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1.
Science ; 369(6499)2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32631870

RESUMO

Microbial communities are essential to fundamental processes on Earth. Underlying the compositions and functions of these communities are nutritional interdependencies among individual species. One class of nutrients, cobamides (the family of enzyme cofactors that includes vitamin B12), is widely used for a variety of microbial metabolic functions, but these structurally diverse cofactors are synthesized by only a subset of bacteria and archaea. Advances at different scales of study-from individual isolates, to synthetic consortia, to complex communities-have led to an improved understanding of cobamide sharing. Here, we discuss how cobamides affect microbes at each of these three scales and how integrating different approaches leads to a more complete understanding of microbial interactions.


Assuntos
Cobamidas/metabolismo , Meio Ambiente , Interações Microbianas , Microbiota , Complexo Vitamínico B/metabolismo , Animais , Archaea/metabolismo , Bactérias/metabolismo , Cobamidas/química , Planeta Terra , Eucariotos/metabolismo , Modelos Biológicos , Complexo Vitamínico B/química
2.
J Dairy Sci ; 103(4): 3125-3132, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32037179

RESUMO

The objective of this study was to evaluate the capacity of 6 mycotoxin binders (MTB) to adsorb 3 AA and 4 water-soluble vitamins (WSV). Two experiments were conducted in in vitro conditions to simulate postruminal digestion with pepsin, malic acid, citric acid, acetic acid, and lactic acid at pH 3.0 and intestinal digestion with bile salts and pancreatin extract at pH 6.5. Experiment 1 was conducted with AA, and experiment 2 was conducted with WSV. Within experiment, main factors were the MTB (bentonite, clinoptiolite, sepiolite, montmorillonite, activated carbon, and yeast cell walls), the substrate (AA: Lys, Met, and Thr; WSV: B1, B2, B3, and B6), and the incubation strategy (substrates alone or mixed). Data were analyzed for the effects of main factors and their interactions. In experiment 1, the adsorption average for AA when incubated separately was 44.3%, ranging from 62.4% for Thr by clinoptiolite to 20.0% for Thr by activated carbon. When incubated together, the average adsorption was reduced to 19.9%, suggesting competition among substrates for adsorption. Adsorption ranged from 29.8% for Thr by yeast cell walls to 5.6% for Met by clinoptiolite, but there were significant interactions among MTB and AA. In experiment 2, the average adsorption of WSV when incubated separately or together was 34.1 and 45.1%, respectively, suggesting possible synergies among substrates. When vitamins were incubated separately, adsorption ranged from 90.5% for vitamin B1 to 4.0% for vitamin B3 by montmorillonite. Vitamins B1 (except by yeast cell walls) and B6 (except by bentonite, sepiolite, and montmorillonite) were absorbed the most, and vitamin B3 was absorbed the least (except by activated carbon and yeast cell walls, which were least together with vitamin B2). When vitamins were incubated together, adsorption ranged from 97.0% for vitamin B1 by montmorillonite to 0% for vitamin B2 by activated carbon and vitamin B3 by bentonite. Vitamins B1 by all MTB and B6 by clinoptiolite, sepiolite, and yeast cell walls were the most adsorbed, and vitamin B3 (except by activated carbon and yeast cell wall) was the least absorbed. There were significant interactions among MTB and WSV. Mycotoxin binders have a high degree of adsorption of the AA and WSV tested in in vitro conditions, which may limit their bioavailability. Results also suggest that when substrates were incubated together some interactions for adsorption occurred, which were competitive among AA and synergic among vitamins.


Assuntos
Aminoácidos/metabolismo , Micotoxinas/metabolismo , Complexo Vitamínico B/metabolismo , Adsorção , Animais , Bentonita/metabolismo , Parede Celular , Carvão Vegetal/metabolismo , Feminino , Humanos , Masculino , Gravidez , Riboflavina/metabolismo , Tiamina/metabolismo , Leveduras
4.
Int J Hyg Environ Health ; 223(1): 124-131, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31588016

