Solid state fermentation to obtain vegetable products bio-enriched with isoflavone aglycones using lactic cultures / Fermentación en sustrato sólido utilizando cultivos lácticos para la obtención de productos vegetales bioenriquecidos con isoflavonas agliconas

The consumption of soybean isoflavones (IS) is associated with several beneficial properties on human health. Some lactic acid bacteria possess ß-glucosidase enzyme, that allows to obtain the active form of IS (aglycone). The solid state fermentation (SSF) has received great attention in the last years in order to obtain several valuable compounds. SSF, using soybean as substrate and Lactobacillus rhamnosus CRL 981 as starter, was studied in the present work. Sucrose was added into soybean paste to study the effect on the behavior of the selected strain. The development of L. rhamnosus CRL 981 through pH and recount measures, sugar intake, organic acid production, ß-glucosidase activity and IS conversion were analyzed. No significant differences in growth and acidity were observed between soybean pastes with and without sucrose added, but the production of lactic acid was higher in the latter paste. The ß-glucosidase activity was detected in both pastes and the complete hydrolysis of IS at 12 h of fermentation was observed. Also, this strain was able to increase the free amino acids in soybean paste. SSF, using soybean as substrate and L. rhamnosus CRL 981 as starter culture, is an alternative process to obtain a soybean product bio-enriched in active IS with attractive nutritional characteristics.

El consumo de isoflavonas de soja (IS) está asociado a diversos beneficios para la salud humana. Ciertas bacterias lácticas poseen la enzima ß-glucosidasa, que permite obtener la forma bioactiva (agliconas) de las IS. La fermentación en sustrato sólido (FSS) ha recibido gran atención en los últimos anos debido a sus numerosas ventajas, y permite la obtención de productos con valor agregado. En el presente trabajo se estudió la FSS utilizando soja como sustrato y Lactobacillus rhamnosus CRL981 como cultivo iniciador. Con el fin de estudiar el efecto de una fuente de carbono externa sobre el comportamiento de la cepa seleccionada, se adicionó sacarosa a la pasta de soja. Se evaluó el crecimiento de L. rhamnosus CRL 981 a través de medidas de pH y recuento en placa. Además, se analizó el consumo de azúcares, producción de ácidos orgánicos, actividad ß-glucosidasa y conversión de IS. No se observaron diferencias significativas en el crecimiento y acidez entre las pastas de soja sin adición de sacarosa y con ella, sin embargo, la producción de ácido láctico fue mayor en esta última. La actividad de ß-glucosidasa se detectó en ambas pastas y se observó la hidrólisis completa de IS a las 12 h de fermentación. Además, esta cepa fue capaz de aumentar los aminoácidos libres en la pasta de soja. La FSS, utilizando soja como sustrato y L. rhamnosus CRL 981 como cultivo iniciador, es un proceso alternativo para obtener un producto de soja bioenriquecido en IS bioactivas con características nutricionales atractivas.

Draft genome sequence of alcohol-tolerant bacteria Pediococcus acidilactici strain K3

Abstract Pediococcus acidilactici strain K3 is an alcohol-tolerant lactic acid bacterium isolated from nuruk, which is a traditional Korean fermentation starter for makgeolli brewing. Draft genome of this strain was approximately 1,991,399 bp (G+C content, 42.1%) with 1525 protein-coding sequences (CDS), of which 44% were assigned to recognized functional genes. This draft genome sequence data of the strain K3 will provide insights into the genetic basis of its alcohol-tolerance.

Lactobacillus plantarum BL011 cultivation in industrial isolated soybean protein acid residue

Abstract In this study, physiological aspects of Lactobacillus plantarum BL011 growing in a new, all-animal free medium in bioreactors were evaluated aiming at the production of this important lactic acid bacterium. Cultivations were performed in submerged batch bioreactors using the Plackett-Burman methodology to evaluate the influence of temperature, aeration rate and stirring speed as well as the concentrations of liquid acid protein residue of soybean, soy peptone, corn steep liquor, and raw yeast extract. The results showed that all variables, except for corn steep liquor, significantly influenced biomass production. The best condition was applied to bioreactor cultures, which produced a maximal biomass of 17.87 g L-1, whereas lactic acid, the most important lactic acid bacteria metabolite, peaked at 37.59 g L-1, corresponding to a productivity of 1.46 g L-1 h-1. This is the first report on the use of liquid acid protein residue of soybean medium for L. plantarum growth. These results support the industrial use of this system as an alternative to produce probiotics without animal-derived ingredients to obtain high biomass concentrations in batch bioreactors.

