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1.
Proc Natl Acad Sci U S A ; 119(42): e2121105119, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36215474

RESUMO

Among mammals, the order Primates is exceptional in having a high taxonomic richness in which the taxa are arboreal, semiterrestrial, or terrestrial. Although habitual terrestriality is pervasive among the apes and African and Asian monkeys (catarrhines), it is largely absent among monkeys of the Americas (platyrrhines), as well as galagos, lemurs, and lorises (strepsirrhines), which are mostly arboreal. Numerous ecological drivers and species-specific factors are suggested to set the conditions for an evolutionary shift from arboreality to terrestriality, and current environmental conditions may provide analogous scenarios to those transitional periods. Therefore, we investigated predominantly arboreal, diurnal primate genera from the Americas and Madagascar that lack fully terrestrial taxa, to determine whether ecological drivers (habitat canopy cover, predation risk, maximum temperature, precipitation, primate species richness, human population density, and distance to roads) or species-specific traits (body mass, group size, and degree of frugivory) associate with increased terrestriality. We collated 150,961 observation hours across 2,227 months from 47 species at 20 sites in Madagascar and 48 sites in the Americas. Multiple factors were associated with ground use in these otherwise arboreal species, including increased temperature, a decrease in canopy cover, a dietary shift away from frugivory, and larger group size. These factors mostly explain intraspecific differences in terrestriality. As humanity modifies habitats and causes climate change, our results suggest that species already inhabiting hot, sparsely canopied sites, and exhibiting more generalized diets, are more likely to shift toward greater ground use.


Assuntos
Evolução Biológica , Primatas , América , Animais , Cercopithecidae , Haplorrinos , Humanos , Madagáscar , Mamíferos , Árvores
2.
J Anat ; 239(5): 1221-1225, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34633083

RESUMO

Teaching and learning anatomy by using human cadaveric specimens has been a foundation of medical and biomedical teaching for hundreds of years. Therefore, the majority of institutions that teach topographical anatomy rely on body donation programmes to provide specimens for both undergraduate and postgraduate teaching of gross anatomy. The COVID-19 pandemic has posed an unprecedented challenge to anatomy teaching because of the suspension of donor acceptance at most institutions. This was largely due to concerns about the potential transmissibility of the SARS-CoV-2 virus and the absence of data about the ability of embalming solutions to neutralise the virus. Twenty embalming solutions commonly used in institutions in the United Kingdom and Ireland were tested for their ability to neutralise SARS-CoV-2, using an established cytotoxicity assay. All embalming solutions tested neutralised SARS-CoV-2, with the majority of solutions being effective at high-working dilutions. These results suggest that successful embalming with the tested solutions can neutralise the SARS-CoV-2 virus, thereby facilitating the safe resumption of body donation programmes and cadaveric anatomy teaching.


Assuntos
COVID-19/virologia , Transmissão de Doença Infecciosa/prevenção & controle , Embalsamamento/métodos , Formaldeído/farmacologia , Pandemias , SARS-CoV-2 , Fixação de Tecidos/métodos , COVID-19/transmissão , Cadáver , Células Cultivadas , Fixadores/farmacologia , Humanos
3.
Front Microbiol ; 12: 681983, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34421842

