RESUMEN
Lignan, a beneficial constituent of Flaxseed (Linum usitatissimum L.) showed great interest in researchers because of its multiple functional properties. Nonetheless, a challenge arises due to the glycosidic structure of lignans, which the gut epithelium cannot readily absorb. Therefore, we screened 18 strains of Lactiplantibacillus plantarum, Lacticaseibacillus casei, Lactobacillus acidophilus, Lacticaseibacillus rhamnosus, Pediococcus pentosaceus, Pediococcus acidilactici, and Enterococcus durans to remove glycosides from flaxseed lignan extract enzymatically. Among our findings, Lactiplantibacillus plantarum SCB0151 showed the highest activity of ß-glucosidase (8.91 ± 0.04 U/mL) and higher transformed efficiency of Secoisolariciresinol (SECO) (8.21 ± 0.13%). The conversion rate of Secoisolariciresinol diglucoside (SDG) and the generation rate of SECO was 58.30 ± 3.78% and 32.13 ± 2.78%, respectively, under the optimized conditions. According to the LC-HRMSMS analysis, SECO (68.55 ± 6.57 µM), Ferulic acid (FA) (32.12 ± 2.50 µM), and Coumaric acid (CA) (79.60 ± 6.21 µM) were identified in the biotransformation products (TP) of flaxseed lignan extract. Results revealed that the TP exhibited a more pronounced anti-inflammatory effect than the flaxseed lignan extract. SECO, FA, and CA demonstrated a more inhibitory effect on NO than that of SDG. The expression of iNOS and COX-2 was significantly suppressed by TP treatment in LPS-induced Raw264.7 cells. The secretion of IL-6, IL-2, and IL-1ß decreased by 87.09 ± 0.99%, 45.40 ± 0.87%, and 53.18 ± 0.83%, respectively, at 60 µg/mL of TP treatment. Given these data, the bioavailability of flaxseed lignan extract and its anti-inflammatory effect were significantly enhanced by Lactiplantibacillus plantarum SCB0151, which provided a novel approach to commercializing flaxseed lignan extract for functional food.
Asunto(s)
Lino , Glucósidos , Lignanos , Lino/química , Lino/metabolismo , Fermentación , Lignanos/farmacología , Lignanos/química , Lignanos/metabolismo , Glicósidos , Butileno Glicoles/metabolismo , Extractos Vegetales/farmacología , Extractos Vegetales/química , Antiinflamatorios/farmacologíaRESUMEN
As a valuable platform chemical, 2,3-Butanediol (2,3-BDO) has a variety of industrial applications, and its microbial production is particularly attractive as an alternative to petroleum-based production. In this study, the regulation of intracellular carbon flux and NADH/NAD+ was used to increase the 2,3-BDO production of Enterobacter aerogenes. The genes encoding lactate dehydrogenase (ldh) and pyruvate formate lyase (pfl) were disrupted using the λ-Red recombination method and CRISPR-Cas9 to reduce the production of several byproducts and the consumption of NADH. Knockout of ldh or pfl increased intracellular NADH/NAD+ by 111 % and 113 %, respectively. Moreover, two important genes in the 2,3-BDO biosynthesis pathway, acetolactate synthase (budB) and acetoin reductase (budC), were overexpressed in E. aerogenes to further amply the metabolic flux toward 2,3-BDO production. And the overexpression of budB or budC increased intracellular NADH/NAD+ by 46 % and 57 %, respectively. In shake-flask cultivation with sucrose as carbon source, the 2,3-BDO titer of the IAM1183-LPBC was 3.55 times that of the wild type. In the 5-L fermenter, the maximal 2,3-BDO production produced by the IAM1183-LPBC was 2.88 times that of the original strain. This work offers new ideas for promoting the biosynthesis of 2,3-BDO for industrial applications.
Asunto(s)
Acetolactato Sintasa , Enterobacter aerogenes , Liasas , Petróleo , Acetolactato Sintasa/metabolismo , Butileno Glicoles/metabolismo , Carbono/metabolismo , Ciclo del Carbono , Enterobacter aerogenes/genética , Enterobacter aerogenes/metabolismo , Fermentación , Formiatos , L-Lactato Deshidrogenasa/genética , Ingeniería Metabólica/métodos , NAD/metabolismo , Piruvatos , SacarosaRESUMEN
Pinoresinol/lariciresinol reductase (PLR), an NADPH-dependent reductase that catalyzes the sequential reduction of pinoresinol into secoisolariciresinol via Lariciresinol, can lead to the structural and stereochemical diversity of lignans. The relationship between substrate-selective reaction of PLR and sequence homology still remains unclear. In this study, we focused on the contribution of the variable region between PLRs in determining substrate selectivity. Here, two CsPLRs (CsPLR1 and CsPLR2) were identified in the tea plant (Camellia sinensis var. sinensis cv. Shuchazao). In vitro enzymatic assays showed that CsPLR1 could convert (+)- and (-)-pinoresinol into lariciresinol or secoisolariciresinol, whereas CsPLR2 catalyzed (+)-pinoresinol enantioselectively into (-)-secoisolariciresinol. Homology modeling and site-directed mutagenesis were used to examine the role of a variable loop in catalysis and substrate selectivity. The L174I mutant in CsPLR1 lost the capacity to reduce either (+)- or (-)-pinoresinol but retained the ability to catalyze the reduction of (-)-lariciresinol. These findings provide a basis for better understanding of the substrate-selective reaction of PLR.
