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2.
Nature ; 581(7807): 190-193, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32404996

RESUMO

The onset of plant cultivation is one of the most important cultural transitions in human history1-4. Southwestern Amazonia has previously been proposed as an early centre of plant domestication, on the basis of molecular markers that show genetic similarities between domesticated plants and wild relatives4-6. However, the nature of the early human occupation of southwestern Amazonia, and the history of plant cultivation in this region, are poorly understood. Here we document the cultivation of squash (Cucurbita sp.) at about 10,250 calibrated years before present (cal. yr BP), manioc (Manihot sp.) at about 10,350 cal. yr BP and maize (Zea mays) at about 6,850 cal. yr BP, in the Llanos de Moxos (Bolivia). We show that, starting at around 10,850 cal. yr BP, inhabitants of this region began to create a landscape that ultimately comprised approximately 4,700 artificial forest islands within a treeless, seasonally flooded savannah. Our results confirm that the Llanos de Moxos is a hotspot for early plant cultivation and demonstrate that-ever since their arrival in Amazonia-humans have markedly altered the landscape, with lasting repercussions for habitat heterogeneity and species conservation.


Assuntos
Produção Agrícola/história , Produtos Agrícolas/história , Florestas , Pradaria , Atividades Humanas , Biodiversidade , Bolívia , Conservação dos Recursos Naturais , Cucurbita/crescimento & desenvolvimento , Mapeamento Geográfico , História Antiga , Manihot/crescimento & desenvolvimento , Manihot/história , Amido , Zea mays/crescimento & desenvolvimento
3.
Bioresour Technol ; 308: 123263, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32247259

RESUMO

Assembly of novel ecofriendly and sustainable (N-PSPB/SHGL) nanosorbent was fabricated based on encapsulation of derived nanoscale spherical biochar from Pisum sativum pods (N-PSPB) with starch hydrogel (SHGL). The mass ratio between starch and N-PSPB was examined and 2% (w/w) was selected as the optimum percentage for fabrication of the assembled hydrogel. High swelling capacity was characterized by N-PSPB/SHGL nanosorbent (500.0%) at room temperature (25 °C), excellent stability for ten cycles with respect to regeneration by 0.1 mol L-1 HCl. Additionally, characterizations of N-PSPB/Starch nanosorbent were established by SEM and BET measurement to characterize surface area (226.94 m2/g) and pore volume (9.88 cm3/g). The N-PSPB/SHGL nanosorbent was subjected to extensive investigations to evaluate its efficiency for removal of naproxen drug (NAP) and chromium (VI). The Cr(VI) and NAP drug adsorptions were fitted to pseudo-second kinetic and correlated with Langmuir isotherm. The adsorption processes were spontaneous and endothermic based on thermodynamic study.


Assuntos
Cromo , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Hidrogéis , Íons , Cinética , Naproxeno , Ervilhas , Amido
4.
Int J Syst Evol Microbiol ; 70(3): 2008-2015, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32228775

RESUMO

A novel bacterium, designated strain PS13T, was isolated from marine sediment collected from the coast of Jeju Island. Strain PS13T was a Gram stain-negative, catalase- and oxidase-positive, aerobic, yellow-pigmented, motile by gliding, and rod-shaped bacterium. Strain PS13T grew optimally at 25 °C and pH 8.0 and in the presence of 3 % (w/v) NaCl. Results of phylogenetic analysis based on 16S rRNA gene sequences showed that strain PS13T belonged to the genus Formosa and was closely related to Formosa algae KMM3553T (98.3 % sequence similarity). The DNA-DNA relatedness (17.3-21.8 %) and average nucleotide identity (83.6-84.6 %) values clearly indicated that strain PS13T represents a distinct species of the genus Formosa. The major fatty acids were C15 : 0 iso, C16 : 1 ω6c/C16 : 1 ω7c and C15 : 1 iso G. The genomic DNA G+C content of the strain PS13T was 32.2 mol%. On the basis of polyphasic characteristics, it is suggested that strain PS13T be assigned to the genus Formosa as the type strain of a novel species, for which the name Formosa sediminum PS13T (=KCCM 43301T=CECT 9918T) sp. nov. is proposed.


