Antimicrobial efficacy of Lactobacillus plantarum strain against the B. cereus, B. subtilis, S. aureus and E.coli strains

The current study aimed to detect the antimicrobial effect of cell free supernatant (CFS) of Lactobacillus plantarum strain against Gram +ve and Gram ­ve bacterial strains. The strain of Lactobacillus plantarum was isolated using selective media MRS agar. The strain was characterized on the basis of the gram staining, colony morphology, the biochemical tests and the DNA sequencing based method of 16S ribotyping. A total of four test strains (The three already isolated and reported strains (E.coli, S. aureus and B. subtilis) and the one recently identified novel strain (B. cereus) were used for the analysis of antagonistic activity of bacteriocin produced by L. plantarum strain. The CFS of L. plantarum showed zone of inhibition against all the test strains (Gram +ve and Gram ­ve bacteria). The conditions favoring the growth of bacteria were associated with the antimicrobial efficacy of CFS. Bacteriocin activity of CFS remained effective after exposure to temperature stress. Wide range of antagonistic potential of CFS of L. plantarum provides an alternative for antibiotics in pharmaceutical industry. Heat resistant feature of bacteriocin suggests its application in food industry.

Performance of lactating cows fed sugarcane silage treated with microbial additives

Background: No studies have been conducted evaluating sugarcane silage associated with both Lactobacillus plantarum and Pediococcus pentosaceus for lactating dairy cows. Objective: To evaluate diets containing different roughages with and without microbial inoculants on intake, digestibility and milk yield of medium-producing cows. Methods: A total of 15 Holstein cows distributed into a randomized block design were used. Dietary treatments were: 1) a corn silage-based diet (CS), 2) a fresh sugarcane-based diet (SC), 3) a sugarcane silage ensiled without inoculant (SS), 4) sugarcane silage ensiled with Lactobacillus buchneri (SSLB), and 5) sugarcane silage ensiled with Lactobacillus plantarum and Pediococcus pentosaceus (SSLP). Results: Digestible organic matter intake (DOMI) was lower (p<0.05) in cows fed SSLB (9.77 kg day-1) when compared with cows fed CS (13.29 kg day-1) and SSLP (12.42 kg day-1). Ensiling of sugarcane increased intake of neutral detergent fiber (NDF) compared to SC (mean of 6.00 kg day-1 versus 4.97 kg day-1; p<0.05). Dry matter digestibility was greater (p<0.05) in CS (77.80%) compared with diets based on sugarcane silage, whereas NDF digestibility was lower for treatments with sugarcane (p<0.05). Milk yield was similar among CS (27.99 kg), SC (25.59 kg), and silages with additives (25.47 and 27.07 for SSLB and SSLP, respectively). Cows fed CS produced more fat-corrected milk (25.89 kg) than those fed sugarcane-based diets (p<0.05). Conclusions: Fresh sugarcane or sugarcane silage with additives can be used as a roughage source for dairy cows producing up to 23.43 kg d-1 fat-corrected milk, considering the total diet is properly balanced.

Antecedentes: No existen estudios que evalúen la adición de Lactobacillus plantarum y Pediococcus pentosaceus en el ensilaje de caña de azúcar para vacas lactantes. Objetivo: Evaluar dietas con diferentes forrajes y ensilajes con y sin inoculantes microbianos sobre el consumo, digestibilidad y producción lactea de vacas de mediana producción. Metodología: Quince vacas Holstein se distribuyeron en un diseño de bloques al azar. Los tratamientos fueron: 1) dieta con ensilaje de maíz (CS), 2) dieta con caña de azúcar fresca (SC), 3) dieta con ensilaje de caña sin inoculantes (SS), 4) dieta con ensilaje de caña de azúcar ensilada con Lactobacillus buchneri (SSLB), y 5) dieta con ensilaje de caña de azúcar ensilada con Lactobacillus plantarum y Pediococcus pentosaceus (SSLP). Resultados: El consumo de materia orgánica digestible fue menor (p<0,05) en la dieta SSLB (9,77 kg day-1) en comparación con CS (13,29 kg dia-1) y SSLP (12,42 kg dia-1). El ensilaje de caña de azúcar promovió un mayor consumo de fibra detergente neutra (NDF) en comparación con SC (promedio de 6,00 kg dia-1 versus 4,97 kg dia-1; p<0,05). La digestibilidad de la materia seca fue mayor (p<0,05) para la dieta CS (77,80%) en comparación con las dietas con ensilaje de caña de azúcar, mientras que la digestibilidad de la NDF fue menor para las dietas a base de caña de azúcar (p<0,05). La producción de leche fue similar entre CS (27,99 kg), SC (25,59 kg) y ensilajes con aditivos (25,47 y 27,07 para SSLB y SSLP, respectivamente). Las vacas alimentadas con ensilaje de maíz produjeron más leche corregida por grasa (25,89 kg) que las alimentadas con dietas a base de caña de azúcar (p<0,05). Conclusión: La caña de azúcar fresca o ensilada con aditivos se puede utilizar como fuente de forraje para vacas que producen hasta 23,43 kg d-1 leche corregida por grasa, siempre que la dieta total esté equilibrada adecuadamente.