Asunto(s)
Camellia sinensis/enzimología , Oxidorreductasas/química , Oxidorreductasas/metabolismo , Butileno Glicoles/metabolismo , Furanos/metabolismo , Lignanos/metabolismo , Mutagénesis Sitio-Dirigida , Oxidorreductasas/genética , Homología de Secuencia de Aminoácido , Especificidad por SustratoRESUMEN
N-acyl-homoserine lactone quorum sensing (AHL-QS) has been shown to regulate many physiological behaviors in Serratia marcescens MG1. In the current study, the effects of AHL-QS on the biosynthesis of acid and neutral products by S. marcescens MG1 and its isogenic ∆swrI with or without supplementing exogenous N-hexanoyl-L-homoserine lactone (C6-HSL) were systematically investigated. The results showed that swrI disruption resulted in rapid pH drops from 7.0 to 4.8, which could be restored to wild type by supplementing C6-HSL. Furthermore, fermentation product analysis indicated that ∆swrI could lead to obvious accumulation for acidogenesis products such as lactic acid and succinic acid, especially excess acetic acid (2.27 g/l) produced at the early stage of fermentation, whereas solventogenesis products by ∆swrI appeared to noticeably decrease by an approximate 30% for acetoin during 32-48 h and by an approximate 20% for 2,3-butanediol during 24-40 h, when compared to those by wild type. Interestingly, the excess acetic acid produced could be removed in an AHL-QS-independent manner. Subsequently, quantitative real-time PCR was used to determine the mRNA expression levels of genes responsible for acidogenesis and solventogenesis and showed consistent results with those of product synthesis. Finally, by close examination of promoter regions of the analyzed genes, four putative luxI box-like motifs were found upstream of genes encoding acetyl-CoA synthase, lactate dehydrogenase, α-acetolactate decarboxylase, and Lys-like regulator. The information from this study provides a novel insight into the roles played by AHL-QS in switching from acidogenesis to solventogenesis in S. marcescens MG1.
Asunto(s)
Acil-Butirolactonas/farmacología , Metabolismo de los Hidratos de Carbono/efectos de los fármacos , Fermentación , Percepción de Quorum , Serratia marcescens/efectos de los fármacos , Serratia marcescens/metabolismo , Ácido Acético/metabolismo , Acetoína/metabolismo , Proteínas Bacterianas/genética , Biomasa , Butileno Glicoles/metabolismo , Metabolismo de los Hidratos de Carbono/genética , Carboxiliasas/genética , Perfilación de la Expresión Génica , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Genes Bacterianos/genética , Glucosa/metabolismo , Concentración de Iones de Hidrógeno , L-Lactato Deshidrogenasa/genética , Ácido Láctico/metabolismo , Redes y Vías Metabólicas/efectos de los fármacos , Redes y Vías Metabólicas/genética , ARN Mensajero/metabolismo , Alineación de Secuencia , Serratia marcescens/genética , Serratia marcescens/crecimiento & desarrollo , Ácido Succínico/metabolismo , Factores de TiempoRESUMEN
The present study aims to develop a process for the production of 2,3-butanediol by Simultaneous Saccharification and Fermentation (SSF) of Oil Palm Front (OPF) biomass. The study compares SSF with Separate Hydrolysis and Fermentation (SHF) of oil palm biomass and batch fermentation using glucose. The results showed that SSF is one of the most attractive techniques for the microbial production of 2,3-butanediol using lignocellulosic biomass. The enzymatic digestibility and fermentative efficiency of alkali pre-treated OPF biomass was checked and the role of various experimental parameters like enzyme loading and inoculum loading were optimized. SSF experiments could give 30.74â¯g/l of BDO in shake flask and 12.53â¯g/l in 500â¯ml bioreactor with a productivity of 0.32 and 0.13â¯g/l/h respectively.
