Identification of Lactic Acid Bacteria in Fruit Pulp Processing Byproducts and Potential Probiotic Properties of Selected Lactobacillus Strains

Revealing the Potential Impacts of Nutraceuticals Formulated with Freeze-Dried Jabuticaba Peel and Limosilactobacillus fermentum Strains Candidates for Probiotic Use on Human Intestinal Microbiota

This study evaluated the impacts of novel nutraceuticals formulated with freeze-dried jabuticaba peel (FJP) and three potentially probiotic Limosilactobacillus fermentum strains on the abundance of bacterial groups forming the human intestinal microbiota, metabolite production, and antioxidant capacity during in vitro colonic fermentation. The nutraceuticals had high viable counts of L. fermentum after freeze-drying (≥ 9.57 ± 0.09 log CFU/g). The nutraceuticals increased the abundance of Lactobacillus ssp./Enterococcus spp. (2.46-3.94%), Bifidobacterium spp. (2.28-3.02%), and Ruminococcus albus/R. flavefaciens (0.63-4.03%), while decreasing the abundance of Bacteroides spp./Prevotella spp. (3.91-2.02%), Clostridium histolyticum (1.69-0.40%), and Eubacterium rectale/C. coccoides (3.32-1.08%), which were linked to positive prebiotic indices (> 1.75). The nutraceuticals reduced the pH and increased the sugar consumption, short-chain fatty acid production, phenolic acid content, and antioxidant capacity, besides altering the metabolic profile during colonic fermentation. The combination of FJP and probiotic L. fermentum is a promising strategy to produce nutraceuticals targeting intestinal microbiota.

Nutraceuticals in the management of autonomic function and related disorders: A comprehensive review

Nutraceuticals have been described as phytocomplexes when derived from foods of plant origin or a pool of secondary metabolites when derived from foods of animal origin, which are concentrated and administered in an appropriate form and can promote beneficial health effects in the prevention/treatment of diseases. Considering that pharmaceutical medications can cause side effects, there is a growing interest in using nutraceuticals as an adjuvant therapeutic tool for several disorders involving autonomic dysfunction, such as obesity, atherosclerosis and other cardiometabolic diseases. This review summarizes and discusses the evidence from the literature on the effects of various nutraceuticals on autonomic control, addressing the gut microbiota modulation, production of secondary metabolites from bioactive compounds, and improvement of physical and chemical properties of cell membranes. Additionally, the safety of nutraceuticals and prospects are discussed. Probiotics, resveratrol, quercetin, curcumin, nitrate, inositol, L-carnosine, and n-3 polyunsaturated fatty acids (n-3 PUFAs) are among the nutraceuticals most studied to improve autonomic dysfunction in experimental animal models and clinical trials. Further human studies are needed to elucidate the effects of nutraceuticals formulated of multitarget compounds and their underlying mechanisms of action, which could benefit conditions involving autonomic dysfunction.

Exploring the Effects of Freeze-Dried Sourdoughs with Lactiplantibacillus pentosus 129 and Limosilactobacillus fermentum 139 on the Quality of Long-Fermentation Bread

Sourdough production is a complex fermentation process. Natural sourdough fermentation without standardization causes great variability in microbial communities and derived products. Starter cultures have emerged as alternatives to natural fermentation processes, which could improve bakery quality and produce bioactive compounds. This study aimed to evaluate the impacts of freeze-drying on the production and viability of sourdoughs with Lactiplantibacillus pentosus 129 (Lp) and Limosilactobacillus fermentum 139 (Lf), as well as their effects on the quality of long-fermentation bread. These strains were selected based on their better performance considering acidification and exopolysaccharide production capacity. Sourdough with Lp and Lf were propagated until the 10th day, when physicochemical and microbiological parameters were determined. The produced sourdoughs were freeze-dried, and bread samples were produced. The freeze-drying process resulted in high survival rates and few impacts on the metabolic activity of Lp and Lf until 60 days of storage. Incorporating Lp and Lf improved the microbiological and physicochemical properties of sourdough and long-fermentation breads. Tested freeze-dried sourdoughs led to reduced bread aging (higher specific volume and decreased starch retrogradation) and increased digestibility. The results show the potential of the freeze-dried sourdoughs produced with Lp and Lf as innovative strategies for standardizing production protocols for the bakery industry, especially for producing long-term fermentation bread.

Cereus jamacaru DC. (mandacaru) fruit as a source of lactic acid bacteria with in vitro probiotic-related characteristics and its protective effects on Pediococcus pentosaceus during lyophilization and refrigeration storage

This study isolated and identified autochthonous lactic acid bacteria (LAB) from mandacaru fruit and evaluated their potential probiotic and technological aptitudes in vitro, as well as the protective effects of freeze-dried mandacaru fruit on the most promising LAB isolate during lyophilization and refrigeration storage. Initially, 212 colonies were isolated from mandacaru fruit, and 34 were preliminarily identified as LAB. Thirteen isolates identified by 16S-rRNA sequencing as Pediococcus pentosaceus were negative for DNase, gelatinase, hemolytic, and biogenic amine production. The selected isolates showed proteolytic activity, diacetyl and exopolysaccharide production, and good tolerance to different NaCl concentrations while having low cellular hydrophobicity and antagonistic activity against pathogens. The survival of isolates sharply decreased after 3 h of exposure to pH 2 and had a good tolerance to 1 % bile salt. A principal component analysis selected P. pentosaceus 57 as the most promising isolate based on the examined technological and probiotic-related physiological properties. This isolate was lyophilized with mandacaru fruit and stored under refrigeration for 90 days. P. pentosaceus 57 lyophilized with mandacaru fruit had high viable cell counts (9.69 ± 0.03 log CFU/mL) and >50 % of physiologically active cells at 90 days of refrigeration storage. The results indicate that mandacaru fruit is a source of P. pentosaceus with aptitudes to be explored as potential probiotic and technological characteristics of interest for the food industry, besides being a good candidate for use in lyophilization processes and refrigeration storage of LAB due to its cryoprotective effects.

Safety Evaluation of a Novel Potentially Probiotic Limosilactobacillus fermentum in Rats

Limosilactobacillus (L) fermentum (strains 139, 263, 296) is a novel probiotic mixture isolated from fruit processing by-products. The use of this formulation has been associated with improvements in cardiometabolic, inflammatory, and oxidative stress parameters. The present study evaluated the safety of a potential multi-strain probiotic by genotoxicity (micronucleus assay) and subchronic toxicity study (13-week repeated dose). In the genotoxicity evaluation, L. fermentum 139, 263, 296 did not increase the frequency of micronuclei in erythrocytes of rats of both sexes at doses up to 1010 CFU/mL. In the subchronic toxicity study, the administration of L. fermentum did not promote adverse health effects, such as behavioral changes, appearance of tumors, changes in hematological and biochemical parameters. In addition, higher doses of L. fermentum 139, 263, 296 have been shown to reduce the levels of pro-inflammatory cytokines. Administration of potentially probiotic L. fermentum did not promote adverse health effects in rats and could be evaluated as a potential probiotic for humans.