RESUMO

OBJECTIVES: Millions of children globally, including the U.S., are exposed to low levels of arsenic from water and food. Arsenic is a known neurotoxicant at high levels but its effects at lower exposure levels are understudied. Arsenic methylation capacity, influenced by B-vitamin intake and status, potentially influences arsenic toxicity. In a cross-secitonal study of 5-8 year-old children from Montevideo, we assessed the relationship between urinary arsenic (U-As) and academic achievement, and tested for effect modification by B-vitamin intake, status, and arsenic methylation capacity. METHODS: Broad math and reading scores were calculated based on six subtests (calculation, math facts fluency, applied problems, sentence reading fluency, letter word identification, passage comprehension) from the Woodcock-Muñoz Achievement Battery. B-vitamin intake was assessed from two non-consecutive 24-h dietary recalls, serum folate and vitamin B-12 levels were measured in a subset of participants. Arsenic methylation capacity was measured as the proportion of urinary monomethylarsonic acid (%MMA). Multiple imputation using chained equations was conducted to account for missing covariate and exposure data. Ordinal regressions assessed associations between U-As and achievement score tertiles in the complete case and imputed samples. A "B-vitamin index" was calculated using principal component analysis. Interactions by urinary %MMA and the B-vitamin index were assessed. RESULTS: Median specific gravity adjusted U-As was 11.7 µg/L (range: 2.6, 50.1). We found no association between U-As and broad math and reading scores, nor effect modification by %MMA or B-vitamins. CONCLUSION: At low-levels of exposure, U-As does not appear to affect children's academic achievement.


Assuntos
Sucesso Acadêmico , Arsênico/metabolismo , Exposição Ambiental/estatística & dados numéricos , Complexo Vitamínico B/metabolismo , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Metilação , Uruguai
5.
Nutrients ; 11(11)2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31739474

RESUMO

Migraines are a common disease with limited treatment options and some dietary factors are recognized to trigger headaches. Although migraine pathogenesis is not completely known, aberrant DNA methylation has been reported to be associated with its occurrence. Folate, an essential micronutrient involved in one-carbon metabolism and DNA methylation, was shown to have beneficial effects on migraines. Moreover, the variability of the methylenetetrahydrofolate reductase gene, important in both folate metabolism and migraine pathogenesis, modulates the beneficial effects of folate for migraines. Therefore, migraine could be targeted by a folate-rich, DNA methylation-directed diet, but there are no data showing that beneficial effects of folate consumption result from its epigenetic action. Furthermore, contrary to epigenetic drugs, epigenetic diets contain many compounds, some yet unidentified, with poorly known or completely unknown potential to interfere with the epigenetic action of the main dietary components. The application of epigenetic diets for migraines and other diseases requires its personalization to the epigenetic profile of a patient, which is largely unknown. Results obtained so far do not warrant the recommendation of any epigenetic diet as effective in migraine prevention and therapy. Further studies including a folate-rich diet fortified with valproic acid, another modifier of epigenetic profile effective in migraine prophylaxis, may help to clarify this issue.


Assuntos
Metilação de DNA , Dieta , Epigênese Genética , Epigenômica , Ácido Fólico , Cefaleia/terapia , Transtornos de Enxaqueca/terapia , Ácido Fólico/metabolismo , Ácido Fólico/uso terapêutico , Cefaleia/dietoterapia , Cefaleia/genética , Cefaleia/metabolismo , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Transtornos de Enxaqueca/dietoterapia , Transtornos de Enxaqueca/genética , Transtornos de Enxaqueca/metabolismo , Complexo Vitamínico B/metabolismo , Complexo Vitamínico B/uso terapêutico
6.
Vopr Pitan ; 88(4): 6-11, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31722135

RESUMO

α-Lipoic acid (also known as thioctic acid) is a natural vitamin-like compound. Lipoic acid contains asymmetrical carbon, which causes the presence of two possible optical isomers (enantiomers): R-lipoic acid (levogyrate isomer) and S-lipoic acid (rightspinning isomer). Lipoic acid functions as a cofactor for several important mitochondrial multienzyme complexes, enhances the uptake of glucose by the cells, and modulates the activity of various signaling molecules and transcription factors. It was shown that α-lipoic acid and its derivative, dihydrolipoic acid, have a direct antioxidant effect due to the neutralization of reactive oxygen species that are destructive to DNA, proteins and lipids of cells. Dihydrolipoic acid enhances the antioxidant properties of ascorbic acid, glutathione and ubiquinone. Available evidence suggests that supplementation with lipoic acid reduces the symptoms of peripheral diabetic neuropathy. Results from randomized controlled trials show that high doses of lipoic acid can improve the glycemic profile of subjects with metabolic disorders. Lipoic acid can be used to control body weight in people with obesity. R-Lipoic acid is synthesized in the human body and is contained in foods in a form covalently associated with lysine (lipoyllysine). Its dose in dietary supplements significantly exceeds the amount in the diet. Most dietary supplements contain a racemic mixture of R- and S-lipoic acid.