Antecedentes: Há carência de estudos avaliando a adição de Lactobacillus plantarum e Pediococcus pentosaceus na silagem de cana-de-açúcar para vacas em lactação. Objetivo: Avaliar dietas contendo diferentes forragens e silagens com e sem inoculantes microbianos sobre o consumo, digestibilidade e produção de leite de vacas de média produção de leite. Métodos: Quinze vacas Holandesas foram distribuídas em um delineamento em blocos casualizados. Os tratamentos foram: 1) dieta com silagem de milho (CS), 2) dieta com cana-de-açúcar fresca (SC), 3) dieta com silagem de cana ensilada sem inoculantes (SS), 4) dieta com silagem de cana-de-açúcar ensilada com Lactobacillus buchneri (SSLB), ou 5) dieta com silagem de cana- de-açúcar ensilada com Lactobacillus plantarum, and Pediococcus pentosaceus (SSLP). Resultados: O consumo de matéria orgânica digestível foi menor (p<0,05) na dieta SSLB (9,77 kg day-1) comparada com CS (13,29 kg dia-1) e SSLP (12,42 kg dia-1). A ensilagem da cana-de-açúcar promoveu maior consumo de fibra em detergente neutro (FDN) em comparação com SC (média de 6,00 kg dia-1 versus 4.97 kg dia-1; p<0.05). A digestibilidade da matéria seca foi maior (p<0,05) para a dieta CS (77,80%) comparada com as dietas com silagem de cana-de-açúcar, enquanto que a digestibilidade da FDN foi menor para as dietas baseadas em cana-de-açúcar (p<0,05). A produção de leite foi similar entre CS (27,99 kg), SC (25,59 kg) e silagens com aditivos (25,47 e 27,07 para SSLB e SSLP, respectivamente). Vacas alimentadas com silagem de milho produziram mais leite corrigido para gordura (25,89 kg) que aquelas alimentadas com dietas baseadas em cana-de-açúcar (p<0,05). Conclusão: A cana-de-açúcar fresca ou ensilada com aditivos pode ser utilizada como fonte volumosa para vacas produzindo até 23,43 kg d-1 leite corrigido para gordura, desde que a dieta total esteja apropriadamente balanceada.

Bio prospecting of Riboflavin producing bacteria from different riboflavin enriched food sources

Riboflavin is an essential, water-soluble vitamin (B2) and a component of basic cellular metabolism. The aim of the present study is to isolate and characterize riboflavin producing bacteria from different food sources. Ten different riboflavin enriched food sources were collected from Vellore district. Totally 72 bacterial strains were isolated and cultured on nutrient agar plates. Out of these, 43 strains were identified as riboflavin producers. Isolated bacterial strains HDS27, HDS07, HDS14, HDS18, HDS38 and HDS54 isolated from milk, mushroom, spinach, lamb kidney, beef liver and mackerel fish were found to be potent riboflavin producers. Based on morphological, biochemical and molecular characterization, the potent strains were identified as Lactobacillus plantarum (HDS27), Bacillus cereus (HDS07), Delftia tsuruhatensis (HDS14), Citrobacter freundii (HDS18), Enterobacter cloacae (HDS38) and Bacillus cereus (HDS54). The selected potent isolates HDS27 from milk and HDS07 from mushroom showed a maximum riboflavin production of 3.69 mg/L and 2.9mg/L respectively. The present study explores the riboflavin producing novel bacteria from different food sources. This is the first report that the Enterobacter cloacae isolated from beef liver, Delftia tsuruhatensis from spinach and Citrobacter freundii from lamb kidney has the ability to produce riboflavin. These potent strains could be a better starter for substituting the conventional bacteria for large scale production of riboflavin in industry.

Capacidad de Lactiplantibacillus plantarum LP5 para inhibir biopelículas de Campylobacter coli / Ability of Lactiplantibacillus plantarum LP5 to inhibit biofilms of Campylobacter coli

Resumen El objetivo de este estudio fue evaluar la capacidad inhibitoria de Lactiplantibacillus plantarum LP5 frente a Campylobacter coli en ensayos de formación de biopelículas in vitro y exclusión competitiva. La formación de biopelículas por C. coli NCTC11366, C. coli DSPV458, C. coli DSPV541 y C. coli DSPV570 fue evaluada mediante medición de DO. La capacidad inhibitoria de L. plantarum LP5 frente a C. coli fue evaluada sobre discos de vidrio, nailon y aluminio. Sobre una biopelícula de L. plantarum se adicionó C. coli para cuantificar el efecto inhibidor de L. plantarum LP5 sobre el patógeno. Las cuatro cepas de C. coli fueron clasificadas como moderadas formadoras de biopelículas. El ensayo de exclusión competitiva mostró que la formación de biopelículas de las cepas de C. coli en todos los materiales fue significativamente mayor que la formación de biopelículas de cada patógeno en presencia de biopelículas de L. plantarum LP5. Si bien es necesario realizar más pruebas para confirmar la capacidad de supervivencia de C. coli en ambientes hostiles hasta llegar al huésped, este estudio permitiría avanzar en el esclarecimiento de su comportamiento mediante la formación de biopelículas.