Detection of oxalyl-CoA decarboxylase (oxc) and formyl-CoA transferase (frc) genes in novel probiotic isolates capable of oxalate degradation in vitro

Oxalate degradation is one of lactic acid bacteria's desirable activities. It is achieved by two enzymes, formyl coenzyme A transferase (frc) and oxalyl coenzyme A decarboxylase (oxc). The current study aimed to screen 15 locally isolated lactic acid bacteria to select those with the highest oxalate degradation ability. It also aimed to amplify the genes involved in degradation. MRS broth supplemented with 20 mM sodium oxalate was used to culture the tested isolates for 72 h. This was followed by an enzymatic assay to detect remaining oxalate. All isolates showed oxalate degradation activity to variable degrees. Five isolates demonstrated high oxalate degradation, 78 to 88%. To investigate the oxalate-degradation potential of the selected isolates, they have been further tested for the presence of genes that encode for enzymes involved in oxalate catabolism, formyl coenzyme A transferase (frc) and oxalyl coenzyme A decarboxylase (oxc). Three strains showed bands with the specific OXC and FRC forward and reverse primers designated as (SA-5, 9 and 37). Species-level identification revealed Loigolactobacillus bifermentans, Lacticaseibacillus paracasei, and Lactiplantibacillus plantarum. Preliminary results revealed that the tested probiotic strains harbored both oxc and frc whose products are putatively involved in oxalate catabolism. The probiotic potential of the selected strains was evaluated, and they showed high survival rates to both simulated gastric and intestinal fluids and variable degrees of antagonism against the tested Gram-positive and negative pathogens and were sensitive to clarithromycin but resistant to both metronidazole and ceftazidime. Finally, these strains could be exploited as an innovative approach to establish oxalate homeostasis in humans and prevent kidney stone formation.

Limosilactobacillus fermentum Strains as Novel Probiotic Candidates to Promote Host Health Benefits and Development of Biotherapeutics: A Comprehensive Review

Fruits and their processing by-products are sources of potentially probiotic strains. Limosilactobacillus (L.) fermentum strains isolated from fruit processing by-products have shown probiotic-related properties. This review presents and discusses the results of the available studies that evaluated the probiotic properties of L. fermentum in promoting host health benefits, their application by the food industry, and the development of biotherapeutics. The results showed that administration of L. fermentum for 4 to 8 weeks promoted host health benefits in rats, including the modulation of gut microbiota, improvement of metabolic parameters, and antihypertensive, antioxidant, and anti-inflammatory effects. The results also showed the relevance of L. fermentum strains for application in the food industry and for the formulation of novel biotherapeutics, especially nutraceuticals. This review provides evidence that L. fermentum strains isolated from fruit processing by-products have great potential for promoting host health and indicate the need for a translational approach to confirm their effects in humans using randomized, double-blind, placebo-controlled trials.

Antagonistic properties of Lactiplantibacillus plantarum MYSVB1 against Alternaria alternata: a putative probiotic strain isolated from the banyan tree fruit

Alternaria alternata, a notorious phytopathogenic fungus, has been documented to infect several plant species, leading to the loss of agricultural commodities and resulting in significant economic losses. Lactic acid bacteria (LAB) hold immense promise as biocontrol candidates. However, the potential of LABs derived from fruits remains largely unexplored. In this study, several LABs were isolated from tropical fruit and assessed for their probiotic and antifungal properties. A total of fifty-five LABs were successfully isolated from seven distinct fruits. Among these, seven isolates showed inhibition to growth of A. alternata. Two strains, isolated from fruits: Ficus benghalensis, and Tinospora cordifolia exhibited promising antifungal properties against A. alternata. Molecular identification confirmed their identities as Lactiplantibacillus plantarum MYSVB1 and MYSVA7, respectively. Both strains showed adaptability to a wide temperature range (10-45°C), and salt concentrations (up to 7%), with optimal growth around 37 °C and high survival rates under simulated gastrointestinal conditions. Among these two strains, Lpb. plantarum MYSVB1 demonstrated significant inhibition (p < 0.01) of the growth of A. alternata. The inhibitory effects of cell-free supernatant (CFS) were strong, with 5% crude CFS sufficient to reduce fungal growth by >70% and complete inhibition by 10% CFS. Moreover, the CFS was inhibitory for both mycelial growth and conidial germination. CFS retained its activity even after long cold storage. The chromatographic analysis identified organic acids in CFS, with succinic acid as the predominant constituent, with lactic acid, and malic acid in descending order. LAB strains isolated from tropical fruits showed promising probiotic and antifungal properties, making them potential candidates for various applications in food and agriculture.

Evaluating the Stability of a Novel Nutraceutical Formulation Combining Probiotic Limosilactobacillus fermentum 296, Quercetin, and Resveratrol Under Different Storage Conditions

This study evaluated the stability of a novel nutraceutical formulation composed of the probiotic Limosilactobacillus fermentum 296, quercetin (QUE), and resveratrol (RES) (LFQR) under different storage conditions. The effects of different relative humidities (RH; 11, 22, and 33%) and storage temperatures (refrigeration temperature -4 °C and room temperature -25 °C) on the stability of LFQR were evaluated through the determination of thermal stability, viable cell counts, bacterial physiological status, antioxidant capacity, and contents of QUE and RES during long-term storage. RH did not affect endothermic reactions and mass reduction in LFQR. After a 15-day-humidification period, L. fermentum 296 had higher viable cell counts in LFQR under refrigeration temperature storage when compared to room temperature storage regardless of the RH. The physiological status of L. fermentum 296 in LFQR was overall similar during 90 days of storage (11% RH) under refrigeration and room temperature. L. fermentum 296 had the highest viable cell counts (> 6 log CFU/g) in LFQR up to day 90 of refrigeration storage (11% RH). LFQR kept high contents of QUE and RES and maintained antioxidant capacity during 90 days of storage under refrigeration and room temperature. The results showed that the higher stability and functionality of LFQR during long-term storage should be guaranteed under 11% RH and refrigeration temperature.

Effects of Simulated Gastrointestinal Conditions on Combined Potentially Probiotic Limosilactobacillus fermentum 296, Quercetin, and/or Resveratrol as Bioactive Components of Novel Nutraceuticals

This study evaluated the effects of simulated gastrointestinal conditions (SGIC) on combined potentially probiotic Limosilactobacillus fermentum 296 (~ 10 log CFU/mL), quercetin (QUE, 160 mg), and/or resveratrol (RES, 150 mg) as the bioactive components of novel nutraceuticals. Four different nutraceuticals were evaluated during exposure to SGIC and analyzed the plate counts and physiological status of L. fermentum 296, contents and bioaccessibility of QUE and RES, and antioxidant capacity. Nutraceuticals with QUE and RES had the highest plate counts (4.94 ± 0.32 log CFU/mL) and sizes of live cell subpopulations (28.40 ± 0.28%) of L. fermentum 296 after SGIC exposure. An index of injured cells (Gmean index, arbitrary unit defined as above 0.5) indicated that part of L. fermentum 296 cells could be entered the viable but nonculturable state when the nutraceuticals were exposed to gastric and intestinal conditions while maintaining vitality. The nutraceuticals maintained high contents (QUE ~ 29.17 ± 0.62 and RES ~ 23.05 mg/100 g) and bioaccessibility (QUE ~ 41.0 ± 0.09% and RES ~ 67.4 ± 0.17%) of QUE and RES, as well as high antioxidant capacity (ABTS assay ~ 88.18 ± 1.16% and DPPH assay 75.54 ± 0.65%) during SGIC exposure, which could be linked to the protective effects on L. fermentum 296 cells. The developed nutraceuticals could cross along the gastrointestinal tract with high concentrations of functioning potentially probiotic cells and bioavailable phenolic compounds to exert their beneficial impacts on consumer health, being an innovative strategy for the co-ingestion of these bioactive components.

