Nutritional attributes and microbial metagenomic profile during solid-state fermentation of soybean meal inoculated with Lactobacillus acidophilus under non-sterile conditions.

BACKGROUND: Soybean meal (SBM) is used widely in animal feed but it contains anti-nutritional factors (ANFs) such as protease inhibitors - immunogenic proteins that limit its utilization. Fermentative processes could help to reduce these ANFs. The aim of this study was to evaluate the nutritional attributes, bacterial community dynamics, and microbial metagenomic profile during the solid-state fermentation of SBM using a strain of the bacterium Lactobacillus acidophilus with or without pre-autoclaving treatment. RESULTS: Following fermentation, there was a reduction in the pH and a concurrent increase in the population of lactic acid bacteria. Fermentation also resulted in an increase in both crude and soluble protein levels. Trypsin inhibitor levels decreased after fermentation, particularly in fermented SBM that had not been pre-autoclaved, with an inactivation rate higher than 90%. Moreover, high-molecular-weight peptides (44-158 kDa), specifically some polypeptides from the soybean immunogen glycinin and ß-conglycinin, underwent degradation during the fermentation process. Bacterial community analysis revealed the dominance of the Lactobacillus genus in all samples, regardless of the treatments applied. Metagenomic profiling identified L. acidophilus as the dominant species in inoculated SBM, irrespective of whether pre-autoclaving was conducted or not. CONCLUSION: This study demonstrates the feasibility of solid-state fermentation with L. acidophilus under non-sterile conditions to inactivate trypsin inhibitor and increase protein concentration and hydrolysate immunogen proteins into low-molecular-weight peptides in SBM. Lactobacillus acidophilus inoculum also inhibited the growth of undesirable bacteria. This knowledge contributes to our understanding of the potential applications of solid-state fermentation with L. acidophilus in improving the nutritional quality of SBM. © 2024 Society of Chemical Industry.

Lactobacillus acidophilus VB1 co-aggregates and inhibits biofilm formation of chronic otitis media-associated pathogens.

This study aims to evaluate the antibacterial activity of Lactobacillus acidophilus, alone and in combination with ciprofloxacin, against otitis media-associated bacteria. L. acidophilus cells were isolated from Vitalactic B (VB), a commercially available probiotic product containing two lactobacilli species, L. acidophilus and Lactiplantibacillus (formerly Lactobacillus) plantarum. The pathogenic bacterial samples were provided by Al-Shams Medical Laboratory (Baqubah, Iraq). Bacterial identification and antibiotic susceptibility testing for 16 antibiotics were performed using the VITEK2 system. The minimum inhibitory concentration of ciprofloxacin was also determined. The antimicrobial activity of L. acidophilus VB1 cell-free supernatant (La-CFS) was evaluated alone and in combination with ciprofloxacin using a checkerboard assay. Our data showed significant differences in the synergistic activity when La-CFS was combined with ciprofloxacin, in comparison to the use of each compound alone, against Pseudomonas aeruginosa SM17 and Proteus mirabilis SM42. However, an antagonistic effect was observed for the combination against Staphylococcus aureus SM23 and Klebsiella pneumoniae SM9. L. acidophilus VB1 was shown to significantly co-aggregate with the pathogenic bacteria, and the highest co-aggregation percentage was observed after 24 h of incubation. The anti-biofilm activities of CFS and biosurfactant (BS) of L. acidophilus VB1 were evaluated, and we found that the minimum biofilm inhibitory concentration that inhibits 50% of bacterial biofilm (MBIC50) of La-CFS was significantly lower than MBIC50 of La-BS against the tested pathogenic bacterial species. Lactobacillus acidophilus, isolated from Vitane Vitalactic B capsules, demonstrated promising antibacterial and anti-biofilm activities against otitis media pathogens, highlighting its potential as an effective complementary/alternative therapeutic strategy to control bacterial ear infections.

Effects of Probiotic-Enriched Minas Cheese (Lactobacillus acidophilus La-05) on Cardiovascular Parameters in 5/6 Nephrectomized Rats.

