ABSTRACT
RESUMEN Leuconostoc mesenteroides pertenece a la familia Streptococcaceae. Son cocobacilos gram positivos, intrínsecamente resistentes a múltiples antibióticos por lo que las opciones de tratamiento pueden ser limitadas. Se presenta el caso de una mujer de 28 años que consultó por sensación febril, astenia y malestar general, se diagnostica leucemia linfoblástica aguda en la internación y posteriomente desarrolla choque séptico por bacteriemia a Leuconostoc mesenteroides.
ABSTRACT Leuconostoc mesenteroides belongs to the family Streptococcaceae. They are gram-positive coccobacilli, intrinsically resistant to multiple antibiotics, therefore treatment options may be limited. We present the case of a 28-year-old woman who consulted for febrile sensation, asthenia and malaise. Acute lymphoblastic leukemia was diagnosed during hospitalization and later the patient developed a septic shock due to Leuconostoc mesenteroides bacteremia.
ABSTRACT
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.
Subject(s)
Brassica , Fruit and Vegetable Juices , Lactobacillus plantarum , Lactobacillus , Leuconostoc , Solanum lycopersicum , Onions , Probiotics , VegetablesABSTRACT
OBJECTIVE: To analyze the microbial contamination and investigate the bacteriostatic efficacy of compound balloonflowers and ephedrine syrup(Ⅱ). METHODS: The compound balloonflowers and ephedrine syrup(Ⅱ) was analyzed for the bacteriostatic efficacy, content of bacteriostatic agent and C18 column was adopted with gradient elution. The mobile phase consisted of 0.02 mol•L-1 ammonium acetate solution and methanol. The detective wavelength was set at 255 nm. The contaminating bacteria detected in the samples were identified by VITEK2 Campact, MALDI-TOF-MS and 16S rRNA sequencing, and homology analysis was conducted for the contaminating bacteria in the samples from the same enterprise. RESULTS: The bacteriostatic efficacy of the products of one enterprise did not meet the requirements of Chinese Pharmacopoeia(2015 edition). There were excessive and uneven contamination of microorganisms in the samples. The dosages of bacteriostatic agents in some enterprises did not conform to the standard requirements. CONCLUSION: Production enterprises should strictly control the dosages of bacteriostatic agents and the stability of the production process, and strengthen the monitoring of the sterilization effect of the whole production process to improve product quality.
ABSTRACT
The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc/Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus, following by Lactobacillus sakei and Leuconostoc mesentereoides; the Enterococcus sp. was not present in the samples.
Subject(s)
Bacterial Load , Food Microbiology , Lactobacillales/classification , Lactobacillales/isolation & purification , Food Packaging , Temperature , Time Factors , VacuumABSTRACT
Se elaboró queso de cabra madurado empleando una cepa liofilizada de Leuconostoc mesenteroides como cultivo iniciador, aislada a partir de la flora natural de quesos de cabra, elaborados artesanalmente con leche cruda de cabra del municipio Torres, estado Lara, Venezuela. El proceso de maduración fue de 4 sem, a 14°C y 70% de humedad relativa. Durante el tiempo de maduración, se evaluaron semanalmente los cambios en pH, sólidos totales y parámetros de textura; mientras que el contenido de proteínas, se determinó al inicio y al final del estudio. Al finalizar la maduración, se realizó un estudio con consumidores para evaluar la aceptabilidad de los quesos obtenidos en comparación con un queso control inoculado con una cepa comercial. El contenido de sólidos totales disminuyó entre 23 y 31% a lo largo del estudio (p<0,05), el pH en 6%, mientras que el contenido proteico no registró cambios al final de la maduración. La dureza y gomosidad en los quesos se incrementaron entre 1,64 y 2N; y 0,72 y 0,83N, respectivamente, con la maduración; correlacionándose positivamente con la variación en sólidos totales (R²>0,90) para ambos quesos mientras que la adhesividad y cohesividad no registraron cambios importantes. En la evaluación sensorial, el queso elaborado con L. mesenteroides obtuvo una aceptabilidad promedio del 70%, al compararlo con un queso de cabra obtenido a partir de una cepa comercial de Lactococcus lactis.
A ripened goat cheese was developed using a lyophilized strain of Leuconostoc mesenteroides as starter culture. This strain was isolated from the natural flora of artisan goat cheese made with raw milk in the municipality of Torres, the State of Lara, Venezuela. The maturation process lasted 4 weeks, at 14°C and 70% relative humidity. During the ripening period, changes in pH, total solids, and texture parameters where registered every week, while protein content was determined at baseline and at the end of the study. After maturation was completed, its acceptability was assessed through a consumer test against a control cheese inoculated with a commercial strain. The total solids content fell between 23 and 31% throughout the study (p<0.05), the pH at 6%, while the protein content was unchanged at the end of ripening. The hardness and gumminess in cheese increased between 1,64 and 2N; and 0,72 and 0,83N, respectively, with maturation; their were positively correlated with the variation in total solids (R²>0,90) for both cheeses while adhesiveness and cohesiveness showed no major changes. In the sensory evaluation, the cheese made from L. mesenteroides obtained an average acceptability of 70%, when compared with a goat cheese obtained from a commercial strain of Lactococcus lactis.