Assuntos
Flavobacteriaceae/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Amido/metabolismo , Técnicas de Tipagem Bacteriana , Composição de Bases , Metabolismo dos Carboidratos , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacteriaceae/isolamento & purificação , Hibridização de Ácido Nucleico , Pigmentação , RNA Ribossômico 16S/genética , República da Coreia , Água do Mar/microbiologia , Análise de Sequência de DNA , Vitamina K 2/química
5.
Acta Crystallogr D Struct Biol ; 76(Pt 4): 357-365, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32254060

RESUMO

Starch is a key energy-storage molecule in plants that requires controlled synthesis and breakdown for effective plant growth. ß-Amylases (BAMs) hydrolyze starch into maltose to help to meet the metabolic needs of the plant. In the model plant Arabidopsis thaliana there are nine BAMs, which have apparently distinct functional and domain structures, although the functions of only a few of the BAMs are known and there are no 3D structures of BAMs from this organism. Recently, AtBAM2 was proposed to form a tetramer based on chromatography and activity assays of mutants; however, there was no direct observation of this tetramer. Here, small-angle X-ray scattering data were collected from AtBAM2 and its N-terminal truncations to describe the structure and assembly of the tetramer. Comparison of the scattering of the AtBAM2 tetramer with data collected from sweet potato (Ipomoea batatas) BAM5, which is also reported to form a tetramer, showed there were differences in the overall assembly. Analysis of the N-terminal truncations of AtBAM2 identified a loop sequence found only in BAM2 orthologs that appears to be critical for AtBAM2 tetramer assembly as well as for activity.


Assuntos
Proteínas de Arabidopsis/química , Arabidopsis/enzimologia , Proteínas Serina-Treonina Quinases/química , Amido/metabolismo , beta-Amilase/química , Sequência de Aminoácidos , Modelos Moleculares , Multimerização Proteica , Estrutura Quaternária de Proteína , Espalhamento de Radiação , Alinhamento de Sequência , Raios X
7.
Anaesthesia ; 75(4): 559, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32128801
8.
Food Chem ; 317: 126464, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32114275

RESUMO

Oat rice kernels were subjected to decortication (DOR), decortication and enzyme deactivation (DDOR), decortication and cooking (DCOR), as well as combined decortication, enzyme deactivation and cooking (DDCOR). The starch fractions were isolated and their structural features were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, solid-state 13C nuclear magnetic resonance, small angle X-ray scattering (SAXS), and scanning electron microscope. In the cooked oat rice samples (DCOR and DDCOR), in addition to losing a significant amount of the A-type crystalline structure, there was an enhancement in the proportion of V-type crystallinity. The cooking process completely destroyed the periodic lamellar structure of oat starch on the SAXS profile. The Mw values (1.195 × 107-1.459 × 107 g/mol) were in the following order: DOR > DDOR > DCOR > DDCOR. The data was in line with the results for crystallinity, double helix content, degree of order, melting enthalpy, and those obtained for textural parameters, resistant starch content, and bile acid binding capacity.


Assuntos
Avena/química , Culinária/métodos , Amido/química , Cristalização , Enzimas/química , Espectroscopia de Ressonância Magnética , Espalhamento a Baixo Ângulo , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
9.
Plant Mol Biol ; 103(3): 355-371, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32193789

RESUMO

KEYMESSAGE: Biphasic starch granules in maize ae mutant underwent the weak to strong SBEIIb-defective effect during endosperm development, leading to no birefringence in their exterior due to extended long branch-chains of amylopectin. Biphasic starch granules are usually detected regionally in cereal endosperm lacking starch branching enzyme (SBE). However, their molecular structure, formation mechanism, and regional distribution are unclear. In this research, biphasic starch granules were observed in the inner region of crown endosperm of maize ae mutant, and had poorly oriented structure with comb-like profiles in their exterior. The inner endosperm (IE) rich in biphasic starch granules and outer endosperm (OE) without biphasic starch granules were investigated. The starch had lower amylose content and higher proportion of long branch-chains of amylopectin in IE than in OE, and the exterior of biphasic starch granules had less amylose and more long branch-chains of amylopectin than the interior. Compared with OE, the expression pattern of starch synthesis related enzymes changed significantly in IE. The granule-bound starch synthase I activity within biphasic starch granules decreased slightly. The IE experienced more severe hypoxic stress than OE, and the up-regulated anaerobic respiration pathway indicated an increase in carbon consumption. The starch in IE underwent the SBEIIb-defective effect from weak to strong due to the lack of sufficient carbon inflow, leading to the formation of biphasic starch granules and their regional distribution in endosperm. The results provided information for understanding the biphasic starch granules.