Assessment of the in-vitro probiotic efficacy and safety of Pediococcus pentosaceus L1 and Streptococcus thermophilus L3 isolated from Laban, a popular fermented milk product

Probiotics are beneficial microorganisms, mostly lactic acid bacteria (LAB), that offer health benefits to the host when consumed in adequate amounts. This study assessed the probiotic efficacy and safety of LAB strains isolated from Laban, a traditional fermented milk product. Seven primarily selected Gram-positive, catalase-negative, non-spore-forming isolates were examined for their antimicrobial activity against the bacterial pathogens Bacillus cereus, Salmonella typhi, Staphylococcus aureus, and Vibrio cholera, and the fungal pathogen Candida albicans. Two isolates, identified as Pediococcus pentosaceus L1 and Streptococcus thermophilus L3, which showed antimicrobial activity against all pathogens, were further evaluated for their probiotic competence. The selected isolates demonstrated strong resistance to low pH, bile salts, and phenol, indicating their potential for gastric endurance. They also exhibited high cell surface hydrophobicity to various hydrocarbons, autoaggregation, and coaggregation properties, demonstrating strong adhesion abilities. In addition, both isolates showed strong antioxidant activity and were non-hemolytic. Although the isolates had some resistance to certain antibiotics, they were generally susceptible to commonly used antibiotics. The two LAB strains also exhibited promising technological properties, such as milk coagulation and exopolysaccharide production, indicating their potential to enhance the quality of dairy products. The results suggest that the LAB strains isolated from Laban have strong potential as probiotics, and due to their food origin, they are highly likely to exhibit maximal efficacy in food and pharmaceutical products for human consumption.

Unrevealing the in vitro impacts of Cereus jacamaru DC. cladodes flour on potentially probiotic strains, selected bacterial populations, and metabolic activity of human intestinal microbiota

This study investigated the potential impacts of the flour from Cereus jamacaru cactus cladodes (CJF), a cactus native to the Brazilian Caatinga biome, on the growth and metabolism of different potentially probiotic strains, as well as on the abundance of selected intestinal bacterial populations and microbial metabolic activity during in vitro colonic fermentation with a pooled human fecal inoculum. Cultivation of the probiotics in a medium with C. jamacaru cladodes flour (20 g/L) resulted in viable cell counts of up to 9.8 log CFU/mL, positive prebiotic activity scores (0.73-0.91), decreased pH and sugar contents, and increased lactic, acetic, and propionic acid production over time, indicating enhanced probiotic growth and metabolic activity. CJF overall increased the relative abundance of Lactobacillus spp./Enterococcus spp. (2.12-3.29%) and Bifidobacterium spp. (4.08-4.32%) and decreased the relative abundance of Bacteroides spp./Prevotella spp. (8.35-6.81%), Clostridium histolyticum (6.91-3.59%), and Eubacterium rectale/Clostridium coccoides (7.70-3.95%) during 48 h of an in vitro colonic fermentation using a pooled human fecal inoculum. CJF stimulated the microbial metabolic activity, with decreased pH, sugar consumption, lactic and short-chain fatty acid production, alterations in overall metabolic profiling and phenolic compound contents, and maintenance of high antioxidant capacity during colonic fermentation. These results show that CJF stimulated the growth and metabolic activity of distinct potential probiotics, increased the relative abundance of beneficial intestinal bacterial groups, and stimulated microbial metabolism during in vitro colonic fermentation. Further studies using advanced molecular technologies and in vivo experimental models could forward the investigation of the potential prebiotic properties of CJF.

Characterization of potential probiotic starter cultures of lactic acid bacteria isolated from Ethiopian fermented cereal beverages, Naaqe, and Cheka

AIMS

To test the in vitro probiotic potential and starter culture capacity of lactic acid bacteria (LAB) isolated from Naaqe and Cheka, cereal-based Ethiopian traditional fermented beverages.

METHODS AND RESULTS

A total of 44 strains were isolated from spontaneously fermented Ethiopian cereal-based beverages, Naaqe and Cheka with 24 putatively identified as LAB and 14 identified up to the species level. The species Limosilactobacillus fermentum (6/12; 50%) and Weissella confusa (5/12, 41.67%) were the predominant species identified from Naaqe, while the two Cheka isolates were L. fermentum and Pediococcus pentosaceus. Six LAB strains inhibited eight of the nine gastrointestinal indicator key pathogens in Ethiopia, including Escherichia coli, Salmonella enterica subsp. enterica var. Typhimurium, Staphylococcus aureus, Shigella flexneri, and Listeria monocytogenes. Three of the LAB isolates exhibited strain-specific immunostimulation in human monocytes. Based on these probiotic properties and growth, six strains were selected for in situ evaluation in a mock fermentation of Naaqe and Cheka. During primary fermentations, L. fermentum 73B, P. pentosaceus 74D, L. fermentum 44B, W. confusa 44D, L. fermentum 82C, and Weissella cibaria 83E and their combinations demonstrated higher pH-lowering properties and colony-forming unit counts compared to the control spontaneous fermentation. The same pattern was also observed in the secondary mock fermentation by the Naaqe LAB isolates.

CONCLUSIONS

In this study, we selected six LAB strains with antipathogenic, immunostimulatory, and starter culture potentials that can be used as autochthonous probiotic starters for Naaqe and Cheka fermentations once their health benefit is ascertained in a clinical trial as a next step.

An In Vitro Study of the Impacts of Sweet Potato Chips with Potentially Probiotic Levilactobacillus brevis and Lactiplantibacillus plantarum on Human Intestinal Microbiota : Impacts of potato chips with probiotics on intestinal microbiota

This study formulated sweet potato chips with powdered potentially probiotic Levilactobacillus brevis (SPLB) and Lactiplantibacillus plantarum (SPLP) and evaluated their impacts on human intestinal microbiota during 48 h of in vitro colonic fermentation. L. brevis and L. plantarum kept high viable cell counts (> 6 log CFU/g) on sweet potato chips after freeze-drying and during 60 days of storage. SPLB and SPLP had satisfactory quality parameters during 60 days of storage. SPLB and SPLP increased the relative abundance of Lactobacillus ssp./Enterococcus spp. (3.84-10.22%) and Bifidobacterium spp. (3.25-12.45%) and decreased the relative abundance of Bacteroides spp./Prevotella spp. (8.56-2.16%), Clostridium histolyticum (8.23-2.33%), and Eubacterium rectale/Clostridium coccoides (8.07-1.33%) during 48 h of in vitro colonic fermentation. SPLB and SPLP achieved high positive prebiotic indexes (> 8.24), decreased pH values and sugar contents, and increased lactic acid and short-chain fatty acid production, proving selective stimulatory effects on beneficial bacterial groups forming the intestinal microbiota. The results showed that SPLB and SPLP have good stability and high viable cell counts of L. brevis and L. plantarum when stored under room temperature and caused positive impacts on human intestinal microbiota, making them potentially probiotic non-dairy snack options.