RESUMO

Hausa koko is an indigenous porridge processed from millet in Ghana. The process involves fermentation stages, giving the characteristic organoleptic properties of the product that is produced largely at a small-scale household level and sold as a street food. Like many other indigenous foods, quality control is problematic and depends on the skills of the processor. In order to improve the quality of the product and standardize the process for large-scale production, we need a deeper understanding of the microbial processes. The aim of this study is to investigate the microbial community involved in the production of this traditional millet porridge and the metabolites produced during processing. High-throughput amplicon sequencing was used to identify the bacterial (16S rRNA V4 hypervariable region) and fungal [Intergenic Transcribed Spacer (ITS)] communities associated with the fermentation, while nuclear magnetic resonance (NMR) was used for metabolite profiling. The bacterial community diversity was reduced during the fermentation processes with an increase and predominance of lactobacilli. Other dominant bacteria in the fermentation included Pediococcus, Weissella, Lactococcus, Streptococcus, Leuconostoc, and Acetobacter. The species Limosilactobacillus fermentum and Ligilactobacillus salivarius accounted for some of the diversities within and between fermentation time points and processors. The fungal community was dominated by the genus Saccharomyces. Other genera such as Pichia, Candida, Kluyveromyces, Nakaseomyces, Torulaspora, and Cyberlindnera were also classified. The species Saccharomyces cerevisiae, Stachybotrys sansevieriae, Malassezia restricta, Cyberlindnera fabianii, and Kluyveromyces marxianus accounted for some of the diversities within some fermentation time points. The species S. sansevieria and M. restricta may have been reported for the first time in cereal fermentation. This is the most diverse microbial community reported in Hausa koko. In this study, we could identify and quantify 33 key different metabolites produced by the interactions of the microbial communities with the millet, composed of organic compounds, sugars, amino acids and intermediary compounds, and other key fermentation compounds. An increase in the concentration of organic acids in parallel with the reduction of sugars occurred during the fermentation process while an initial increase of amino acids followed by a decrease in later fermentation steps was observed.

4.
Nutrients ; 12(4)2020 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-32235410

RESUMO

BACKGROUND: Bifidobacterium represents an important early life microbiota member. Specific bifidobacterial components, exopolysaccharides (EPS), positively modulate host responses, with purified EPS also suggested to impact microbe-microbe interactions by acting as a nutrient substrate. Thus, we determined the longitudinal effects of bifidobacterial EPS on microbial communities and metabolite profiles using an infant model colon system. METHODS: Differential gene expression and growth characteristics were determined for each strain; Bifidobacterium breve UCC2003 and corresponding isogenic EPS-deletion mutant (B. breve UCC2003del). Model colon vessels were inoculated with B. breve and microbiome dynamics monitored using 16S rRNA sequencing and metabolomics (NMR). RESULTS: Transcriptomics of EPS mutant vs. B. breve UCC2003 highlighted discrete differential gene expression (e.g., eps biosynthetic cluster), though overall growth dynamics between strains were unaffected. The EPS-positive vessel had significant shifts in microbiome and metabolite profiles until study end (405 h); with increases of Tyzzerella and Faecalibacterium, and short-chain fatty acids, with further correlations between taxa and metabolites which were not observed within the EPS-negative vessel. CONCLUSIONS: These data indicate that B. breve UCC2003 EPS is potentially metabolized by infant microbiota members, leading to differential microbial metabolism and altered metabolite by-products. Overall, these findings may allow development of EPS-specific strategies to promote infant health.


Assuntos
Bifidobacterium breve/genética , Bifidobacterium breve/fisiologia , Colo/metabolismo , Colo/microbiologia , Suplementos Nutricionais , Microbioma Gastrointestinal/fisiologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Saúde do Lactente , Polissacarídeos Bacterianos/genética , Polissacarídeos Bacterianos/metabolismo , Bifidobacterium breve/crescimento & desenvolvimento , Expressão Gênica , Humanos , Lactente , Mutação , RNA Ribossômico 16S/genética
5.
Appl Microbiol Biotechnol ; 104(9): 3869-3884, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32170384

RESUMO

Bacteriocins are antimicrobial peptides produced by bacteria, and their production is regarded as a desirable probiotic trait. We found that Lactobacillus gasseri LM19, a strain isolated from human milk, produces several bacteriocins, including a novel bacteriocin, gassericin M. These bacteriocins were purified from culture and synthesised to investigate their activity and potential synergy. L. gasseri LM19 was tested in a complex environment mimicking human colon conditions; it not only survived, but expressed the seven bacteriocin genes and produced short-chain fatty acids. Metagenomic analysis of these in vitro colon cultures showed that co-inoculation of L. gasseri LM19 with Clostridium perfringens gave 16S ribosomal RNA metagenomic profiles with more similarity to controls than to vessels inoculated with C. perfringens alone. These results indicate that L. gasseri LM19 could be an interesting candidate for maintaining homeostasis in the gut environment.