Dairy foods have become an interest in chronic kidney disease (CKD) due to their nutritional profile, which makes them a good substrate for probiotics incorporation. This study evaluated the effect of probiotic-enriched Minas cheese with Lactobacillus acidophilus La-05 in an experimental rat model for CKD on cardiac, inflammatory, and oxidative stress parameters. Male Wistar rats were divided into 4 groups (n = 7/group): 5/6 nephrectomy + conventional Minas cheese (NxC); 5/6 nephrectomy + probiotic Minas cheese (NxPC); Sham + conventional Minas cheese (ShamC); Sham + probiotic Minas cheese (ShamPC). Offering 20 g/day of Minas cheese with Lact. acidophilus La-05 (108-109 log CFU/g) for 6 weeks. The cardiomyocyte diameter was determined. Superoxide dismutase (SOD) activity in plasma, heart, kidney, and colon tissue was performed. At the end of supplementation, no significant changes in lipid profile and renal parameters were found. The NxPC group showed a decrease in cardiomyocyte diameter compared to the NxC group (16.99 ± 0.85 vs. 19.05 ± 0.56 µm, p = 0.0162); also they showed reduced plasmatic SOD activity (502.8 ± 49.12 vs. 599.4 ± 94.69 U/mL, p < 0.0001). In summary, probiotic-enriched Minas cheese (Lact. acidophilus La-05) consumption suggests a promisor cardioprotective effect and was able to downregulate SOD activity in a rat model of CKD.

Lactic acid bacteria secreted proteins as potential Listeria monocytogenes quorum sensing inhibitors.

Listeria monocytogenes is an important human and animal pathogen able to cause an infection named listeriosis and is mainly transmitted through contaminated food. Among its virulence traits, the ability to form biofilms and to survive in harsh environments stand out and lead to the persistence of L. monocytogenes for long periods in food processing environments. Virulence and biofilm formation are phenotypes regulated by quorum sensing (QS) and, therefore, the control of L. monocytogenes through an anti-QS strategy is promising. This study aimed to identify, by in silico approaches, proteins secreted by lactic acid bacteria (LAB) potentially able to interfere with the agr QS system of L. monocytogenes. The genome mining of Lacticaseibacillus rhamnosus GG and Lactobacillus acidophilus NCFM revealed 151 predicted secreted proteins. Concomitantly, the three-dimensional (3D) structures of AgrB and AgrC proteins of L. monocytogenes were modeled and validated, and their active sites were predicted. Through protein-protein docking and molecular dynamic, Serine-type D-Ala-D-Ala carboxypeptidase and L,D-transpeptidase, potentially secreted by L. rhamnosus GG and L. acidophilus NCFM, respectively, were identified with high affinity to AgrB and AgrC proteins, respectively. By inhibiting the translocation of the cyclic autoinducer peptide (cyclic AIP) via AgrB, and its recognition in the active site of AgrC, these LAB proteins could disrupt L. monocytogenes communication by impairing the agr QS system. The application of the QS inhibitors predicted in this study can emerge as a promising strategy in controlling L. monocytogenes in food processing environment and as an adjunct to antibiotic therapy for the treatment of listeriosis.

Encapsulation of probiotic Lactobacillus acidophilus ATCC 4356 in alginate-galbanum (Ferula Gummosa Boiss) gum microspheres and evaluation of the survival in simulated gastrointestinal conditions in probiotic Tahini halva.

One of the famous traditional confectionery products is Tahini halva. The aim of this study was the production of probiotic halva using free Lactobacillus acidophilus (FLA) and microencapsulated Lactobacillus acidophilus (MLA) with sodium alginate and galbanum gum as the second layer. The survival rate of MLA and FLA during heat stress, storage time, and simulation gastrointestinal condition in Tahini halva was assessed. The survival rates of MLA and FLA under heat stress were 50.13% and 34.6% respectively. During storage in Tahini halva, the cell viability loss was 3.25 Log CFU g-1 and 6.94 Log CFU g-1 for MLA and FLA, separately. Around 3.58 and 4.77 Log CFU g-1 bacteria were reduced after 6 h of exposure in simulated gastrointestinal conditions, for MLA and FLA respectively. These results suggest that the use of alginate and galbanum gum is a promising approach to protecting L. acidophilus against harsh environmental conditions.

Probiotic fermented whey-milk beverages: Effect of different probiotic strains on the physicochemical characteristics, biological activity, and bioactive peptides.

The effect of probiotic strains (Lactobacillus acidophilus La-03 (La-03); Lactobacillus acidophilus La-05 (La-05); Bifidobacterium Bb-12 (Bb-12) or Lacticaseibacillus casei-01 (L. casei-01)) on the characteristics of fermented whey-milk beverages during storage (4 °C, 30 days) was evaluated. The products were assessed for biological and antioxidant activities, physicochemical characteristics, and bioactive peptides. Probiotic addition increased α-amylase and α-glucosidase inhibition and antioxidant activities, mainly at 15 days of storage. L. casei-01 showed higher metabolic activity (higher titratable acidity and lower pH values) and the presence of anti-hypertensive peptides, while La-5 and Bb-12 showed higher α-glucosidase inhibition, improvements in the high saturated hypercholesterolemic index, and peptides with ACE-inhibitory, antimicrobial, immunomodulatory, and antioxidant activities. Our findings suggest that probiotic fermented whey-milk beverages may exert antidiabetic and antioxidant properties, being suggested La-5 or Bb-12 as probiotics and 15 days of storage.