Asunto(s)
Butileno Glicoles/metabolismo , Fermentación , Aceite de Palma/metabolismo , Biomasa , Reactores Biológicos , Metabolismo de los Hidratos de Carbono , Hidrólisis , Aceite de Palma/químicaRESUMEN
Phytoestrogens are plant-derived polyphenols with structural and functional similarities to mammalian oestrogens. The aim of this work was to study the metabolism of phytoestrogens by children's intestinal microbiota and to compare it with previous results in adults. Faecal samples of 24 healthy children were subjected to phytoestrogen fermentation assay. Only one child produced equol, while O-desmethylangolensin was found in all. Urolithin production was detected in 14 children and enterolactone in 10. Further comparison with the metabolism of phytoestrogens by adult intestinal microbiota reflected that glycitein, dihydrogenistein, urolithins D and E, enterolactone, secoisolariciresinol and arctigenin were the most important metabolites differentiating between adult and child microbial gut metabolism. Although the child intestinal microbiota showed the ability to metabolise isoflavones, ellagitannins and lignans to a certain extent, it generally showed a reduced metabolism of phytoestrogens, with a lack of 5-hydroxy equol and enterodiol, and less urolithins and enterolactone producers.
Asunto(s)
Microbioma Gastrointestinal , Fitoestrógenos/metabolismo , 4-Butirolactona/análogos & derivados , 4-Butirolactona/metabolismo , Adulto , Butileno Glicoles/metabolismo , Estudios de Casos y Controles , Preescolar , Cumarinas/metabolismo , Equol/metabolismo , Heces/microbiología , Femenino , Furanos/metabolismo , Humanos , Taninos Hidrolizables/metabolismo , Lactante , Isoflavonas/metabolismo , Lignanos/metabolismo , Masculino , Polifenoles/metabolismoRESUMEN
A Bacillus sp. strain named BRC1 is capable of producing 2,3-butanediol (2,3-BD) using hydrolysates of the Jerusalem artichoke tuber (JAT), a rich source of the fructose polymer inulin. To enhance 2,3-BD production, we undertook an extensive analysis of the Bacillus sp. BRC1 genome, identifying a putative gene (sacC) encoding a fructan hydrolysis enzyme and characterizing the activity of the resulting recombinant protein expressed in and purified from Escherichia coli. Introduction of the sacC gene into Bacillus sp. BRC1 using an expression vector increased enzymatic activity more than twofold. Consistent with this increased enzyme expression, 2,3-BD production from JAT was also increased from 3.98 to 8.10 g L-1. Fed-batch fermentation of the recombinant strain produced a maximal level of 2,3-BD production of 28.6 g L-1, showing a high theoretical yield of 92.3%.
Asunto(s)
Bacillus/genética , Butileno Glicoles/metabolismo , Glicósido Hidrolasas/metabolismo , Helianthus/química , Extractos Vegetales/química , Tubérculos de la Planta/química , Secuencia de Aminoácidos , Bacillus/enzimología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Técnicas de Cultivo Celular por Lotes , Clonación Molecular , Escherichia coli/genética , Genes Bacterianos , Glicósido Hidrolasas/genética , Inulina/metabolismo , Plásmidos/genética , Plásmidos/metabolismo , Proteínas RecombinantesRESUMEN
Secoisolariciresinol diglucoside (SDG), a lignan extracted from flaxseed, has been shown to suppress benign prostatic hyperplasia (BPH). However, little is known about the mechanistic basis for its anti-BPH activity. The present study showed that enterolactone (ENL), the mammalian metabolite of SDG, shared the similar binding site of G1 on a new type of membranous estrogen receptor, G-protein-coupled estrogen eceptor 1 (GPER), by docking simulations method. ENL and G1 (the specific agonist of GPER) inhibited the proliferation of human prostate stromal cell line WPMY-1 as shown by MTT assay and arrested cell cycle at the G0/G1 phase, which was displayed by propidium iodide staining following flow cytometer examination. Silencing GPER by short interfering RNA attenuated the inhibitory effect of ENL on WPMY-1 cells. The therapeutic potential of SDG in the treatment of BPH was confirmed in a testosterone propionate-induced BPH rat model. SDG significantly reduced the enlargement of the rat prostate and the number of papillary projections of prostatic alveolus and thickness of the pseudostratified epithelial and stromal cells when comparing with the model group. Mechanistic studies showed that SDG and ENL increased the expression of GPER both in vitro and in vivo. Furthermore, ENL-induced cell cycle arrest may be mediated by the activation of GPER/ERK pathway and subsequent upregulation of p53 and p21 and downregulation of cyclin D1. This work, in tandem with previous studies, will enhance our knowledge regarding the mechanism(s) of dietary phytochemicals on BPH prevention and ultimately expand the scope of adopting alternative approaches in BPH treatment.