Assuntos
Antibacterianos/biossíntese , Bacteriocinas/biossíntese , Lactobacillus gasseri/metabolismo , Leite Humano/microbiologia , Probióticos/metabolismo , Colo/microbiologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Lactobacillus gasseri/genética , Metagenoma , Família Multigênica , Técnicas de Cultura de Órgãos
6.
Am J Primatol ; 82(4): e23125, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32202661

RESUMO

Due to the impact of anthropogenic activities on forest extent and integrity across Madagascar, it is increasingly necessary to assess how endangered lemur populations inhabiting human-dominated forest fragments can effectively sustain themselves ecologically. Our research addresses this concern by exploring how the distribution patterns of a small population of crowned lemurs (Eulemur coronatus), occupying a degraded forest fragment at Oronjia Forest New Protected Area in northern Madagascar, are impacted by the availability of key ecological and anthropogenic factors. We hypothesize that the distribution of E. coronatus within the fragment is limited by the availability of critical ecological resources and conditions and the intensity of anthropogenic features and activities. To examine this, we used MaxEnt to develop a species distribution model using presence-only occurrence records and 10 independent background covariates detailing the site's ecological and anthropogenic aspects. The results indicate that the realized distribution patterns of E. coronatus within human-dominated forest fragments are strongly associated with sections of forest that contain sparsely and sporadically distributed resources, such as freshwater and continuous hardwood vegetation. We conclude that the distribution of E. coronatus at Oronjia is shaped by their need to maximize foraging opportunities in a degraded forest landscape where they are subject to both environmental and anthropogenic stressors.


Assuntos
Ecossistema , Florestas , Lemuridae , Distribuição Animal , Conservação dos Recursos Naturais , Água Doce , Atividades Humanas , Madagáscar
7.
Appl Environ Microbiol ; 86(8)2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32060027

RESUMO

Lactobacillus johnsonii FI9785 makes two capsular exopolysaccharides-a heteropolysaccharide (EPS2) encoded by the eps operon and a branched glucan homopolysaccharide (EPS1). The homopolysaccharide is synthesized in the absence of sucrose, and there are no typical glucansucrase genes in the genome. Quantitative proteomics was used to compare the wild type to a mutant where EPS production was reduced to attempt to identify proteins associated with EPS1 biosynthesis. A putative bactoprenol glycosyltransferase, FI9785_242 (242), was less abundant in the Δeps_cluster mutant strain than in the wild type. Nuclear magnetic resonance (NMR) analysis of isolated EPS showed that deletion of the FI9785_242 gene (242) prevented the accumulation of EPS1, without affecting EPS2 synthesis, while plasmid complementation restored EPS1 production. The deletion of 242 also produced a slow-growth phenotype, which could be rescued by complementation. 242 shows amino acid homology to bactoprenol glycosyltransferase GtrB, involved in O-antigen glycosylation, while in silico analysis of the neighboring gene 241 suggested that it encodes a putative flippase with homology to the GtrA superfamily. Deletion of 241 also prevented production of EPS1 and again caused a slow-growth phenotype, while plasmid complementation reinstated EPS1 synthesis. Both genes are highly conserved in L. johnsonii strains isolated from different environments. These results suggest that there may be a novel mechanism for homopolysaccharide synthesis in the Gram-positive L. johnsoniiIMPORTANCE Exopolysaccharides are key components of the surfaces of their bacterial producers, contributing to protection, microbial and host interactions, and even virulence. They also have significant applications in industry, and understanding their biosynthetic mechanisms may allow improved production of novel and valuable polymers. Four categories of bacterial exopolysaccharide biosynthesis have been described in detail, but novel enzymes and glycosylation mechanisms are still being described. Our findings that a putative bactoprenol glycosyltransferase and flippase are essential to homopolysaccharide biosynthesis in Lactobacillus johnsonii FI9785 indicate that there may be an alternative mechanism of glucan biosynthesis to the glucansucrase pathway. Disturbance of this synthesis leads to a slow-growth phenotype. Further elucidation of this biosynthesis may give insight into exopolysaccharide production and its impact on the bacterial cell.


