. The heat map in combination with hierarchical cluster analysis showed that the abundance of metabolites significantly varied with the starter cultures over the storage, and high abundance of metabolites was observed in either St or coculture samples. The St-Ba/Lp treatment showed relatively high abundance for the vast majority of metabolites. These findings suggest that the profile of the metabolites characterizing fermented milk samples may depend on the starter cultures, and incorporation of probiotics may considerably influence the metabolomic activities of fermented milks.

Recovery of Indigenous probiotic Lactobacillus plantarum Mut-7 on healthy Indonesian adults after consumption of fermented milk containing these bacteria

Probiotics are live microorganisms that confer health benefits on the host when administered in adequate amounts, such as to support the balance of gut microbiota. In this study, the selected indigenous probiotic strain, Lactobacillus plantarum Mut-7, was used as a starter culture to produce fermented milk. A total of 28 healthy Indonesian youngsters and adults (male/female: 16/12; age 19.4-22.9 years old; normal BMI range 18.6-22.7 kg/m²) were supplemented with the fermented milk. This study aimed to determine the recovery of L. plantarum Mut-7 through molecular analysis from the subjects feces after ingestion of 140 mL fermented milk containing 7.0 log₁₀ CFU/ml of L. plantarum Mut-7 for 15 days. Molecular detection was performed using the rep-PCR technique and sequencing of DNA 16S rRNA. Consumption of fermented milk containing L. plantarum Mut-7 enabled reduction of total E. coli and Coliform non-E. coli in several subjects. It was able to increase the total LAB and total L. plantarum in subjects' feces. The number of L. plantarum and mesophilic LAB increased by 5.5 ± 1.6 log₁₀ CFU/g, 1.8 ± 0.8 log₁₀. On the other side, thermophilic LAB increased by 2.8 ± 3.0 log₁₀ CFU/g in 23 out of 28 subjects. These findings proved that L. plantarum survived in the human gastrointestinal tract. Based on the molecular identification technique using rep-PCR technique and sequencing of gene 16S rRNA, two isolates had similarity to L. plantarum Mut-7 by a coefficient value of 100%.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-021-05046-z.

In vitro assessment of health-promoting benefits of sheep ‘Testouri’ cheese

This study aimed to produce probiotic ‘Testouri’, traditional Tunisian sheep cheese, by direct-to-vat inoculum of probiotic adjuncts.

The potential of Testouri sheep cheeses was evaluated by an assessment of gross composition and proteolytic, antibacterial, antidiabetic and antioxidant activities during storage at 4 °C for 28 days. Results highlighted that no significant differences were observed in compositional parameters of the samples at day 0. Probiotic counts in cheeses remained at 8 log CFU g−1 during storage. Probiotic cheeses exhibited measurable antibacterial activities with the maximum value (diameter of 12 ± 0.07 mm) on Staphylococcus aureus strain. Also, α-glucosidase and α-amylase inhibitions ranged from 42 ± 0.77 to 58 ± 0.88% and 20 ± 0.9 to 47 ± 1.3%, respectively, during storage. Additionally, cheeses inoculated with probiotics exhibited significant increases in proteolytic and antioxidant activities compared to the control sample.

Therefore, Testouri cheese can be considered a good carrier of probiotics and can be promoted for commercial uses.

Production of probiotic Mozzarella cheese by incorporating locally isolated Lactobacillus acidophilus

Purpose

The present study was conducted to isolate and screen the potential probiotic strains for incorporation in Mozzarella cheese.

Methods

Probiotic cultures were isolated from different randomly purchased yogurt samples and were identified as Lactobacillus sp., Bifidobacteria sp., and Pediococcus sp. after morphological and biochemical characterization. Heat tolerance of isolates was tested at 55 °C and 65 °C to determine the survival of isolates in conditions similar to commercial cheese production. Lactobacillus acidophilus (S2) showed remarkable heat tolerance among all strains and was therefore selected to assess the probiotic potential. It showed good survival at acidic pH values (2–3). Moreover, it also showed > 50% tolerance to bile salt and was resistant to antibiotics, chloramphenicol, tetracycline, gentamycin, and vancomycin and also exhibited anti-microbial activity against Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus. Thus, heat-tolerant Lactobacillus acidophilus (S2) isolate was an ideal strain for incorporation in Mozzarella cheese as probiotics. Three types of cheeses viz., cheese A with free cells of Lactobacillus acidophilus (S2), cheese B with encapsulated cells of Lactobacillus acidophilus (S2), and control cheese having no probiotics, were made.