ABSTRACT
Exopolysaccharides (EPS) from lactic acid bacteria (LAB) have many applications in food industry, and pharmaceutical field. To improve EPS production in Lactobacillus rhamnosus PN04 and Leuconostoc mesenteroides VTCC-B-643, these bacteria were co-cultured together. There were shape changes in Lactobacillus rhamnosus into curved rod. Their EPS were estimated after co-cultured. After ethanol precipitation method, the colorimetric method were done using phenol-sulfuric acid assay, the EPS from L. rhamnosus PN04 increased from 2.446 mg/l to 4.228 mg/l while Leuconostoc mesenteroides increased from 3.217 mg/l to 4.712 mg/l. By SDS-PAGE analysis in both straight and curved Lactobacillus rhamnosus, there were the expressed proteins with the estimated molecular weight of 14, 60, 66 kDa while the curved Lactobacillus rhamnosus showed another proteins with molecular weight of 14, 20, 31, 45, 60, 66, 95 kDa. The results suggested that there were the interaction between two these strains. This is the first report showed there were differences in EPS production and protein expression after co-culture of Lactobacillus rhamnosus PN04 and Leuconostoc mesenteroides VTCC-B-643.
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Das sementes da mamona extrai-se o óleo de rícino, utilizado in natura ou em sua forma modificada nas áreas médica, farmacêutica e industrial. Um de seus derivados químicos - o Poliquilgerm® - evidencia propriedades antifúngicas sobre Candida albicans e bacteriostática/ bactericida sobre Escherichia coli no nível de 99,9%. Considerando-se essas propriedades, aplicouse o Poliquilgerm® em culturas de Leuconostoc mesenteroides, uma das espécies de bactéria contaminante dos mostos em indústrias sucroalcooleiras. Esta bactéria quando presente em mostos produz além do ácido láctico, a dextrana, que é um polímero da glicose que aumenta a viscosidade dos fluidos dos processos. No presente trabalho avaliou-se o efeito de diferentes concentrações do Poliquilgerm® sobre a viscosidade produzida por L. mesenteroides em diferentes meios de cultivo, condições de pH, e temperatura. Verificou-se 20,56% de diminuição da viscosidade quando se utilizou 1,0% do produto, além da inibição do crescimento da bactéria após 20 horas em contato com 1,0 e 0,2% de Poliquilgerm®. L. mesenteroides apresentou melhor crescimento em valores de pH 6,0, tanto a 28 como a 33º C, evidenciado pela maior produção de biomassa. Além disso, em meio de cultura neste pH verificou-se maior porcentagem de diminuição da viscosidade em ambas as concentrações utilizadas. Estas mesmas concentrações alcançaram até 100% de diminuição das UFC/mL após 24 horas em contato com o produto, evidenciado por quantificação da biomassa e confirmado mediante plaqueamento pela técnica "Pour Plate".
Castor-oil, extracted from seeds of Ricinus communis L., is normally used in natura or in its modified form in the medical, pharmaceutical and industrial areas. One of its chemical derivates Poliquilgerm® has shown antifungal properties on Candida albicans, and bacteriostatic/bactericide effects on Escherichia coli reaching 99.9%. Considering these features, in the present study Poliquilgerm® was applied in cultures of Leuconostoc mesenteroides, a frequent contaminant bacterium of musts in the sugar and alcohol industries. This bacterium, when a contaminant of must, produces lactic acid as well as dextran, a polymer of glucose which may increase the viscosity of fluids in the operation. The present study evaluated the effect of different concentrations of Poliquilgerm® on viscosity produced by L. mesenteroides cultures under different conditions of various culture media, pH and temperature. A 20.56% decrease in viscosity was verified when 1.0% of the product was used, and bacterium growth inhibition after 20 hours in media with 1.0 and 0.2% of Poliquilgerm®. L. mesenteroides showed a higher growth rate in pH 6.0, at both 28 and 33º C, evidenced by greater biomass production. Also, in the culture media at this pH a greater decrease in viscosity percentages was verified at both concentrations used. The media with these same concentrations reached up to 100% decrease of UFC/mL after 24 hours in the presence of the product, observed by biomass quantification and confirmed by the Pour Plate technique.