Assuntos
Antioxidantes/uso terapêutico , Neuropatias Diabéticas/dietoterapia , Suplementos Nutricionais , Obesidade/dietoterapia , Ácido Tióctico/uso terapêutico , Complexo Vitamínico B/uso terapêutico , Animais , Antioxidantes/metabolismo , Peso Corporal/efeitos dos fármacos , Neuropatias Diabéticas/metabolismo , Neuropatias Diabéticas/patologia , Humanos , Mitocôndrias/enzimologia , Mitocôndrias/patologia , Proteínas Mitocondriais/metabolismo , Complexos Multienzimáticos/metabolismo , Obesidade/metabolismo , Obesidade/patologia , Espécies Reativas de Oxigênio/metabolismo , Estereoisomerismo , Ácido Tióctico/metabolismo , Complexo Vitamínico B/metabolismo
7.
Biochemistry (Mosc) ; 84(8): 829-850, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31522667

RESUMO

Thiamine (vitamin B1) is a precursor of the well-known coenzyme of central metabolic pathways thiamine diphosphate (ThDP). Highly intense glucose oxidation in the brain requires ThDP-dependent enzymes, which determines the critical significance of thiamine for neuronal functions. However, thiamine can also act through the non-coenzyme mechanisms. The well-known facilitation of acetylcholinergic neurotransmission upon the thiamine and acetylcholine co-release into the synaptic cleft has been supported by the discovery of thiamine triphosphate (ThTP)-dependent phosphorylation of the acetylcholine receptor-associated protein rapsyn, and thiamine interaction with the TAS2R1 receptor, resulting in the activation of synaptic ion currents. The non-coenzyme regulatory binding of thiamine compounds has been demonstrated for the transcriptional regulator p53, poly(ADP-ribose) polymerase, prion protein PRNP, and a number of key metabolic enzymes that do not use ThDP as a coenzyme. The accumulated data indicate that the molecular mechanisms of the neurotropic action of thiamine are far broader than it has been originally believed, and closely linked to the metabolism of thiamine and its derivatives in animals. The significance of this topic has been illustrated by the recently established competition between thiamine and the antidiabetic drug metformin for common transporters, which can be the reason for the thiamine deficiency underlying metformin side effects. Here, we also discuss the medical implications of the research on thiamine, including the role of thiaminases in thiamine reutilization and biosynthesis of thiamine antagonists; molecular mechanisms of action of natural and synthetic thiamine antagonists, and biotransformation of pharmacological forms of thiamine. Given the wide medical application of thiamine and its synthetic forms, these aspects are of high importance for medicine and pharmacology, including the therapy of neurodegenerative diseases.


Assuntos
Hipoglicemiantes/metabolismo , Metformina/metabolismo , Tiamina/análogos & derivados , Tiamina/metabolismo , Complexo Vitamínico B/metabolismo , Animais , Encéfalo/metabolismo , Coenzimas , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Metformina/administração & dosagem , Metformina/efeitos adversos , Camundongos , Fosforilação , Transporte Proteico/fisiologia , Ratos , Tiamina/efeitos adversos , Tiamina/farmacologia , Deficiência de Tiamina/etiologia , Deficiência de Tiamina/prevenção & controle , Tiamina Pirofosfato/metabolismo , Complexo Vitamínico B/efeitos adversos , Complexo Vitamínico B/farmacologia
8.
PLoS Pathog ; 15(7): e1007942, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31323076

RESUMO

Exotic invasive species can influence the behavior and ecology of native and resident species, but these changes are often overlooked. Here we hypothesize that the ghost ant, Tapinoma melanocephalum, living in areas that have been invaded by the red imported fire ant, Solenopsis invicta, displays behavioral differences to interspecific competition that are reflected in both its trophic position and symbiotic microbiota. We demonstrate that T. melanocephalum workers from S. invicta invaded areas are less aggressive towards workers of S. invicta than those inhabiting non-invaded areas. Nitrogen isotope analyses reveal that colonies of T. melanocephalum have protein-rich diets in S. invicta invaded areas compared with the carbohydrate-rich diets of colonies living in non-invaded areas. Analysis of microbiota isolated from gut tissue shows that T. melanocephalum workers from S. invicta invaded areas also have different bacterial communities, including a higher abundance of Wolbachia that may play a role in vitamin B provisioning. In contrast, the microbiota of workers of T. melanocephalum from S. invicta-free areas are dominated by bacteria from the orders Bacillales, Lactobacillales and Enterobacteriales that may be involved in sugar metabolism. We further demonstrate experimentally that the composition and structure of the bacterial symbiont communities as well as the prevalence of vitamin B in T. melanocephalum workers from S. invicta invaded and non-invaded areas can be altered if T. melanocephalum workers are supplied with either protein-rich or carbohydrate-rich food. Our results support the hypothesis that bacterial symbiont communities can help hosts by buffering behavioral changes caused by interspecies competition as a consequence of biological invasions.


