Immobilization of Lactobacillus bulgaricus with gellan gum and its application in continuous fermentation of D-lactic acid from corn straw / 生物工程学报

Biorefinery of chemicals from straw is an effective approach to alleviate the environmental pollution caused by straw burning. In this paper, we prepared gellan gum immobilized Lactobacillus bulgaricus T15 gel beads (LA-GAGR-T15 gel beads), characterized their properties, and established a continuous cell recycle fermentation process for D-lactate (D-LA) production using the LA-GAGR-T15 gel beads. The fracture stress of LA-GAGR-T15 gel beads was (91.68±0.11) kPa, which was 125.12% higher than that of the calcium alginate immobilized T15 gel beads (calcium alginate-T15 gel beads). This indicated that the strength of LA-GAGR-T15 gel beads was stronger, and the strain was less likely to leak out. The average D-LA production was (72.90±2.79) g/L after fermentation for ten recycles (720 h) using LA-GAGR-T15 gel beads as the starting strain and glucose as the substrate, which was 33.85% higher than that of calcium alginate-T15 gel beads and 37.70% higher than that of free T15. Subsequently, glucose was replaced by enzymatically hydrolyzed corn straw and fermented for ten recycles (240 h) using LA-GAGR-T15 gel beads. The yield of D-LA reached (1.74±0.79) g/(L·h), which was much higher than that of using free bacteria. The wear rate of gel beads was less than 5% after ten recycles, which indicated that LA-GAGR is a good carrier for cell immobilization and can be widely used in industrial fermentation. This study provides basic data for the industrial production of D-LA using cell-recycled fermentation, and provides a new way for the biorefinery of D-LA from corn straw.

Absorción mineral y retención ósea en ratas normales en crecimiento por el consumo de un yogur experimental reducido en lactosa que contiene galactooligosacáridos (GOS) / Mineral absorption and bone retention in normal growing rats by consumption of an experimental lactose-reduced yogurt containing galactooligosaccharides (GOS)

Introducción: Los GOS son prebióticos naturales presentes en la leche materna que pue-den obtenerse enzimáticamente a partir de la lactosa de leche de vaca durante la fabricación de yogur. El producto lácteo resultante será reducido en lactosa y contendrá prebióticos y bacterias potencialmente probióticas. Sin embargo, mantendrá la baja relación Ca/Pi que aporta la leche de vaca, lo que podría alterar el remodelamiento óseo y la mineralización. Objetivo: comparar si un yogur reducido en lactosa que contiene GOS (YE) ofrece ventajas adicionales respecto de un yogur regular sin GOS (YR) sobre las absorciones (Abs) de Ca y Pi, retención y calidad ósea durante el crecimiento normal. Al destete, ratas machos fueron divididas en 3 grupos alimentados con AIN ́93-G (C), YE o YR durante 28 días. Resultados: YE mostró el mayor aumento de lactobacilos fecales; producción de ácidos grasos de cadena corta especialmente p, profundidad de las criptas colónicas y menor pH cecal. El %AbsCa y %AbsPi aumentó en el siguiente órden: YE> YR> C (p < 0,05). El contenido de Ca y Pi en fémur, la densidad y contenido mineral óseos y los parámetros biomecánicos fueron similares en YE y C, mientras que YR mostró valores significativa-mente menores (p < 0,05). Conclusiones: YE aumentó las Abs y biodisponibilidad de minerales, alcanzando la retención y calidad ósea de C. El aumento en las Abs observado en YR no logró obtener la retención y calidad ósea de C. Conclusión: YE habría contrarrestado el efecto negativo del mayor aporte de Pi de la leche de vaca y sería una buena estrategia para lograr el pico de masa ósea y calidad del hueso adecuados, especialmente en individuos intolerantes a la lactosa. (AU)

Breast milk contains an optimal calcium/phosphate (Ca/Pi) ratio and GOS. These natural prebiotics can be enzymatically produced via cow's milk lactose inyogurt manufacture. This milk product is low in lactose and contains prebiotics and potentially probiotic bacteria but maintains a low Ca/Pi ratio that could alter bone remodeling and mineralization. We evaluated if a lactose-reduced yogurt containing GOS (YE) offers additional advantages over regular yogurt without GOS (YR) on Ca and Pi absorption (Abs), bone retention and quality during normal growth. Weaning male rats were divided into 3 groups fed AIN'93-G (C), YE or YR for 28 days. Results: YE showed the highest increase in fecal lactobacilli; short-chain fatty acids production, especially propionate and butyrate; intestine crypt depth, and the lowest cecal pH. AbsCa% and AbsPi% increased in this order: YE> YR> C (p <0.05). Ca and Pi content in femur, bone density and mineral content, and biomechanical parameters were similar in YE and C, while YR showed the significantly lowest value (p < 0.05). Conclusions: YE increased mineral Abs reaching the retention and bone quality of C. Although YR increased Abs, bone retention and quality did not achieve C values. Seemingly, YE compensated for the negative effect of the higher Pi supply and would be a good strategy to achieve adequate peak bone mass and bone quality, especially in lactose intolerant individuals. (AU)

Desenvolvimento de bebidas lácteas probióticas adicionadas de polpa de morango e suplementadas com L-triptofano elaboradas a partir de leite bubalino e bovino / Development of probiotic dairy beverages with strawberry pulp and supplemented with L-tryptophan from buffalo and bovine milk