Antibacterial and Immunostimulatory Activity of Potential Probiotic Lactic Acid Bacteria Isolated from Ethiopian Fermented Dairy Products

Lactic acid bacteria (LAB) form a group of bacteria to which most probiotics belong and are commonly found in fermented dairy products. Fermented foods and beverages are foods made through desired microbial growth and enzymatic conversions of food components. In this study, 43 LAB were isolated from Ethiopian traditional cottage cheese, cheese, and yogurt and evaluated for their functional and safety properties as candidate probiotics. Twenty-seven isolates, representative of each fermented food type, were selected and identified to the species level. Limosilactobacillus fermentum was found to be the predominant species in all samples studied (70.4%), while 11.1% of isolates were identified as Lactiplantibacillus plantarum. All 27 isolates tested showed resistance to 0.5% bile salt, while 26 strains were resistant to pH 3. The LAB isolates were also evaluated for antagonistic properties against key pathogens, with strain-specific features observed for their antimicrobial activity. Five strains from cottage cheese (Lactiplantibacillus plantarum 54B, 54C, and 55A, Lactiplantibacillus pentosus 55B, and Pediococcus pentosaceus 95E) showed inhibitory activity against indicator pathogens that are key causes of gastrointestinal infections in Ethiopia, i.e., Escherichia coli, Salmonella enterica subsp. enterica var. Typhimurium, Staphylococcus aureus, Shigella flexneri, and Listeria monocytogenes. Strain-specific immunomodulatory activity monitored as nuclear factor kappa B (NF-κB) and interferon regulatory factor (IRF) activation was documented for Lactiplantibacillus plantarum 54B, 55A and P. pentosaceus 95E. Antibiotic susceptibility testing confirmed that all LAB isolates were safe concerning their antibiotic resistance profiles. Five isolates (especially Lactiplantibacillus plantarum 54B, 54C, and 55A, Lactiplantibacillus pentosus 55B, and P. pentosaceus 95E) showed promising results in all assays and are novel probiotic candidates of interest for clinical trial follow-up.

Effect of food matrix and fermentation on angiotensin-converting enzyme inhibitory activity and β-glucan release after in vitro digestion in oat-based products

The aim of this study was to determine the effects of fermentation and food matrix on the ACE inhibitory activities of the peptides obtained after in vitro gastrointestinal digestion, protein profiles (SDS-PAGE) and β-glucan amounts of oat products. Furthermore, the physicochemical and microbiological properties of fermented oat drinks and oat yogurt-like product obtained from oat fermentation were evaluated. Oat grains were mixed with a certain ratio of water 1:3 w/v (oat:water, yogurt consistency) and 1:5 w/v (oat:water, drink consistency), and this mixture was fermented with yogurt culture and probiotic Lactobacillus plantarum and fermented drinks and yogurt were produced. The results indicated that the fermented oat drink and the oat yogurt-like product had L. plantarum viability over 10⁷ cfu/g. After the in vitro gastrointestinal digestion of the samples, the hydrolysis levels ranged from 57.70 % to 82.06 %.The hydrolysis level of the samples with fermented-drink consistency was significantly higher than the samples with yogurt consistency (p < 0.05).The SDS-PAGE profiles of the non-digested samples showed that the bands had molecular weights of 12-15 kDa and around 35 kDa. Bands whose molecular weights were around 35 kDA disappeared after gastric digestion. ACE inhibitory activities of the fractions composed of molecular weights of 2 kDa and 2-5 kDa obtained after in vitro gastrointestinal digestion of the oat samples were in the range of 46.93-65.91 %. The effect of fermentation on the ACE inhibitory activities of the peptide mixture with molecular weights between 2 and 5 kDa was not statistically significant, however, fermentation caused an increase in the ACE inhibitory activities of the peptide mixture with a molecular weight<2 kDa (p < 0.05). The β-glucan amounts of fermented and non-fermented oat products were in the range of 0.57-1.28 %. The β-glucan amounts detected after gastric digestion decreased considerably and β-glucan could not be detected in the supernatant after gastrointestinal digestion. This indicated that β-glucan did not solubilize in the supernatant (bioaccessible) and remained in the pellet. In conclusion, fermentation is a valuable process for releasing peptides with moderately high ACE inhibitory effects from the parent oat proteins.

Characterization, High-Density Fermentation, and the Production of a Directed Vat Set Starter of Lactobacilli Used in the Food Industry: A Review

Lactobacilli have been widely concerned for decades. Bacteria of the genus Lactobacillus have been commonly employed in fermented food to improve the appearance, smell, and taste of food or prolong its shelf-life. They comprise 261 species (by March 2020) that are highly diverse at the phenotypic, ecological, and genotypic levels. Some Lactobacilli strains have been documented to be essential probiotics, which are defined as a group of living microorganisms that are beneficial to the health of the host when ingested in sufficiency. However, the characterization, high-density fermentation, and the production of a directed vat set (DVS) starter of Lactobacilli strains used in the food industry have not been systematically reported. This paper mainly focuses on reviewing Lactobacilli as functional starter cultures in the food industry, including different molecular techniques for identification at the species and strain levels, methods for evaluating Lactobacilli properties, enhancing their performance and improving the cell density of Lactobacilli, and the production techniques of DVS starter of Lactobacilli strains. Moreover, this review further discussed the existing problems and future development prospects of Lactobacilli in the food industry. The viability and stability of Lactobacilli in the food industry and gastrointestinal environment are critical challenges at the industrial scale. The new production equipment and technology of DVS starter of Lactobacilli strains will have the potential for large-scale application, for example, developing low-temperature spray drying, freezing granulation drying, and spray freeze-drying.

Identification of cellulolytic lactic acid bacteria from the intestines of laying hens given AKBISprob based on 16S ribosomal ribonucleic acid gene analysis

Background and Aim:

Supplementation of AKBISprob (developed in a previous study) in feed can improve production efficiency and poultry health, especially laying hens. In addition, it can also increase cellulolytic lactic acid bacteria (LAB) in chicken intestines, but these bacteria are still unknown; thus, they need to be identified. This study aimed to identify cellulolytic LAB in the intestines of laying hens administered AKBISprob based on 16S ribosomal ribonucleic acid (16S rRNA) gene analysis.

Materials and Methods:

The samples used in this study were 13 LAB isolates from the intestines of laying hens that were given AKBISprob 4%. Cellulolytic LAB DNA was isolated and 16S rRNA gene was amplified by polymerase chain reaction, followed by sequencing, bioinformatics analysis, and phylogenetic tree construction.

Results:

From 10 cellulolytic LAB isolates with a clear zone of >6 mm, four were selected and their DNA was amplified with BaCF and UniB primers ~1500 bp DNA fragments. Of these, the P31H62 isolate was genetically close to Enterococcus hirae strain 1-1X-16 with 92.90% maximum identity, the P33S52 isolate had homology with Enterococcus mundtii strain ZU 26 with 96.76% maximum identity, and the P33S62 isolate was closely related to E. hirae strain SJ3 with 72.96% maximum identity. The phylogenetic tree revealed that the cellulolytic LAB isolates P31H62 and P33S52 were in one cluster closely related to the genus Enterococcus.

Conclusion:

This study suggests that the isolates P31H62, P33S62, and P33S52 from the intestines of laying hens administered 4% AKBISprob are cellulolytic LAB belonging to the genus Enterococcus.