Influence of anaerobic biotransformation process of agro-industrial waste with Lactobacillus acidophilus on the rheological parameters: case of study of pig manure.

This study evaluated the rheological behavior of the pig waste biotransformation process to produce lactic acid (LA) and biomass with Lactobacillus acidophilus in a stirred reactor. In addition, cell growth, carbohydrate consumption, and LA production were measured at three different agitation speeds, 100, 150, and 200 rpm at 37 °C, with a reaction time of 52 h. During the development of the process, the kinetic and rheological parameters were obtained using the logistic, Gompertz, generalized Gompertz, Ostwald de Waele, and Herschel-Bulkley mathematical models, respectively. The substrate used was pig manure, to which molasses was added at 12% v/v to increase the concentration of carbohydrates. The results suggest that mass exchange is favorable at low agitation speeds. Nevertheless, the presence of molasses rich in carbohydrates as a carbon source modifies the characteristics of the fluid, dilatant (n > 1) at the beginning of the process to end up as pseudoplastic (n < 1) due to the addition of exopolysaccharides and the modification of the physical structure of the substrate. This effect was confirmed by the Herschel-Bulkley model, which presented a better fit to the data obtained, in addition to finding a direct relationship between viscosity and pH that can be used as variables for the control of bioconversion processes of pig manure into biomass rich in Lactobacillus acidophilus.

Microencapsulation of Probiotics by Oil-in-Water Emulsification Technique Improves Cell Viability under Different Storage Conditions.

Probiotics are associated with health benefits to the host. However, their application can be limited due to a decrease in cell viability during processing, storage, and passage through the gastrointestinal tract. Microencapsulation is a simple and efficient alternative to improve the physical protection and stability of probiotics. The present study aimed to produce and characterize alginate or gelatin-based microparticles containing Lactobacillus acidophilus NRRL B-4495 or Lactiplantibacillus plantarum NRRL B-4496 by oil-in-water (O/W) emulsification and to evaluate the stability under storage conditions. The results showed that L. acidophilus and L. plantarum encapsulated in gelatin (LAEG and LPEG) presented diameters of 26.08 ± 1.74 µm and 21.56 ± 4.17 µm and encapsulation efficiencies of 89.6 ± 4.2% and 81.1 ± 9.7%, respectively. However, those encapsulated in alginate (LAEA and LPEA) showed an encapsulation efficiency of <1.0%. Furthermore, LAEG was stable for 120 days of storage at 5 °C and 25 °C. Therefore, encapsulation in gelatin by O/W emulsification is a promising strategy for protecting and stabilizing probiotic bacteria, enabling future application in foods.

Doderlin: isolation and characterization of a broad-spectrum antimicrobial peptide from Lactobacillus acidophilus

Lactobacillus acidophilus are Gram-positive bacteria distributed in diverse environments, and as a component of the normal microbiota of gastrointestinal and urogenital tract, they are relevant for human beings. Classified as lactic acid bacteria, due to the production of lactic acid, Lactobacillus can also produce antimicrobial peptides (AMPs), which is a compound synthesized by all forms of life aiming for protecting themselves from threats and to increase their competitivity to survive in a specific environment. AMPs are molecules capable of inhibiting the growth of microorganisms and, due to the indiscriminate use of conventional antibiotics and the emergence of multi-resistant bacteria, they have become an alternative, not only for treating multi-resistant infections, but also for the identification of probiotic products and food conservation. Considering the rampant rise of bacterial resistance to classical antimicrobials, the present study aimed to isolate and characterize AMPs from L. acidophilus extracts. Lactobacillus acid extract was pre-fractionated on disposable cartridges, followed by a high-performance liquid chromatography (HPLC). The collected fractions were evaluated in a liquid growth inhibition assay allowing to identify eight fractions with antimicrobial activity, and one of them showed antimicrobial activity against Candida albicans and, for this reason, was further characterized by mass spectrometry (MS). A peptide with a molecular mass of 1788.01 Da, showing the primary sequence NEPTHLLKAFSKAGFQ, as determined by MS, was named as Doderlin. Interestingly, antimicrobial molecules isolated from L. acidophilus have already been described previously, but few reports describe AMPs effective against C. albicans as the one reported here. We show here that this newly discovered molecule has a biological property with potential to be used in pharmaceutical and food companies, in the fight against contamination and/or for treating infections caused by microorganisms, respectively.