O objetivo deste estudo foi desenvolver uma formulação de bebida láctea bubalina probiótica adicionada de polpa de morango, comparando os efeitos do uso do leite de búfala e de vaca na elaboração dos produtos e verificando a possibilidade de suplementação com triptofano nos produtos lácteos probióticos. Como primeira etapa do trabalho, bebidas lácteas probióticas foram elaboradas a partir de leite bubalino e bovino, fermentadas com Streptococcus thermophilus TA040, Lactobacillus bulgaricus LB340 e Lactobacillus acidophilus La5, e formuladas com 0, 25 e 50% de soro em sua formulação. As bebidas foram avaliadas quanto à cinética de fermentação das culturas láticas utilizadas, ao teor de proteína, gordura e sólidos totais não gordurosos, pós-acidificação, viabilidade das culturas fermentadoras e sua capacidade de sobrevivência ao estresse gastrointestinal in vitro. As bebidas lácteas bubalinas apresentaram resultados superiores as bebidas bovinas. O uso do leite de búfala na elaboração das bebidas lácteas promoveu benefícios quanto as culturas láticas presentes nos produtos, exercendo efeito protetivo e influindo na preservação da viabilidade das bactérias ao longo do armazenamento refrigerado e durante a simulação do estresse gastrointestinal in vitro. As bebidas lácteas elaboradas com 25% apresentaram os resultados mais próximos aos obtidos pelos produtos controle, sem adição de soro, sendo selecionadas para a segunda parte do estudo. Nesta etapa, as formulações de bebida láctea com 25% de soro, foram acrescidas de um preparado com polpa de morango e bebidas sem adição da fruta, utilizadas como controle. As bebidas lácteas bubalinas frutadas, apresentaram menor teor de gordura e melhores características reológicas, com maior viscosidade e consistência do que os produtos controle, sem afetar a pós-acidificação, o perfil de ácido graxo, assim como, a viabilidade e a resistência às condições de estresse gastrointestinal in vitro das culturas fermentadoras. A avaliação da possibilidade de suplementar lácteos probióticos com triptofano foi realizada em conjunto com a Universidade de Milão. Para isso, iogurtes probióticos receberam adição de triptofano antes ou após a fermentação, sendo avaliados com relação ao perfil de pós-acidificação, quantidade de triptofano nos produtos, número de células viáveis por plaqueamento e citometria de fluxo ao longo do armazenamento a 25° e 4°C. Complementarmente, a influência da presença do triptofano no crescimento e produção de compostos antimicrobianos pelas culturas láticas, também foi avaliada. A adição de triptofano após a fermentação dos iogurtes, que foram armazenados sob refrigeração (4°C), além de não afetar a pós-acidificação dos produtos, apresentou benefícios quanto a viabilidade L. acidophilus, redução do dano e aumento do número de células vivas, promovendo teor maior do aminoácido nos iogurtes. A presença do triptofano nos meios de cultivo, também influenciou de forma positiva o crescimento de S. thermophilus e L. acidophilus, melhorando o desenvolvimento das bactérias durante a fermentação e influindo em uma maior atividade antilistérica por parte do S. thermophilus. Diante da influência positiva da aplicação do leite de búfala na elaboração das bebidas lácteas, assim como, a adição do triptofano em iogurtes probióticos, a suplementação do aminoácido em bebidas lácteas bubalinas frutadas permitiria a obtenção de um produto funcional, onde seus benefícios estariam relacionados tanto ao consumo do probiótico presente no produto quanto a complementação de triptofano na dieta do consumidor

The aim of this study was to develop a formulation of probiotic buffalo dairy beverage added with strawberry pulp, comparing the effects of using buffalo and cow's milk in the preparation of products and verifying the possibility of tryptophan supplementation in probiotic dairy products. As a first stage of the work, probiotic dairy beverages were made from buffalo and bovine milk, fermented with Streptococcus thermophiles TA040, Lactobacillus bulgaricus LB340 and Lactobacillus acidophilus La5, and formulated with 0, 25 and 50% whey in their formulation. The beverages were evaluated for the fermentation kinetics of the used lactic cultures, the levels of protein, fat and total no fat solids, post-acidification, fermenting cultures viability and their ability to survive gastrointestinal stress in vitro. Buffalo milk use in dairy beverages production promoted benefits regarding the lactic cultures present in the products, exerting a protective effect and influencing the viability preservation of bacteria during the cold storage and simulation of gastrointestinal stress in vitro. Dairy beverages made with 25% whey addition showed results similar to those obtained by the control products, without whey addition, being selected for the second part of the study. In this part, the dairy beverages formulations with 25% whey, were added with a preparation were added with a strawberry pulp preparation and dairy beverages without added fruit, used as a control. Fruity bubaline dairy beverages had lower fat content and better rheological characteristics, with higher viscosity and consistency than control products, without affecting post-acidification, fatty acid profile, as well as viability and resistance to in vitro gastrointestinal condition of fermented cultures. The possibility of supplementing probiotic dairy products with tryptophan was evaluated in partnership with the University of Milan. For this, probiotic yogurts received the addition of tryptophan before or after fermentation, being evaluated in relation to the post-acidification profile, tryptophan amount in the products, viable cell number per plating and flow cytometry during storage at 25°C and 4°C. In addition, the influence of the tryptophan presence on the growth and production of antimicrobial compounds by lactic cultures was also evaluated. The addition of tryptophan after the yogurt fermentation, which were stored under refrigeration (4°C), in addition to not affecting the post-acidification of the products, showed benefits to the viability of L. acidophilus, reduced the damage and increased the number of cells promoting higher amino acid content in yogurts. Tryptophan presence in the culture media also positively influenced the growth of S. thermophiles and L. acidophilus, improving the development of bacteria during fermentation and influencing better antilisteric activity in the part of S. thermophiles. In view of the buffalo milk positive influence observed after the application in dairy beverage preparation, as well as the addition of tryptophan in probiotic yoghurts, amino acid supplementation in fruity buffalo dairy beverages would allow to obtain a functional product, where its benefits would be related both to the consumption of the probiotic present in the product as to the supplementation of tryptophan in the consumer's diet