L-(+)-Lactic acid production by Lactobacillus rhamnosus B103 from dairy industry waste

ABSTRACT Lactic acid, which can be obtained through fermentation, is an interesting compound because it can be utilized in different fields, such as in the food, pharmaceutical and chemical industries as a bio-based molecule for bio-refinery. In addition, lactic acid has recently gained more interest due to the possibility of manufacturing poly(lactic acid), a green polymer that can replace petroleum-derived plastics and be applied in medicine for the regeneration of tissues and in sutures, repairs and implants. One of the great advantages of fermentation is the possibility of using agribusiness wastes to obtain optically pure lactic acid. The conventional batch process of fermentation has some disadvantages such as inhibition by the substrate or the final product. To avoid these problems, this study was focused on improving the production of lactic acid through different feeding strategies using whey, a residue of agribusiness. The downstream process is a significant bottleneck because cost-effective methods of producing high-purity lactic acid are lacking. Thus, the investigation of different methods for the purification of lactic acid was one of the aims of this work. The pH-stat strategy showed the maximum production of lactic acid of 143.7 g/L. Following purification of the lactic acid sample, recovery of reducing sugars and protein and color removal were 0.28%, 100% and 100%, respectively.

Evaluation of caries-associated virulence of biofilms from Candida albicans isolated from saliva of pediatric patients with sickle-cell anemia

A previous study demonstrated that the amount of Candida spp. in saliva is higher in children with sickle-cell disease. The results from a recent study demonstrate its participation in the etiology of dental caries. Objective This study assessed caries-associated virulence (production of acid, extracellular polysaccharides, proteins and metabolic activity) of biofilms from Candida albicans isolated from saliva of patients with sickle-cell anemia in comparison to isolates obtained from matched healthy children. Material and Methods The isolates were previously obtained from 25 children (4-6 years) and their matched controls (healthy children). One isolate of C. albicans per children was used, totaling 25 isolates per group. The C. albicans biofilms were grown for five days and analyzed regarding the production of lactic acid, extracellular polysaccharides, proteins and metabolic activity. The production of lactic acid was determined by the enzymatic method. The concentration of extracellular polysaccharides was determined by the phenol-sulphuric acid method, and the concentration of the protein was analyzed using the QuantiPro BCA kit. The XTT reduction was used to verify the metabolic activity. The data were analyzed with GraphPad Prism at 5%. Results The Mean±standard deviation for acid production, extracellular polysaccharides, proteins and metabolic activity of isolates from sickle-cell group was, respectively: 7.1±5.0 mmol/L; 15.6±2.5 μg glucose/mg biofilm; 7,503±3,097 μg/mL; A490 3.5±0.7. For isolates from control group the values obtained were: 3.5±3.3 mmol/L; 12.8±3.4 μg glucose/mg biofilm; 4,995±682 μg/mL; A490 3.4±0.5. The C. albicans isolates from patients with sickle-cell anemia produced a significantly greater quantity of acids (p=0.025), polysaccharides (p=0.025) and proteins (p=0.047) compared with the isolates from control group. However, there was ...