Result

Microbiological analysis of prepared cheese revealed lesser loss of Lactobacillus acidophilus (S2) from encapsulated form (3.41 × 108 CFU/mL) compared to free cells of Lactobacillus acidophilus (S2) (1.10 × 107 CFU/mL). Coliforms were observed in control cheese after 10 days of storage, whereas no coliforms were observed in cheese A and cheese B even after 15 days of storage. Organoleptic properties of cheese A and cheese B were almost the same with an acceptability score of 2.7 ± 0.1 and 2.65 ± 0.1, respectively. Control cheese got the lowest scores after 15 days of storage.

Conclusion

The addition of probiotics in cheese not only prolongs the shelf-life of cheese but also increases the organoleptic properties of the cheese, making cheese a good delivery system for probiotics.

Enhanced Viability of Probiotics against Gastric Acid by One-Step Coating Process with Poly-L-Lysine: In Vitro and In Vivo Evaluation

Due to their low acid tolerance, a majority of probiotics face difficulties with regard to surviving in the gastric environment long enough to reach the intestinal surfaces where they colonize and provide health benefits. We prepared a probiotic delivery system that can enhance their viability in acidic conditions by developing a one-step poly-L-lysine (PLL) coating process. We determined whether the coating process was successful by measuring the zeta potential and observing it with confocal scanning microscopy. PLL-coated L. plantarum (PLL-LP), incubated in a solution of pH 2 for 2 h, exhibited a higher viability (6.86 ± 0.12 log CFU/mL of viable cells) than non-coated L. plantarum (non-coated LP), which exhibited only 2.7 ± 1.23 log CFU/mL of viable cells. In addition, a higher amount of L. plantarum was detected in the feces of mice orally administered PLL-LP (6.2 ± 0.4 log CFU/g of feces) than in the feces of the control groups. In addition to enhancing probiotic viability in pH 2 solution, the PLL coating showed no effect on the probiotic growth pattern and the viability of either freeze-dried L. plantarum or L. plantarum, stored at −20 °C and 4 °C, respectively. Overall, these results indicated that the PLL coating is a promising potential probiotic delivery system.

Utilization of optimized processing conditions for high yield synthesis of conjugated linoleic acid by L. plantarum AB20-961 and L. plantarum DSM2601 in semi-dry fermented sausage

The aim of this study was to utilize optimized processing conditions to obtain the highest conjugated linoleic acid (CLA) contents in semi-dry fermented sausages produced with L. plantarum AB20-961 and L. plantarum DSM 2601. Optimized conditions were 5.7 meat pH, 5% hydrolyzed safflower oil addition, 10⁸ CFU/g added starter culture, fermentation time of 73 h for L. plantarum DSM2601 and 79 h for L. plantarum AB20-961, 24 °C fermentation temperature, 65 °C internal cooking temperature and 90% relative humidity. Results indicated that CLA contents in sausages were increased 21% by L. plantarum AB20-961 and 121% by L. plantarum DSM2601 after fermentation compared to initial CLA level determined on manufacturing day (P < .05). After fermentation, an increased CLA content of sausages remained stable during heat processing and storage. Sausages incorporated with L. plantarum strains and hydrolyzed safflower oil had the highest TBARS and PUFA levels, and the lowest pH and moisture content (P < .05). Differences were not found in sensorial and other physicochemical properties among sausage treatment groups. This study demonstrated that high CLA content can be achieved in sausages by utilizing optimum processing conditions described above and starter cultures (L. plantarum AB20-961 and L. plantarum DSM2601) without any adverse effects on quality of the final product.

Characterization and ACE Inhibitory Activity of Fermented Milk with Probiotic Lactobacillus plantarum K25 as Analyzed by GC-MS-Based Metabolomics Approach

Addition of probiotics to yogurt with desired health benefits is gaining increasing attention. To further understand the effect of probiotic Lactobacillus plantarum on the quality and function of fermented milk, probiotic fermented milk (PFM) made with probiotic L. plantarum K25 and yogurt starter (L. delbrueckii ssp. bulgaricus and Streptococcus thermophilus) was compared with the control fermented milk (FM) made with only the yogurt starter. The probiotic strain was shown to survive well with a viable count of 7.1 ± 0.1 log CFU/g in the PFM sample after 21 days of storage at 4°C. The strain was shown to promote formation of volatiles such as acetoin and 2,3-butanediol with milk fragrance, and it did not cause post-acidification during refrigerated storage. Metabolomics analysis by GC-MS datasets coupled with multivariate statistical analysis showed that addition of L. plantarum K25 increased formation of over 20 metabolites detected in fermented milk, among which γ-aminobutyric acid was the most prominent. Together with several other metabolites with relatively high levels in fermented milk such as glyceric acid, malic acid, succinic acid, glycine, alanine, ribose, and 1,3-dihydroxyacetone, they might play important roles in the probiotic function of L. plantarum K25. Further assay of the bioactivity of the PFM sample showed significant (p < 0.05) increase of ACE inhibitory activity from 22.3% at day 1 to 49.3% at day 21 of the refrigerated storage. Therefore, probiotic L. plantarum K25 could be explored for potential application in functional dairy products.