Synthesis of silver nanoparticles using Lactobacillus bulgaricus and assessment of their antibacterial potential / Síntese de nanopartículas de prata usando Lactobacillus bulgaricus e avaliação de seu potencial antibacteriano

Many pathogenic strains have acquired multidrug-resistant patterns in recent a year, which poses a major public health concern. The growing need for effective antimicrobial agents as novel therapies against multidrug-resistant pathogens has drawn scientist attention toward nanotechnology. Silver nanoparticles are considered capable of killing multidrug-resistant isolates due to their oligo-dynamic effect on microorganisms. In this research study NPs were synthesized using the gram-positive bacteria Lactobacillus bulgaricus and its activity against selected pathogenic strains. Lactobacillus bulgaricus pure cultures were isolated from raw milk and grown in "De Man, Rogasa, and Sharp" broth for synthesis of nanoparticles. Lactobacillus bulgaricus culture was centrifuged and Cell free supernatant of it was employed with aqueous silvery ions and evaluated their antibacterial activities against bacterial strains i.e. Staphylococcus aureus, Staphylococcus epidermidis and Salmonella typhi using agar well diffusion assay. Antibiotic profiling against selected pathogenic strains were also conducted using disc diffusion method. The synthesis and characterization of silver nanoparticles were monitored primarily by the conversion of the pale-yellow color of the mixture into a dark-brown color and via ultraviolet-visible absorption spectroscopy and Scanning electron microscopy respectively. The result showed that that AgNPs with size (30.65-100 nm) obtained from Lactobacillus bulgaricus were found to exhibit antibacterial activities against selected bacterial strains. Taken together, these findings suggest that Lactobacillus bulgaricus has great potential for the production of AgNPs with antibacterial activities and highly effective in comparison to tested antibiotics.

Muitas cepas patogênicas adquiriram padrões multirresistentes nos últimos anos, o que representa um grande problema de saúde pública. A crescente necessidade de agentes antimicrobianos eficazes como novas terapias contra patógenos multirresistentes atraiu a atenção dos cientistas para a nanotecnologia. As nanopartículas de prata são consideradas capazes de matar isolados multirresistentes por causa de seu efeito oligodinâmico em microrganismos. Neste estudo de pesquisa, as NPs foram sintetizadas usando a bactéria Gram-positiva Lactobacillus bulgaricus e sua atividade contra cepas patogênicas selecionadas. Culturas puras de Lactobacillus bulgaricus foram isoladas do leite cru e cultivadas em caldo "De Man, Rogasa e Sharp" para síntese de nanopartículas. A cultura de Lactobacillus bulgaricus foi centrifugada, e o sobrenadante livre de células foi empregado com íons prateados aquosos, avaliando-se suas atividades antibacterianas contra cepas bacterianas, isto é, Staphylococcus aureus, Staphylococcus epidermidis e Salmonella typhi usando ensaio de difusão em poço de ágar. O perfil de antibióticos contra cepas patogênicas selecionadas também foi conduzido usando o método de difusão em disco. A síntese e a caracterização das nanopartículas de prata foram monitoradas principalmente pela conversão da cor amarelo-pálida da mistura em uma cor marrom-escura e por espectroscopia de absorção visível e ultravioleta e por microscopia eletrônica de varredura, respectivamente. O resultado mostrou que AgNPs com tamanho de 30,65-100 nm, obtidas de Lactobacillus bulgaricus, exibiram atividades antibacterianas contra cepas bacterianas selecionadas. Tomados em conjunto, esses achados sugerem que o Lactobacillus bulgaricus tem um grande potencial para a produção de AgNPs com atividades antibacterianas e altamente eficazes em comparação aos antibióticos testados.

Synthesis of silver nanoparticles using Lactobacillus bulgaricus and assessment of their antibacterial potential / Síntese de nanopartículas de prata usando Lactobacillus bulgaricus e avaliação de seu potencial antibacteriano

Many pathogenic strains have acquired multidrug-resistant patterns in recent a year, which poses a major public health concern. The growing need for effective antimicrobial agents as novel therapies against multidrug-resistant pathogens has drawn scientist attention toward nanotechnology. Silver nanoparticles are considered capable of killing multidrug-resistant isolates due to their oligo-dynamic effect on microorganisms. In this research study NPs were synthesized using the gram-positive bacteria Lactobacillus bulgaricus and its activity against selected pathogenic strains. Lactobacillus bulgaricus pure cultures were isolated from raw milk and grown in "De Man, Rogasa, and Sharp" broth for synthesis of nanoparticles. Lactobacillus bulgaricus culture was centrifuged and Cellfree supernatant of it was employed with aqueous silvery ions and evaluated their antibacterial activities against bacterial strains i.e. Staphylococcus aureus, Staphylococcus epidermidis and Salmonella typhi using agar well diffusion assay. Antibiotic profiling against selected pathogenic strains were also conducted using disc diffusion method. The synthesis and characterization of silver nanoparticles were monitored primarily by the conversion of the pale-yellow color of the mixture into a dark-brown color and via ultraviolet-visible absorption spectroscopy and Scanning electron microscopy respectively. The result showed that that AgNPs with size (30.65-100 nm) obtained from Lactobacillus bulgaricus were found to exhibit antibacterial activities against selected bacterial strains. Taken together, these findings suggest that Lactobacillus bulgaricus has great potential for the production of AgNPs with antibacterial activities and highly effective in comparison to tested antibiotics.