Limosilactobacillus fermentum, Current Evidence on the Antioxidant Properties and Opportunities to be Exploited as a Probiotic Microorganism

The unbalance in the production and removal of oxygen-reactive species in the human organism leads to oxidative stress, a physiological condition commonly linked to the occurrence of cancer, neurodegenerative, inflammatory, and metabolic disorders. The implications of oxidative stress in the gut have been associated with gut microbiota impairments and gut dysbiosis. Some lactobacilli strains have shown an efficient antioxidant system capable of protecting against oxidative stress and related-chronic diseases. Recently, in vitro and experimental studies and some clinical trials have demonstrated the efficacy of the administration of various Limosilactobacillus fermentum strains to modulate beneficially the host antioxidant system resulting in the amelioration of a variety of systemic diseases phenotypes. This review presents and discusses the currently available studies on identifying L. fermentum strains with anti-oxidant properties, their sources, range of the administered doses, and duration of the intervention in experiments with animals and clinical trials. This review strives to serve as a relevant and well-cataloged reference of L. fermentum strains with capabilities of inducing anti-oxidant effects and health-promoting benefits to the host, envisaging their broad applicability to disease control.

Effect of Lactic Acid Fermentation on Volatile Compounds and Sensory Characteristics of Mango (Mangifera indica) Juices

Fermentation is a sustainable bio-preservation technique that can improve the organoleptic quality of fruit juices. Mango juices were fermented by monoculture strains of Lactiplantibacillus plantarum subsp. plantarum (MLP), Lacticaseibacillus rhamnosus (MLR), Lacticaseibacillus casei (MLC), Levilactobacillus brevis (MLB), and Pediococcus pentosaceus (MPP). Volatile compounds were sorbed using headspace solid phase microextraction, separated, and identified with gas chromatography-mass spectrometry. Forty-four (44) volatile compounds were identified. The control, MPP, and MLB had higher amounts of ethyl acetate, ethyl butyrate, 2-hexenal, 2,6-nonadienal, 2,2-dimethylpropanal, β-selinene, γ-gurjunene, α-copaene, and δ-cadinene, while MLC, MLP, and MLR had higher amounts of 2,3-butanedione and a cyclic hydrocarbon derivate. Consumers (n = 80) assessed their overall liking and characterized sensory attributes (appearance, color, aroma, flavor, consistency, acidity, and sweetness) using check-all-that-apply, and penalty analysis (just-about-right). Overall liking was associated with ‘mango color’, ‘pulp’, ‘mango aroma’, ‘sweet’, ‘natural taste’, and ‘mango flavor’ that described the control, MLB, MLC and MPP. Juices MLR and MLP were described as ‘bitter’, ‘sour’, ‘aftertaste’, and ‘off-flavor’. Multivariate analysis revealed relationships between the volatile compounds, mango juices fermented by different lactic acid bacteria, and sensory characteristics. Thus, the type of lactic acid bacteria strains determined the volatile and sensory profile of mango juices.

Potentially Probiotic Limosilactobacillus fermentum Fruit-Derived Strains Alleviate Cardiometabolic Disorders and Gut Microbiota Impairment in Male Rats Fed a High-Fat Diet

High-fat diet (HFD) consumption is a risk factor for dyslipidemias, insulin resistance, and arterial hypertension linked with gut dysbiosis. Probiotic administration has been suggested as a safe therapeutic strategy for gut microbiota modulation and treatment and/or prevention of cardiometabolic disorders. Here, we assessed the effects of a potentially probiotic formulation containing strains of the Limosilactobacillus (L.) fermentum 139, 263, and 296 on the cardiometabolic disorders and gut microbiota derangements provoked by the HFD consumption. Male Wistar rats were allocated into control diet (CTL, n = 6), HFD (n = 6), and HFD receiving L. fermentum formulation (HFD-LF, n = 6) groups for 4 weeks. L. fermentum formulation (10⁹ colony-forming unit (CFU)/ml of each strain) was daily administered by oral gavage. After 4-week follow-up, biochemical measurements, blood pressure (BP), heart rate (HR), sympathetic tone, and gut microbiota composition were evaluated. HFD consumption for 4 weeks increased lipid profile, insulin resistance, sympathetic tone, and blood pressure and impaired gut microbiota composition in male rats. Administration of L. fermentum formulation improved the gut microbiota composition, lipid profile, insulin resistance, autonomic dysfunction, and BP in rats fed with a HFD. Administration of a potentially fruit-derived probiotic formulation of L. fermentum strains improved gut microbiota composition and alleviated hyperlipidemia, insulin resistance, and sympathetic hyperactivity and increased BP in rats fed a HFD. Our findings may encourage the development of randomized controlled trials to assess the effects of L. fermentum treatment in subjects with cardiometabolic disorders.

Selection of Lactic Acid Bacteria with In Vitro Probiotic-Related Characteristics from the Cactus Pilosocereus gounellei (A. Weber ex. K. Schum.) Bly. ex Rowl

Pilosocereus gounellei (A. Weber ex. K. Schum.) Bly. ex Rowl., popularly known as xique-xique, is a cactus from the Caatinga biome, which is rich in bioactive compounds but has not been previously studied as a source of lactic acid bacteria (LAB) with probiotic aptitudes. This study aimed to identify, characterize, and select LAB isolates with in vitro probiotic-related characteristics from xique-xique cladodes and fruit. Isolates with the most promising probiotic-related characteristics were evaluated regarding their in vitro technological properties and capability of surviving in chestnut milk, whey protein drink, and mate tea with mint during 21 days of refrigeration storage. Seventeen recovered isolates had typical characteristics of LAB. Six out of these seventeen LAB isolates passed the safety tests and were included in experiments to evaluate the in vitro probiotic-related characteristics. Based on the results of a principal component analysis, the isolates 69, 82, 98, and 108 had the best performances in experiments to evaluate the probiotic-related characteristics. In addition to showing good technological properties, the four selected LAB isolates had high viable counts (>7.3 log cfu/mL) and high sizes of physiologically active cell subpopulations in chestnut milk, whey protein drink, and mate tea during refrigeration storage. These four isolates were identified by 16S-rRNA sequencing as being Lacticaseibacillus paracasei or Lacticaseibacillus casei. The results indicate xique-xique as a source of potentially probiotic LAB isolates.

Limosilactobacillus fermentum Strains with Claimed Probiotic Properties Exert Anti-oxidant and Anti-inflammatory Properties and Prevent Cardiometabolic Disorder in Female Rats Fed a High-Fat Diet

This study assessed the effects of a mixed formulation containing Limosilactobacillus (L.) fermentum 139, L. fermentum 263, and L. fermentum 296 on cardiometabolic parameters, inflammatory markers, short-chain fatty acid (SCFA) fecal contents, and oxidative stress in colon, liver, heart, and kidney tissues of female rats fed a high-fat diet (HFD). Female Wistar rats were allocated into control diet (CTL, n = 6), HFD (n = 6), and HFD receiving L. fermentum formulation (HFD-LF, n = 6). L. fermentum formulation (1 × 10⁹ CFU/mL of each strain) was administered two twice a day for 4 weeks. Administration of L. fermentum increased acetate and succinate fecal contents and reduced hyperlipidemia and hyperglycemia in rats fed a HFD (p < 0.05). Administration of L. fermentum decreased low-grade inflammation and improved antioxidant capacity along the gut, liver, heart, and kidney tissues in female rats fed a HFD (p < 0.05). Administration of L. fermentum prevented dyslipidemia, inflammation, and oxidative stress in colon, liver, heart, and kidney in female rats fed a HFD.