Assuntos
Proteínas de Bactérias/genética , Glucanos/biossíntese , Lactobacillus johnsonii/genética , Polissacarídeos Bacterianos/biossíntese , Proteoma/genética , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Glucanos/genética , Lactobacillus johnsonii/metabolismo , Polissacarídeos Bacterianos/genética , Proteoma/metabolismo , Alinhamento de Sequência
8.
Carbohydr Res ; 486: 107837, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31655418

RESUMO

Gentiobiose-derived oligosaccharides were synthesized by the acceptor reaction of glucansucrase E81 obtained from Lactobacillus reuteri E81 with sucrose and gentiobiose as donor-acceptor sugars, respectively. The reaction products were monitored by TLC analysis and gentiobiose-derived oligosaccharides up to DP 8 were formed during the acceptor reaction as determined by ESI-MS/MS analysis. The glycosylation of the gentiobiose with α-(1 → 6) linkages and α-(1 → 3) linkages was shown by 1H and 13C NMR analysis confirming the structure of these gentiobiose-derived oligosaccharides. The in vitro prebiotic function of the oligosaccharides was determined in which probiotic strains were stimulated whereas no growth was observed in pathogen strains. Gentiobiose-derived oligosaccharides showed immune-modulatory functions in vitro and triggered the production of IL-4, IL12 and TNF-α cytokines in HT29 cells in a dose dependent manner. This study showed the production and functional characterisation of gentiobiose-derived oligosaccharides establishing a promising avenue for future applications.


Assuntos
Dissacarídeos/química , Dissacarídeos/farmacologia , Glicosiltransferases/metabolismo , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Prebióticos , Células HT29 , Humanos
9.
Glycobiology ; 29(1): 45-58, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30371779

RESUMO

Lactobacillus reuteri is a gut symbiont inhabiting the gastrointestinal tract of numerous vertebrates. The surface-exposed serine-rich repeat protein (SRRP) is a major adhesin in Gram-positive bacteria. Using lectin and sugar nucleotide profiling of wild-type or L. reuteri isogenic mutants, MALDI-ToF-MS, LC-MS and GC-MS analyses of SRRPs, we showed that L. reuteri strains 100-23C (from rodent) and ATCC 53608 (from pig) can perform protein O-glycosylation and modify SRRP100-23 and SRRP53608 with Hex-Glc-GlcNAc and di-GlcNAc moieties, respectively. Furthermore, in vivo glycoengineering in E. coli led to glycosylation of SRRP53608 variants with α-GlcNAc and GlcNAcß(1→6)GlcNAcα moieties. The glycosyltransferases involved in the modification of these adhesins were identified within the SecA2/Y2 accessory secretion system and their sugar nucleotide preference determined by saturation transfer difference NMR spectroscopy and differential scanning fluorimetry. Together, these findings provide novel insights into the cellular O-protein glycosylation pathways of gut commensal bacteria and potential routes for glycoengineering applications.


Assuntos
Adesinas Bacterianas/química , Limosilactobacillus reuteri/química , Adesinas Bacterianas/genética , Adesinas Bacterianas/metabolismo , Glicosilação , Limosilactobacillus reuteri/genética , Limosilactobacillus reuteri/metabolismo , Mutação , Ressonância Magnética Nuclear Biomolecular , Sequências Repetitivas de Aminoácidos
10.
Biotechnol Biofuels ; 11: 62, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29541159