Asunto(s)
4-Butirolactona/análogos & derivados , Antineoplásicos Fitogénicos/metabolismo , Butileno Glicoles/metabolismo , Lino/química , Glucósidos/metabolismo , Lignanos/metabolismo , Modelos Moleculares , Hiperplasia Prostática/metabolismo , Receptores Acoplados a Proteínas G/agonistas , 4-Butirolactona/química , 4-Butirolactona/metabolismo , Animales , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/uso terapéutico , Sitios de Unión , Butileno Glicoles/química , Butileno Glicoles/uso terapéutico , Línea Celular Tumoral , Proliferación Celular , Suplementos Dietéticos , Regulación Neoplásica de la Expresión Génica , Glucósidos/química , Glucósidos/uso terapéutico , Glicósidos/química , Glicósidos/metabolismo , Glicósidos/uso terapéutico , Humanos , Lignanos/química , Lignanos/uso terapéutico , Masculino , Simulación del Acoplamiento Molecular , Proteínas de Neoplasias/agonistas , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Próstata/metabolismo , Próstata/patología , Hiperplasia Prostática/dietoterapia , Hiperplasia Prostática/patología , Interferencia de ARN , Distribución Aleatoria , Ratas , Ratas Wistar , Receptores de Estrógenos/química , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Semillas/químicaRESUMEN
Conversion of lignocellulosic biomass into value-added products provides important environmental and economic benefits. Here we report the engineering of an unconventional metabolism for the production of tricarboxylic acid (TCA)-cycle derivatives from D-xylose, L-arabinose and D-galacturonate. We designed a growth-based selection platform to identify several gene clusters functional in Escherichia coli that can perform this nonphosphorylative assimilation of sugars into the TCA cycle in less than six steps. To demonstrate the application of this new metabolic platform, we built artificial biosynthetic pathways to 1,4-butanediol (BDO) with a theoretical molar yield of 100%. By screening and engineering downstream pathway enzymes, 2-ketoacid decarboxylases and alcohol dehydrogenases, we constructed E. coli strains capable of producing BDO from D-xylose, L-arabinose and D-galacturonate. The titers, rates and yields were higher than those previously reported using conventional pathways. This work demonstrates the potential of nonphosphorylative metabolism for biomanufacturing with improved biosynthetic efficiencies.
Asunto(s)
Arabinosa/metabolismo , Butileno Glicoles/metabolismo , Escherichia coli/metabolismo , Ácidos Hexurónicos/metabolismo , Lignina/metabolismo , Xilosa/metabolismo , Vías Biosintéticas , Escherichia coli/enzimología , Escherichia coli/genética , Ácidos Cetoglutáricos/metabolismo , Ingeniería Metabólica , Familia de MultigenesRESUMEN
A nonpathogenic bacterial strain Bacillus amyloliquefaciens TUL 308 synthesized minor 2,3-butanediol (2,3-BD) amounts from glucose, fructose, sucrose, and glycerol, and efficiently produced the diol from molasses and hydrolysates of food processing residues. Batch fermentations yielded 16.53, 10.72, and 5 g/L 2,3-BD from enzymatic hydrolysates of apple pomace, dried sugar beet pulp, and potato pulp (at initial concentrations equivalent to 45, 20, and 30 g/L glucose, respectively), and 25.3 g/L 2,3-BD from molasses (at its initial concentration equivalent to 60 g/L saccharose). Fed-batch fermentations in the molasses-based medium with four feedings with either glucose or sucrose (in doses increasing their concentration by 25 g/L) resulted in around twice higher maximum 2,3-BD concentration (of about 60 and 50 g/L, respectively). The GRAS Bacillus strain is an efficient 2,3-BD producer from food industry byproducts.
Asunto(s)
Bacillus amyloliquefaciens/metabolismo , Butileno Glicoles/metabolismo , Manipulación de Alimentos , Beta vulgaris/metabolismo , Biomasa , Reactores Biológicos , Cromatografía Líquida de Alta Presión , Medios de Cultivo , Fermentación , MelazaRESUMEN
Two recombinants of alkaliphilic Bacillus subtilis LOCK 1086, constructed via different strategies such as cloning the gene encoding bacterial hemoglobin from Vitreoscilla stercoraria (vhb) and overexpression of the gene encoding acetoin reductase/2,3-butanediol dehydrogenase (bdhA) from B. subtilis LOCK 1086, did not produce more 2,3-butanediol (2,3-BD) than the parental strain. In batch fermentations, this strain synthesized 9.46 g/L in 24 h and 12.80 g/L 2,3-BD in 46 h from sugar beet molasses and an apple pomace hydrolysate, respectively. 2,3-BD production by B. subtilis LOCK 1086 was significantly enhanced in fed-batch fermentations. The highest 2,3-BD concentration (75.73 g/L in 114 h, productivity of 0.66 g/L × h) was obtained in the sugar beet molasses-based medium with four feedings with glucose. In a medium based on the apple pomace hydrolysate with three feedings with sucrose, B. subtilis LOCK 1086 produced up to 51.53 g/L 2,3-BD (in 120 h, productivity of 0.43 g/L × h).