Application of Potentially Probiotic Fruit-Derived Lactic Acid Bacteria Loaded into Sodium Alginate Coatings to Control Anthracnose Development in Guava and Mango During Storage

This study evaluated the efficacy of potentially probiotic fruit-derived lactic acid bacteria (LAB) strains loaded into sodium alginate (SA) coatings to control the anthracnose development in guava cv. Paluma and mango cv. Palmer caused by distinct pathogenic Colletotrichum species (C. asianum, C. fructicola, C. tropicale, C. siamense, C. karstii, and C. gloeosporioides) during 15 days of room temperature storage (25 ± 0.5 °C). The effects of the formulated coatings on physicochemical parameters indicative of overall postharvest quality of guava and mango were evaluated. The eight examined LAB strains caused strong inhibition on the mycelial growth of all target Colletotrichum species in vitro. LAB strains with the highest inhibitory effects (Levilactobacillus brevis 59, Lactiplantibacillus pentosus 129, and Limosilactobacillus fermentum 263) on the target Colletotrichum species were incorporated into SA coatings. These strains had viable counts of > 6 log CFU/mL in SA coatings during 15 days of room temperature storage. Application of coatings with SA + L. brevis 59, SA + L. pentosus 129, and SA + L. fermentum 263 delayed the development and decreased the severity of anthracnose lesions in guava and mango artificially contaminated with either of the tested Colletotrichum species. These coatings impacted positively on some physicochemical parameters indicative of postharvest quality and more prolonged storability of guava and mango. The formulated SA coatings loaded with tested fruit-derived potentially probiotic LAB strains could be innovative and effective strategies to control postharvest anthracnose and extend the storability of guava and mango.

Unraveling the probiotic efficiency of bacterium Pediococcus pentosaceus OBK05 isolated from buttermilk: An in vitro study for cholesterol assimilation potential and antibiotic resistance status

The present study describes the probiotic potential and functional properties of the lactic acid bacterium Pediococcus pentosaceus OBK05 isolated from buttermilk. The isolate OBK05 was assessed for its probiotic properties. The isolate showed notable tolerance to pH 2.0 and 3.0 (8.44, 8.35 log CFU/mL), oxbile of 0.5% at 2 and 4 h of incubation (6.97, 6.35 log CFU/mL) and higher aggregation (auto-aggregation, adhesion to hydrocarbons) than the referral strain, Lactobacillus acidophilus MTCC 10307. The adhesion efficiency to HT-29 cells was found to be maximum, corresponding to 93.5% and 97% at 1 and 2 h incubation, respectively. In addition, the isolate OBK05 showed antagonistic solid activity against bacterial pathogens like Pseudomonas aeruginosa MTCC 424 and Bacillus subtilis MTCC 1133. The phenotypic antibiotic resistance of the isolate was examined before and after curing plasmids. Among the known five structural genes responsible for different antibiotic resistance, four genes indicating antibiotic resistance to kanamycin-Aph (3´´)-III, streptomycin-strA, vancomycin-vanA and ciprofloxacin-gyrA were detected by PCR amplification of genomic DNA. Further, the horizontal gene transfer from OBK05 isolate to pathogens was not found for these antibiotic resistance markers when filter and food mating were carried out as no transconjugants developed on media plates containing respective antibiotics. This indicates that the intrinsic resistance is harbored on chromosomal genes, and hence it is nontransferable to other microbes. In addition, strain OBK05 exhibited good DPPH scavenging activity of 56 to 77% and liberated free amino acid from conjugated bile acid. The strain OBK05 demonstrated a strong ability to reduce cholesterol at 12 h (17%), 24 h (27%) and 48 h (67%) of incubation.

Evaluation of Pediococcus pentosaceus strains as probiotic adjunct cultures for soybean milk post-fermentation

Soybean milk is an economical substitute for dairy products. Pediococcus pentosaceus has been used as a food additive to improve taste, nutrition, and food safety. In this study, four P. pentosaceus strains (CICC 24444, QK-1, MQ-1 and RQ-1) isolated from various food sources and known to exhibit broad-spectrum antibacterial activities were used to ferment soybean milk, and their fermentation characteristics and the properties of the resulting beverages were evaluated. The results revealed that the P. pentosaceus strains can inhibited the growth of five types of pathogenic bacteria (Salmonella enterica subsp. enterica serotype Enteritidis, Yersinia enterocolitica, Shigella dysenteriae, Escherichia coli, and Staphylococcus aureus), and their in vitro survival rates in the simulated stomach and intestinal environments were above 90%, satisfying the probiotic requirements. Isomaltose oligosaccharide was used as a protective agent to resist low-temperature freeze-drying damage and ensure a high survival rate, and P. pentosaceus was directly injected into fermented soymilk. The acidification of fermented soybean milk was the weakest with P. pentosaceus QK-1, and the viable bacterial counts of all strains were stable after 28 days of storage. After fermentation, the antioxidant ability was enhanced. Arginine and β-alanine levels increased after fermentation, and the adjunct culture of P. pentosaceus QK-1 increased proline levels. Our data indicate that P. pentosaceus QK-1 is a suitable strain for the development of functional plant-based beverages.

Effects of a Mixed Limosilactobacillus fermentum Formulation with Claimed Probiotic Properties on Cardiometabolic Variables, Biomarkers of Inflammation and Oxidative Stress in Male Rats Fed a High-Fat Diet

High-fat diet (HFD) consumption has been linked to dyslipidemia, low-grade inflammation and oxidative stress. This study investigated the effects of a mixed formulation with Limosilactobacillusfermentum 139, L. fermentum 263 and L. fermentum 296 on cardiometabolic parameters, fecal short-chain fatty acid (SCFA) contents and biomarkers of inflammation and oxidative stress in colon and heart tissues of male rats fed an HFD. Male Wistar rats were grouped into control diet (CTL, n = 6), HFD (n = 6) and HFD with L. fermentum formulation (HFD-Lf, n = 6) groups. The L.fermentum formulation (1 × 10⁹ CFU/mL of each strain) was administered twice a day for 4 weeks. After a 4-week follow-up, biochemical parameters, fecal SCFA, cytokines and oxidative stress variables were evaluated. HFD consumption caused hyperlipidemia, hyperglycemia, low-grade inflammation, reduced fecal acetate and propionate contents and increased biomarkers of oxidative stress in colon and heart tissues when compared to the CTL group. Rats receiving the L. fermentum formulation had reduced hyperlipidemia and hyperglycemia, but similar SCFA contents in comparison with the HFD group (p < 0.05). Rats receiving the L. fermentum formulation had increased antioxidant capacity throughout the colon and heart tissues when compared with the control group. Administration of a mixed L. fermentum formulation prevented hyperlipidemia, inflammation and oxidative stress in colon and heart tissues induced by HFD consumption.