RESUMO

BACKGROUND: Rice straw and husk are globally significant sources of cellulose-rich biomass and there is great interest in converting them to bioethanol. However, rice husk is reportedly much more recalcitrant than rice straw and produces larger quantities of fermentation inhibitors. The aim of this study was to explore the underlying differences between rice straw and rice husk with reference to the composition of the pre-treatment liquors and their impacts on saccharification and fermentation. This has been carried out by developing quantitative NMR screening methods. RESULTS: Air-dried rice husk and rice straw from the same cultivar were used as substrates. Carbohydrate compositions were similar, whereas lignin contents differed significantly (husk: 35.3% w/w of raw material; straw 22.1% w/w of raw material). Substrates were hydrothermally pre-treated with high-pressure microwave processing across a wide range of severities. 25 compounds were identified from the liquors of both pre-treated rice husk and rice straw. However, the quantities of compounds differed between the two substrates. Fermentation inhibitors such as 5-HMF and 2-FA were highest in husk liquors, and formic acid was higher in straw liquors. At a pre-treatment severity of 3.65, twice as much ethanol was produced from rice straw (14.22% dry weight of substrate) compared with the yield from rice husk (7.55% dry weight of substrate). Above severities of 5, fermentation was inhibited in both straw and husk. In addition to inhibitors, high levels of cellulase-inhibiting xylo-oligomers and xylose were found and at much higher concentrations in rice husk liquor. At low severities, organic acids and related intracellular metabolites were released into the liquor. CONCLUSIONS: Rice husk recalcitrance to saccharification is probably due to the much higher levels of lignin and, from other studies, likely high levels of silica. Therefore, if highly polluting chemical pre-treatments and multi-step biorefining processes are to be avoided, rice husk may need to be improved through selective breeding strategies, although more careful control of pre-treatment may be sufficient to reduce the levels of fermentation inhibitors, e.g. through steam explosion-induced volatilisation. For rice straw, pre-treating at severities of between 3.65 and 4.25 would give a glucose yield of between 37.5 and 40% (w/DW, dry weight of the substrate) close to the theoretical yield of 44.1% w/DW, and an insignificant yield of total inhibitors.

11.
Food Chem ; 248: 52-60, 2018 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-29329870

RESUMO

High-field and low-field proton NMR spectroscopy were used to analyse lipophilic extracts from ground roast coffees. Using a sample preparation method that produced concentrated extracts, a small marker peak at 3.16 ppm was observed in 30 Arabica coffees of assured origin. This signal has previously been believed absent from Arabicas, and has been used as a marker for detecting adulteration with robusta. Via 2D 600 MHz NMR and LC-MS, 16-O-methylcafestol and 16-O-methylkahweol were detected for the first time in Arabica roast coffee and shown to be responsible for the marker peak. Using low-field NMR, robusta in Arabica could be detected at levels of the order of 1-2% w/w. A surveillance study of retail purchased "100% Arabica" coffees found that 6 out of 60 samples displayed the 3.16 ppm marker signal to a degree commensurate with adulteration at levels of 3-30% w/w.


Assuntos
Café/química , Diterpenos/análise , Análise de Alimentos/métodos , Espectroscopia de Ressonância Magnética/métodos , Coffea/química , Contaminação de Alimentos/análise , Limite de Detecção , Reprodutibilidade dos Testes
12.
Food Chem ; 242: 45-52, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29037713

RESUMO

Cereal-associated Lactic Acid Bacteria (LAB) are well known for homopolymeric exopolysaccharide (EPS) production. Herein, the structure of an EPS isolated from sourdough isolate Lactobacillus brevis E25 was determined. A modified BHI medium was used for production of EPS-E25 in order to eliminate potential contaminants. Analysis of sugar monomers in EPS revealed that glucose was the only sugar present. Structural characterisation of EPS by NMR and methylation analysis revealed that E25 produced a highly branched α-glucan with (α1→3) and (α1→6) glycosidic linkages, and was similar in structure to a previously reported EPS from Lactobacillus reuteri 180. The 1H and 13C NMR data were contrasted with newly recorded data for known polysaccharides (alternan, commercial dextran) which also contain α-(1,3,6)Glc branch points. It was found in both E25 EPS and alternan that NMR parameters could be used to distinguish glucose residues that had the same substitution pattern but occupied different positions in the structure.