Asunto(s)
Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Butileno Glicoles/metabolismo , Ingeniería Metabólica/métodos , Redes y Vías Metabólicas/genética , Beta vulgaris/metabolismo , Fermentación , Expresión Génica , Residuos Industriales , Malus/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Recombinación Genética , Vitreoscilla/enzimología , Vitreoscilla/genéticaRESUMEN
Consumption of flaxseed lignans is associated with various health benefits; however, little is known about the bioavailability of purified lignans in flaxseed. Data on their bioavailability and hence pharmacokinetics (PK) are necessary to better understand their role in putative health benefits. In the present study, we conducted a comparative PK analysis of the principal lignan of flaxseed, secoisolariciresinol diglucoside (SDG), and its primary metabolites, secoisolariciresinol (SECO), enterodiol (ED) and enterolactone (EL) in rats. Purified lignans were intravenously or orally administered to each male Wistar rat. SDG and its primary metabolites SECO, ED and EL were administered orally at doses of 40, 40, 10 and 10 mg/kg, respectively, and intravenously at doses of 20, 20, 5 and 1 mg/kg, respectively. Blood samples were collected at 0 (pre-dose), 5, 10, 15, 20, 30 and 45 min, and at 1, 2, 4, 6, 8, 12 and 24 h post-dosing, and serum samples were analysed. PK parameters and oral bioavailability of purified lignans were determined by non-compartmental methods. In general, administration of the flaxseed lignans SDG, SECO and ED demonstrated a high systemic clearance, a large volume of distribution and short half-lives, whereas administration of EL at the doses of 1 mg/kg (intravenously) and 10 mg/kg (orally administered) killed the rats within a few hours of dosing, precluding a PK analysis of this lignan. PK parameters of flaxseed lignans exhibited the following order: systemic clearance, SDG < SECO < ED; volume of distribution, SDG < SECO < ED; half-life, SDG < ED < SECO. The percentage of oral bioavailability was 0, 25 and < 1 % for SDG, SECO and ED, respectively.
Asunto(s)
Estrógenos/metabolismo , Lino/química , Lignanos/metabolismo , Fitoestrógenos/metabolismo , Semillas/química , 4-Butirolactona/administración & dosificación , 4-Butirolactona/efectos adversos , 4-Butirolactona/análogos & derivados , 4-Butirolactona/metabolismo , 4-Butirolactona/farmacocinética , Administración Oral , Animales , Disponibilidad Biológica , Butileno Glicoles/administración & dosificación , Butileno Glicoles/efectos adversos , Butileno Glicoles/metabolismo , Butileno Glicoles/farmacocinética , Suplementos Dietéticos/efectos adversos , Relación Dosis-Respuesta a Droga , Estrógenos/administración & dosificación , Estrógenos/efectos adversos , Estrógenos/farmacocinética , Glucósidos/administración & dosificación , Glucósidos/efectos adversos , Glucósidos/metabolismo , Glucósidos/farmacocinética , Semivida , Inyecciones Intravenosas , Absorción Intestinal , Cinética , Lignanos/administración & dosificación , Lignanos/efectos adversos , Lignanos/farmacocinética , Masculino , Tasa de Depuración Metabólica , Fitoestrógenos/administración & dosificación , Fitoestrógenos/efectos adversos , Fitoestrógenos/farmacocinética , Distribución Aleatoria , Ratas WistarRESUMEN
Phytoestrogens are plant-derived compounds that may interact with estrogen receptors and mimic estrogenic effects. It remains unclear whether the individual variability in metabolizing phytoestrogens contributes to phytoestrogens-induced beneficial or detrimental effects. Our aim was to determine whether there is any interaction between metabolic rates (MR) of phytoestrogens and genetic polymorphisms in related xenobiotic metabolizing enzyme genes. MR was used to assess phytoestrogen exposure and individual metabolic ability. The amount of phytoestrogens in urine was measured by ultra-high performance liquid chromatography-tandem mass spectrometry in 600 idiopathic infertile male patients and 401 controls. Polymorphisms were genotyped using the SNPstream platform combined with the Taqman method. Prototypes and metabolites of secoisolariciresinol (SEC) have inverse effects on male reproduction. It was found that low MR of SEC increased the risk of male infertility (OR 2.49, 95 % CI 1.78, 3.48, P trend = 8.00 × 10(-8)). Novel interactions were also observed between the MR of SEC and rs1042389 in CYP2B6, rs1048943 in CYP1A1, and rs1799931 in NAT2 on male infertility (P inter = 1.06 × 10(-4), 1.14 × 10(-3), 3.55 × 10(-3), respectively). By analyzing the relationships between urinary phytoestrogen concentrations, their metabolites and male infertility, we found that individual variability in metabolizing SEC contributed to the interpersonal differences in SEC's effects on male reproduction.