Aplicação do plasma de baixa temperatura sob pressão atmosférica no controle de biofilmes cariogênicos / Application of low temperature plasma under atmospheric pressure in the control cariogenic biofilms

O objetivo geral do presente estudo foi avaliar a aplicação dos jatos de plasma de baixa temperatura sob pressão atmosférica (PBTPA) produzidos por gás de argônio e hélio como gases de trabalho, no controle de biofilmes cariogênicos. Para tanto, foram estabelecidos os parâmetros físicos dos PBTPA gerados com argônio e hélio que se mostraram efetivos frente a biofilmes mono, dual e polimicrobianos compostos por combinações das espécies Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Lactobacillus casei, Lactobacillus acidophilus, Candida albicans e Actinomyces naeslundii. Os biofilmes mono, dual e multi-espécies foram submetidos ao tratamento com PBTPA produzidos por dois dispositivos diferentes, um obtido comercialmente (kINPen09®) que usou argônio como gás de trabalho, e outro protótipo desenvolvido pela FEG-UNESP (Faculdade de Engenharia de Guaratinguetá) que usou hélio. Análises quantitativas e microscópicas (confocal, microscopia eletrônica de varredura) foram realizadas. Foi incluído controle negativo (sem tratamento), positivo (clorexidina 0,12%) e controle de gás, utilizando apenas fluxo de gás, sem produzir plasma. Além disso, os efeitos celulares do PBTPAargônio e hélio sobre biofilme dual e multi-espécies também foram analisados em microscopia eletrônica de varredura e microscopia de varredura a laser confocal. Todos os ensaios foram realizados em triplicata em três experimentos independentes. Os resultados foram tabulados e analisados quanto à distribuição. A seguir, os testes estatísticos mais adequados foram selecionados. O nível de significância foi de 5%. Os resultados obtidos para os tratamentos dos biofilmes mono, dual ou multi-espécies com PBTPA-argônio e hélio foram todos significativos em comparação ao controle negativo em todos os tempos analisados. Para PBTPA-argônio, não houve recuperação de S. gordonii e S. sanguinis em todos tempos analisados. Para PBTPA-hélio, os melhores resultados foram obtidos em 5 e 7 minutos de exposição dos biofilmes ao PBTPA. Finalmente, tanto o dispositivo gerador de PBTPA que trabalhou com gás argônio quanto o dispositivo que trabalhou com gás hélio, demonstraram resultados promissores e poderão contribuir para o desenvolvimento de novos protocolos de Odontologia de Intervenção Mínima. (AU) The general objective of this study was to evaluate the application of lowtemperature plasma under atmospheric pressure (PBTPA) of argon and helium flow, in the control of cariogenic biofilms. For this, the effective physical parameters of PBTPA-argon and helium in mono, dual and polymicrobial biofilms composed of combinations of the species Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Lactobacillus casei, Lactobacillus acidophilus, Candida albicans and Actinomyces naeslundii were established. The multi-species biofilms were treated by different PBTPA generating devices, one obtained commercially (kINPen09®) that used argon as working gas, and another prototype developed by FEG-UNESP (Faculdade de Engenharia de Guaratinguetá) that used helium as working gas. Quantitative and microscopic analyzes (confocal, scanning electron microscopy) were performed. Negative control (no treatment), positive control (chlorhexidine 2%) and gas control (argon) were included. Besides that, cellular effects of PBTPA-argon and helium on dual and multi-species biofilms were analyzed by scanning electron microscopy (SEM) and confocal laser scanning microscopy. The results obtained for the treatments of mono, dual or multispecies biofilms with both PBTPA-argon and helium were all significant when compared to the negative control at all times analyzed. For PBTPA-argon, there was no recovery of S. gordonii and S. sanguinis at all analyzed times. For PBTPA-helium, the best results were obtained at 5 and 7 min of exposure of biofilms to PBTPA. All the tests were carried out in triplicate in three independent experiments. The results are tabulated and analyzed in terms of distribution. Next, the most suitable statistical tests were selected. The level of significance was 5%. The results obtained for the treatments of mono, dual or multi-species biofilms with PBTPA-argon and helium were all significant compared to the negative control at all analyzed times. Finally, both PBTPA generating could contribute to the development of new protocols for Minimal Intervention Dentistry (AU)