Assuntos
Glucanos/química , Levilactobacillus brevis/química , Polissacarídeos Bacterianos/química , Dextranos/química , Grão Comestível/química , Limosilactobacillus reuteri/química , Espectroscopia de Ressonância Magnética
13.
Sci Rep ; 7(1): 14259, 2017 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-29079838

RESUMO

In addition to ethanol, yeasts have the potential to produce many other industrially-relevant chemicals from numerous different carbon sources. However there remains a paucity of information about overall capability across the yeast family tree. Here, 11 diverse species of yeasts with genetic backgrounds representative of different branches of the family tree were investigated. They were compared for their abilities to grow on a range of sugar carbon sources, to produce potential platform chemicals from such substrates and to ferment hydrothermally pretreated rice straw under simultaneous saccharification and fermentation conditions. The yeasts differed considerably in their metabolic capabilities and production of ethanol. A number could produce significant amounts of ethyl acetate, arabinitol, glycerol and acetate in addition to ethanol, including from hitherto unreported carbon sources. They also demonstrated widely differing efficiencies in the fermentation of sugars derived from pre-treated rice straw biomass and differential sensitivities to fermentation inhibitors. A new catabolic property of Rhodotorula mucilaginosa (NCYC 65) was discovered in which sugar substrate is cleaved but the products are not metabolised. We propose that engineering this and some of the other properties discovered in this study and transferring such properties to conventional industrial yeast strains could greatly expand their biotechnological utility.


Assuntos
Biodiversidade , Biocombustíveis/microbiologia , Rhodotorula/metabolismo , Carbono/metabolismo , Fermentação , Oryza/química , Rhodotorula/crescimento & desenvolvimento , Especificidade da Espécie , Açúcares/metabolismo
14.
Carbohydr Res ; 451: 110-117, 2017 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-28851488

RESUMO

Naturally occurring 2,7-anhydro-alpha-N-acetylneuraminic acid (2,7-anhydro-Neu5Ac) is a transglycosylation product of bacterial intramolecular trans-sialidases (IT-sialidases). A facile one-pot two-enzyme approach has been established for the synthesis of 2,7-anhydro-sialic acid derivatives including those containing different sialic acid forms such as Neu5Ac and N-glycolylneuraminic acid (Neu5Gc). The approach is based on the use of Ruminoccocus gnavus IT-sialidase for the release of 2,7-anhydro-sialic acid from glycoproteins, and the conversion of free sialic acid by a sialic acid aldolase. This synthetic method, which is based on a membrane-enclosed enzymatic synthesis, can be performed on a preparative scale. Using fetuin as a substrate, high-yield and cost-effective production of 2,7-anhydro-Neu5Ac was obtained to high-purity. This method was also applied to the synthesis of 2,7-anhydro-Neu5Gc. The membrane-enclosed multienzyme (MEME) strategy reported here provides an efficient approach to produce a variety of sialic acid derivatives.


Assuntos
Glicoproteínas/metabolismo , Ácido N-Acetilneuramínico/análogos & derivados , Ácido N-Acetilneuramínico/química , Ácido N-Acetilneuramínico/metabolismo , Neuraminidase/metabolismo , Ruminococcus/enzimologia , Ruminococcus/metabolismo
15.
J Proteome Res ; 16(7): 2516-2526, 2017 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-28585834