Asunto(s)
Arilamina N-Acetiltransferasa/genética , Butileno Glicoles/orina , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP2B6/genética , Infertilidad Masculina/metabolismo , Lignanos/orina , Fitoestrógenos/orina , Polimorfismo de Nucleótido Simple , Adulto , Pueblo Asiatico/genética , Biotransformación , Butileno Glicoles/efectos adversos , Butileno Glicoles/metabolismo , Estudios de Casos y Controles , Humanos , Infertilidad Masculina/inducido químicamente , Infertilidad Masculina/enzimología , Infertilidad Masculina/orina , Lignanos/efectos adversos , Lignanos/metabolismo , Masculino , Fitoestrógenos/efectos adversos , Fitoestrógenos/metabolismo , Adulto JovenRESUMEN
Secoisolariciresinol-diglycoside (SDG), a natural dietary lignan of flaxseeds now available in dietary supplements, is converted by intestinal bacteria to the mammalian lignans enterodiol and enterolactone. High levels of these lignans in blood and urine are associated with reduced risk of many chronic diseases. Our objective was to determine the bioavailability and pharmacokinetics of SDG in purified flaxseed extracts under dose-ranging and steady-state conditions, and to examine whether differences in secoisolariciresinol-diglycoside purity influence bioavailability. Pharmacokinetic studies were performed on healthy postmenopausal women after oral intake of 25, 50, 75, 86 and 172 mg of secoisolariciresinol-diglycoside. Extracts differing in secoisolariciresinol-diglycoside purity were compared, and steady-state lignan concentrations measured after daily intake for one week. Blood and urine samples were collected at timed intervals and secoisolariciresinol, enterodiol and enterolactone concentrations measured by mass spectrometry. Secoisolariciresinol-diglycoside was efficiently hydrolyzed and converted to secoisolariciresinol. Serum concentrations increased rapidly after oral intake, peaking after 5-7 h and disappearing with a plasma elimination half-life of 4.8 h. Maximum serum concentrations of the biologically active metabolites, enterodiol and enterolactone were attained after 12-24 h and 24-36 h, respectively, and the half-lives were 9.4 h and 13.2 h. Linear dose-responses were observed and secoisolariciresinol bioavailability correlated (r(2) = 0.835) with cumulative lignan excretion. There were no significant differences in the pharmacokinetics of extracts differing in purity, and steady-state serum lignan concentrations were obtained after one-week of daily dosing. In conclusion, this study defines the pharmacokinetics of secoisolariciresinol-diglycoside and shows it is first hydrolyzed and then metabolized in a time-dependent sequence to secoisolariciresinol, enterodiol and ultimately enterolactone, and these metabolites are efficiently absorbed.
Asunto(s)
4-Butirolactona/análogos & derivados , Butileno Glicoles/metabolismo , Lino/metabolismo , Glicósidos/metabolismo , Mucosa Intestinal/metabolismo , Lignanos/metabolismo , Posmenopausia/metabolismo , 4-Butirolactona/sangre , 4-Butirolactona/metabolismo , 4-Butirolactona/farmacocinética , 4-Butirolactona/orina , Anciano , Butileno Glicoles/sangre , Butileno Glicoles/farmacocinética , Butileno Glicoles/orina , Suplementos Dietéticos , Femenino , Lino/química , Glicósidos/sangre , Glicósidos/farmacocinética , Glicósidos/orina , Humanos , Lignanos/sangre , Lignanos/farmacocinética , Lignanos/orina , Persona de Mediana EdadRESUMEN
2,3-Butanediol (2,3-BD) is an organic compound, which is widely used as a fuel and fuel additive and applied in chemical, food, and pharmaceutical industries. Contemporary strategies for its economic synthesis include the development of microbial technologies that use starch as cheap and renewable feedstock. The present work encompasses the metabolic engineering of the excellent 2,3-BD producer Klebsiella pneumoniae G31. In order to perform direct starch conversion into 2,3-BD, the amyL gene encoding quite active, liquefying α-amylase in Bacillus licheniformis was cloned under lac promoter control in the recombinant K. pneumoniae G31-A. The enhanced extracellular over-expression of amyL led to the highest extracellular amylase activity (68 U/ml) ever detected in Klebsiella. The recombinant strain was capable of simultaneous saccharification and fermentation (SSF) of potato starch to 2,3-BD. In SSF batch process by the use of 200 g/l starch, the amount of total diols produced was 60.9 g/l (53.8 g/l 2,3-BD and 7.1 g/l acetoin), corresponding to 0.31 g/g conversion rate. The presented results are the first to show successful starch conversion to 2,3-BD by K. pneumoniae in a one-step process.