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Amido/metabolismo , Zea mays/enzimologia , Enzima Ramificadora de 1,4-alfa-Glucana/classificação , Enzima Ramificadora de 1,4-alfa-Glucana/genética , Endosperma/enzimologia , Endosperma/ultraestrutura , Amido/ultraestrutura
10.
Plant Foods Hum Nutr ; 75(2): 298-304, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32189232

RESUMO

The study examined the effects of various methods of thermal treatment of Lord cultivar potato tubers on changes in starch, polyphenols, vitamin C, antioxidant activity, and mineral compounds. Following heat treatment in order to determine further transformations of starch, the potatoes were stored at 2 °C/24 h. Changes in starch, bioactive compounds and antioxidant properties varied depending on the treatment method. In general, higher retention of bioactive compounds was noted for tubers treated with "dry" methods, such as microwaving or grilling than for tubers treated with "wet" methods, e.g., boiling in water, steam cooking or cooking in a combi oven. These samples were also characterised by a higher resistant starch content. Cold storage resulted in an increase in the proportion of resistant starch. Total phenols content ranged from 210.96 (boiling) to 348.46 mg/100 g DW (grilling) and vitamin C content ranged from 43.79 (boiling) to 68.83 mg/100 g DW (microwaving). DPPH radical scavenging activity was the highest for the grilled tubers. The results indicate microwaving and grilling as the most favourable thermal treatments of potato.


Assuntos
Solanum tuberosum , Ácido Ascórbico , Culinária , Tubérculos , Amido
11.
Chem Pharm Bull (Tokyo) ; 68(3): 251-257, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32115532

RESUMO

A concise spherical granulation method is required to prepare extemporaneously granules remanufactured from oral dosage forms for administration to individuals who cannot swallow tablets or capsules. In this study, we determined the feasibility of spherical granulation using a planetary centrifugal mixer. A model formulation, 20% ibuprofen (IBP) granules, was prepared using a lactose/cornstarch (7 : 3, w/w) mixture or D-mannitol as diluents, and changes in granule characteristics (mean diameter (d50), distribution range of granule size (span), and yield) were evaluated according to the amount of water added and the granulation time. The amount of water was assessed using the plastic limit value as measured using a digital force gauge. We successfully produced granules, and larger amounts of water and longer granulation times resulted in larger d50 values and smaller span values. The optimal granulation time was 45 s and the optimal water contents were 70 and 67.5% of the plastic limit value for the lactose/cornstarch mixture and D-mannitol, respectively. When compared to commercial 20% IBP granules, powder X-ray diffraction and differential scanning calorimetry analyses showed that the granulation process did not alter the crystallinity of the drug. Thus, this novel granulation method using a planetary centrifugal mixer may be a promising technique for compounding in pharmacies and in pharmaceutical manufacturing.


Assuntos
Centrifugação , Ibuprofeno/química , Lactose/química , Manitol/química , Amido/química , Varredura Diferencial de Calorimetria , Ibuprofeno/isolamento & purificação , Tamanho da Partícula , Difração de Pó , Propriedades de Superfície
12.
Bioresour Technol ; 305: 122900, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32146048

RESUMO

Starch agricultural leftover is a potential substrate for photosynthetic bacteria to produce hydrogen. In this work, the effect of initial pH on photo-fermentation biohydrogen production process and electron balance were investigated. The modified Gompertz model was adopted, and hydrogen yield, sugar consumption and metabolite evolution were monitored with initial pH varying from 5 to 9. Results showed that hydrogen was produced mainly through acetic acid and butyric acid metabolism pathways when starch taken as carbon source. It was found that the maximum hydrogen yield (642 ± 22 mL) and highest hydrogen production rate (77.78 mL/(L·h)) were obtained at initial pH of 7. 37.65% substrates electrons diverted towards hydrogen. Lower hydrogen yield, hydrogen production rate and lower electrons diversion were obtained at other initial pH levels. Also, the lag phase time was 0.04 h when pH was 7, which was significantly lower than other levels.