Muitas cepas patogênicas adquiriram padrões multirresistentes nos últimos anos, o que representa um grande problema de saúde pública. A crescente necessidade de agentes antimicrobianos eficazes como novas terapias contra patógenos multirresistentes atraiu a atenção dos cientistas para a nanotecnologia. As nanopartículas de prata são consideradas capazes de matar isolados multirresistentes por causa de seu efeito oligodinâmico em microrganismos. Neste estudo de pesquisa, as NPs foram sintetizadas usando a bactéria Gram-positiva Lactobacillus bulgaricus e sua atividade contra cepas patogênicas selecionadas. Culturas puras de Lactobacillus bulgaricus foram isoladas do leite cru e cultivadas em caldo "De Man, Rogasa e Sharp" para síntese de nanopartículas. A cultura de Lactobacillus bulgaricus foi centrifugada, e o sobrenadante livre de células foi empregado com íons prateados aquosos, avaliando-se suas atividades antibacterianas contra cepas bacterianas, isto é, Staphylococcus aureus, Staphylococcus epidermidis e Salmonella typhi usando ensaio de difusão em poço de ágar. O perfil de antibióticos contra cepas patogênicas selecionadas também foi conduzido usando o método de difusão em disco. A síntese e a caracterização das nanopartículas de prata foram monitoradas principalmente pela conversão da cor amarelo-pálida da mistura em uma cor marrom-escura e por espectroscopia de absorção visível e ultravioleta e por microscopia eletrônica de varredura, respectivamente. O resultado mostrou que AgNPs com tamanho de 30,65-100 nm, obtidas de Lactobacillus bulgaricus, exibiram atividades antibacterianas contra cepas bacterianas selecionadas. Tomados em conjunto, esses achados sugerem que o Lactobacillus bulgaricus tem um grande potencial para a produção de AgNPs com atividades antibacterianas e altamente eficazes em comparação aos antibióticos testados.

Effect of cheese containing Lactobacillus delbrueckii subsp. Lactis CRL 581 on blood pressure in prehypertensive and stage 1 hypertensive subjects / Efecto de un queso con LactobacillusdelbrueckiisubspLactis CRL 581 sobre la hipertensión arterial en individuos con prehipertensión o estadio 1 de hipertensión arterial

Hypertension is one of the main risk factors for cardiovascular disease. Functional foods containing bioactive peptides have been proposed as a strategy to decrease blood pressure (BP) in subjects under no pharmacological treatment. The aim of this study was to compare the effect of low-sodium, low-fat (LSLF) cheese and LSLF cheese containing Lactobacillus delbrueckii subsp. lactis CRL 581 (LSLF581) on BP in pre-hypertensive and stage 1 hypertensive subjects. Sixty-one pre-hypertensive and stage 1 hypertensive subjects assigned to one of twos (LSLF, n= 29 and LSLF581, n= 32) participated in this 12-month prospective, randomized, double-blind, crossover trial. Twenty-four h ambulatory BP monitoring was performed at the beginning and at the end of each four-week study period. Systolic and diastolic BP decreased in both study groups, but differences between groups were not significant (systolic, -1.78 and -0.2 mmHg; diastolic, -1.54 and -0.42 mmHg in LSLF581 and LSLF, respectively). Although our results could not support a BP lowering effect of LSLF581, small BP reductions could favorably prevent cardiovascular disease development.

La hipertensión arterial es uno de los principales factores de riesgo de enfermedad cardiovascular. Los alimentos funcionales que contienen biopéptidos constituyen una estrategia útil para disminuir la presión arterial (PA) en personas que no están bajo tratamiento farmacológico. El objetivo del estudio fue comparar el efecto de un queso bajo en sodio y bajo en grasas (BSBG) y el mismo queso con Lactobacillus delbrueckii subsp. lactis CRL 581 (BSBG581) sobre la PA en personas con prehipertensión y estadio 1 de hipertensión arterial. Realizamos un estudio prospectivo, randomizado, cruzado y doble ciego durante 12 meses en 61 personas con prehipertensión y estadio 1 de hipertensión arterial, asignadas a dos grupos: BSBG (n= 29) y BSBG581 (n= 32). Se realizó monitoreo ambulatorio de la PA (MAPA) durante 24 h al comienzo y al final de cada etapa del estudio (cuatro semanas). La PA sistólica y diastólica disminuyó en ambos grupos, aunque las diferencias entre grupos no fueron significativas (sistólica, -1.78 y -0.2 mmHg; diastólica -1.54 y -0.42 mmHg en BSBG581 y BSBG respectivamente). Aunque nuestros resultados no pueden confirmar el efecto hipotensor del queso BSBG581, las reducciones moderadas de la PA podrían prevenir el desarrollo de enfermedad cardiovascular.