Asunto(s)
Butileno Glicoles/metabolismo , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/metabolismo , Ingeniería Metabólica , Almidón/metabolismo , Bacillus/enzimología , Bacillus/genética , Clonación Molecular , Expresión Génica , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Análisis de Secuencia de ADN , Solanum tuberosum/química , alfa-Amilasas/genética , alfa-Amilasas/metabolismoRESUMEN
BACKGROUND: 2,3-Butanediol (BD) is considered as one of the key platform chemicals used in a variety of industrial applications. It is crucial to find an efficient sugar-utilizing strain and feasible carbon source for the economical production of BD. METHODOLOGY/PRINCIPAL FINDINGS: Efficient BD production by a newly isolated Enterobacter cloacae subsp. dissolvens SDM was studied using crop-biomass cassava powder as substrate. The culture conditions and fermentation medium for BD production were optimized. Under the optimal conditions, 78.3 g l(-1) of BD was produced after 24 h in simultaneous saccharification and fermentation (SSF), with a yield of 0.42 g BD g(-1) cassava powder and a specific productivity of 3.3 g l(-1) h(-1). A higher BD concentration (93.9 g l(-1)) was produced after 47 h in fed-batch SSF. CONCLUSIONS/SIGNIFICANCE: The results suggest that strain SDM is a good candidate for the BD production, and cassava powder could be used as an alternative substrate for the efficient production of BD.
Asunto(s)
Butileno Glicoles/metabolismo , Enterobacter cloacae/metabolismo , Manihot/química , Extractos Vegetales/metabolismo , Análisis de Varianza , Reactores Biológicos , Medios de Cultivo , Fermentación , Concentración de Iones de Hidrógeno , Hidrólisis , Compuestos de Nitrógeno/metabolismo , Análisis de RegresiónRESUMEN
The enzymatic digestibility of alkali/peracetic acid (PAA)-pretreated bagasse was systematically investigated. The effects of initial solid consistency, cellulase loading and addition of supplemental ß-glucosidase on the enzymatic conversion of glycan were studied. It was found the alkali-PAA pulp showed excellent enzymatic digestibility. The enzymatic glycan conversion could reach about 80% after 24 h incubation when enzyme loading was 10 FPU/g solid. Simultaneous saccharification and fermentation (SSF) results indicated that the pulp could be well converted to ethanol. Compared with dilute acid pretreated bagasse (DAPB), alkali-PAA pulp could obtain much higher ethanol and xylose concentrations. The fermentation broth still showed some cellulase activity so that the fed pulp could be further converted to sugars and ethanol. After the second batch SSF, the fermentation broth of alkali-PAA pulp still kept about 50% of initial cellulase activity. However, only 21% of initial cellulase activity was kept in the fermentation broth of DAPB. The xylose syrup obtained in SSF of alkali-PAA pulp could be well converted to 2,3-butanediol by Klebsiella pneumoniae CGMCC 1.9131.
Asunto(s)
Biotecnología/métodos , Butileno Glicoles/metabolismo , Celulasa/metabolismo , Celulosa/metabolismo , Etanol/metabolismo , Saccharum/metabolismo , Álcalis/farmacología , Celobiosa/metabolismo , Celulosa/farmacología , Medios de Cultivo , Fermentación , Glucosa/metabolismo , Hidrólisis , Ácido Peracético/farmacología , Saccharum/efectos de los fármacos , Xilosa/metabolismoRESUMEN
Nutritional value is a priority in new product development. Using vegetable or marine oils, rich in polyunsaturated fatty acids, in dairy beverage formulations is an option to provide the consumers with healthier products. However, these formulations are prone to oxidation, which is responsible for rapid flavour degradation and the development of potentially toxic reaction products during storage. Flaxseed lignans, secoisolariciresinol diglucoside (SDG), and its mammalian metabolites have antioxidant activity and could be used in beverage formulations to prevent oxidation. Commercially available SDG extract was added to the formulation of dairy beverages enriched with flaxseed oil. As an alternative approach, dairy beverages were produced from milk naturally rich in SDG metabolites obtained through the alteration of cow diet. Resistance to oxidation was determined from the kinetics of hexanal and propanal production during heat and light exposure treatments. Increasing SDG concentration in dairy beverage slightly reduced redox potential but had no effect on oxygen consumption during oxidation treatments. The presence of SDG in dairy beverage significantly improved resistance to heat- and light-induced oxidation. However, purified enterolactone, a mammalian metabolite from SDG, prevented oxidation at much lower concentrations. The use of milk from dairy cow fed flaxseed meal did not improve resistance to oxidation in dairy beverage. Enterolactone concentration in milk was increased by the experimental diet but it remained too low to observe any significant effect on dairy beverage oxidation.