Assuntos
Formigas/microbiologia , Formigas/fisiologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Espécies Introduzidas , Microbiota/fisiologia , Adaptação Fisiológica , Animais , Dieta , Ecossistema , Comportamento Alimentar , Especificidade da Espécie , Simbiose/fisiologia , Complexo Vitamínico B/metabolismo , Wolbachia/fisiologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-31202182

RESUMO

The multifactorial nature of Late Onset Alzheimer's Disease (LOAD), the AD form of major relevance on epidemiological and social aspects, has driven the original investigation by LC-MS and top-down proteomics approach of the protein repertoire of the brain tissue of TgCRND8 model mice fed with a diet deficient in B vitamins. The analysis of the acid-soluble fraction of brain tissue homogenates identified a list of proteins and peptides, proteoforms and PTMs. In order to disclose possible modulations, their relative quantification in wild type and AD model mice under both B vitamin deficient and control diets was performed. The levels of metallothionein III, guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2 and brain acid soluble protein 1 showed statistically significant alterations depending on genotype, diet or both effects, respectively. Particularly, metallothionein III exhibited increased levels in TgCRND8 mice under B vitamin deficient diet with respect to wild type mice under both diets. Brain acid soluble protein 1 showed the opposite, revealing decreased levels in all diet groups of AD model mice with respect to wild type mice in control diet. Lower levels of brain acid soluble protein 1 were also observed in wild type mice under deficiency of B vitamins. These results, besides contributing to increase the knowledge of AD at molecular level, give new suggestions for deeply investigating metallothionein III and brain acid soluble protein 1 in AD.


Assuntos
Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Hiper-Homocisteinemia/metabolismo , Proteoma/metabolismo , Complexo Vitamínico B/análise , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/metabolismo , Animais , Química Encefálica , Proteínas de Ligação a Calmodulina/genética , Proteínas de Ligação a Calmodulina/metabolismo , Cromatografia Líquida , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Hiper-Homocisteinemia/etiologia , Hiper-Homocisteinemia/genética , Masculino , Espectrometria de Massas , Camundongos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteoma/química , Proteoma/genética , Complexo Vitamínico B/metabolismo
10.
J Agric Food Chem ; 67(25): 7082-7086, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31199642

RESUMO

Vitamins are important nutrients for many fermentations, but they are generally costly. Agricultural lignocellulose biomass contains considerable amounts of vitamin B compounds, but these water-soluble vitamins are easily lost into wastewater discharge during pretreatment or detoxification of lignocellulose in biorefinery processes. Here, we showed that the dry acid pretreatment and biodetoxification process allowed the preservation of significant amounts of vitamin B, which promoted l-lactic acid fermentation efficiency significantly. Supplementation with specific vitamin B compounds, VB3 and VB5, into corn stover hydrolysate led to further increases of cellulosic l-lactic acid yield and fermentation rates. This study provided a new solution for the enhancement of biorefinery fermentation efficiency by using vitamin B compounds in lignocellulose biomass.


Assuntos
Ácido Láctico/metabolismo , Lignina/metabolismo , Pediococcus acidilactici/metabolismo , Complexo Vitamínico B/metabolismo , Fermentação , Hidrólise , Lignina/química , Pediococcus acidilactici/crescimento & desenvolvimento , Caules de Planta/química , Caules de Planta/metabolismo , Caules de Planta/microbiologia , Resíduos/análise , Zea mays/química , Zea mays/metabolismo , Zea mays/microbiologia
11.
Ter Arkh ; 91(4): 122-129, 2019 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-31094486

