Growth kinetic models of five species of Lactobacilli and lactose consumption in batch submerged culture

Abstract Kinetic behaviors of five Lactobacillus strains were investigated with Contois and Exponential models. Awareness of kinetic behavior of microorganisms is essential for their industrial process design and scale up. The consistency of experimental data was evaluated using Excel software. L. bulgaricus was introduced as the most efficient strain with the highest biomass and lactic acid yield of 0.119 and 0.602 g g-1 consumed lactose, respectively. The biomass and carbohydrate yield of L. fermentum and L. lactis were slightly less and close to L. bulgaricus. Biomass and lactic acid production yield of 0.117 and 0.358 for L. fermentum and 0.114 and 0.437 g g-1 for L.actobacillus lactis were obtained. L. casei and L. delbrueckii had the less biomass yield, nearly 11.8 and 22.7% less than L. bulgaricus, respectively. L. bulgaricus (R 2 = 0.9500 and 0.9156) and L. casei (R 2 = 0.9552 and 0.8401) showed acceptable consistency with both models. The investigation revealed that the above mentioned models are not suitable to describe the kinetic behavior of L. fermentum (R 2 = 0.9367 and 0.6991), L. delbrueckii (R 2 = 0.9493 and 0.7724) and L. lactis (R 2 = 0.8730 and 0.6451). Contois rate equation is a suitable model to describe the kinetic of Lactobacilli. Specific cell growth rate for L. bulgaricus, L. casei, L. fermentum, L. delbrueckii and L. lactis with Contois model in order 3.2, 3.9, 67.6, 10.4 and 9.8-fold of Exponential model.

Optimization of growth and bacteriocin production by Lactobacillus sakei subsp. sakei2a

Lactobacillus sakei subsp. sakei 2a is a bacteriocinogenic lactic acid bacterium isolated from Brazilian pork sausage, capable of inhibiting the growth of microbial pathogens, mainly Listeria monocytogenes. In order to optimize bacteriocin production for industrial applications, this study evaluated the effect of supplementation of MRS broth with glucose, Tween 20, Tween 80, sodium citrate, potassium chloride and cysteine, and effect of the initial pH and temperature of incubation of the medium on production of bacteriocins by L. sakei 2a. Adding glucose and Tween 20 to the medium, an initial pH of 5.0 or 5.5, and incubation temperatures of 25 °C or 30 °C resulted to the highest bacteriocin yields. Thus, a 2⁴ factorial design with the four variables was performed, and statistical analysis showed that it was an adequate model (R² = 0.8296). In the studied range, the four parameters significantly influenced bacteriocin production, with the maximum yield produced at an initial pH between 5.5 and 7.0, a temperature between 25 and 30 °C and supplementation of the MRS broth with glucose from 3.25 to 6.0 g L⁻¹ and Tween 20 from 0.575 to 1.15% (v/v). Response Surface Methodology analysis indicated that the highest bacteriocin production (12800 AU mL⁻¹) occurred in the MRS broth supplemented with 5.5 g L⁻¹ glucose and 1.05% Tween 20 at an initial pH of 6.28 and an incubation temperature of 25 °C. The amount of bacteriocin produced in commercial MRS broths under the same conditions was only 5600AU mL⁻¹.

Effects of probiotic fermented milk on biofilms, oral microbiota, and enamel

The aim of this study was to evaluate in vitro and in vivo the effects of 2 brands of probiotic fermented milk on biofilms, oral microbiota, and enamel. For the in situ experiment, ten volunteers wore palatine devices containing four blocks of bovine dental enamel over 3 phases, during which 20% sucrose solution, Yakult® (Treatment A), and Batavito® (Treatment B) were dropped on the enamel blocks. Salivary microbial counts were obtained and biofilm samples were analyzed after each phase. For the in vivo experiment, the same ten volunteers drunk Yakult® (Treatment C) and Batavito® (Treatment D) in two phases. Saliva samples were collected for microbial analysis after each phase. The in situ study showed that in comparison with Treatment A, Treatment B resulted in fewer total cultivable anaerobes and facultative microorganisms in biofilms, higher final microhardness, lower percentage change in surface hardness, and smaller integrated subsurface enamel hardness. In the in vivo study, Treatment D resulted in a reduction in the counts of all microorganisms. The results suggested that the probiotic fermented milk Batavito®, but not Yakult®, reduced the amount of oral microorganisms and mineral loss in bovine enamel.