Effect of Encapsulated Lactobacillus bulgaricus on Innate Immune System and Hematological Parameters in Rainbow Trout (Oncorhynchus mykiss), Post-Administration of Pb

The present study was conducted to investigate the effects of probiotic and encapsulated Lactobacillus bulgaricus on hematological and immunological factors after lead toxicity in rainbow trout (Oncorhynchus mykiss). Two hundred and forty fish weighing about 16 ± 3.8 g were divided randomly in to four groups including two groups which were fed by a diet containing ~ 10⁸ CFU g^-1Lactobacillus bulgaricus and encapsulated Lactobacillus bulgaricus bacteria and also the third group diet without Lactobacillus bulgaricus. After 45 days, in addition to probiotic (~ 10⁸ CFU g^-1), 500 μg kg of lead nitrate was added to the food of the three groups for 21 days. The fourth group (control) was first fed to the normal diet for 45 days then exposed to Pb. Blood samples were collected at days 45, 52, 59, and 66, and hematological and some immunological parameters were assessed. Results showed that hemoglobin, red blood cells, white blood cells, and lysozyme activity in the two probiotics groups were increased significantly up to 45 day (P < 0.05), but followed by a decreasing trend by adding Pb. Complement and bactericidal activity were enhanced significantly in the bulgaricus group (P < 0.05). Respiratory burst activity at day 45 in group bulgaricus had significant increase (P < 0.05) and decreased in all groups particularly after Pb exposure (P < 0.05). The achieved data shows that microencapsulation of probiotics with alginate-chitosan may be a suitable method to improve the fish condition against heavy metal.

Selection of lactic acid bacteria with promising probiotic aptitudes from fruit and ability to survive in different food matrices

Lactic acid bacteria (LAB) are among the most prevalent microorganisms forming the autochthonous microbiota of fruit. This study aimed to select LAB isolates with probiotic aptitudes from apple, banana, grape, and orange through evaluation of in vitro safety, technological, and functional-related properties. The ability of most promising selected isolates to survive in commercial apple and orange juice, meat stew, vegetable puree, and UHT milk during 28 days of refrigeration storage was evaluated. Ninety-three isolates identified preliminarily as LAB were recovered from fruit and 66 of these isolates passed safety tests. Most of these isolates were pre-identified as belonging to Lactobacillus or Enterococcus genus based on MALDI-ToF MS profiling. These 66 isolates were categorized into three homogeneous groups based on a preliminary cluster analysis run with data from experiments to measure technological characteristics. Nine LAB isolates were selected as the most promising for probiotic use based on a principal component analysis run with data from experiments to measure probiotic-related properties. Four of these isolates were sensitive to different antibiotics and identified (16S-rRNA gene sequencing) as Lactobacillus brevis (recently reclassified as L. brevis) or Lactobacillus spp. These 4 selected isolates had high viable counts and high percentages of physiologically active cells in apple and orange juice, beef stew, vegetable puree, and UHT milk during refrigeration storage. The results showed that apple, banana, orange, and grape are potential sources of LAB with aptitudes to be exploited for a possible probiotic use and distinguished abilities to survive in different food matrices.

Effect of lactic acid fermentation of watermelon juice on its sensory acceptability and volatile compounds

Fermentation increases food shelf-life but is characterized by changes that affect product's perception. Watermelon juice was fermented with Lactobacillus plantarum (WJ-LP), L. rhamnosus (WJ-LR), L. casei (WJ-LC), L. brevis (WJ-LB) and Pediococcus pentosaceus (WJ-PP). Their sensory characteristics and volatile compounds were investigated by consumers and Headspace Solid Phase Microextraction integrated with Gas Chromatography-Mass Spectrometry, respectively. WJ-PP and WJ-LB were most liked and perceived with 'watermelon-flavor', 'natural taste', 'sweet' and 'watermelon-color' while WJ-LC, WJ-LP and WJ-LR were least liked and perceived as 'sour', 'bitter', 'off-flavor', 'aftertaste' and 'intense-flavor'. Fifty-four volatiles were identified. After fermentation, alcohols, ketones, monoterpenes, acids, and furans increased while aldehydes and alkanes decreased. Lactic acid fermentation introduced 4-decanone and 2,3-butanedione in WJ-LB, WJ-LC, WJ-LP and WJ-LR, however, heptanal, 2-heptenal, 2,6-nonadienal, 2-decenal, and 2,4-decadienal in WJ-LC, heptanal, 2-hexenal, 2-heptenal, 2,6-nonadienal, 2-decenal and octanal in WJ-LR and 2,6-dimethyl-2,6-octadiene in WJ-LP disappeared. Juice sensory profiles were associated with their volatile compounds.

Profiling of Potential Antibacterial Compounds of Lactic Acid Bacteria against Extremely Drug Resistant (XDR) Acinetobacter baumannii

A total of 20 of isolates of lactic acid bacteria (LAB) were selected and screened for antagonistic activity against clinical strains of 30 clinical isolates of extremely drug-resistant (XDR) Acinetobacter baumannii using the well diffusion assay method. Results showed that 50% of the highly LAB strains possessed inhibitory activity against (up to 66%) of the XDR A. baumannii strains tested. The supernatant of the twenty LAB strains was subjected to gas chromatography mass spectrometry (GCMS) revealed that the common compound found in the active isolates against XDR A. baumannii was 3-Isobutyl-2,3,6,7,8,8a-hexahydropyrrolo[1,2-a]pyrazine-1,4-dione, a known potential diketopiperazine group. The molecular docking study against potential antibacterial targets with selected ligands was performed to predict the binding mode of interactions, which is responsible for antibacterial activity. The docking analysis of the potent compounds supported the potential antibacterial activity exhibiting high inhibition constant and binding affinity in silico.

Probiotic properties of yeasts isolated from Brazilian fermented table olives

AIMS

To investigate the probiotic potential of yeasts isolated from naturally fermented Brazilian table olives.

METHODS AND RESULTS

Eighteen yeast strains were tested in terms of: safety; survival of gastrointestinal and digestion conditions; antimicrobial activity; cellular hydrophobicity; autoaggregation ability and adhesion to epithelial cells; coaggregation and inhibition of pathogenic bacteria adhesion. Six yeasts showed favourable results for all probiotic attributes: Saccharomyces cerevisiae CCMA 1746, Pichia guilliermondii CCMA 1753, Candida orthopsilosis CCMA 1748, Candida tropicalis CCMA 1751, Meyerozyma caribbica CCMA 1758 and Debaryomyces hansenii CCMA 1761. These yeasts demonstrated resistance to 37°C, pH 2·0 and bile salts, and survived in vitro digestion (≥10⁶  CFU per ml). Furthermore, the yeasts exhibited a hydrophobic cell surface (42·5-92·2%), autoaggregation capacity (41·0-91·0%) and adhesion to Caco-2 (62·0-82·8%) and HT-29 (57·6-87·3%) epithelial cell lines. Also, the strains showed antimicrobial activity against Salmonella Enteritidis as well as the ability to coaggregate and reduce the adhesion of this pathogen to intestinal cells.

CONCLUSIONS

Autochthonous yeasts from naturally fermented Brazilian table olives have probiotic properties, with potential for development of new probiotic food products.

SIGNIFICANCE AND IMPACT OF STUDY

These data are important and contribute to the knowledge of new potential probiotic yeasts capable of surviving gastrointestinal tract conditions and inhibiting pathogenic bacteria.