Elaboração e caracterização de iogurte saborizado com polpa de oiti (Licania tomentosa)

Objetivou-se elaboração e caracterização de iogurte saborizado com polpa de oiti (Licania tomentosa). Foram produzidos quatro formulações com diferentes concentrações da polpa de oiti. Os parâmetros físico-químicos foram pH, Acidez em ácido lático, Umidade, Atividade de água (Aw), Cinzas, Lipídeos, Proteínas, Sólidos Solúveis Totais (ºBrix), Carboidratos totais, Valor Calórico (Kcal), Açúcares Redutores, Açúcares não redutores e Açúcares Totais. As análises microbiológicas foram realizadas durante 21 dias de armazenamento. As análises físico-químicas foram submetidos à análise de variância (ANOVA) e ao teste de Tukey. As análises microbiológicas atenderam aos limites estabelecidos pela legislação. E os iogurtes apresentaram dentro dos padrões, sendo uma opção para a região produtora dessa fruta.

Fermented beverage based on water-soluble soybean extract / Bebida fermentada à base de extrato hidrosolúvel de soja

Functional foods are those that, beyond basic nutrition, promote health benefits. This study aimed to produce a fermented beverage from a water-soluble soybean extract and low-lactose semi-skimmed milk. The beverage was prepared using a blend (v/v) containing 62% water-soluble soybean extract, 33% low-lactose semi-skimmed milk, and 5% of an inoculum containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus. The fermentation was carried out with monitoring of the lactic acid bacteria (LAB) counts, pH, and titrable acidity (% lactic acid). The consumption-ready fermented beverage was added of strawberry syrup and posteriorly characterized by its centesimal composition and sensory attributes as appearance, aroma, flavour, texture, overall impression, and purchase intent. Additionally, the LAB count and presence of pathogens in the final product were evaluated. After 14 h of fermentation, the refrigerated product presented L. bulgaricus and S. thermophilus counts of 8.5 × 103 and 7.4 × 107 CFU/mL, respectively. The product contained 14.93% carbohydrates, 0.76% fats, 0.96% ash, 22.76% totalsolids, and 2.19% protein. Because the product did not present any pathogens, it was adequate according to the standards of microbiological safety determined by Brazilian legislation. Regarding the sensory evaluation, the panelists assigned a mean score of 7.0 for the attributes evaluated, indicating 'liked moderately' to the drink. In addition, 61% of the evaluators responded that they 'certainly or probably would buy' the product if it were available on the market.

Alimentos funcionais são aqueles que, além da nutrição básica, promovem benefícios à saúde. Este trabalho teve como objetivo produzir uma bebida fermentada a partir de extrato hidrosolúvel de soja (EHS) e leite semidesnatado com baixa lactose. A bebida foi preparada utilizando uma mistura (v/v) contendo 62% de EHS, 33% de leite semidesnatado com baixa lactose e 5% de inóculo contendo Lactobacillus delbrueckii subsp. Bulgaricus e Streptococcus salivarius subsp. Thermophilus. A fermentação foi acompanhada durante 14 horas, através das contagens das bactérias ácido lácticas, pH e a acidez titulável (% de ácido láctico). A bebida fermentada pronta para consumo foi adicionada de uma calda de morango e caracterizada por sua composição centesimal, bem como por avaliação sensorial para os atributos: aparência, aroma, sabor, impressão global e intenção de compra. Além disso, a contagem das bactérias lácticas e presença de patógenos no produto foi avaliada. Após 14 horas de fermentação, o produto final refrigerado apresentou contagens de 8,5x103 UFC/mL e 7,4x107 UFC/mL para as bactérias L. bulgaricus e S. thermophilus respectivamente. O produto apresentou 14,93% de carboidratos, 0,76% de gordura, 0,96% de cinzas, 22,76% de sólidos totais e 2,19% de proteína. O produto não apresentou quaisquer patógenos, portanto, foi adequado aos padrões determinados pela legislação brasileira quanto à segurança microbiólogica. Com relação à avaliação sensorial, os provadores atribuíram em média nota 7,0 para todos os parâmetros avaliados, indicando que "gostarammoderadamente" da bebida. Ademais 61% dos avaliadores apontaram que "certamente ou provavelmente comprariam" o produto se estivesse disponível no mercado.

Microbiological and physical-chemical characteristics of fermented milk beverages / Características microbiológicas e físico-químicas de bebidas lácteas fermentadas

This study aimed to evaluate some microbiological and physical-chemical characteristics of fermented milk beverages collected at the main supermarkets in Belo Horizonte (MG). 40 samples of the products corresponding to five distinct brands were collected. They were submitted to the following analyses: Most Probable Number (MPN) of total (30ºC) and thermal tolerant coliforms (45ºC), Salmonella spp., coagulase positive Staphylococcus, molds and yeasts, lactic acid bacteria, pH, titratable acidity and contents of moisture, total solids, protein and fat. The analyses were carried out during the last week of shelf life. The microbiological quality of the samples was good and the counts of lactic bacteria were above the minimum established by the official legislation. Streptococcus and Lactobacillus were isolated and identified from the products and Lactobacillus delbrueckii was molecularly identified in three samples. The mean values for the contents of fat and protein, titratable acidity, pH, moisture and total solids ranged from 1.24 to 1.98%; 1.88 to 2.22%; 0.54 to 0.66%; 3.91 to 4.16; 81.18 to 83.25% and 16.75 to 18.82%, respectively. All samples had protein content in agreement with the official legislation.