Apoptosis of human tongue squamous cell carcinoma cell (CAL-27) induced by Lactobacillus sp. A-2 metabolites

Objective: To study the effect of Lactobacillus sp. A-2 metabolites on viability of CAL-27 cells and apoptosis in CAL-27 cells. Methods: Lactobacillus sp. A-2 metabolites 1 and 2 (LM1 and LM2) were obtained by culturing Lactobacillus sp. A-2 in reconstituted whey medium and whey-inulin medium; the cultured CAL-27 cells were treated with different concentrations of LM1 and LM2 (0, 3, 6, 12, 24, 48 mg/mL) and assayed by methyl thiazolyltetrazolium (MTT) method; morphological changes of apoptotic cell were observed under fluorescence microscopy by acridine orange (Ao) fluorescent staining; flow cytometry method (FCM) and agarose gel electrophoresis were used to detect the apoptosis of CAL-27 cells treated LM1 and LM2. Results: The different concentrations of LM1 and LM2 could restrain the growth of CAL-27 cells, and in a dose-dependent manner; the apoptosis of CAL-27 cells was obviously induced and was time-dependent. Conclusions: Viability of CAL-27 cells was inhibited by Lactobacillus sp. A-2 metabolites; Lactobacillus sp. A-2 metabolites could induce CAL-27 cells apoptosis; study on the bioactive compounds in the Lactobacillus sp. A-2 metabolites and their molecular mechanism is in progress. .

Optimization of nutritional and non-nutritional factors involved for production of antimicrobial compounds from Lactobacillus pentosus SJ65 using response surface methodology

Bacteriocins from lactic acid bacteria are ribosomal synthesized antibacterial proteins/ peptides having wide range of applications. Lactobacillus pentosus SJ65, isolated from fermented Uttapam batter (used to prepare south Indian pan cake), produces bacteriocin having a broad spectrum of activity against pathogens. Optimization studies are of utmost important to understand the source of utilization and the conditions to enhance the production of metabolites. In the present study, an attempt was made to identify the parameters involved for maximal production of antimicrobial compounds especially bacteriocin from the isolate L. pentosus SJ65. Initially, optimal conditions, such as incubation period, pH, and temperature were evaluated. Initial screening was done using methodology onevariable-at-a-time (OVAT) for various carbon and nitrogen sources. Further evaluation was carried out statistically using Plackett-Burman design and the variables were analyzed using response surface methodology using central composite design. The optimum media using tryptone or soy peptone, yeast extract, glucose, triammonium citrate, MnSO4, dipotassium hydrogen phosphate and tween 80 produced maximum bacteriocin activity.

Queijo minas frescal suplementado com probiótico para o controle de Candida sp. isolados da cavidade bucal de usuários de próteses totais - estudo duplo-cego randomizado / Minas frescal cheese supplemented with probiotics for control of Candida sp. isolated from oral cavity of complete denture wearers - double-blind randomized trial