Abstract The objective of this study was to evaluate the inhibitory capacity of Lactiplantibacillus plantarum LP5 against Campylobacter coli in in vitro biofilm formation and competitive exclusion assays. Biofilm formation by C. coli NCTC11366, C. coli DSPV458, C. coli DSPV541 and C. coli DSPV570 was evaluated by OD measurement. The inhibitory capacity of L. plantarum LP5 against C. coli was evaluated on glass, nylon and aluminium discs, added with L. plantarum and incubated at 37°C for 72 h. C. coli was added to each washed well. The plates were incubated at 42°C for 72 h in microaerophilic conditions and the biofilms were detached for quantification. The four strains of C. coli were classified as moderate biofilm former. The competitive exclusion test showed that the biofilm formation of the C. coli strains in all materials was significantly higher than the biofilm formation of each pathogen in the presence of L. plantarum LP5 biofilms. Although it is necessary to carry out more tests to confirm the ability of C. coli to survive in hostile environments until reaching the host, this study would allow progress in the elucidation of its behaviour through the formation of biofilms.

Probiotic supplementation affects IGF-1 and leptin levels in Nile tilapia hepatopancreatic tissue / Suplementação com probiótico afeta os níveis de IGF-1 e leptina no tecido hepatopancreático de tilápias-do-nilo

This work aimed to assess the effect of the probiotic strain, Lactobacillus plantarum, on the levels of leptin, IGF-1 and their receptors on the hepatopancreatic tissues of Nile tilapia (Oreochromis niloticus) and then correlate fish growth performance and gut microbiological parameters. Fish juveniles (±23g) were reared in a recirculation system with constant aeration and temperature (25°C). They were distributed into six polyethylene tanks (45L) and fed twice a day at 5% of the tank biomass with the respective diets: control (commercial diet without probiotic) and supplemented with L. plantarum inoculum (1 x 108 CFU mL-1), both in triplicate. After 30 days of feeding, L. plantarum-fed fishes showed greater weekly growth rate, final weight, and feed conversion rate, in addition to higher count of lactic-acid bacteria and lower count of pathogenic bacteria in the intestinal tract, when compared to the control group. The immunostaining intensity for IGF-1 and leptin hormones was lower after L. plantarum supplementation than in the control group, with no change in the level for receptors. This reduction could implicate important changes in fish metabolism and homeostasis.(AU)

O presente trabalho teve como objetivo avaliar o efeito da cepa probiótica Lactobacillus plantarum sobre os níveis de leptina, IGF-1 e seus receptores no tecido hepatopancreático de tilápia-do-nilo (Oreochromis niloticus) e correlacionar com o desempenho zootécnico e os parâmetros microbiológicos intestinais dos peixes. Juvenis de tilápia-do-nilo (±23g) foram distribuídos em seis tanques de polietileno (45L) conectados a um sistema de recirculação, com aeração e temperatura constantes (25°C). Os peixes foram alimentados duas vezes ao dia, a 5% da biomassa do tanque, com as respectivas dietas: controle (dieta comercial sem probiótico) e suplementada com L. plantarum (1 x 108 UFC mL-1), ambas em triplicata. Após 30 dias de cultivo, os peixes alimentados com L. plantarum apresentaram maiores ganho de peso semanal, peso final e conversão alimentar, bem como maior contagem de bactérias ácido-láticas e menor contagem de bactérias patogênicas no trato intestinal das tilápias alimentadas com dieta probiótica, em comparação ao grupo controle. A intensidade da imunomarcação para os hormônios IGF-1 e leptina foi menor com a suplementação de L. plantarum do que no grupo controle, sem alterar os níveis de seus receptores. Essa redução pode implicar mudanças importantes no metabolismo e na homeostase dos peixes.(AU)

Production, characterization and kinetic model of biosurfactant produced by lactic acid bacteria