RESUMO

Flavan-3-ols and methylxanthines have potential beneficial effects on human health including reducing cardiovascular risk. We performed a randomized controlled crossover intervention trial to assess the acute effects of consumption of flavan-3-ol-enriched dark chocolate, compared with standard dark chocolate and white chocolate, on the human metabolome. We assessed the metabolome in urine and blood plasma samples collected before and at 2 and 6 h after consumption of chocolates in 42 healthy volunteers using a nontargeted metabolomics approach. Plasma samples were assessed and showed differentiation between time points with no further separation among the three chocolate treatments. Multivariate statistics applied to urine samples could readily separate the postprandial time points and distinguish between the treatments. Most of the markers responsible for the multivariate discrimination between the chocolates were of dietary origin. Interestingly, small but significant level changes were also observed for a subset of endogenous metabolites. 1H NMR revealed that flavan-3-ol-enriched dark chocolate and standard dark chocolate reduced urinary levels of creatinine, lactate, some amino acids, and related degradation products and increased the levels of pyruvate and 4-hydroxyphenylacetate, a phenolic compound of bacterial origin. This study demonstrates that an acute chocolate intervention can significantly affect human metabolism.


Assuntos
Chocolate/análise , Flavonoides/administração & dosagem , Metaboloma/fisiologia , Compostos Fitoquímicos/administração & dosagem , Aminoácidos/sangue , Aminoácidos/urina , Creatinina/sangue , Creatinina/urina , Estudos Cross-Over , Feminino , Flavonoides/sangue , Flavonoides/urina , Humanos , Ácido Láctico/sangue , Ácido Láctico/urina , Masculino , Metabolômica/métodos , Fenilacetatos/sangue , Fenilacetatos/urina , Compostos Fitoquímicos/sangue , Compostos Fitoquímicos/urina , Período Pós-Prandial , Ácido Pirúvico/sangue , Ácido Pirúvico/urina , Fatores Sexuais
16.
Food Chem ; 216: 106-13, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27596398

RESUMO

This work reports a new screening protocol for addressing issues of coffee authenticity using low-field (60MHz) bench-top (1)H NMR spectroscopy. Using a simple chloroform-based extraction, useful spectra were obtained from the lipophilic fraction of ground roast coffees. It was found that 16-O-methylcafestol (16-OMC, a recognized marker compound for robusta beans) gives rise to an isolated peak in the 60MHz spectrum, which can be used as an indicator of the presence of robusta beans in the sample. A total of 81 extracts from authenticated coffees and mixtures were analysed, from which the detection limit of robusta in arabica was estimated to be between 10% and 20% w/w. Using the established protocol, a surveillance exercise was conducted of 27 retail samples of ground roast coffees which were labelled as "100% arabica". None were found to contain undeclared robusta content above the estimated detection limit.


Assuntos
Café/química , Diterpenos/análise , Espectroscopia de Ressonância Magnética/métodos , Sementes/química , Café/classificação , Análise de Alimentos , Sementes/classificação
17.
Carbohydr Polym ; 136: 923-9, 2016 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-26572430

RESUMO

Pectins extracted from a variety of sources and modified with heat and/or pH have previously been shown to exhibit activity towards several cancer cell lines. However, the structural basis for the anti-cancer activity of modified pectin requires clarification. Sugar beet and citrus pectin extracts have been compared. Pectin extracted from sugar beet pulp only weakly affected the viability of colon cancer cells. Alkali treatment increased the anti-cancer effect of sugar beet pectin via an induction of apoptosis. Alkali treatment decreased the degree of esterification (DE) and increased the ratio of rhamnogalacturonan I (RGI) to homogalacturonan. Low DE per se did not play a significant role in the anti-cancer activity. However, the enzymatic removal of galactose and, to a lesser extent, arabinose from the pectin decreased the effect on cancer cells indicating that the neutral sugar-containing RGI regions are important for pectin bioactivity.