Os probióticos são organismos vivos que quando ingeridos em quantidades adequadas, conferem benefícios aos indivíduos. Um destes benefícios é a capacidade de inibir o crescimento de micro-organismos patogênicos como Candida. Para avaliar a redução ou inibição de Candida em usuários de próteses totais promovida pela ingestão de probióticos, foram recrutados 135 pacientes, dos quais 59 permaneceram até o final do período experimental de 8 semanas. A ingestão dos probióticos ocorreu através de sua incorporação em queijo minas frescal. Foram selecionados pacientes usuários de próteses totais, uni ou bimaxilares albergando Candida na cavidade bucal. As amostras foram coletadas através de um enxaguado bucal 1 semana antes do início do experimento e ao final do período experimental de 8 semanas. Foi determinado o número de UFC de Candida/ml da amostra. Os sujeitos da pesquisa (n=59) receberam embalagens com 20g de queijo minas frescal a cada 14 dias por 8 semanas consecutivas. Os participantes foram divididos aleatoriamente em três grupos, experimental 1 e 2, e controle. Os grupos experimentais receberam os queijos suplementados com probióticos, respectivamente, Lactobacillus acidophilus NCFM e Lactobacillus rhamnosus Lr-32, e o grupo controle recebeu o queijo sem suplementação probiótica. Os queijos possuíam semelhança quanto a aroma e cor. Além da quantificação de Candida, foram realizados testes para identificação das espécies e avaliação da atividade enzimática da fosfolipase e proteinase. Os resultados inferem que os probióticos L. acidophilus NCFM e L. rhamnosus Lr-32 suplementados em queijo minas frescal foram capazes de reduzir os níveis de Candida bucal, em pacientes usuários de próteses totais, após ingestão diária dos queijos por 8 semanas consecutivas. Antes e após 8 semanas do experimento, Candida albicans foi a espécie mais isolada dos pacientes nos três grupos avaliados...

Probiotics are living organisms which when ingested in adequate amounts confer benefits to individuals. One of these benefits is the ability to inhibit the growth of pathogenic microorganisms such as Candida. Reduction or inhibition of Candida isolated from complete denture wearers, uni or bimaxillary, was evaluated by ingestion of minas frescal cheese supplemented with probiotics. 135 patients were recruited, who 59 remained until the end of the experiment. The participants were patients in treatment at the Faculdade de Odontologia da Universidade de São Paulo. The samples were collected through a rinsed mouthwash at the base line and 8 weeks of experiment, before the installation of the new prosthesis. The samples were inoculated on Saubouraud agar dextrose with chloramphenicol plates, incubated for 24-48 hours, in order to quantify in colony-forming units per milliliter (CFU/mL) of Candida presents in the oral cavity of these patients. Subjects who presented fungus positive culture received packages containing 20g of minas frescal cheese every 14 days for 8 consecutive weeks. The participants were divided into three groups: two experimental and one control. The experimental groups received the cheeses supplemented with probiotics Lactobacillus acidophilus NCFM and Lactobacillus rhamnosus Lr-32. The control group received the cheese without probiotic supplementation. The cheeses had similarity as flavoring and coloring. In addition to the quantification of Candida, tests for species identification, phospholipase and proteinase activities were carried out. The results infer that L. acidophilus NCFM and L. rhamnosus Lr-32 supplemented in minas frescal cheese were able to reduce the levels of oral Candida in complete denture wearers, after daily intake of cheeses for 8 weeks of the experiment. At baseline and after 8 weeks of the experiment Candida albicans was the most frequently isolated from denture wearers in all groups...

Combined effects of inoculation level and sequence on biochemical and microbiological characteristics of probiotic doogh

The combined effects of inoculation level [4 or 8-fold compared to standard inoculation] and sequence [standard inoculation before fermentation and 3-fold inoculation at the end of fermentation=1+3, Two-fold inoculation before fermentation and the same at the end of fermentation=2+2, 2+6, 4-fold before fermentation=4, 4+4, and 8] of culture inoculum containing probiotics on biochemical and microbiological characteristics of probiotic Doogh during fermentation and over 21 days of refrigerated storage [4°C] were investigated. The probiotic microorganisms were L. acidophilus LA-5 and Bifidobacterium lactis BB-12. Overall, the treatments 8, 4 and 4+4 resulted in the highest viability at the end of fermentation as well as at early days of refrigerated storage. During the second half of cold storage period, the greatest viability of probiotics was related to the treatment 2+6. The treatment '8' showed the shortest incubation time as well as the highest pH drop rate and acidity increase rate during fermentation and over the storage period