BACKGROUND Biosurfactants are surface active molecules produced by microorganisms which have the ability to disrupt the plasma membrane. Biosurfactant properties are important in the food, pharmaceu tical and oil industries. Lactic acid bacteria can produce cell-bound and excreted biosurfactants. RESULTS The biosurfactant-producing ability of three Lactobacillus strains was analyzed, and the effects of carbon and nitrogen sources and aeration conditions were studied. The three species of lactobacillus eval uated were able to produce biosurfactants in anaerobic conditions, which was measured as the capacity of one extract to reduce the surface tension compared to a control. The decreasing order of biosurfactant production was L. plantarum>Lactobacillus sp.>L. acidophilus. Lactose was a better carbon source than glu cose, achieving a 23.8% reduction in surface tension versus 12.9% for glucose. Two complex nitrogen sources are required for growth and biosurfactant production. The maximum production was reached at 48 h under stationary conditions. However, the highest level of production occurred in the exponential phase. Biosurfactant exhibits a critical micelle concentration of 0.359 ± 0.001 g/L and a low toxicity against E. coli. Fourier transform infrared spectroscopy indicated a glycoprotein structure. Additionally, the kinetics of fermentation were modeled using a logistic model for the biomass and the product, achieving a good fit (R2 > 0.9). CONCLUSIONS L. plantarum derived biosurfactant production was enhanced using adequate carbon and nitrogen sources, the biosurfactant is complex in structure and because of its low toxicity could be applied to enhance cell permeability in E. coli

Enzymatic preparation of manno-oligosaccharides from locust bean gum and palm kernel cake, and investigations into its prebiotic activity

BACKGROUND: Manno-oligosaccharides (MOS) is known as a kind of prebiotics. Mannanase plays a key role for the degradation of mannan to produce MOS. In this study, the mannanases of glycoside hydrolase (GH) families 5 Man5HJ14 and GH26 ManAJB13 were employed to prepare MOS from locust bean gum (LBG) and palm kernel cake (PKC). The prebiotic activity and utilization of MOS were assessed in vitro using the probiotic Lactobacillus plantarum strain. RESULTS: Galactomannan from LBG was converted to MOS ranging in size from mannose up to mannoheptose by Man5HJ14 and ManAJB13. Mannoheptose was got from the hydrolysates produced by Man5HJ14, which mannohexaose was obtained from LBG hydrolyzed by ManAJB13. However, the same components of MOS ranging in size from mannose up to mannotetrose were observed between PKC hydrolyzed by the mannanases mentioned above. MOS stability was not affected by high-temperature and high-pressure condition at their natural pH. Based on in vitro growth study, all MOS from LBG and PKC was effective in promoting the growth of L. plantarum CICC 24202, with the strain preferring to use mannose to mannotriose, rather than above mannotetrose. CONCLUSIONS: The effect of mannanases and mannan difference on MOS composition was studied. All of MOS hydrolysates showed the stability in adversity condition and prebiotic activity of L. plantarum, which would have potential application in the biotechnological applications.

Immunogenicity of engineered Lactobacillus plantarum expressing porcine epidemic diarrhea virus S1 gene / 生物工程学报

To investigate whether the engineered Lactobacillus plantarum expressing the porcine epidemic diarrhea virus (PEDV) S1 gene can protect animals against PEDV, guinea pigs were fed with recombinant L. plantarum containing plasmid PVE5523-S1, with a dose of 2×10⁸ CFU/piece, three times a day, at 14 days intervals. Guinea pigs fed with wild type L. plantarum and the engineered L. plantarum containing empty plasmid pVE5523 were used as negative controls. For positive control, another group of guinea pigs were injected with live vaccine for porcine epidemic diarrhea and porcine infectious gastroenteritis (HB08+ZJ08) by intramuscular injection, with a dose of 0.2 mL/piece, three times a day, at 14 days intervals. Blood samples were collected from the hearts of the four groups of guinea pigs at 0 d, 7 d, 14 d, 24 d, 31 d, 41 d and 48 d, respectively, and serum samples were isolated for antibody detection and neutralization test analysis by enzyme-linked immunosorbent assay (ELISA). The spleens of guinea pigs were also aseptically collected to perform spleen cells proliferation assay. The results showed that the engineered bacteria could stimulate the production of secretory antibody sIgA and specific neutralizing antibody, and stimulate the increase of IL-4 and IFN-γ, as well as the proliferation of spleen cells. These results indicated that the engineered L. plantarum containing PEDV S1 induced specific immunity toward PEDV in guinea pigs, which laid a foundation for subsequent oral vaccine development.

Effect of Lactobacillus plantarum JX025073.1 on intestinal floraand blood lipid in mice / 预防医学

Objective @#To learn the regulatory effect of Lactobacillus plantarum JX025073.1 on intestinal flora and blood lipid in mice, so as to provide the basis for the nutritional intervention of probiotics in hyperlipidemia population.@*Methods @#Thirty male ICR mice were randomly divided into a control group, a model group and a intervention group. The mice in the control group were fed with basic diet, and in the other two groups were fed with high fat diet. The mice in the intervention group was given 0.4 mL of Lactobacillus plantarum JX025073.1 fermentation liquid by gavage every day, and in the other two groups were given 0.4 mL of normal saline. The body weight of mice, the mass of heart, liver, spleen and kidney organs were weighed, and the organ index was calculated. The contents of total cholesterol (TC), triacylglycerol/triglyceride ( TG ), low density lipoprotein cholesterol ( LDL-C ) in serum, TC, TG in liver and in feces were determined by biochemical analyzer. Bifidobacterium, Lactobacillus and Escherichia coli in feces were cultured and counted. @* Results @#After 42 days, compared with the control group, The mice in the model group had higher body weights, higher levels of TC, TG and LDL-C in serum, higher levels of TC, TG in liver and in feces, more Escherichia coli, less Bifidobacterium and less Lactobacillus ( P<0.05 ). Compared with the model group, the mice in the intervention group had lower body weight, lower levels of TC, TG and LDL-C in serum, lower levels of TC in liver, less Escherichia coli, higher levels of TC in feces, more Bifidobacterium and more Lactobacillus ( P<0.05 ). @*Conclusion @#Lactobacillus plantarum JX025073.1 can effectively regulate the blood lipid and intestinal flora of mice fed with high fat diet.