Potential use of lactobacillus casei TISTR 1500 for the bioconversion from palmyra sap and oil palm sap to lactic acid

Lactic acid is a product that finds several applications in food, cosmetic, pharmaceutical and chemical industries. The main objective of this work is to evaluate potential use of the sap from palmyra (Borassus flabellifer Linn.) and oil palm (Elaeis guineensis) as substrate for lactic acid production by Lactobacillus casei TISTR 1500. The effects of acid hydrolysis, pH control and nutrient supplement of palmyra sap and oil palm sap on fermentation performance were investigated. It was found that lactic acid fermentation using palmyra sap was not significantly affected by either acid hydrolysis or pH control. The addition of MRS increased biomass and product yield. The final lactic acid concentration, dry cell weight and productivity were increased by increasing the total sugars of palmyra sap concentrations up to 134.0 g L-1. The kinetic parameters for the palmyra sap at 134.0 g L-1 total sugars were calculated to be of: specific growth rate (u) 0.05 h-1, the maximum productivity (R M) 2.02 g lactic acid L-1 h-1, cellular yield coefficient (Y X/S) 0.20 g cell g-1 sugar, and lactic acid yield (Y P/S) 0.78 g g-1. When oil palm sap was used as carbon source for L. casei TISTR 1500, pH control did not significantly affect lactic acid production. The addition of MRS medium into oil palm sap improved the biomass and the product yield for which the lactic acid production in static flask at 37ºC and pH 5.5 using 20 g L-1 of total sugars was improved to be of 0.55 g L-1 h-1. Oil palm sap could be served as a good potential source of raw materials for efficient production of lactic acid by L. casei TISTR 1500.

Improved growth model for two-stage continuous cultures of Lactobacillus helveticus

An unstructured model for growth and lactic acid production during two-stage continuous cultures of Lactobacillus helveticus was previously developed. The Verlhust model was considered to describe growth kinetics. Production models was based on modified Luedeking-Piret expressions involving an inhibitory effect for the first stage (seed culture) and a nutritional limitation effect for the second stage (culture). To account for the decrease of the biomass concentration observed in the second stage, the dilution rate Dc was replaced by an exponential term of the dilution rate (alpha exp (Dc/beta)) in the growth and product relations. Contrarily to the previous model, the important decrease of the biomass concentration observed at steady state in the second stage at high dilution rates, namely close to wash out, was correctly described by the new model. It also proved to satisfactory describes production data and volumetric productivity.

Qualidade de leites fermentados funcionais elaborados a partir de bactérias ácido-lácticas isoladas de queijo de coalho / Quality of functional fermented milks produced by the use of lactic acid bacteria isolated from coalho cheese

Leites fermentados foram elaborados a partir de bactérias ácido-lácticas com propriedades funcionais, isoladas de queijo de coalho com e sem a adição de concentrado proteico de soro (CPS). Características físico-químicas, microbiológicas e sensoriais dos produtos elaborados foram analisadas durante 40 dias de estocagem sob refrigeração a 8-10ºC. Todos os leites fermentados elaborados, independentemente da adição de CPS e da cultura utilizada, apresentaram contagens adequadas de bactérias (>10(8)UFC/mL) durante todo o período de avaliação, o que garantiria seu possível potencial funcional. Leites fermentados por Lactobacillus acidophilus apresentaram melhor aceitação (P<0,05) pelos provadores aos 10 dias de estocagem; enquanto, aos 40 dias, o leite fermentado por Weissella confusa sem CPS resultou em pior aceitação (P<0,05). A associação de Lactobacillus acidophilus e Weissella confusa ou somente Lactobacillus acidophilus, independentemente da adição de CPS, seriam recomendados para elaboração industrial de novos leites fermentados potencialmente funcionais a partir de culturas lácticas brasileiras.

Fermented milks were produced using whey protein concentrate (WPC) and potentially functional lactic acid bacteria, which were isolated from coalho cheese produced in. Physical-chemical, microbiological, and sensorial characteristics of the fermented milks were analyzed during 40 days under refrigeration at 8-10ºC. All products, irrespectively of WPC adding or culture used, showed appropriated bacterial counts (>10(8)CFU/mL) throughout the evaluation time, which would guarantee their functional potential. Lactobacillus acidophilus fermented milks presented better sensorial approval (P<0.05) when evaluated at 10-day storage; while Weissella confusa fermented milks presented lower acceptance (P<0.05) at 40-day storage. The association of Lactobacillus acidophilus and Weissella confusa or Lactobacillus acidophilus isolatedly, irrespectively of WPC adding, should be recommended for the industrial elaboration of novel functional fermented milks using Brazilian lactic cultures as starters.