Influence of phenolic compounds on the growth and arginine deiminase system in a wine lactic acid bacterium

The influence of seven phenolic compounds, normally present in wine, on the growth and arginine deiminase system (ADI) of Lactobacillus hilgardii X1B, a wine lactic acid bacterium, was established. This system provides energy for bacterial growth and produces citrulline that reacts with ethanol forming the carcinogen ethyl carbamate (EC), found in some wines. The influence of phenolic compounds on bacterial growth was compound dependent. Growth and final pH values increased in presence of arginine. Arginine consumption decreased in presence of protocatechuic and gallic acids (31 and 17%, respectively) and increased in presence of quercetin, rutin, catechin and the caffeic and vanillic phenolic acids (between 10 and 13%, respectively). ADI enzyme activities varied in presence of phenolic compounds. Rutin, quercetin and caffeic and vanillic acids stimulated the enzyme arginine deiminase about 37-40%. Amounts of 200 mg/L gallic and protocatechuic acids inhibited the arginine deiminase enzyme between 53 and 100%, respectively. Ornithine transcarbamylase activity was not modified at all concentrations of phenolic compounds. As gallic and protocatechuic acids inhibited the arginine deiminase enzyme that produces citrulline, precursor of EC, these results are important considering the formation of toxic compounds.

Desarrollo de un queso maduro con adición del cultivo probiótico lactobacillus paracasei subsp. paracasei LC-01 / Development of mature cheese with the adittion of the probiotic culture lactobacillus paracasei subsp. paracasei LC-01

The probiotic culture Lactobacillus paracasei subsp. paracasei LC-01 was incorporated to a mature cheese in order to obtain a functional product for a minimal reasonable period before its consumption. The ideal period of maturation for the cheese was determined by evaluating with consumers the acceptability of the flavor and texture of samples after 13.30 and 45 days of maturation to 12 ºC and 85 percent RH. The process of cheese elaboration was modified by pressing with a number of viable probiotic cells up to 1 x 106 UFC. A significant increment (alpha=5 percent) was detected in the re-counts of Lactobacillus paracasei subsp. paracasei for the three studied times of maturation. The pH value of the product fell throughout the 45 days of maturation. There were not significant differences (alpha=5 percent) in the flavor and texture acceptability of the cheeses put under different times of maturation. The probiotic population stayed stable (Ix 107 UFCI g average)for a 15 days maturated cheese, throughout 45 days of storage at 5ºC.

A un queso maduro se le incorporó el cultivo probiótico Lactobacillus paracasei subsp. paracasei LC-01 para obtener un producto funcional por un período mínimo razonable para su consumo. Se determinó un período ideal de maduración para el queso evaluando con consumidores la aceptabilidad del sabor y la textura de muestras de 13,30 y 45 días de maduración a 12 ºC y 85 por ciento HR. Se modificó el proceso de elaboración del queso para obtener un queso recién prensado con un número de células probióticas viables mayor a 1 x 106 UFC. Se encontró un incremento significativo (alfa=5 por ciento) en los recuentos del Lactobacillus paracasei subsp. paracasei para los tres tiempos de maduración estudiados con respecto al queso recién prensado. Los valores de pH del producto disminuyeron a través de los 45 días de maduración. No se hallaron diferencias significativas (alfa=5 por ciento) en la aceptabilidad del sabor y la textura para los quesos sometidos a los distintos tiempos de maduración. La población del probiótico se mantuvo estable (1 x 107 UFC/ g en promedio) para un queso madurado 15 días, a lo largo de 49 días de almacenamiento a 5ºC, sin que se haya registrado una tendencia de descenso o crecimiento significativa (alfa=5 por ciento).