O objetivo geral do presente estudo foi avaliar a aplicação dos jatos de plasma de baixa temperatura sob pressão atmosférica (PBTPA) produzidos por gás de argônio e hélio como gases de trabalho, no controle de biofilmes cariogênicos. Para tanto, foram estabelecidos os parâmetros físicos dos PBTPA gerados com argônio e hélio que se mostraram efetivos frente a biofilmes mono, dual e polimicrobianos compostos por combinações das espécies Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Lactobacillus casei, Lactobacillus acidophilus, Candida albicans e Actinomyces naeslundii. Os biofilmes mono, dual e multi-espécies foram submetidos ao tratamento com PBTPA produzidos por dois dispositivos diferentes, um obtido comercialmente (kINPen09®) que usou argônio como gás de trabalho, e outro protótipo desenvolvido pela FEG-UNESP (Faculdade de Engenharia de Guaratinguetá) que usou hélio. Análises quantitativas e microscópicas (confocal, microscopia eletrônica de varredura) foram realizadas. Foi incluído controle negativo (sem tratamento), positivo (clorexidina 0,12%) e controle de gás, utilizando apenas fluxo de gás, sem produzir plasma. Além disso, os efeitos celulares do PBTPAargônio e hélio sobre biofilme dual e multi-espécies também foram analisados em microscopia eletrônica de varredura e microscopia de varredura a laser confocal. Todos os ensaios foram realizados em triplicata em três experimentos independentes. Os resultados foram tabulados e analisados quanto à distribuição. A seguir, os testes estatísticos mais adequados foram selecionados. O nível de significância foi de 5%. Os resultados obtidos para os tratamentos dos biofilmes mono, dual ou multi-espécies com PBTPA-argônio e hélio foram todos significativos em comparação ao controle negativo em todos os tempos analisados. Para PBTPA-argônio, não houve recuperação de S. gordonii e S. sanguinis em todos tempos analisados. Para PBTPA-hélio, os melhores resultados foram obtidos em 5 e 7 minutos de exposição dos biofilmes ao PBTPA. Finalmente, tanto o dispositivo gerador de PBTPA que trabalhou com gás argônio quanto o dispositivo que trabalhou com gás hélio, demonstraram resultados promissores e poderão contribuir para o desenvolvimento de novos protocolos de Odontologia de Intervenção Mínima. (AU)

In vitro gastrointestinal resistance of Lactobacillus acidophilus in some dairy products.

In this study, different dairy products such as ice cream, yoghurt, white pickled cheese, and fermented acidophilus milk were manufactured by using either Lactobacillus acidophilus DSM 20,079 or Lactobacillus acidophilus NCFM. The counts of L. acidophilus in the samples on days 1, 15, and 30 of the storage were determined. Additionally, the samples contained L. acidophilus were passed through a dynamic gastrointestinal model designed in laboratory conditions to compare the protective effect of different dairy products on viability of L. acidophilus against stress factors of the gastrointestinal model. The counts of L. acidophilus NCFM and L. acidophilus DSM 20,079 in the samples decreased by between 0.04 and 0.37 log units and by between 0.11 and 0.27 log units, respectively, within 30 days of storage. During the passage through the gastrointestinal model, the highest percentage reduction in the counts of L. acidophilus was determined in yoghurt followed by fermented acidophilus milk, white pickled cheese, and ice cream, respectively. The reduction in the counts of L. acidophilus in the samples during the passage through the model increased with extension of storage time. The results of this study showed that the reduction in the counts L. acidophilus in the samples during the passage through the model was influenced significantly by the matrix of the dairy product and storage period.

Efecto antibacteriano del aceite esencial de Minthostachys mollis (Griseb) L. frente a Streptococcus mutans y Lactobacillus acidophilus / Antibacterial effect of Minthostachys mollis(Griseb) L.essential oil against Streptococcus mutansand Lactobacillus acidophilus

Introducción: El uso de los aceites esenciales de plantas medicinales ha demostrado poseer propiedades antibacterianas frente a diversas especies bacterianas. Objetivo: Identificar la composición química del aceite esencial de Minthostachys mollis (Griseb) L. y determinar su actividad antibacteriana frente a Streptococcus mutans y Lactobacillus acidophilus. Métodos: Se realizó un estudio experimental in vitro. Se empleó el software EpiInfoTM para el cálculo de las repeticiones. Se obtuvo aceite esencial de M. mollis proveniente de la región altoandina del Perú. La composición química fue analizada por cromatografía de gases acoplada a espectrometría de masas. La actividad antibacteriana se evaluó por medio del método de difusión en disco, además, se identificó la concentración mínima inhibitoria y la concentración mínima bactericida. Resultados: Los principales constituyentes del aceite esencial fueron mentona (32,9 por ciento) y eucaliptol (28,06 por ciento). El aceite esencial fue efectivo para inhibir el crecimiento de S. mutans y L. acidophilus, con halos de inhibición de 19,040 ± 0,883 mm y 18,008 ± 0,861 mm. La clorhexidina al 0,12 por ciento fue más efectiva que el aceite esencial para inhibir el crecimiento de L. acidophilus (p < 0,05). Una concentración de 1,6 por ciento (v/v) del aceite esencial fue inhibitoria y bactericida frente a S. mutans; para L. acidophilus una concentración de 3,2 por ciento (v/v) fue inhibitoria. Conclusiones: Los principales constituyentes del aceite esencial de M. mollis fueron mentona y eucaliptol y demostró ser efectivo para inhibir el crecimiento de S. mutans y L. acidophilus(AU)