Solid substrate fermentation of cassava fibrous residue for production of alpha-amylase, lactic acid and ethanol.

There is serious concern about the disposal of solid residues left after large scale extraction of starch from cassava. Owing to the high starch content (55-65% on dry weight basis) and organic matter of these wastes, an attempt has been made to utilize it for the production of three bioproducts, i.e. alpha-amylase, lactic acid and ethanol in solid substrate fermentation by incubating the solid residue at different moisture holding capacity (40-80%) and incubation period (12- 60 hr for alpha-amylase, 24-144 hr for ethanol and 2-10 days for lactic acid). The highest product yield was obtained at 60% moisture holding capacity of the residue and period of incubation varied from 36 hr (alpha-amylase), 120 hr (ethanol) to 6 days (lactic acid). This study showed that the solid residues from cassava starch factories could serve as a low-cost substrate for bioproducts production.

Cell entrapment of Lactobacillus casei subsp. casei ATCC 39392 for lactic acid production

In this study, lactic acid production by repeated batch fermentation using cell entrapped methods was compared. Barium alginate beads, agar gel and polyurethane foam cubes were employed as carriers to immobilize Lactobacillus casei subsp. casei for the purpose of L [+]-lactic acid production. Increasing concentrations of lactic acid during fermentation were better tolerated by barium alginate entrapped cells. Alginate beads had a considerable effect on lactic acid production and reduced the fermentation time by half. The volumetric productivity with barium alginate and agar immobilized cells were 0.625 and 0.425 [g/lh] respectively, whereas it was 0.375 [g/lh for conventional free-cell fermentation. Beside biocompatibility, barium alginate immobilized cells exhibited good mechanical strength during repetitive fermentations and could be used in repetitive batch cultures for more than 40 days. The novelty of this study is lactic acid production by repeated batch fermentation with immobilized L. casei using polyurethane foam [PUF] in an economical culture medium composed of whey and corn steep liquor supplemented by glucose

Lactic acid production by a strain of Lactococcus lactis subs lactis isolated from sugar cane plants

A Lactococcus lactis subs lactis strain was selected from 20 lactic acid strains isolated from the leaves of sugar cane plants, variety CC 85-92. The effects of substrate concentration and pH control on lactic acid (LA) production, glucose conversion (GC) and yield (Yp/s) were investigated using this strain. In batch fermentation at 32ºC, with 60 gl-1 of glucose and a pH of 6.0, concentrations of up to 35 gl-1 of lactic acid were obtained. Maximum production and glucose conversion was achieved at low glucose concentrations. The strain shows great potential for lactic acid production from glucose, even without using pH control during fermentation (13.7 gl-1).

Isolation of adh mutant of Lactobacillus rhamnosus for production of L(+) Lactic acid

Lactobacillus rhamnosus, a facultative anaerobe, which produces L (+) lactic acid and ethanol under anaerobic conditions, is used in the present study. An adh- mutant of Lactobacillus rhamnosus MTCC 1408, was developed by chemical mutagenesis, which could produce pure L(+) lactic acid as the only product. Batch fermentation kinetics of the wild type and the mutant strain were studied in glucose-yeast extract medium under conditions of temperature 40ºC and pH 6.2 anaerobically. The biomass yield was similar in both wild type and mutant strains, however lactic acid yield increased by 6.6 percent. A chemically defined media was optimized for supplementation of succinate, acetate and citrate for better biomass formation using single variable optimisation. It was further optimised for varying concentrations of vitamins, amino acids and trace metals by response surface method. The batch biomass yield (0.1g/g) and lactic acid yield (0.88g/g) in the optimised chemically defined media were similar to those obtained in the glucose-yeast extract medium.