Asunto(s)
Antioxidantes/administración & dosificación , Ácidos Grasos Insaturados/química , Lino/química , Alimentos Fortificados , Lignanos/administración & dosificación , Leche/química , 4-Butirolactona/análogos & derivados , 4-Butirolactona/análisis , 4-Butirolactona/metabolismo , 4-Butirolactona/farmacología , Animales , Butileno Glicoles/administración & dosificación , Butileno Glicoles/metabolismo , Bovinos , Dieta , Femenino , Glucósidos/administración & dosificación , Glucósidos/metabolismo , Calor , Lignanos/análisis , Lignanos/metabolismo , Lignanos/farmacología , Oxidación-Reducción , Estrés Oxidativo , Procesos FotoquímicosRESUMEN
Many natural products, including vitamin E, garlic, purpurogallin, flaxseed and its components [secoisolariciresinol diglucoside (SDG) and flax lignan complex (FLC)] and resveratrol have been reported to suppress hypercholesterolemic atherosclerosis. It is known that all of the drugs that suppress the development of atherosclerosis do not regress and/or slow the progression of atherosclerosis. To be of potential benefit in patients with established atherosclerosis, a drug should produce regression and/or slow the progression of atherosclerosis. In this review, the effects of vitamin E, SDG and FLC in the regression and slowing of progression of hypercholesterolemic atherosclerosis and their mechanisms have been described. The effectiveness of vitamin E in patients with established coronary disease is very controversial. However, in experimental animal controlled studies, vitamin E does not regress or slow the progression of hypercholesterolemic atherosclerosis. The mechanisms of the ineffectiveness of vitamin E in regression and slowing of progression of atherosclerosis have been discussed. SDG is effective in slowing the progression of atherosclerosis and partially effective in regression of hypercholesterolemic atherosclerosis. These effects are associated with reduction in oxidative stress. FLC does not regress hypercholesterolemic atherosclerosis but slows the progression of hypercholesterolemic atherosclerosis. Slowing of progression is associated with reduction on oxidative stress. In conclusion, vitamin E does not regress or slow the progression of established atherosclerosis. SDG slows the progression and regresses established atherosclerosis. FLC does not regress but slows the progression of established atherosclerosis.
Asunto(s)
Aterosclerosis/tratamiento farmacológico , Aterosclerosis/metabolismo , Productos Biológicos/farmacología , Butileno Glicoles/farmacología , Glucósidos/farmacología , Estrés Oxidativo/efectos de los fármacos , Fitoterapia , Vitamina E/farmacología , Animales , Antioxidantes/farmacología , Butileno Glicoles/metabolismo , Progresión de la Enfermedad , Lino , Glucósidos/metabolismo , Humanos , Hipercolesterolemia/tratamiento farmacológico , Hipercolesterolemia/metabolismo , Lignanos/farmacología , Vitamina E/metabolismoRESUMEN
The medium for one-step fermentation of raw inulin extract from Jerusalem artichoke tubers by Paenibacillus polymyxa ZJ-9 to produce R,R-2,3-butanediol (R,R-2,3-BD) was developed. Inulin, K(2)HPO(4) and NH(4)Cl were found to be the key factors in the fermentation according to the results obtained from the Plackett-Burman experimental design. The optimal concentration range of the three factors was examined by the steepest ascent path, and their optimal concentration was further investigated according to the Box-Behnken design and determined to be 77.14 g/L, 3.09 g/L and 0.93 g/L, respectively. Under the optimal conditions, the concentration of the obtained R,R-2,3-BD was 36.92 g/L, at more than 98% optical purity. Compared with other investigated carbon resources, fermentation of the raw inulin extract afforded the highest yield of R,R-2,3-BD. This process featured one-step fermentation of inulin without further hydrolyzing, which greatly decreased the raw material cost and thus facilitated its practical application.