Introduction: The use of essential oils from medicinal plants has been shown to possess antibacterial properties against various bacterial species. Objective: To identify the chemical composition of the essential oil of Minthostachys mollis (Griseb) L. and determine its antibacterial activity against Streptococcus mutans and Lactobacillus acidophilus. Methods: An experimental study was performed in vitro. EpiInfoTM software was used to calculate the repetitions. Essential oil of M. mollis was obtained from the high Andean region of Peru. The chemical composition was analyzed by gas chromatography coupled to mass spectrometry; antibacterial activity was evaluated by means of the disk diffusion method, in addition the minimum inhibitory concentration and the minimum bactericidal concentration were identified. Results: The main constituents of the essential oil were menthone (32.9 percent) and eucalyptol (28.06 percent). The essential oil was effective in inhibiting the growth of S. mutans and L. acidophilus, with inhibition halos of 19.040 ± 0.883 mm and 18.008 ± 0.861 mm. Chlorhexidine 0.12 percent was more effective than essential oil in inhibiting the growth of L. acidophilus (p < 0.05). A concentration of 1.6 percent (v/v) of the essential oil was inhibitory and bactericidal against S. mutans; for L. acidophilus a concentration of 3.2 percent (v/v) was inhibitory. Conclusions: The main constituents of the essential oil of M. mollis were menthone and eucalyptol and it was shown to be effective in inhibiting the growth of S. mutans and L. acidophilus(AU)

Ohmic heating processing of milk for probiotic fermented milk production: Survival kinetics of Listeria monocytogenes as contaminant post-fermentation, bioactive compounds retention and sensory acceptance.

The survival kinetics of Listeria monocytogenes (9 log CFU/mL) as a post-fermentation contaminant in probiotic fermented milk (Lactobacillus acidophilus La-5, 8-9 log CFU/mL) processed with milk subjected to ohmic heating (0, 4, 6, and 8 V/cm; CONV, OH4, OH6, OH8, 90-95 °C/5 min) was investigated using Weibull predictive model. Additionally, the presence of bioactive compounds (antioxidant activity, inhibition of the enzymes α-glucosidase, α-amylase, and angiotensin-converting) and sensory analysis (consumer test) of probiotic fermented milks were evaluated. Overall, OH provided a decrease in the viability of Listeria monocytogenes, suitable Lactobacillus acidophilus counts, and satisfactory results in the gastrointestinal tract survival. The Weibull model presented an excellent fit to the data of all conditions. Furthermore, lower δ values (217-298 against 665 h, CONV), and increased R2 values (0.99 against 0.98, CONV) were obtained for the OH-treated samples, emphasizing the best performance of OH data. In addition, OH improved the generation of bioactive compounds as well as the sensory acceptance. Indeed, considering functional and safety purposes, OH presented as an interesting technology to be used in milk for manufacturing probiotic fermented milk.

Effect of Milk Fermented with Lactobacillus acidophilus NCDC15 on Nutrient Digestibility, Faecal Biomarkers and Immune Response in Murrah calves

Abstract In neonates, rapid change in diet imbalances gut health allowing colonization of opportunistic pathogens that confer harmful effects on animal health causing reduced digestion and malabsorption of nutrients. In this milieu, probiotic feeding can be a promising approach in promoting animal health and stabilization of gastrointestinal microbiota. Hence, the present study was designed to investigate the effect of Lactobacillus acidophilus NCDC15 enriched fermented milk on nutrient digestibility, faecal biomarkers and immune response in Murrah buffalo calves. Twenty-four, neonatal calves (5-7 days) were randomly allocated into four groups for 90 days. The control group (CT) was provided a basal diet of calf starter and green fodder (maize and jowar), without any probiotic fermented milk (PFM) supplementation. Basal diet was supplemented with probiotic fermented milk at 100, 200 and 300 mL/calf/day, in PFM100, PFM200 and PFM300 groups, respectively. Nutrient digestibility remained similar among the groups. Faecal acetate was higher (P<0.05) in PFM200 and PFM300, while, faecal butyrate was increased (P<0.05) with all levels of probiotic supplementation than control. Faecal Lactobacillus and Bifidobacterium count were increased (P<0.05) with a concomitant reduction in coliform population (P<0.05) among all the treatments. Cell-mediated and humoral immune response were higher (P<0.001) in PFM200 and PFM300 than CT. Overall, it can be concluded that inclusion of Lactobacillus acidophilus NCDC15 in the form of fermented milk upto 300 mL/calf/day improved immunity and faecal biomarkers in Murrah buffalo calves without any adverse effect on nutrient utilization which may positively impact growth performance in Murrah buffalo calves.