RESUMO

The review discusses thesteps of vitamin B12 metabolism and its role in maintaining of neurological functions. The term "vitamin B12 (cobalamin)" refers to several substances (cobalamins) of a very similar structure. Cobalamin enters the body with animal products. On the peripherу cobalamin circulates only in binding with proteins transcobalamin I and II (complex cobalamin-transcobalamin II is designated as "holotranscobalamin"). Holotranscobalamin is absorbed by different cells, whereas transcobalamin I-binded vitamin B12 - only by liver and kidneys. Two forms of cobalamin were identified as coenzymes of cellular reactions which are methylcobalamin (in cytoplasm) and hydroxyadenosylcobalamin (in mitochondria). The main causes of cobalamin deficiency are related to inadequate intake of animal products, autoimmune gastritis, pancreatic insufficiency, terminal ileum disease, syndrome of intestinal bacterial overgrowth. Relative deficiency may be seen in excessive binding of vitamin B12 to transcobalamin I. Cobalamin deficiency most significantly affects functions of blood, nervous system and inflammatory response. Anemia occurs in 13-15% of cases; macrocytosis is an early sign. The average size of neutrophils and monocytes is the most sensitive marker of megaloblastic hematopoiesis. The demands in vitamin B12 are particularly high in nervous tissue. Hypovitaminosis is accompanied by pathological lesions both in white and gray brain matter. Several types of neurological manifestations are described: subacute combined degeneration of spinal cord (funicular myelinosis), sensomotor polyneuropathy, optic nerve neuropathy, cognitive disorders. The whole range of neuropsychiatric disorders with vitamin B12 deficiency has not been studied well enough. Due to certain diagnostic difficulties they are often regarded as "cryptogenic", "reactive", "vascular¼ origin. Normal or decreased total plasma cobalamin level could not a reliable marker of vitamin deficiency. In difficult cases the content of holotranscobalamin, methylmalonic acid / homocysteine, and folate in the blood serum should be investigated besides carefully analysis of clinical manifestations.


Assuntos
Deficiência de Vitaminas/complicações , Doenças do Sistema Nervoso/etiologia , Complexo Vitamínico B/metabolismo , Animais , Biomarcadores , Transcobalaminas , Deficiência de Vitamina B 12/diagnóstico , Deficiência de Vitamina B 12/etiologia , Deficiência de Vitamina B 12/terapia
12.
Muscle Nerve ; 60(2): 124-136, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31074875

RESUMO

Complementary and alternative treatment modalities are commonly utilized by patients for neuropathy and neuropathic pain due to perceived lack of benefit from conventional medical treatment. As the association between metabolic syndrome and neuropathy is increasingly recognized, diet and lifestyle interventions are becoming important components in the management of neuropathy. Progress in the understanding of the gut-immune interaction highlights the role the gut microbiome and inflammation plays in the modulation of neuropathy and neuropathic pain. Evidence for nutritional interventions, exercise, supplements, acupuncture, and mindfulness-based practices in the treatment of neuropathic pain is encouraging. This article reviews the available evidence to support the safe use of complementary and alternative treatments for commonly encountered conditions associated with neuropathy and neuropathic pain. Muscle Nerve 60: 124-136, 2019.


Assuntos
Dietoterapia , Suplementos Nutricionais , Terapia por Exercício , Estilo de Vida , Neuralgia/terapia , Doenças do Sistema Nervoso Periférico/terapia , Complexo Vitamínico B/uso terapêutico , Acetilcarnitina/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Curcumina/uso terapêutico , Dieta , Disbiose/metabolismo , Exercício Físico , Ácidos Graxos Ômega-3/uso terapêutico , Ácido Fólico/análogos & derivados , Ácido Fólico/uso terapêutico , Microbioma Gastrointestinal , Humanos , Medicina Integrativa , Síndrome Metabólica/metabolismo , Neuralgia/metabolismo , Doenças do Sistema Nervoso Periférico/metabolismo , Fosfato de Piridoxal/uso terapêutico , Ácido Tióctico/uso terapêutico , Vitamina B 12/análogos & derivados , Vitamina B 12/uso terapêutico , Complexo Vitamínico B/metabolismo , Deficiência de Vitaminas do Complexo B , Vitamina D/uso terapêutico
13.
Appl Microbiol Biotechnol ; 103(11): 4455-4465, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30968162