O objetivo do presente trabalho foi avaliar as características microbiológicas e físico-químicas de bebidas lácteas fermentadas. Foram coletadas 40 amostras de bebidas lácteas fermentadas pertencentes a cinco marcas distintas, em grandes redes de supermercados de Belo Horizonte. Em cada amostra, foram avaliados os seguintes parâmetros: número mais provável de coliformes totais (30ºC), número mais provável de coliformes termotolerantes (45ºC), pesquisa de Salmonella spp., contagem de Staphylococcus coagulase positiva, contagem de bolores e leveduras, contagem total de bactérias lácticas viáveis, umidade, sólidos totais, teor de proteína, teor de gordura, pH e acidez titulável. As análises foram realizadas na última semana do período de validade. As amostras apresentaram qualidade microbiológica satisfatória, bem como contagens totais de bactérias lácticas viáveis superiores ao mínimo estabelecido pela legislação. Streptococcus e Lactobacillus foram identificados em todas as marcas de bebidas lácteas fermentadas analisadas, e em três delas foi possível identificar a espécie Lactobacillus delbrueckii. Os valores médios encontrados para os teores de gordura, proteína, acidez titulável, pH, umidade e sólidos totais variaram de 1,24 a 1,98%, 1,88 a 2,22%, 0,54 a 0,66%, 3,91 a 4,16, 81,18 a 83,25% e 16,75 a 18,82%, respectivamente. Todas as marcas de bebidas lácteas fermentadas apresentaram teor médio de proteína superior ao mínimo preconizado pela legislação.

Las leches fermentadas potencialmente probióticas frente a la inflamación intestinal y el cáncer / Potential of probiotic fermented milks in intestinal inflammation and cancer

Mediante modelos con animales se demostró que el consumo de leches fermentadas con microorganismos potencialmente probióticos puede modular la respuesta inmunitaria del hospedador, manteniéndolo en estado de vigilancia, lo que le ayudaría a enfrentar enfermedades como la inflamación intestinal y algunos tipos de cáncer, mejorando su calidad de vida...

Optimization of process variables for enhanced lactic acid production utilizing paneer whey as substrate in submerged fermentation process

In the present study lactic acid production was enhanced by optimizing the three process variables viz; inoculum size, temperature and pH using three factor five level CCRD [central composite rotatable design] by Lactobacillus delbruckii under SMF [submerged fermentation process]. Paneer [dairy byproduct] whey was used as sole substrate for lactic acid production. Design Expert 8.0.2.0 software depicted that an optimum concentration of 8% [v/v] size of inoculum, 5.50 pH and 36.53°C temperature gave lactic acid and biomass yield of 5.61 g/L[-1] and 4.27 g/L[-1], respectively. Lactic acid production was scale up in 7.5 L bioreactor under optimized conditions and it gave lactic acid and biomass yield of 39.2 +/- 1.4 and 47.6 +/- 0.8 g/L[-1], respectively. micro[g], Y[P/S], Y[P/X] and productivity were found to be 0.14 h[-1], 0.66 g/g, 0.7 g/g and 1.98 g/L[-1] h, respectively. Leudking Piret equation deduced that lactic acid production was growth associated which varies from earlier reports. Lactic acid was characterized by FTIR [Fourier transform infrared spectroscopy] and HPLC

Biochemical characteristics and viability of probiotic and yogurt bacteria in yogurt during the fermentation and refrigerated storage

This research aimed to investigate the viability of probiotic bacteria [Lactobacillus acidophilus LA-5 and Bifidobacterium lactisBB-12] and yogurt bacteria [Streptococcus thermophiles and Lactobacillus delbrueckii ssp. bulgaricus] in yogurt during the fermentation, immediately after fermentation and during refrigerated storage [21 d, 4°C]. Also the biochemical characteristics of milk as affected by the commercial 4-strain mixed starter culture were investigated. Storage time affected the viability of all bacterial species. The concentration of lactic acid during the fermentation increased in parallel with the titrable acidity, and the concentration of acetic acid was proportional to the viability of Bifidobacterium lactis. The acetaldehyde level was decreased in the yogurt from day 0 up to the end of the storage. Streptococcus thermophiles and Lactobacillus delbrueckii ssp. bulgaricuswere multiplied considerably during the fermentation. Streptococcus thermophiles could maintain its viability to the highest level, but Lactobacillus delbrueckii ssp. Bulgaricus lost its viability rapidly during the cold storage compared to Streptococcus thermophilus. The multiplication and viability of probiotic bacteria were also influenced by the associative strains and species of yogurt organisms. Bifidobacteria counts were satisfactory. The loss of viability for bifidobacteria was gradual and steady during the storage, and they showed good stability during the storage as compared to Lactobacillus acidophilus

Effect of probiotics on the development of dimethylhydrazine-induced preneoplastic lesions in the mice colon

PURPOSE: To determine the effect of probiotics on the development of chemically induced (1, 2-dimethylhydrazine) colonic preneoplastic lesions, in mice. METHODS: The animals were divided into five groups. The control group was injected with carcinogen alone and the other groups also received probiotics (1- Lactobacillus delbrueckii UFV-H2b20; 2- Bifidobacterium animalis var. lactis Bb12; 3- L. delbrueckii UFV-H2b20 plus B. animalis var. lactis Bb12; and 4- Saccharomyces boulardii) administered orally in drinking water throughout fourteen weeks. RESULTS: Consumption of lactobacilli and bifidobacteria alone resulted in a significant reduction of the total number of aberrant crypt foci (55.7% and 45.1%, respectively). Significant reduction in the number of these small foci (<3 aberrant crypts) was only observed in the group treated with lactobacilli (52.2%) in comparison to control group. The number of larger foci (>3 aberrant crypts) crypts had no significant reduction. CONCLUSION: L. delbrueckii UFV-H2b20 and B. animalis var. lactis Bb12 administered alone protect colonic preneoplastic lesions in mice, while the combined treatment of these bacteria and the administration of S.boulardii were not effective in reducing such colonic lesions.