Antimicrobial Activity of Colloidal Selenium Nanoparticles in Chitosan Solution against Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans

ABSTRACT Objective: To investigate the antimicrobial activity of colloidal selenium nanoparticles in chitosan solution (Cts-Se-NPs) against Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans. Material and Methods: Cts-Se-NPs solution was prepared using a simple chemical reduction method. The MIC and MBC against S. mutans, L. acidophilus, and C. albicans were determined using the broth dilution assay. Results: The Cts-Se-NPs had remarkable antimicrobial activity against S. mutans, L. acidophilus, and C. albicans. The MIC values of the Cts-Se-NPs were lowest for S. mutans (0.068 mg/ml) compared to L. acidophilus (0.137 mg/ml), and C. albicans (0.274 mg/ml). The MBC values of the Cts-Se-NPs against the microorganisms after one, two, six, and 24 hours indicated that the concentration of 0.274 mg/ml of Cts-Se-NPs completely killed S. mutans, L. acidophilus, and C. albicans after one, two, and six hours, respectively. At the concentration of 0.137 mg/ml, S. mutans and L. acidophilus were killed after six and 24 hours, respectively. Conclusion: These findings encourage the potential use of Cts-Se-NPs in dentistry, while further clinical research is required in this area.

Effects of fructans and probiotics on the inhibition of Klebsiella oxytoca and the production of short-chain fatty acids assessed by NMR spectroscopy.

Generally, the selection of fructans prebiotics and probiotics for the formulation of a symbiotic has been based on arbitrary considerations and in vitro tests that fail to take into account competitiveness and other interactions with autochthonous members of the intestinal microbiota. However, such analyzes may be a valuable step in the development of the symbiotic. The present study, therefore, aims to investigate the effect of lactobacilli strains and fructans (prebiotic compounds) on the growth of the intestinal competitor Klebsiella oxytoca, and to assess the correlation with short-chain fatty acids production. The short-chain fatty acids formed in the fermentation of the probiotic/prebiotic combination were investigated using NMR spectroscopy, and the inhibitory activities were assessed by agar diffusion and co-culture methods. The results showed that Lactobacillus strains can inhibit K. oxytoca, and that this antagonism is influenced by the fructans source and probably associated with organic acid production.

Modulation of the intestinal microbiota and the metabolites produced by the administration of ice cream and a dietary supplement containing the same probiotics.

The aim of the present work was to compare the capacity to modulate the intestinal microbiota and the production of metabolites after 14 d administration of a commercial dietary supplement and a manufactured ice cream, both containing the same quantity of inulin and the same viable counts of Lactobacillus acidophilus LA-5 and Bifidobacterium animalis BB-12, using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) model. Samples of the colonic contents were evaluated microbiologically by real-time quantitative PCR (qRT-PCR) and next-generation sequencing and chemically by the production of SCFA (acetate, propionate and butyrate) and ammonium ions ($\text{NH}_4^ + $). Statistical analyses were carried out for all the variables using the two-way ANOVA followed by the Tukey multiple comparisons test (P < 0·05) for metabolite production, qRT-PCR and the bioinformatics analysis for microbiota diversity. Dietary supplement and ice cream were able to deliver the probiotic L. acidophilus and B. animalis to the simulated colon and modulate the microbiota, increasing beneficial micro-organisms such as Bifidobacterium spp., Bacteroides spp. and Faecalibacterium spp. for dietary supplement administration, and Lactobacillus spp. for ice cream supplementation. However, the ice cream matrix was probably more favourable for the maintenance of the metabolic activity of the probiotics in the SHIME® model, due to the larger amounts of acetate, propionate, butyrate and ammonium ions obtained after 14 d of supplementation. In conclusion, both ways of probiotic supplementation could be efficient, each with its own particularities.

Survival of Lactobacillus acidophilus LA-5 and Escherichia coli O157:H7 in Minas Frescal cheese made with oregano and rosemary essential oils.