Development of probiotic yogurt: effect of strain combination on nutritional, rheological, organoleptic and probiotic properties

Seven combinations of yogurt; C1 [yogurt starter culture (YSC)], T1, [YSC + Lactobacillus acidophilus (LA)], T2 [YSC + Bifidobacterium bifidum (BB)], T3 [YSC + Lactobacillus plantarum (LP)], T4 [YSC + Lactobacillus casei (LC)], T5 [YSC + LA + BB] and T6 [YSC + LP + LC] were developed. Nutritional [proximate and minerals], rheological [total soluble solids (TSS), pH, titratable acidity (TA), water holding capacity, synersis, viscosity] organoleptic and probiotic properties [viability, acid tolerance, bile salt tolerance] were assessed with standard methods. Nutritional composition differed significantly among samples except for the iron and zinc (P < 0.05). Yogurt containing LP as single or in combination with LC resulted in significantly higher ash, protein, calcium and phosphorous level. Probiotic combination also significantly affected the rheological properties of yogurts (P < 0.05). Yogurt with LP and LC as single or in combination lead to significantly higher TSS and viscosity while significantly low syneresis, whereas yogurt with LA as single or in combination resulted in low pH and high TA (P < 0.05). Interestingly, combination of LA and BB increased TSS, reduced pH and syneresis as compare to these bacteria as single probiotic source. Panel experts found yogurt with LP more flavourful. Combination of multi-strain and multi-species probiotic resulted in improved texture but we found no significant difference in overall acceptability. Combination of probiotic strains also resulted in better probiotic potential with multi-species combination found to be even more effective. BB seemed more stable than three other probiotic strains. The present study can be helpful to dairy industry in developing new probiotic products and may provide a rational for selecting a combination of probiotic strains.

Effect of different strategies of Lactobacillus plantarum incorporation in chorizo sausages

BACKGROUND

Chorizo is a high-value Spanish-type dry fermented sausage, highly appreciated by consumers. In this kind of product, Lactobacillus plantarum plays an important role in the fermentation process and can also be considered as a probiotic. The impact of different strategies for incorporating probiotic L. plantarum into the physico-chemical, microbiological, and sensorial characteristics of chorizo sausages was studied. These strategies were: free cells (Cfc); alginate beads (Calg); water-in-oil emulsion (Cwo), and water-in-oil-in-water emulsion (Cwow). Proximate composition, weight loss, pH, a_w , color, and microbiological behavior were evaluated during the ripening (20 days) of chorizo.

RESULTS

The strategy of incorporating L. plantarum significantly affected the proximate composition, pH, and a_w of sausages. However, the traditional red color of chorizo was maintained for all formulations. The incorporation of probiotics as free cells or encapsulated in alginate beads resulted in higher counts of lactic acid bacteria and L. plantarum, lower counts of Enterobacteriaceae, and in acceptable sensory scores.

CONCLUSION

Overall, the quality of chorizo sausages was conditioned by the incorporation strategy, and the addition of probiotics in alginate beads (Calg) was the most effective strategy. © 2019 Society of Chemical Industry.

Rapid Calorimetric Detection of Bacterial Contamination: Influence of the Cultivation Technique