Suitability of MRS-bile agar for the selective enumeration of mixed probiotic bacteria in presence of mesophilic lactic acid cultures and yoghurt bacteria

Measuring the viability of probiotic microorganisms in food products using plate count methodology is a common practice due to the simplicity [ease of performance], inexpensive and routine testing characters of this method. In present study, the suitability of de man rogosa and sharpe agar [MRS] bile agar medium for the selective enumeration of mixed probiotic bacteria [Lactobacillus acidophilus LA-5, L. casei 431 and Bifidobacterium lactis BB-12] in presence of mesophilic lactic cultures [Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. Cremoris] and yoghurt bacteria [Streptococcus thermophilus and Lactobacillus delbrueckii ssp. Bulgaricus] was investigated. Yoghurt bacteria did not grow neither in presence of 0.15% nor 0.30% of bile salts, as was expected. Mesophilic lactic starters could grow at both concentrations of bile salts at all incubation temperatures except 37°C. According to these results, MRS-bile agar [0.15 bile salts] could be successfully used for selective enumeration of mixed probiotic cultures in presence of mesophilic culture and/or yoghurt bacteria when plates were incubated at 37°C for 72 h

Vitamin B12 content analysis of favorite Korean restaurant foods, convenient foods and bakery products

There is a limitation to estimate vitamin B12 intake due to the lack of data on vitamin B12 content of Korean commercial foods. In this study, vitamin B12 content was determined in favorite Korean restaurant foods, convenient or instant foods, fast foods and bakery products through a modified microbioassay using Lactobacillus delbrueckii ATCC 7830. Bulgogi and seafood & green pepper griddle had high vitamin B12 content, 3.50 and 2.96 microg/100 g, respectively. Pork suyook, pork griddle and pollack griddle had 0.48, 0.31 and 0.32 microg/100 g of vitamin B12, respectively. In stew, soft-tofu stew with seafood and doenjang stew with seafood had relatively high vitamin B12 content, 1.93 and 1.44 microg/100 g, respectively. Bibimbap and 4 different types of rice porridge, beef & mushroom, chicken & ginseng, seafood or abalone, had 0.36, 0.08, 0.09, 1.64 and 0.13 microg/100 g of vitamin B12, respectively. One serving of haejanggguk, yookejang, chuotang and galbitang had 5.97, 2.04, 2.63 and 1.91 microg of vitamin B12, respectively. One serving of samgetang and sulongtang had 2.89 microg and 6.64 microg of vitamin B12. In noodles, one serving of cram noodle soup, bibim-nangmyeon, and mul-nangmyeon had 18.8, 1.21 and 0.38 microg of vitamin B12, respectively. One regular gimbap and one triangle gimbap contained 1.09-2.53 and 0.54-1.11 microg of vitamin B12, respectively. One cheese-burger, chicken-burger and bulgogi-burger had 0.76, 0.62 and 0.54 microg of vitamin B12, respectively. A plain bagel and a waffle contained 0.13 and 0.17 microg/100 g of vitamin B12, respectively. Ready-made tomato sauce or cream sauce for spaghetti in a retort pouch contained only a trace of vitamin B12. In conclusion, these results should contribute to improving the present food vitamin B12 content database, most of which were cited from foreign data, thereby it could be helpful to estimate the vitamin B12 intake of Koreans more accurately than before. It will also provide new information for dietary education related to vitamin B12 and health.

Ausência de efeito do Lactobacillus delbrueckii H2B20 na prevenção de díarréia em crianças hospitalizadas por curto período / Lack of effect of Lactobacillus delbrueckii H2B20 in the prevention of diarrhea in children hospitalized for short period

Objetivo: Avaliar o uso do Lactobacillus delbruechii UFV H2B20 na prevenção de diarréia em crianças hospitalizadas. Método: Trata-se de estudo prospectivo, randomizado e duplo cego, no qual foram incluidas 139 crianças hospitalizadas com idades de 1 a 36 meses em enfermaria geral do Hospital Infantil João Paulo II/FHEMIG, em Belo Horizonte, no período de agosto de 2004 a julho de 2006...

Objectives: The objective of this trial was to evaluate the use of lactobacillus delbrueckii UFV H2B20 in the prevention of diarrhea in hospitalized children. Methods: It is a prospective, randomized and double blind trial in which were included 139 children from 1 to 36 months old who were hospitalized in the João Paulo II/FHEMIG children's Hospital, in Belo Horizonte, from August 2004 to July 2006...