Characterization of plantaricin IIA-1A5 biosynthesized by Lactobacillus plantarum IIA-1A5 in corn steep liquor based medium

Aims@#To characterize the plantaricin IIA-1A5 crude extract that biosynthesized by Lactobacillus plantarum IIA-1A5 using corn steep liquor (CSL) based medium. @*Methodology and results@#Lactobacillus plantarum IIA-1A5 was grown in several media containing different components including corn steep liquor (CSL), molasses and MRS (de Man Rogosa Sharpe) as control medium for 24 h at 37 °C. Antibacterial activities of the cell-free supernatant were expressed as diameter of inhibition zones observed by paper disc method. The results showed that CSL medium produced cell-free supernatant of L. plantarum IIA-1A5 with significantly higher antibacterial activity againts Staphylococcus aureus ATCC 25923 (9.81 mm), Lactobacillus monocytogenes ATCC 7644 (9.61 mm), Bacillus cereus (8.97 mm) and Escherichia coli ATCC 25922 (9.23 mm) were not significantly different compared to control MRS broth media (9.59 mm). CSL medium added only with 3% yeast extract and Tween 80 produced supernatant which showed similar antibacterial activity either to 10% molasses or control medium (Medium K and B). The CSL medium was considered more efficient and low cost, therefore this medium was selected for production and characterization of plantaricin IIA-1A5 crude extract. Further characterization performed by SDS PAGE analysis showed that crude plantaricin had molecular weight of approximately 9.9 kDa, higher than that produced in control medium (8.0 kDa). However, both plantaricins were categorized under the same class for small bacteriocin (class II). This study also revealed the plantaricin IIA-1A5 produced in CSL medium was stable to heat and pH and not significantly different compared to control MRS broth media. The antibacterial activity of plantaricin IIA-1A5 crude extract against S. aureus ATCC 25923 (10.09 mm) was not significantly different with 1000 ppm sodium benzoate (9.70 mm) and 300 ppm sodium nitrite (9.82 mm).@*Conclusion, significance and impact of study@#The CSL medium produced cell-free supernatant of L. plantarum IIA 1A5 had significant antibacterial activity characterization againts S. aureus ATCC 25923, L. monocytogenes ATCC 7644, B. cereus and E. coli ATCC 25922. Comparison of the inhibition activity of plantaricin IIA-1A5 crude extract against pathogen with synthetic preservatives indicated that plantaricin IIA-1A5 crude extract have the potency to replace synthetic preservatives. CSL based medium is potential to be used for low-cost plantaricin IIA-1A5 production.

Isolation and identification of phosphate solubilizing bacteria from indigenous microorganisms (IMO) of cow rumen in East Java, Indonesia as eco-friendly biofertilizer

Aims@#Phosphate is an essential nutrient required for plant growth, but its solubility in the soil is relatively low (0.1%). Microbes can dissolve phosphate to meet crop requirements. This study aimed to isolate phosphate solubilizing bacteria from indigenous microorganisms (IMO) of cow rumen.@*Methodology and results@#The selection of isolates on a Pikovskaya medium was using a clear zone index and a spectrophotometer for phosphate solubilization measurements. Hypersensitivity was tested on tobacco leaves and tested antagonists within isolates. The results found that four selected isolates had the highest phosphate dissolving potential, namely, MTA1, SMAD1, SMAD2, and SMAD3. The culture of selected isolates on plate media showed that the morphological characters of the four colonies are the same. They had round form (circular), the edge of the colony were smooth, flat elevation, white and cream color. Isolate MTA1 had the highest phosphate solubilizing activity compared to the others. The isolate that showed the highest phosphate solubilizing activity were identified based on 16S rRNA gene. The result of molecular identification showed that strain MTA1 was closely related to Lactobacillus plantarum with a similarity level of 99%. L. plantarum performed the highest ability to form a clear zone (7.66 mm). The highest concentration of soluble phosphate was observed on day 5 (278.42 mg/L).@*Conclusion, significance, and impact of the study@#Lactobacillus plantarum which was isolated from the IMO of cow rumen in East Java, Indonesia was identified as one of the phosphate solubilizing bacteria that are useful for the development of eco-friendly biofertilizer. The application of phosphate solubilizing microbes can be used to increase the soil fertility.