Modern isothermal microcalorimeters (IMC) are able to detect the metabolic heat of bacteria with an accuracy sufficient to recognize even the smallest traces of bacterial contamination of water, food, and medical samples. The modern IMC techniques are often superior to conventional detection methods in terms of the detection time, reliability, labor, and technical effort. What is missing is a systematic analysis of the influence of the cultivation conditions on calorimetric detection. For the acceptance of IMC techniques, it is advantageous if already standardized cultivation techniques can be combined with calorimetry. Here we performed such a systematic analysis using Lactobacillus plantarum as a model bacterium. Independent of the cultivation techniques, IMC detections were much faster for high bacterial concentrations (>102 CFU⋅mL-1) than visual detections. At low bacterial concentrations (<102 CFU⋅mL-1), detection times were approximately the same. Our data demonstrate that all kinds of traditional cultivation techniques like growth on agar (GOA) or in agar (GIA), in liquid media (GL) or on agar after enrichment via membrane filtration (GF) can be combined with IMC. The order of the detection times was GF < GIA ≈ GL ≈ GOA. The observed linear relationship between the calorimetric detection times and the initial bacterial concentrations can be used to quantify the bacterial contamination. Further investigations regarding the correlation between the filling level (in mm) of the calorimetric vessel and the specific maximum heat flow (in μW⋅g-1) illustrated two completely different results for liquid and solid media. Due to the better availability of substrates and the homogeneous distribution of bacteria growing in a liquid medium, the volume-related maximum heat flow was independent on the filling level of the calorimetric vessels. However, in a solid medium, the volume-related maximum heat flow approached a threshold and achieved a maximum at low filling levels. This fundamentally different behavior can be explained by the spatial limitation of the growth of bacterial colonies and the reduced substrate supply due to diffusion.

Effect of Probiotic Bacillus Coagulans and Lactobacillus Plantarum on Alleviation of Mercury Toxicity in Rat

The objective of this study was to evaluate the efficiency of probiotics (Lactobacillus plantarum and Bacillus coagulans) against mercury-induced toxicity using a rat model. Mercury (Hg) is a widespread heavy metal and was shown to be associated with various diseases. Forty-eight adult male Wistar rats were randomly divided into six groups (control, mercury-only, each probiotic-only, and mercury plus each probiotic group). Hg-treated groups received 10 ppm mercuric chloride, and probiotic groups were administrated 1 × 10⁹ CFU of probiotics daily for 48 days. Levels of mercury were determined using cold vapor technique, and some biochemical factors (list like glutathione peroxidase (GPx), superoxide dismutase (SOD), creatinine, urea, bilirubin, alanine transaminase (ALT), and aspartate transaminase (AST)) were measured to evaluate changes in oxidative stress. Oral administration of either probiotic was found to provide significant protection against mercury toxicity by decreasing the mercury level in the liver and kidney and preventing alterations in the levels of GPx and SOD. Probiotic treatment generated marked reduction in the levels of creatinine, urea, bilirubin, ALT, and AST indicating the positive influence of the probiotics on the adverse effects of Hg in the body.

Physicochemical, Nutritional, and Organoleptic Characterization of a Skimmed Goat Milk Fermented with the Probiotic Strain Lactobacillus plantarum C4

The benefits of goat milk, fermented milks, and probiotics for the humans are well documented. In this study, a novel fermented goat milk was manufactured with the putative probiotic strain Lactobacillus plantarum C4 together with L. bulgaricus and Streptococcus thermophilus. Ultrafiltration was chosen as the skimmed milk concentration method because it produced the best viscosity and syneresis and a high casein content. The viability rate of all bacterial strains was >10⁷ cfu/mL, even after 5 weeks of storage or after in vitro gastrointestinal digestion, which is especially important for exertion of the probiotic strain functionalities. This fermented milk is also a good source of nutrients, having a low lactose and fat content, high protein proportion, and good mineral concentration. According to these data and the overall acceptability described by panelists, this fermented milk is a healthy dairy product comparable with commercially available fermented milks.

Comparative study of the synbiotic effect of inulin and fructooligosaccharide with probiotics with regard to the various properties of fermented soy milk

Numerous combinations of probiotics were explored to find the suitable starter culture for the development of synbiotic soy yoghurt which can give good product characteristics and may be acceptable among consumers. Prebiotics (fructooligosaccharide (FOS) and inulin) were supplemented in an attempt to reduce the after-taste of soymilk, improve acidification profile and growth of probiotics. The addition of prebiotics in soy milk significantly enhanced the acidification rate (10.82 to 23.00 × 10^-3 pH units/min) and condensed the fermentation completion time. FOS-supplemented fermented soy milk showed better acidification and post-acidification profile as compared to inulin supplemented samples. The Streptococcus salivarius subsp. thermophilus (ST) - Lactobacillus acidophilus (LA) with FOS gave the better textural properties with firmer gel (350.10), lower adhesiveness (-93.10) and springiness (0.92), higher gumminess (164.50) and average cohesiveness (0.47). FOS-supplemented ST-LA-fermented samples showed good gel characteristics with higher elastic modulus (1672.39 Pa), viscous modulus (416.41 Pa), complex modulus (1723.53 Pa), lower tan δ (14) and higher overall acceptability scores (7.40) on a 9-point hedonic scale. Developed synbiotic soy fermented milk showed more than the 9 log cfu/ml count throughout storage which is required for probiotic functional food.