RESUMO

In this study, stress tolerance devices consisting of heat shock protein (HSP) genes from thermophiles Geobacillus and Parageobacillus were introduced into riboflavin-producing strain Bacillus subtilis 446 to improve its stress tolerance and riboflavin production. The 12 HSP homologs were selected from 28 Geobacillus and Parageobacillus genomes according to their sequence clustering and phylogenetically analysis which represents the diversity of HSPs from thermophilic bacillus. The 12 HSP genes and 2 combinations of them (PtdnaK-PtdnaJ-PtgrpE and PtgroeL-PtgroeS) were heterologously expressed in B. subtilis 446 under the control of a strong constitutive promoter P43. Most of the 14 engineered strains showed increased cell density at 44 to 48 °C and less cell death at 50 °C compared with the control strains. Among them, strains B.s446-HSP20-3, B.s446-HSP20-2, and B.s446-PtDnaK-PtDnaJ-PtGrpE increased their cell densities over 25% at 44 to 48 °C. They also showed 5-, 4-, and 4-fold improved cell survivals after the 10-h heat shock treatment at 50 °C, respectively. These three strains also showed reduced cell death rates under osmotic stress of 10% NaCl, indicating that the introduction of HSPs improved not only the heat tolerance of B. subtilis 446 but also its osmotic tolerance. Fermentation of these three strains at higher temperatures of 39 and 43 °C showed 23-66% improved riboflavin titers, as well as 24-h shortened fermentation period. These results indicated that implanting HSPs from thermophiles to B. subtilis 446 would be an efficient approach to improve its stress tolerance and riboflavin production.


Assuntos
Bacillus subtilis/fisiologia , Expressão Gênica , Proteínas de Choque Térmico/metabolismo , Proteínas Recombinantes/metabolismo , Riboflavina/metabolismo , Estresse Fisiológico , Complexo Vitamínico B/metabolismo , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/genética , Bacillus subtilis/efeitos da radiação , Geobacillus/enzimologia , Geobacillus/genética , Proteínas de Choque Térmico/genética , Resposta ao Choque Térmico , Temperatura Alta , Viabilidade Microbiana/efeitos dos fármacos , Viabilidade Microbiana/efeitos da radiação , Pressão Osmótica , Regiões Promotoras Genéticas , Proteínas Recombinantes/genética , Cloreto de Sódio/metabolismo
14.
Int J Cancer ; 144(5): 947-956, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29786139

RESUMO

One-carbon metabolism biomarkers are easily measured in plasma, but analyzing them one at a time in relation to disease does not take into account the interdependence of the many factors involved. The relative dynamics of major one-carbon metabolism branches can be assessed by relating the functional B-vitamin marker total homocysteine (tHcy) to transsulfuration (total cysteine) and methylation (creatinine) outputs. We validated the ratios of tHcy to total cysteine (Hcy:Cys), tHcy to creatinine (Hcy:Cre) and tHcy to cysteine to creatinine (Hcy:Cys:Cre) as functional markers of B-vitamin status. We also calculated the associations of these ratios to colorectal cancer (CRC) risk. Furthermore, the relative contribution of potential confounders to the variance of the ratio-based B-vitamin markers was calculated by linear regression in a nested case-control study of 613 CRC cases and 1,190 matched controls. Total B-vitamin status was represented by a summary score comprising Z-standardized plasma concentrations of folate, cobalamin, betaine, pyridoxal 5'-phosphate and riboflavin. Associations with CRC risk were estimated using conditional logistic regression. We found that the ratio-based B-vitamin markers all outperformed tHcy as markers of total B-vitamin status, in both CRC cases and controls. In addition, associations with CRC risk were similar for the ratio-based B-vitamin markers and total B-vitamin status (approximately 25% lower risk for high vs. low B-vitamin status). In conclusion, ratio-based B-vitamin markers were good predictors of total B-vitamin status and displayed similar associations as total B-vitamin status with CRC risk. Since tHcy and creatinine are routinely clinically analyzed, Hcy:Cre could be easily implemented in clinical practice.


Assuntos
Biomarcadores Tumorais/metabolismo , Carbono/metabolismo , Neoplasias Colorretais/metabolismo , Complexo Vitamínico B/metabolismo , Betaína/metabolismo , Estudos de Casos e Controles , Creatinina/metabolismo , Cisteína/metabolismo , Feminino , Ácido Fólico/metabolismo , Homocisteína/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estado Nutricional/fisiologia , Fosfato de Piridoxal/metabolismo , Riboflavina/metabolismo , Vitamina B 12/metabolismo
15.
ISME J ; 13(2): 334-345, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30228381