Evaluación de Lactobacillus plantarum microencapsulado y su viabilidad bajo condiciones gastrointestinales simuladas e inhibición frente a Escherichia coli O157:H7 / Evaluation of microencapsulated Lactobacillus plantarum and its viability under simulated gastrointestinal conditions and inhibition against Escherichia coli O157: H7

RESUMEN Se evaluó la viabilidad de Lactobacillus plantarum microencapsulado, su efecto de inhibición sobre Escherichia coli O157:H7 y su crecimiento en condiciones gastrointestinales simuladas. Se utilizaron L. plantarum ATCC 8014® y E. coli ATCC 43888®. Se realizaron pruebas de inhibición de L. plantarum sobre E. coli y test de susceptibilidad a CTX (30 µg), P (10 IU), GN (10 µg), DCX (1 µg), CIP (5 µg) y KF (30 µg) para ambas cepas. En la bacteria láctica se determinó la cinética de fermentación y la presencia de péptidos y aminoácidos por HPLC en ambas cepas. Se evaluó el crecimiento a 37 y 45°C de L. plantarum y se valoró la viabilidad de su microencapsulación mediante condiciones gastrointestinales (bilis, sales biliares y pH ácido), al igual que la supervivencia y estabilidad de preparado y sus características físicas y morfológicas. Los resultados indicaron que L. plantarum inhibió a E. coli y el microencapsulado, resultados positivos con una viabilidad del 83,3%; eficiencia de 88,4%; humedad de 7,79%; actividad de agua 0,4; humectabilidad de 1 min, 56 s; solubilidad del 96%; morfología esférica y tamaño entre 15,18 a 35,68 pm. Finalmente, se observó un alto potencial de L. plantarum como agente inhibidor para E. coli O157:H7.

ABSTRACT The viability of microencapsulated Lactobacillus plantarum, its inhibition effect on Escherichia coli O157: H7 and growth in simulated gastrointestinal conditions was evaluated. L. plantarum ATCC 8014® and E. coli ATCC 43888® were used. Inhibition tests of L. plantarum on E. coli and susceptibility test to CTX (30 µg), P (10 IU), GN (10 µg) DCX (1 µg), CIP (5 µg) and KF (30) were performed µg) for both strains. In the lactic bacterium the fermentation kinetics were determined, and the presence of peptides and amino acids by HPLC in both strains. The growth at 37 ° C and 45 ° C of L. plantarum was evaluated and the viability of its microencapsulation was assessed by gastrointestinal conditions (Bile, Bile salts and acidic pH), as well as the survival and stability of the preparation and its physical characteristics and morphological. The results indicated that L. plantarum inhibited E. coli and the microencapsulated positive results with a viability of 83.3%, efficiency 88.4%, Humidity 7.79%, water activity 0.4, wettability of 1 min, 56 s, 96% solubility, spherical morphology and size between 15.18 to 35.68 pm. Finally, a high potential of L. plantarum was observed as an inhibitory agent for E. coli O157: H7.

Optimal Conditions for Production of Fermented Flour from Pumpkin (Cucurbita pepo L.) for Infant Foods

The aim of this study was to determine the optimal conditions for production of a fermented pumpkin flour by lactic fermentation using Lactobacillus plantarum and the effect of the fermentation on nutritional potential and functional properties of pumpkin. To achieve this, pumpkin fruit was collected in the Ngaoundere main market, peeled, sliced, and the flesh obtained was grated, pasteurized at 90ºC for 5 minutes and placed under lactic fermentation using L. plantarum (108 cfu/mL). The sample obtained was dried at 45ºC ± 2ºC for 24 hours and crushed to obtain a flour with particle size ≤ 500 µm. According to the Doehlert's plan used, time and temperature of fermentation varied from 24 to 96 hours and 30 to 50°C respectively. Responses sought were the optimal levels of total carotenoids and reducing sugars in the flours. Chemical composition of flour was determined to evaluate the effect of fermentation on food matrix used. Results indicate that to produce a pumpkin flour with highest content in both carotenoids and reducing sugars, optimal conditions of lactic fermentation with L. plantarum are 70h at 45°C. Under these conditions, there is a decrease of 72.1% of proteins and 67% of fibers, against an increase of 106% of reducing sugars. Total carotenoids content decreased by 4.6%, but the level is still higher than the threshold recommended for infant food formulation, while mineral content increases with fermentation. A reduction of anti-nutrients (phytates, tannins, phenolic compounds and oxalates) of more than 50% is also observed when fermenting pumpkin. The functional properties of fermented pulp show a decrease of water absorption capacity of 24% and an increase of 134.4% in bulk density. Fermented pumpkin flour could be used in infant food formulation, but need to be associated with other sources of proteins and minerals.