Efficacy of Potentially Probiotic Fruit-Derived Lactobacillus fermentum, L. paracasei and L. plantarum to Remove Aflatoxin M1 In Vitro

This study evaluated the efficacy of potentially probiotic fruit-derived Lactobacillus isolates, namely, L. paracasei 108, L. plantarum 49, and L. fermentum 111, to remove aflatoxin M₁ (AFM₁) from a phosphate buffer solution (PBS; spiked with 0.15 µg/mL AFM₁). The efficacy of examined isolates (approximately 10⁹ cfu/mL) as viable and non-viable cells (heat-killed; 100 °C, 1 h) to remove AFM₁ was measured after 1 and 24 h at 37 °C. The recovery of AFM₁ bound to bacterial cells after washing with PBS was also evaluated. Levels of AFM₁ in PBS were measured with high-performance liquid chromatography. Viable and non-viable cells of all examined isolates were capable of removing AFM₁ in PBS with removal percentage values in the range of 73.9–80.0% and 72.9–78.7%, respectively. Viable and non-viable cells of all examined Lactobacillus isolates had similar abilities to remove AFM₁. Only L. paracasei 108 showed higher values of AFM₁ removal after 24 h for both viable and non-viable cells. Percentage values of recovered AFM₁ from viable and non-viable cells after washing were in the range of 13.4–60.6% and 10.9–47.9%, respectively. L. plantarum 49 showed the highest AFM₁ retention capacity after washing. L. paracasei 108, L. plantarum 49, and L. fermentum 111 could have potential application to reduce AFM₁ to safe levels in foods and feeds. The cell viability of examined isolates was not a pre-requisite for their capacity to remove and retain AFM₁.

ISOLASI BAKTERI ASAM LAKTAT ASAL JUS NANAS SEBAGAI KANDIDAT PROBIOTIK

Lactic acid bacteria (LAB) are the main group of probiotic bacteria that widely used in fruit juice fermentation products. Fruit juice contains antioxidants that can prevent free radicals. The objective of this study was to identify LAB isolated from pineapple juice that possess probiotic properties and to analyze the antioxidant activity of pineapple juice after being fermented with the LAB. LAB isolates from pineapple juice were evaluated for their probiotic properties (tolerance to acidic conditions and bile salts, antimicrobial activity against pathogenic bacteria, and sensitivity to antibiotics) and their adherence properties (autoaggregation, coaggregation, and hydrophobicity). The best isolates obtained are then inoculated into pineapple juice. From 5 types of pineapple juice, 5 isolates with LAB characteristics were obtained, i.e NHC6, NHC7, NHC8, NHC9, and NPC1. Isolate NHC6 had a good tolerance to acidic conditions (pH 2) and 0,5% bile salt, had antimicrobial activity, was sensitive to ampicillin, showed the best adherance properties and was identified as Lactobacillus plantarum. L. plantarum NHC6 was then added to pineapple juice. Addition of L. plantarum NHC6 to pineapple juice reduced the ᵒBrix and pH values during incubation. After 24 hours of incubation, the antioxidant activity was 89,05%, with LAB growth of 8,33 log CFU/mL, thus 24 hours incubation was considered the best fermentation time for pineapple juice.

Reliability of MALDI-TOF mass spectrometry to identify oral isolates of Streptococcus salivarius and Lactobacillus spp

OBJECTIVE

The aim of this study is to evaluate the performance of MALDI-TOF mass spectrometry in identifying bacteria isolated in the oral cavity known to be of probiotic interest.

DESIGN

We evaluated Bruker MALDI Biotyper for the identification of 92 clinical oral isolates of probiotic interest (31 Streptococcus salivarius and 61 Lactobacillus spp.) by comparing direct colony method with on-plate formic acid extraction. Isolates were previously identified by use of biochemical methods and molecular biology.

RESULTS

Using the manufacturer's suggested genus and species level cutoff scores, the direct colony method identified 42 (45.7%) isolates at the genus level and 35 (38%) at the species level while the on-plate extraction method correctly identified 90 (97.8%) isolates at the genus level and 82 (89.1%) at the species level. The difference between the two methods was statistically significant at the genus and species levels (P ≤ 0.0001). After dividing the isolates into two subgroups, the analysis was repeated. The direct colony method identified correctly all isolates of Streptococcus salivarius at the species level. In contrast, the direct colony method allowed the identification of only 11 (18%) lactobacilli at the genus level and 4 (6.6%) at the species level. The on-plate extraction method was statistically (P ≤ 0.0001) more efficient since 59 (96.7%) lactobacilli were identified at the genus level and 51 (83.6%) at the species level.

CONCLUSIONS

MALDI Biotyper can efficiently identify Streptococcus salivarius regardless of the preparative method but on-plate extraction is superior to direct colony method for the identification of lactobacilli.

Lactobacillus plantarum PMO 08 as a Probiotic Starter Culture for Plant-Based Fermented Beverages

Lactobacillus plantarum PMO 08 was evaluated as a starter culture for plant-based probiotic beverages. Its viability under various culture conditions and acidification ability in standardized tomato medium, fermentation parameters, and beverage properties were assessed. Lactobacillus plantarum PMO 08 could grow under various culture conditions; there was a high correlation between the incubation time to reach the optimal conditions and the inoculation concentration of lactic acid bacteria (LAB) (r² = 0.997). Acidity (0.958 ± 0.002%) and LAB count (9.78 ± 0.14 Log₁₀ CFU/mL) were significantly higher when fermented with L. plantarum than with the yogurt starter culture. A survival rate of 96% and 95% in artificial gastric juice and artificial intestinal juice, respectively, indicated that the probiotic requirements were met. The total polyphenol and glutamine content, and antioxidant activity increased after fermentation. The proline content significantly increased in L. plantarum PMO 08- fermented beverage. Thus, L. plantarum PMO 08 is an effective starter culture for non-dairy probiotic beverages whose functional quality may be improved by fermentation.

Fruits and fruit by-products as sources of bioactive compounds. Benefits and trends of lactic acid fermentation in the development of novel fruit-based functional beverages

Current awareness about the benefits of a balanced diet supports ongoing trends in humans towards a healthier diet. This review provides an overview of fruits and fruit-by products as sources of bioactive compounds and their extraction techniques, and the use of lactic acid fermentation of fruit juices to increase their functionality. Fruit matrices emerge as a technological alternative to be fermented by autochthonous or allochthonous lactic acid bacteria (LAB such as Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and other Lactobacillus species), and also as probiotic vehicles. During fermentation, microbial enzymes act on several fruit phytochemicals producing new derived compounds with impact on the aroma and the functionality of the fermented drinks. Moreover, fermentation significantly reduces the sugar content improving their nutritional value and extending the shelf-life of fruit-based beverages. The generation of new probiotic beverages as alternatives to consumers with intolerance to lactose or with vegan or vegetarian diets is promising for the worldwide functional food market. An updated overview on the current knowledge of the use of fruit matrices to be fermented by LAB and the interaction between strains and the fruit phytochemical compounds to generate new functional foods as well as their future perspectives in association with the application of nanotechnology techniques are presented in this review.

Development and in vitro evaluation of novel nutraceutical formulations composed of Limosilactobacillus fermentum, quercetin and/or resveratrol

This study developed and carried out an in vitro evaluation of nutraceutical formulations composed of potentially probiotic Limosilactobacillus fermentum (L. fermentum 139, L. fermentum 263 or L. fermentum 296), quercetin and/or resveratrol. L. fermentum strains had counts of >9 log CFU/g and contents of QUE and RES of >200 µg/mg in formulations after freeze-drying. Formulations with QUE and RES protected L. fermentum during exposure to in vitro acidic stomach conditions. L. fermentum strains had counts of >6 log CFU/g on day 60 and/or 90 of refrigeration storage. Contents of QUE (>29%) and RES (>50%) in formulations were potentially bioaccessible. Higher counts of L. fermentum and higher contents of QUE and RES were found in formulations stored under refrigerated rather than under room temperature. All nutraceutical formulations had antioxidant properties. Combinations of probiotic L. fermentum and QUE and/or RES should be an innovative strategy to develop added-value nutraceutical formulations.