RESUMO

Ostreococcus tauri, a picoeukaryotic alga that contributes significantly to primary production in oligotrophic waters, has a highly streamlined genome, lacking the genetic capacity to grow without the vitamins thiamine (B1) and cobalamin (B12). Here we demonstrate that the B12 and B1 auxotrophy of O. tauri can be alleviated by co-culturing with a heterotrophic bacterial partner Dinoroseobacter shibae, a member of the Rhodobacteraceae family of alpha-proteobacteria, genera of which are frequently found associated with marine algae. D. shibae lacks the complete pathway to synthesise three other B-vitamins: niacin (B3), biotin (B7), and p-aminobenzoic acid (a precursor for folate, B9), and the alga is in turn able to satisfy the reciprocal vitamin requirements of its bacterial partner in a stable long-term co-culture. Bioinformatics searches of 197 representative marine bacteria with sequenced genomes identified just nine species that had a similar combination of traits (ability to make vitamin B12, but missing one or more genes for niacin and biotin biosynthesis enzymes), all of which were from the Rhodobacteraceae. Further analysis of 70 species from this family revealed the majority encoded the B12 pathway, but only half were able to make niacin, and fewer than 13% biotin. These characteristics may have either contributed to or resulted from the tendency of members of this lineage to adopt lifestyles in close association with algae. This study provides a nuanced view of bacterial-phytoplankton interactions, emphasising the complexity of the sources, sinks and dynamic cycling between marine microbes of these important organic micronutrients.


Assuntos
Clorófitas/metabolismo , Clorófitas/microbiologia , Rhodobacteraceae/metabolismo , Simbiose , Complexo Vitamínico B/metabolismo , Biotina/metabolismo , Clorófitas/genética , Processos Heterotróficos , Niacina/metabolismo , Fitoplâncton/metabolismo , Tiamina/metabolismo , Vitamina B 12/metabolismo
16.
FEMS Yeast Res ; 19(1)2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30321337

RESUMO

The overproduction of riboflavin (vitamin B2) by Ashbya gossypii, one of the most distinctive traits of this filamentous hemiascomycete, has been proposed to act as an ecological defense mechanism, since it is triggered by environmental stress. The interaction of endogenous riboflavin with light generates reactive oxygen species (ROS) and induces oxidative DNA damage in mammalian cells, but exogenous riboflavin was shown to protect A. gossypii spores against ultraviolet light. Envisioning a better understanding of this biotechnologically relevant trait, here we investigated the putative genotoxic effects associated with the overproduction of riboflavin by A. gossypii. For assessing that we developed the Ashbya Comet Assay, which was able to reproducibly measure oxidative (H2O2/menadione-mediated) and non-oxidative (camptothecin-mediated) DNA damage in A. gossypii. Using this protocol, we determined that exposure to sunlight-mimicking light during growth significantly increased the DNA damage accumulation in riboflavin-overproducing cells, but not in non-overproducing ones. The exposure of overproducing cells to light induced the intracellular accumulation of ROS and increased the production of riboflavin 1.5-fold. These results show that riboflavin-overproducing strains are highly susceptible to photo-induced oxidative DNA damage and draw attention for the importance of controlling the exposure to light of biotechnological riboflavin production processes with A. gossypii.


Assuntos
Dano ao DNA/efeitos dos fármacos , Eremothecium/efeitos da radiação , Luz , Mutagênicos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Riboflavina/metabolismo , Complexo Vitamínico B/metabolismo , Ensaio Cometa , DNA Fúngico/efeitos dos fármacos , Eremothecium/metabolismo
17.
Curr Opin Biotechnol ; 56: 18-29, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30138794

RESUMO

Vitamins are essential compounds in human and animal diets. Their demand is increasing globally in food, feed, cosmetics, chemical and pharmaceutical industries. Most current production methods are unsustainable because they use non-renewable sources and often generate hazardous waste. Many microorganisms produce vitamins naturally, but their corresponding metabolic pathways are tightly regulated since vitamins are needed only in catalytic amounts. Metabolic engineering is accelerating the development of microbial cell factories for vitamins that could compete with chemical methods that have been optimized over decades, but scientific hurdles remain. Additional technological and regulatory issues need to be overcome for innovative bioprocesses to reach the market. Here, we review the current state of development and challenges for fermentative processes for the B vitamin group.


Assuntos
Bactérias/metabolismo , Biotecnologia , Complexo Vitamínico B/metabolismo , Ração Animal , Bactérias/classificação , Bactérias/genética , Cosméticos/química , Suplementos Nutricionais , Fermentação , Engenharia Metabólica , Redes e Vias Metabólicas , Preparações Farmacêuticas/química , Complexo Vitamínico B/economia , Leveduras/classificação , Leveduras/genética , Leveduras/metabolismo
18.
PLoS One ; 13(12): e0209700, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30576372

RESUMO

Pyrroloquinoline quinone (PQQ) is believed to be a new B vitamin-like compound, and PQQ supplementation has received attention as a possible treatment for diseases including dementia and diabetes. However, the distribution of PQQ in foods is unclear, due to the difficulty in analyzing the compound. Therefore, in this study, enzymatic and LC-MS/MS methods were optimized to enable an accurate analysis of PQQ in foods. The optimized methods were applied to the screening of foods, in which PQQ contents were identified in ng/g or ng/mL levels. Furthermore, we newly found that some foods related to acetic acid bacteria contain PQQ at 1.94~5.59 ng/mL higher than beer, which is known to contain relatively high amounts of PQQ. These results suggest that the optimized methods are effective for the screening of foods containing PQQ. Such foods with high PQQ content may be valuable as functional foods effective towards the treatment of certain diseases.