Production of low value and eco-friendly bio-preservatives from Lactobacillus plantarumgrown on dairy whey

Aim: The current study aimed to evaluate the potential of milk whey medium to produce low value bio-preservatives. Methodology: Lactobacillus plantarum NZ7100 was obtained from NIZO Food Research, Netherlands. To analyze optimal biomass, desired product and precursor production under whey/whey permeate supplemented with various yeast extract concentration (0, 5, 10, 15 and 20 g l-1) and other economical media, batch fermentation was conducted and metabolites were analyzed using HPLC. Results: The study showed that whey permeate containing 15 g l-1 yeast extract supported maximum biomass formation of 1.7 g l-1 with significant production of total lactic acid and D-lactic acid of about 9.78 g l-1 and 4.41 g l-1. The kinetic parameters evaluated with commercial growth medium such as MRS-glucose and MRS-lactose demonstrated relatively lesser growth and lactate yield in whey permeate medium than in MRS medium. Interpretation: The study demonstrated the prospective of utilizing whey permeate medium to co-produce effective, eco- friendly, low cost natural preservatives using L. plantarum for usage in food and feed industry.

Lactobacillus plantarum as a malolactic starter culture in winemaking: a new (old) player?

Malolactic fermentation (MLF) is a process in winemaking responsible for the conversion of L-malic acid to L-lactic acid and CO2, which reduces the total acidity, improves the biological stability, and modifies the aroma profile of wine. MLF takes place during or after alcoholic fermentation and is carried out by one or more species of lactic acid bacteria (LAB), which are either present in grapes and cellars or inoculated with malolactic starters during the winemaking process. Although the main bacterium among LAB used in commercial starter cultures for MLF has traditionally been Oenococcus oeni, in the last decade, Lactobacillus plantarum has also been reported as a malolactic starter, and many works have shown that this species can survive and even grow under harsh conditions of wine (i.e., high ethanol content and low pH values). Furthermore, it has been proved that some strains of L. plantarum are able to conduct MLF just as efficiently as O. oeni. In addition, L. plantarum exhibits a more diverse enzymatic profile than O. oeni, which could play an important role in the modification of the wine aroma profile. This enzymatic diversity allows obtaining several starter cultures composed of different L. plantarum biotypes, which could result in distinctive wines. In this context, this review focuses on showing the relevance of L. plantarum as a MLF starter culture in winemaking.

Dietary effect of Lactobacillus plantarum CJLP55 isolated from kimchi on skin pH and its related biomarker levels in adult subjects / 한국영양학회지

PURPOSE: The skin pH is maintained by epidermal lactate, free fatty acids (FFAs), and free amino acids (FAAs). As a significant determinant of skin health, the skin pH is increased (less acidic) under abnormal and aged skin conditions. In a search for dietary alternatives that would promote an acidic skin pH, this study investigated the dietary effects of Lactobacillus plantarum CJLP55 isolated from Korean kimchi on the skin pH, and epidermal levels of lactate, FFAs, and FAAs in adult subjects. METHODS: Seventy eight subjects (mean age 24.9 ± 0.5 years, range 19 ~ 37 years) were assigned randomly to ingest CJLP55, Lactobacillus strain from kimchi, (n = 39, CJLP group) or placebo supplements (n = 39, placebo group) for 12 weeks in a double-blind, placebo-controlled trial. Skin pH and epidermal levels of lactate, FFAs and FFAs were assessed at 0, 6 and 12 weeks. RESULTS: Although significant decreases in skin pH were observed in both the CJLP and placebo groups at 6 weeks, the skin pH was decreased significantly only in the CJLP group at 12 weeks. In parallel, the epidermal level of lactate in the CJLP group was also increased by 25.6% at 12 weeks. On the other hand, the epidermal level of FAAs were not altered in the CJLP and placebo groups, but the epidermal level of total FFAs, including palmitic acid and stearic acid, was lower in the CJLP group than in the placebo group over 12 weeks. The changes in the other FFAs, such as palmitoleic acid and oleic acid, were similar in the CJLP and placebo groups over 12 weeks. CONCLUSION: Overall, a dietary supplement of CJLP55 promotes acidic skin pH with a selective increase in epidermal lactate in adult subjects.

Microencapsulation of Lactobacillus plantarum 299v incorporated with oligofructose in chitosan coated-alginate beads and its storage stability in ambarella juice

Aims@#Microencapsulation has been used to protect the viability of probiotics in harsh environments such as gastrointestinal conditions and food composition. The present study aimed to optimize the microencapsulation of Lactobacillus plantarum 299v (Lp299v) using co-extrusion by varying two parameters (calcium chloride (CaCl2) and oligofructose (FOS) concentrations) and storage stability of the beads produced in ambarella juice at refrigerated and room temperature. @*Methodology and results@#Chitosan coated-alginate microcapsule prepared with 4.0% (w/v) FOS and 2.5% (w/v) CaCl2 showed highest microencapsulation efficiency (93%). The microcapsules were subjected to gastrointestinal treatment and storage test in ambarella juice. Both encapsulated Lp299v with and without FOS showed higher viabilities compared with free cells after incubated in simulated gastric juice (SGJ) and simulated intestinal juice (SIJ). After 5 h of incubation in SIJ, the viabilities of both encapsulated probiotic with and without FOS were more than 107 CFU/mL. The Lp299v were stored in ambarella juice under refrigerated (4 °C) and room temperature (25 °C) for 4 weeks. At 25 °C, all forms of Lp299v lost their viabilities after one week. On the other hand, at 4 °C, viable cells count of both encapsulated Lp299v with and without FOS were reported to be more than 107 CFU/mL after 4 weeks of storage. @*Conclusion, significance and impact of study@#Microencapsulation with FOS was able to improve Lp299v’s viability during storage in low pH fruit juices compared to those without FOS. The microencapsulated probiotics could be applied in ambarella juice for the development of functional food.