Assuntos
Antineoplásicos/química , Apoptose , Beta vulgaris/química , Pectinas/química , Extratos Vegetais/química , Antineoplásicos/farmacologia , Células HT29 , Humanos , Pectinas/farmacologia , Extratos Vegetais/farmacologia
18.
Microb Biotechnol ; 9(4): 496-501, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26401596

RESUMO

Lactobacillus johnsonii FI9785 has an eps gene cluster which is required for the biosynthesis of homopolymeric exopolysaccharides (EPS)-1 and heteropolymeric EPS-2 as a capsular layer. The first gene of the cluster, epsA, is the putative transcriptional regulator. In this study we showed the crucial role of epsA in EPS biosynthesis by demonstrating that deletion of epsA resulted in complete loss of both EPS-1 and EPS-2 on the cell surface. Plasmid complementation of the epsA gene fully restored EPS production, as confirmed by transmission electron microscopy and nuclear magnetic resonance (NMR) analysis. Furthermore, this complementation resulted in a twofold increase in the expression levels of this gene, which almost doubled amounts of EPS production in comparison with the wild-type strain. Analysis of EPS by NMR showed an increased ratio of the heteropolysaccharide to homopolysaccharide in the complemented strain and allowed identification of the acetylated residue in EPS-2 as the (1,4)-linked ßGlcp unit, with the acetyl group located at O-6. These findings indicate that epsA is a positive regulator of EPS production and that EPS production can be manipulated by altering its expression.


Assuntos
Genes Bacterianos , Genes Essenciais , Lactobacillus johnsonii/genética , Lactobacillus johnsonii/metabolismo , Polissacarídeos Bacterianos/biossíntese , Deleção de Genes , Teste de Complementação Genética , Lactobacillus johnsonii/ultraestrutura , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Transmissão , Família Multigênica
19.
Carbohydr Polym ; 132: 546-53, 2015 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-26256381

RESUMO

Pectin modified with pH, heat or enzymes, has previously been shown to exhibit anti-cancer activity. However, the structural requirements for modified pectin bioactivity have rarely been addressed. In this study several pectin extracts representing different structural components of pectin were assessed for effects against colon cancer cells. Rhamnogalacturonan I (RGI) extracts reduced proliferation of DLD1 and HCT116 colon cancer cells in a dose- and time-dependent manner. RGI reduced ICAM1 gene expression and siRNA-mediated knockdown of ICAM1 expression decreased cell proliferation providing a potential novel mechanism for the anti-cancer activity of pectin. Structural analysis of bioactive and non-bioactive RGIs suggested that a homogalacturonan component is maybe essential for the anti-proliferative activity, furthering the understanding of the structural requirements for pectin bioactivity.


Assuntos
Molécula 1 de Adesão Intercelular/metabolismo , Pectinas/química , Antineoplásicos/química , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Células HCT116 , Humanos , Molécula 1 de Adesão Intercelular/química , Molécula 1 de Adesão Intercelular/genética , Espectroscopia de Ressonância Magnética , Pectinas/toxicidade , Interferência de RNA , RNA Interferente Pequeno/metabolismo
20.
Asian Cardiovasc Thorac Ann ; 22(8): 987-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24887878

RESUMO

A 41-year-old male smoker presented with choking and coughing up food associated with repeated vomiting. Four years previously, following recurrent episodes of pancreatitis, he required percutaneous necrosectomy. He subsequently had a cholecystectomy and mesh repair of the abdominal wall, and later developed multiple problems including a gastrobronchial fistula. Computed tomography revealed a fistulous connection for which he had a combined procedure. Through a thoracolaparotomy approach, the left lower lobe and fistulous connection were removed along with the surrounding diaphragm and the associated fundus of the stomach. The diaphragm defect was repaired without mesh.


Assuntos
Fístula Brônquica/cirurgia , Gastrectomia/métodos , Fístula Gástrica/cirurgia , Pancreatite/complicações , Toracotomia , Adulto , Biópsia , Fístula Brônquica/diagnóstico , Fístula Brônquica/etiologia , Diafragma/cirurgia , Fístula Gástrica/diagnóstico , Fístula Gástrica/etiologia , Humanos , Masculino , Pancreatite/diagnóstico , Pancreatite/cirurgia , Recidiva , Reoperação , Tomografia Computadorizada por Raios X , Resultado do Tratamento
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