Characterization and immunomodulatory activity of an exopolysaccharide produced by Lactobacillus plantarum JLK0142 isolated from fermented dairy tofu

A purified neutral exopolysaccharide (EPS) designated as EPS0142 was obtained from Lactobacillus plantarum JLK0142. EPS0142 consisted of glucose and galactose in an approximate molar ratio of 2.13:1.06 and had a molecular weight of 1.34 × 10⁵ Da. The FT-IR spectrum showed that EPS0142 had a typical polysaccharide absorption pattern. ¹H NMR and ¹³C NMR spectra analysis showed the presence of N-acetylated sugar residues. EPS0142 had no toxic effects on RAW 264.7 cells and significantly improved their phagocytic activity and NO secretion in vitro. Further in vivo studies revealed that the spleen index and splenic lymphocyte proliferation activities of the cyclophosphamide-induced immunosuppression mice treated with a middle-dose (50 mg/kg body weight) or a high-dose (100 mg/kg body weight) of EPS0142 were significantly increased (P < 0.01). In addition, the intestinal immunoglobulin A (sIgA) content and the serum levels of the cytokines, IL-2 and TNF-α, were also significantly (P < 0.05) improved in the high-dose EPS0142 group compared to that in the model control group. These data indicate that the EPS isolated from L. plantarum JLK0142 can effectively improve the immunomodulatory activity of RAW 264.7 cells and stimulate the immune system in cyclophosphamide-induced immunosuppressed mice.

A randomized synbiotic trial to prevent sepsis among infants in rural India

Sepsis in early infancy results in one million annual deaths worldwide, most of them in developing countries. No efficient means of prevention is currently available. Here we report on a randomized, double-blind, placebo-controlled trial of an oral synbiotic preparation (Lactobacillus plantarum plus fructooligosaccharide) in rural Indian newborns. We enrolled 4,556 infants that were at least 2,000 g at birth, at least 35 weeks of gestation, and with no signs of sepsis or other morbidity, and monitored them for 60 days. We show a significant reduction in the primary outcome (combination of sepsis and death) in the treatment arm (risk ratio 0.60, 95% confidence interval 0.48-0.74), with few deaths (4 placebo, 6 synbiotic). Significant reductions were also observed for culture-positive and culture-negative sepsis and lower respiratory tract infections. These findings suggest that a large proportion of neonatal sepsis in developing countries could be effectively prevented using a synbiotic containing L. plantarum ATCC-202195.

Assessment of technological characteristics of non-fat yoghurt manufactured with prebiotics and probiotic strains

Microbiological, physicochemical, aroma and organic acid characteristics of non-fat yoghurt incorporated with β-glucan and probiotic Lactobacillus plantarum strains (AB6-25, AC18-82 and AK4-11) combination as adjunct culture were investigated during a 21 day storage period at 4 °C. Four treatment yoghurts contained 0.25, 0.5, 1 and 1.5 % β-glucan. Treatments also included probiotic combination and commercial culture. Treatments were compared with three controls produced containing commercial culture, commercial culture and probiotic combination, and commercial culture, Lactobacillus acidophilus and inulin. The results indicated that β-glucan promote the viability of lactobacilli. However, the addition of β-glucan (except 0.25 %) resulted in enhanced syneresis (P < 0.05). In general, the use of 0.25 % β-glucan had no significant effect on pH, fat, protein and organic acid content of non-fat yoghurt. The results obtained from this research demonstrated that the use of 0.25 % β-glucan has no adverse effect on the characteristics of non-fat yogurt produced with probiotic combination.

A Lactobacillus plantarum strain isolated from kefir protects against intestinal infection with Yersinia enterocolitica O9 and modulates immunity in mice

Lactobacillus plantarum C4, previously isolated from kefir and characterized as a potential probiotic strain, was tested for its protective and immunomodulatory capacity in a murine model of yersiniosis. The inoculation of BALB/c mice with a low pathogenicity serotype O9 strain of Yersinia enterocolitica results in a prolonged intestinal infection with colonization of Peyer's patches. Pretreatment with C4 was without effect on fecal excretion of yersiniae, but shortened the colonization of Peyer's patches. This protective effect was associated with pro-inflammatory status in the intestinal mucosa (TNF-α production in infected mice was increased by C4) and an increase in total IgA secretion. At a systemic level, C4 did not promote a pro-inflammatory response, although production of the immunoregulatory cytokine IFN-γ was enhanced. These findings suggest that L. plantarum C4 can increase resistance to intestinal infections through its immunomodulatory activity.