The effects of the incorporation of the essential oils from Origanum vulgare L. (OVEO; 0.07 µL/g) and Rosmarinus officinalis L. (ROEO; 2.65 µL/g) in combination in Minas Frescal cheese on the counts of the probiotic Lactobacillus acidophilus LA-5 and Escherichia coli O157:H7 were evaluated during refrigerated storage (7 ±â€¯0.5 °C). The terpenes of OVEO and ROEO, survival of the probiotic strain during in vitro digestion, as well as the physicochemical and sensory aspects were also monitored in Minas Frescal cheese. All terpenes decreased in cheese when the storage time increased. The incorporation of OVEO and ROEO delayed the increase in L. acidophilus LA-5 counts in cheese, but did not affect its ability to survive in cheese under simulated gastrointestinal conditions. The decreases in counts of E. coli O157:H7 observed in the first 15 days of refrigerated storage were strongly correlated (r ≥ 0.82) with the terpenes detected in cheese. Scores attributed for aroma, flavor, overall impression and purchase intention of cheese with OVEO and ROEO increased with the increase of the storage time. The incorporation of OVEO and ROEO in combination could be a strategy to control E. coli O157:H7 in probiotic Minas cheese during storage; however, the amounts of these substances should be cautiously selected considering possible negative sensory impacts in this product.

Análise sensorial de bebida láctea fermentada suplementada com extrato hidrossolúvel de babaçu e Lactobacillus acidophilus / Sensory analisys of fermented milk drink supplemented with babassu soluble extract and Lactobacillus acidophilus

Este trabalho teve como objetivo a análise sensorial de bebida láctea fermentada suplementada com extrato hidrossolúvel de babaçu e cultura probiótica. A fermentação foi realizada utilizando-se a cultura probiótica Lactobacillus acidophilus. As bebidas foram formuladas através de planejamento fatorial completo 25 com dois fatores e cinco níveis: extrato hidrossolúvel de babaçu (25,9; 30; 40; 50 e 54,1%) e soro de queijo (15,9; 20; 30; 40 e 44,1%) e 8 % de sacarose, gerando 11 formulações. Para se escolher a melhor formulação de bebida, foi realizado a análise sensorial de aceitação dos atributos de sabor, aroma, aparência, consistência e impressão global com 40 provadores não treinados. Os resultados da análise sensorial indicaram que comercialmente apenas as amostras A3 (30% extrato hidrossolúvel de babaçu) e A9 (54,1% extrato hidrossolúvel de babaçu ) alcançaram valores de índice de aceitabilidade IA(%) maiores que 70 % em todos os atributos, com índices variando de 72,22 a 77,77 %.

Development, characterization and viability study of probiotic microcapsules produced by complex coacervation followed by freeze-drying / Desenvolvimento, caracterização e estudo da viabilidade de microcápsulas probióticas produzidas por coacervação complexa seguida de liofilização

Technique of complex coacervation was used to produce microcapsules of Lactobacillus acidophilus La-5 encapsulated in gelatin and gum arabic which were then freeze-drying. Microcapsules were characterized using scanning electron and optical microscopy, and resistance of probiotics was evaluated during release into a simulated gastrointestinal tract and storage at different temperatures. The complex coacervation process produced microcapsules with a high encapsulation efficiency (77.60% and 87.53%), ranging from 127.14-227.05 m with uniform distribution. Microencapsulation was an efficient approach to achieve significant protection of probiotics against simulated gastrointestinal conditions compared with free cells. Encapsulation also improved the viability of probiotics during storage at either 18 ºC for 120 days, 7 ºC for 105 days or 25 ºC for 45 days. Therefore, complex coacervation was demonstrated to be adequate and promising for encapsulation of probiotics.(AU)

A técnica de coacervação complexa foi utilizada para a produção de microcápsulas contendo Lactobacillus acidophilus La-5 em gelatina e goma arábica seguida de secagem por liofilização. As microcápsulas foram caracterizadas por microscopia óptica e eletrônica de varredura, assim como a resistência dos probióticos frente à liberação in vitro ao trato gastrointestinal simulado e ao armazenamento em diferentes condições de temperatura também foram avaliados. O processo de coacervação complexa formou microcápsulas com alta eficiência de encapsulação (77,60% e 87,53%), tamanho compreendido entre 127,14 e 227,05 µm e distribuição uniforme. As microcápsulas foram eficientes em promover a proteção substancial dos probióticos frente às condições gastrointestinais simuladas, em comparação às células livres. A encapsulação também foi eficiente em manter a viabilidade dos probióticos durante o armazenamento em temperaturas de 18 ºC por 120 dias, 7 ºC por 105 dias e 25 ºC por 45 dias. Dessa forma, a coacervação complexa se mostra adequada e promissora para a encapsulação dos probióticos.(AU)