Construction and application of mCherry red fluorescent protein fusion expression system in lactic acid bacteria / 生物工程学报

In order to enrich the library of domestic research about new red fluorescent marker in lactic acid bacteria (LAB), we described a new fusion expression system in Lactobacillus plantarum WCFS1 based on the pSIP vector. This system contained red fluorescent protein mCherry as a marker and bile salt hydrolase gene (bsh) as a reporter gene. Moreover, in this study, four different promoters (PsppA, PldhL, P32 and PslpA) were used to regulate the expression of the fusion protein mCherry-BSH, completing the inducible and constitutive expression in lactic acid bacteria. The recombinant protein mCherry-BSH presented activity of red fluorescence and bile salt hydrolase (BSH). The successful construction of the fusion expression system in LAB using a red fluorescent protein mCherry provides favorable conditions for the distribution, intestinal colonization and survival rate of lactic acid bacteria, so as to reveal the function mechanism of its probiotic characteristics; and the system also could lay the foundation for researches on protein expression, cellular localization and properties identification of active protein in lactic acid bacteria.

Characteristics of Vegetable Juice Fermented with Lactobacillus plantarum MKHA15 and Leuconostoc mesenteroids MKSR

The objective of this study was to develop fermented vegetable juices that possess antidiabetic and antioxidant activities. Lactobacillus plantarum MKHA15 (MKHA15) and Leuconostoc mesenteroides MKSR (MKSR) were applied to ferment onion, cabbage, and tomato juices at 37℃ and 30℃ for 72 h, respectively, and their functionality was tested using the 12 h hour-fermented juice by MKHA15, and 48 h hour-fermented juice by MKSR. Inhibition of α-glucosidase activity was observed in all fermented juices. The onion juice fermented by MKHA15 showed significantly higher α-glucosidase inhibition activity compared to other juices. All juices showed more than 70% inhibition of α-amylase activity. The DPPH radical scavenging activity of onion juice fermented by MKSR showed significantly lower activity than cabbage and tomato juices; however, no difference was observed between the types of starter cultures. The SOD-like activity of cabbage juice fermented by MKSR was the highest among the fermented juices. The juices fermented by MKHA15 showed higher reducing power than those by MKSR. Therefore, we believe that cabbage, onion and tomato juice fermented by MKHA15 and MKSR would be useful in probiotic juices, as they possess antidiabetic and antioxidant activities.

Risk Assessment of Specific Strains of Lactobacillus plantarum Used as "Other Substances"

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the risk of "other substances" in food supplements sold in Norway. These risk assessments will provide NFSA with the scientific basis for regulation of the addition of “other substances” to food supplements and other foods. "Other substances" are described in the food supplement directive 2002/46/EC as substances other than vitamins or minerals that have a nutritional and/or physiological effect. It is added mainly to food supplements, but also to other foods. VKM has not in this series of risk assessments of "other substances" evaluated any claimed beneficial effects from these substances, only possible adverse effects. The present report is a risk assessment of Lactobacillus plantarum W62, Lactobacillus plantarum 299v and Lactobacillus plantarum HEAL9 based on previous risk assessments and also publications retrieved from literature search. The risk of the Lactobacillus strains listed above was assessed for the general population. However, in previous assessments of probiotics published by VKM, concerns have been identified for specific groups. Therefore, the risk was assessed for the age group with immature gastro-intestinal microbiota (age group 0-36 months), population with mature gastro-intestinal microbiota (>3 years) and vulnerable groups with mature gastro-intestinal tract. VKM has also assessed the risk of L. plantarum W62, L. plantarum 299v and L. plantarum HEAL9 in food supplements and other foods independent of the dose and have assessed exposure in general terms. VKM concludes that it is unlikely that L. plantarum W62, L. plantarum 299v and L. plantarum HEAL9 would cause adverse health effects in the general healthy population with mature gastro-intestinal tract. However, no data on long-term adverse effects on infants and young children were identified. As evidence is accruing that the early microbial composition of the neonatal gut is important for the development of the gut microbiota and the immune system of the growing child, it is not possible to exclude that a daily supply of a single particular bacterial strain over a prolonged period of time to an immature gastro-intestinal tract may have long-term, although still unknown, adverse effects on that development.