Lactobacillus delbrueckii UFV-H2b20 induces type 1 cytokine production by mouse cells in vitro and in vivo

Lactobacillus delbrueckii UFV-H2b20 has been shown to increase clearance of bacteria injected into the blood of germ-free mice. Moreover, it induces the production of type 1 cytokines by human peripheral mononuclear cells. The objective of the present study was to investigate the production of inflammatory cytokines [interleukin-12 (IL-12 p40), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ)] triggered in vitro by live, heat-killed or lysozyme-treated L. delbrueckii UFV-H2b20 and in vivo by a live preparation. Germ-free, L. delbrueckii-monoassociated and lipopolysaccharide (LPS)-resistant C3H/HeJ mice were used as experimental models. UFV-H2b20 induced the production of IL-12 p40 and TNF-α by peritoneal cells and IFN-γ by spleen cells from germ-free or monoassociated Swiss/NIH mice and LPS-hyporesponsive mice (around 40 ng/mL for IL-12 p40, 200 pg/mL for TNF-α and 10 ng/mL for IFN-γ). Heat treatment of L. delbrueckii did not affect the production of these cytokines. Lysozyme treatment decreased IL-12 p40 production by peritoneal cells from C3H/HeJ mice, but did not affect TNF-α production by these cells or IFN-γ production by spleen cells from the same mouse strain. TNF-α production by peritoneal cells from Swiss/NIH L. delbrueckii-monoassociated mice was inhibited by lysozyme treatment. When testing IL-12 p40 and IFN-γ levels in sera from germ-free or monoassociated Swiss/NIH mice systemically challenged with Escherichia coli we observed that IL-12 p40 was produced at marginally higher levels by monoassociated mice than by germ-free mice (40 vs 60 ng/mL), but IFN-γ was produced earlier and at higher levels by monoassociated mice (monoassociated 4 and 14 ng/mL 4 and 8 h after infection, germfree 0 and 7.5 ng/mL at the same times). These results show that L. delbrueckii UFV-H2b20 stimulates the production of type 1 cytokines in vitro and in vivo, therefore suggesting...

Optimization of b-galactosidase production using Kluyveromyces lactis NRRL Y-8279 by response surface methodology

This paper investigates the production and optimization of b-galactosidase enzyme using synthetic medium by Kluyveromyces lactis NRRL Y-8279 in shake flask cultures. Among the different cell disintegration methods used, the highest specific activity was obtained when the cells were permeabilized using isoamyl alcohol. Response surface methodology was used to investigate the effects of four fermentation parameters (agitation speed, pH, initial substrate concentration and incubation time) on b-galactosidase enzyme production. Results of the statistical analysis showed that the fit of the model was good in all cases. Maximum specific enzyme activity of 4218.4 U g-1 was obtained at the optimum levels of process variables (pH 7.35, agitation speed 179.2 rpm, initial sugar concentration 24.9 g l-1 and incubation time 50.9 hrs). The response surface methodology was found to be useful in optimizing and determining the interactions among process variables in b-galactosidase enzyme production.

Bebida fermentada probiótica de soro de leite / Probiotic drink of milk serum

O presente trabalho propôs desenvolver uma bebida composta por soro de leite fermentado com microrganismos probióticos, saborizada com polpa de frutas, caracterizando-a em seus aspectos físico-químicos, microbiológicos e sensoriais. Foram elaborados três tratamentos diferidos apenas pelo tipo de fermento lácteo empregado. Os resultados mostraram a viabilidade tecnológica de apenas um tratamento composto por fermento YC-X11, contendo cepas mistas de L.delbrueckii subsp. bulgaricus e S.salivarius subsp. thermophilus, o qual foi submetida a análise físico-químicas e microbiológicas para caracterização do produto e posterior avaliação sensorial pelo método de escala hedônica. Obteve-se uma bebida probiótica inovadora, de excelente valor nutritivo, dentro dos parâmetros de identidade microbiológica e físico-química e de grande aceitação pelo consumidor final.

Effect of Lactobacillus delbrueckii on cholesterol metabolism in germ-free mice and on atherogenesis in apolipoprotein E knock-out mice

Elevated blood cholesterol is an important risk factor associated with atherosclerosis and coronary heart disease. Several studies have reported a decrease in serum cholesterol during the consumption of large doses of fermented dairy products or lactobacillus strains. The proposed mechanism for this effect is the removal or assimilation of intestinal cholesterol by the bacteria, reducing cholesterol absorption. Although this effect was demonstrated in vitro, its relevance in vivo is still controversial. Furthermore, few studies have investigated the role of lactobacilli in atherogenesis. The aim of the present study was to determine the effect of Lactobacillus delbrueckii on cholesterol metabolism in germ-free mice and the possible hypocholesterolemic and antiatherogenic action of these bacteria using atherosclerosis-prone apolipoprotein E (apo E) knock-out (KO) mice. For this purpose, Swiss/NIH germ-free mice were monoassociated with L. delbrueckii and fed a hypercholesterolemic diet for four weeks. In addition, apo E KO mice were fed a normal chow diet and treated with L. delbrueckii for 6 weeks. There was a reduction in cholesterol excretion in germ-free mice, which was not associated with changes in blood or liver cholesterol concentration. In apo E KO mice, no effect of L. delbrueckii was detected in blood, liver or fecal cholesterol. The atherosclerotic lesion in the aorta was also similar in mice receiving or not these bacteria. In conclusion, these results suggest that, although L. delbrueckii treatment was able to reduce cholesterol excretion in germ-free mice, no hypocholesterolemic or antiatherogenic effect was observed in apo E KO mice.