Assuntos
Análise de Alimentos , Cofator PQQ/isolamento & purificação , Complexo Vitamínico B/metabolismo , Cromatografia Líquida , Dietoterapia , Alimentos , Humanos , Cofator PQQ/química , Cofator PQQ/metabolismo , Espectrometria de Massas em Tandem , Complexo Vitamínico B/química
19.
Nutrients ; 10(12)2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30513795

RESUMO

A diet rich in B-group vitamins is essential for optimal body and brain function, and insufficient amounts of such vitamins have been associated with higher levels of neural inflammation and oxidative stress, as marked by increased blood plasma homocysteine. Neural biomarkers of oxidative stress quantified through proton magnetic spectroscopy (1H-MRS) are not well understood, and the relationship between such neural and blood biomarkers is seldom studied. The current study addresses this gap by investigating the direct effect of 6-month high-dose B-group vitamin supplementation on neural and blood biomarkers of metabolism. Using a randomized, double-blind, placebo-controlled design, 32 healthy adults (20 female, 12 male) aged 30⁻65 years underwent blood tests (vitamin B6, vitamin B12, folate, and homocysteine levels) and 1H-MRS of the posterior cingulate cortex (PCC) and dorsolateral prefrontal cortex (DLPFC) before and after supplementation. Results confirmed the supplement was effective in increasing vitamin B6 and vitamin B12 levels and reducing homocysteine, whereas there was no change in folate levels. There were significant relationships between vitamin B6 and N-acetylaspartate (NAA), choline, and creatine, as well as between vitamin B12 and creatine (ps < 0.05), whereas NAA in the PCC increased, albeit not significantly (p > 0.05). Together these data provide preliminary evidence for the efficacy of high-dose B-group supplementation in reducing oxidative stress and inflammation through increasing oxidative metabolism. It may also promote myelination, cellular metabolism, and energy storage.


Assuntos
Antioxidantes/farmacologia , Encéfalo/efeitos dos fármacos , Suplementos Nutricionais , Estresse Oxidativo/efeitos dos fármacos , Complexo Vitamínico B/farmacologia , Adulto , Idoso , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Biomarcadores/metabolismo , Encéfalo/metabolismo , Cognição , Transtornos Cognitivos , Creatina/metabolismo , Método Duplo-Cego , Feminino , Homocisteína/metabolismo , Humanos , Inflamação/prevenção & controle , Masculino , Pessoa de Meia-Idade , Complexo Vitamínico B/sangue , Complexo Vitamínico B/metabolismo
20.
Compr Physiol ; 8(4): 1291-1311, 2018 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-30215865

RESUMO

Nine compounds are classified as water-soluble vitamins, eight B vitamins and one vitamin C. The vitamins are mandatory for the function of numerous enzymes and lack of one or more of the vitamins may lead to severe medical conditions. All the vitamins are supplied by food in microgram to milligram quantities and in addition some of the vitamins are synthesized by the intestinal microbiota. In the gastrointestinal tract, the vitamins are liberated from binding proteins and for some of the vitamins modified prior to absorption. Due to their solubility in water, they all require specific carriers to be absorbed. Our current knowledge concerning each of the vitamins differs in depth and focus and is influenced by the prevalence of conditions and diseases related to lack of the individual vitamin. Because of that we have chosen to cover slightly different aspects for the individual vitamins. For each of the vitamins, we summarize the physiological role, the steps involved in the absorption, and the factors influencing the absorption. In addition, for some of the vitamins, the molecular base for absorption is described in details, while for others new aspects of relevance for human deficiency are included. © 2018 American Physiological Society. Compr Physiol 8:1291-1311, 2018.


Assuntos
Ácido Ascórbico/metabolismo , Trato Gastrointestinal/metabolismo , Complexo Vitamínico B/metabolismo , Animais , Ácido Ascórbico/farmacocinética , Transporte Biológico Ativo , Absorção Gastrointestinal , Humanos , Complexo Vitamínico B/farmacocinética
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