Evaluación de la flora bacteriana en un ensilado natural de maíz / Evaluation of the bacterial flora in natural corn silage

Silage is the best method for forage conservation, keeping it in a fresh condition and with high nutrient content. In order to study the natural evolution of maize silage without additives during 50 days after sealed, pH, temperature changes, number and type of the indigenous bacteria were studied every 5 days. The initial pH decreased from 6.40 to 4.10 and temperature stabilized at 26 degrees C. The mesophilic aerobic bacteria were quickly reduced across time. Enterococci were descended gradually. Clostridia remained in a low quantity. The microorganisms most frequently isolated were Escherichia coli, Clostridium butyricum, Enterococcus faecalis and Lactobacillus plantarum; this acid lactic bacteria was the principal cause of the abundant production of anaerobic fermentation of sugars in the forage reaching the pH which maintained the silage in adequate conditions.

Rat liver responsiveness to gluconeogenic substrates during insulin-induced hypoglycemia

Hepatic responsiveness to gluconeogenic substrates during insulin-induced hypoglycemia was investigated. For this purpose, livers were perfused with a saturating concentration of 2 mM glycerol, 5 mM L-alanine or 5 mM L-glutamine as gluconeogenic substrates. All experiments were performed 1 h after an ip injection of saline (CN group) or 1 IU/kg of insulin (IN group). The IN group showed higher (P<0.05) hepatic glucose production from glycerol, L-alanine and L-glutamine and higher (P<0.05) production of L-lactate, pyruvate and urea from L-alanine and L-glutamine. In addition, ip injection of 100 mg/kg glycerol, L-alanine and L-glutamine promoted glucose recovery. The results indicate that the hepatic capacity to produce glucose from gluconeogenic precursors was increased during insulin-induced hypoglycemia.

Acidosis láctica fatal en paciente con síndrome de inmunodeficiencia adquirido y tratamiento antiretroviral de alto grado de actividad: comunicación de un caso / Fatal lactic acidosis in a patient with acquired immunodeficiency syndrome treated with highly active antiretroviral therapy: case report

Type B lactic acidosis occurs without any evidence of cellular hypoxia and is associated with the use of drugs or toxins. We report a 36 years old woman with acquired immunodeficiency syndrome that was admitted to the hospital with a severe lactic acidosis. She had been treated with didanosine, stavudine and efavirenz for four months prior to admission. Despite the use of high bicarbonate doses and vasoactive drugs, the patient had a catastrophic evolution and died in shock and multiple organ failure, 68 hours after admission

Effect of FSH and insulin on lipogenesis in cultures of Sertoli cells from immature rats

Follicle-stimulating hormone (FSH) and insulin regulate glycide metabolism in Sertoli cells, thus stimulating lactate production. These stimulatory effects of FSH and insulin do not require protein synthesis, suggesting a modulation of enzyme activity and/or regulation of glucose transport. The present investigation was performed to characterize the hormonal control of lipid metabolism in Sertoli cells. The data indicate that FSH and insulin have a regulatory effect on lipid metabolism in Sertoli cells. After 8 h of preincubation with insulin (5 mug/ml), the activity of the enzyme ATP-citrate lyase in sultured Sertoli cells was increased from 0.19 to 0.34 nmol NAD+ formed mug protein(-1) min(-1). FSH (100 ng/ml) had no effect on this enzyme. Glycerol phosphate dehydrogenase activity was not affected by any of the hormones tested. When Sertoli cells from 19-day old rats were incubated with [1,2-14C] acetate for 90 or 360 min, the [14C] label was present predominantly in triglyceride and phospholipid fractions with minor amounts in other lipids. In Sertoli cells pretreated for 16 h with insulin and FSH, an increase in acetate incorporation into lipids was observed. Most of the label was in esterified lipids and this percentage increased with the time of treatment; this increase was remarkable in triglycerides of control cells (18.8 percent to 30.6 percent). Since Sertoli cell triglycerides participate in the control of spermatogenesis, the present data suggest that the hormonal control of lipid metabolism in Sertoli cells is important not only for maintaining the energy of the cell itself, but also for the control of the spermatogenesis process.