Investigation of acid and bile tolerance of native lactobacilli isolated from fecal samples and commercial probiotics by growth and survival studies

This study aimed at applying both growth and survival approaches to compare three native strains of lactobacilli, belonging to Lactobacillus plantarum, Lactobacillus rhamnosus and Lactobacillus acidophilus species, with two commercial probiotic strains in their tolerance to acid and bile. The association between the data obtained from the methods was studied. The results of the different methods applied in this study, did not confirm each other for all the examined strains. However, the native strain of L. plantarum and the commercial strain of L. acidophilus repeatedly demonstrated the most and least bile resistances, respectively. The former excelled in all growth approaches but showed moderate acid resistance in the survival studies. Bile stress seemed to have more detrimental effects on all examined strains. The overall results suggest that the growth-rate designed studies and survival studies evaluating transit tolerance, might bring up different results when the examined strains belong to different species of lactobacilli showing different growth and metabolic activities. The strain of L. plantarum examined here could thus be considered as a potential probiotic, regarding its overall resistance to acid and bile

Effect of a probiotic mixed culture on texture profile and sensory performance of Minas fresh cheese in comparison with the traditional products / Efeito de uma cultura probiótica mista sobre o perfil de textura e o desempenho sensorial de queijo Minas frescal, em comparação aos produtos tradicionais

The effect of a mixed probiotic culture on instrumental texture, and on sensorial and related properties of Minas fresh cheese during refrigerated storage was investigated. Three cheese-making trials were prepared: T1, with the traditional type O starter culture (Lactococcus lactis subsp. lactis + L. lactis subsp. cremoris), T2 with only lactic acid and T3, with lactic acid and the probiotic ABT culture (Lactobacillus acidophilus La-5 + Bifidobacterium animalisBb-12 + Streptococcus thermophilus). Instrumental texture profile analysis and related properties were monitored during storage for up to 21 days. Lb. acidophilus and B. animalis were present in high levels throughout storage of cheeses T3, above 6 log cfu.g-1, threshold required for probiotic activity, and stimulation of the La-5 growth was observed. Cheeses with added probiotic ABT culture, as well as those made adding lactic acid only, showed to be less brittle and with more favorable sensorial features, due to higher pH values. Results indicated that the use of probiotic ABT culture complementary to lactic acid for the purpose of substituting the type O (Lc. lactis subsp. lactis + Lc. lactis subsp. cremoris) culture, traditionally employed for Minas cheese production, is advantageous.

Efeito de uma cultura probiótica mista sobre o perfil de textura e o desempenho sensorial de queijo Minas frescal, em comparação aos produtos tradicionais. O presente trabalho investigou o efeito de uma cultura probiótica mista sobre a textura instrumental, as características sensoriais e as propriedades relacionadas de queijoMinas frescal durante seu armazenamento refrigerado. Três variáveis de elaboração de queijo Minas frescal foram estudadas: T1, empregando-se a cultura lática mesofílica tradicional tipo O (Lactococcus lactis subsp. lactis + L. lactis subsp. cremoris), T2,produzido somente com ácido lático e T3, empregando-se ácido lático e a cultura probiótica ABT (Lactobacillus acidophilus La-5 + Bifidobacterium animalis Bb-12 + Streptococcus thermophilus). O perfil de textura instrumental e as propriedades relacionadas foram monitorados durante 21 dias de armazenamento dos queijos. As populações de Lb. acidophilus e de B. animalis estiveram elevadas durante o armazenamento do queijo T3, acima de 6 log UFC.g-1,população mínima requerida para apresentar efeito probiótico, e foiobservado um estímulo da multiplicação de La-5. Os queijos produzidos com a cultura probiótica ABT, assim como aqueles somente com ácido lático, apresentaram-se menos frágeis e com atributos sensoriais mais favoráveis, devido ao pH mais elevado. Os resultados indicaram ser vantajoso o emprego da cultura probiótica ABT complementarmente ao ácido lático para o propósito de substituição da cultura tipo O (Lc. lactis subsp. lactis + Lc. lactis subsp. cremoris), tradicionalmenteempregada para a produção de queijo Minas frescal.

Regulación de la microbiota intestinal en voluntarios sanos mediante el consumo de un producto con el probiotico Lactobacillus johnsonii La1 / Regulation of the intestinal microbiota of healthy volunteers through the intake of the probiotic lactobacillus johnsonii la1

A basic mechanism implicated in the human health-promoting properties of probiotics is their ability to maintain the homeostasis of the intestinal microbiota. This study evaluates how the ingestion of different amounts of the probiotic Lactobacillus johnsonii La1 (La1) influences the main bacterial populations of the fecal microbiota. Eight asymptomatic volunteers participated in the study. After a basal period, they ingested 100 mL of a product containing 10(8) La1/mL during the first week, 200 mL during the second week and 500 ml during the third week. Fecal samples were obtained at the end of each period and during the 2 weeks post-ingestion. Lactobacilli were determined by culture on MRS agar and La1 colonies were confirmed by ERIC-PCR. The main populations of fecal bacteria were identified by fluorescent probes and flow cytometry. At baseline, 18.3 percent of the total fluorescent bacteria were F. praunitzii, 13.2 percent Bacteroides, 2.05 percent Bifidobacterium and 0.95 percent Lactobacillus. Fecal excretion of La1 increased during the ingestion period but it was cleared from the stools of the volunteers 2 weeks later. La1 intake increased the populations of Lactobacillus (p=0.056) and Bifidobacterium (p=0.067), which are considered as beneficial for the host, while it decreased those of F. prausnitzii (p=0.005) a potentially pathogenic microorganism. These bacterial populations returned to their baseline levels during the post-ingestion period. The regular intake of a La1-containing product beneficially affects the homeostasis of the human fecal microbiota probably contributing to the health-promoting effects of this probiotic.

Uno de los principales mecanismos implicados en las propiedades saludables de los probióticos es su capacidad de mantener la homeostasis de la microbiota intestinal. Este estudio evalúa cómo el consumo de distintas cantidades del probiótico Lactobacillus johnsonii La1 (La1) contribuye en la modulación de las principales poblaciones de la microbiota fecal. Ocho voluntarios asintomáticos participaron en el estudio. Después de un periodo basal, consumieron 100 mL de un producto que contenía 10(8) La1/mL durante la primera semana, 200 mL durante la segunda semana y 500 mL durante la tercera semana. Se obtuvieron muestras de deposición al final de cada uno de estos períodos y luego a los 7 y 14 días de haber terminado el consumo del producto. Las cantidades de lactobacilos excretados fueron determinadas por cultivo en agar MRS y las colonias de La1 fueron confirmadas por ERIC-PCR. Algunas de las principales poblaciones de bacterias fecales fueron evaluadas por hibridación in situ con sondas fluorescentes (FISH) y citometría de flujo. A nivel basal, 18.3 por ciento del número total de bacterias fluorescentes detectadas eran F. praunitzii,13.2 por ciento Bacteroides, 2.05 por ciento Bifidobacterium y 0.95 por ciento Lactobacillus. La excreción fecal de La1 aumentó durante el período de consumo pero desapareció después de 14 días de haber terminado el período de ingestión. El consumo de La1 aumentó las poblaciones de Lactobacillus (p=0.056) y Bifidobacterium (p=0.067) que son consideradas como beneficiosas para el huésped mientras que disminuyó aquella de F. prausnitzii (p=0.005), un microorganismo potencialmente patogénico. Las poblaciones bacterianas afectadas volvieron a sus niveles basales durante el periodo post-ingestión. Estos resultados indican que el consumo regular de La1 modula la homeostasis de la microbiota intestinal, lo cual contribuye probablemente a los efectos beneficiosos de este probiótico sobre la salud.

Evaluación de la actividad de cultivos probióticos sobre Listeria monocytogenes durante la producción y almacenamiento de yogur / Evaluation of the activity of probiotic cultures over Listeria monocytogenes during the production and storage of yogurt

The effect of probiotic cultures over Listeria monocytogenes during the production and storage of yogurt was evaluated. A yogurt mixture (10.6 per cent non-fat solid liquids, 3 per cent fat and 0.3 per cent gelatin) was prepared, homogenized and pasteurized. Yogurt was inoculated with 0, 10(2), 10(4) and 10(6) CFU/mL of L. monocytogenes and 0.02 per cent of traditional lactic culture YC 180 (Streptococcus thermophilus and Lactobacillus bulgaricus) and probiotic culture ABY-1 (Bifidobacterium longum, B. bifidum, B, infantis, Lactobacillus acidophilus, Streptococcus thermophilus y Lactobacillus delbrueckii subsp. bulgaricus). It was incubated for 3 h at 43 degrees C until pH reached an approximate value of 4.8, followed by refrigeration at 5 degrees C for 21 days. During fermentation, samples were taken every hour, and during storage every 3 days, analyzing pH and lactic, bifidobacteria and pathogen count for each time. It was demonstrated that there was no significant simple effect for the type of culture used (ABY-1 and YC 180) (p = 0.684) over the amount of L. monocytogenes present in yogurt during the fermentation and storage periods. The presence of bifidobacteria in the ABY-1 culture did not present a significant effect over L. monocytogenes. Neither the effect of time presented a significant effect over L. monocytogenes (p = 0.448). In this case, the ABY-1 and YC 180 cultures present a bacteriostatic effect over the pathogen. The probiotic cultures had a bacteriostatic but not bactericidal effect over L. monocytogenes. This is not related to the protective effect of these cultures in bowel, since in-vivo conditions favor the production of antimicrobial substances, such as bacteriocins that act over pathogens.

Role of non-H2O2 producing lactobacilli and anaerobes in normal and complicated pregnancy.

Lactobacilli (Doederlein's bacilli) are the most important predominant protective agents of the vaginal microbial ecosystem and alteration in vaginal pH directly speculates the concentration of lactobacilli. Currently, recognition of anaerobic lactobacilli (non-H2O2 producing lactobacilli) had further raised its significance. Therefore, the present study was aimed to explore the role of non-H2O2 lactobacilli and its association with other anaerobes in 100 cases of complicated pregnancy, 75 cases of normal pregnancy and 35 cases in non-pregnant women. Vaginal and cervical swabs were obtained and were inoculated in special and suitable media. Anaerobic lactobacilli (non-H2O2 producing) were more common genital microbes in women of complicated pregnancy (56.0%) than in normal pregnancy (34.7%) and in control group (14.2%). Rate of recovery of non-H2O2 producing lactobacilli increased when pathogenic bacteria especially anaerobes dominate the genital microflora. Anaerobic lactobacilli were seen in higher numbers when they were associated with bacteroides sp and other anaerobes. They were significantly reduced when aerobes predominated in flora; the correlation have been discussed.

Avaliaçäo do método de plaqueamento em gotas para contagem de microrganismos em alimentos / Evaluation of the drop plate count method for the microbial enumeration in foods

Foi feita uma avaliaçäo do método de plaqueamento em gotas, comparado com o plaqueamento em superfície e em profundidade, para verificar a concordância entre os resultados obtidos pelos três métodos. Näo foi observada diferença significativa para qualquer dos microrganismos ou alimentos testados

Obstipaçäo na prática pediátrica: importância da flora anaeróbia

No presente trabalho, o autor salienta a grande freqüência da obstipaçäo na criança, especialmente de bom nível econômico da clínica particular. Analisa suas causas principais, a sintomatologia e dá relevo especial ao papel da flora anaeróbia na fisiopatologia enterocólica e suas possíveis complicaçöes, particularmente as infecciosas

Preferential utilization of glucose during batch fermentation of whey by Lactobacillus bulgaricus

Em fermentaçöes descontínuas, por Lactobacillus bulgaricus, de soro de leite näo esterilizado, foram observadas duas fases. Na primeira, a lactose foi hidrolisada pela bactéria e a glicose foi imediatamente fermentada, acumulando-se galactose no meio em fermentaçäo. Na segunda fase, a galactose foi assimilada pelo microrganismo. Somente no começo da primeira fase observou-se crescimento celular