Assuntos
Elétrons , Amido , Fermentação , Hidrogênio , Concentração de Íons de Hidrogênio
13.
PLoS One ; 15(3): e0228547, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32119679

RESUMO

Some excipients are currently available for the formulation of pharmaceutical suspensions. The objective of this study is to develop cheap and effective starch-based excipient that can be used as an effective alternative for the formulation of pharmaceutical suspensions. Carboxymethylated Plectranthus edulis, Vatke (P. edulis) [fam., Lamiaceae], starch was evaluated as a suspending agent in metronidazole benzoate suspensions in comparison with sodium carboxymethyl cellulose (NaCMC) at a concentration range of 1-4% (w/v). The resulting suspensions were evaluated for their sedimentation volume (%), degree of flocculation, rheology, redispersibility, and dissolution rate. Stability studies were performed for 3 months. The apparent viscosities of the formulations prepared with carboxymethylated P. edulis starch at reaction condition E (CMPS-E) was significantly lower than that of NaCMC (p < 0.05). The flowability of the suspensions, at all concentration levels of the suspending agents, were in the order of CMPS-E > NaCMC. AT 1% concentrations, carboxymethylated P. edulis starch (76 ± 1.5%) provided significantly higher (p < 0.05) sedimentation volume than NaCMC (40 ± 1.5%). At 3% and 4%, both gave comparable sedimentation volume (100%). Potassium dihydrogen phosphate (KH2PO4) employed as a flocculating agent significantly increased (p < 0.05) the sedimentation volume of the suspensions prepared with carboxymethylated P.edulis starch and NaCMC. The redispersibilities of CMPS-E were better than those of NaCMC. All suspensions showed a release of greater than 85% of drug within 1 h. The results of stability studies showed that all suspension formulations were stable. From the foregoing, it can be concluded that carboxymethylated P. edulis starch could be used as an alternative suspending agent.


Assuntos
Benzoatos/química , Composição de Medicamentos , Excipientes/química , Metronidazol/química , Plectranthus , Amido/química , Reologia , Suspensões
14.
Food Chem ; 315: 126230, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32014665

RESUMO

The dense packing and encapsulation of starch by protein are considered important for the digestion of noodles and the textural attributes. This study aims to elucidate the effect of gluten on the noodle texture and starch digestion rates. The structure of cooked noodles was characterized using a scanning electron microscope and Fourier-transform infrared-microscopy. The texture of cooked noodles remained similar when the gluten content was varied from 8 to 12%; however, the hardness increased significantly beyond 14% gluten content. The enzyme-digestion of cooked noodles was largely dependent on the protein content and the cooking time, and the digestibility of cooked noodles was increased when the noodle was over-cooked compared to optimum-cooked. The physical barrier provided by the protein network as well as the dense noodle structure is dependent on both the amount of protein and the cooking time. These factors, further moderate both hardness and enzyme susceptibility of cooked noodles.


Assuntos
Farinha/análise , Glutens/química , Amido/química , Culinária , Digestão , Dureza , Amido/metabolismo , Fatores de Tempo
15.
Bioresour Technol ; 302: 122810, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32028146

RESUMO

A two-stage process consisting of a pre-acidification unit and an Upflow Anaerobic Sludge Blanket (UASB) reactor (UASBT-S) was compared with a one-stage UASB reactor (UASBO-S) to evaluate the treatment stability of starch wastewater (SW). The Two-stage process provided higher treatment stability than UASBO-S. Sludge floatation occurred in the UASBO-S when the organic loading rate (OLR) was increased to 4 g-COD/L/d, beyond which a paste-like membrane structure adhered to the granules was observed. Further analysis suggests that the substrate derived polysaccharide components embedded in the loosely-bound extracellular polymeric substances (LB-EPS), triggered significant increase in the protein/polysaccharide ratio in the tightly-bound EPS (TB-EPS), and was suggested to result in the granules floatation and disintegration. During the pre-acidification, the starch was mainly converted to acetic and propionic acids. The pre-acidification was beneficial for reducing the EPS content fluctuations in the UASBT-S, which greatly improved settling capability and strength of the granular sludge.


Assuntos
Esgotos , Águas Residuárias , Anaerobiose , Reatores Biológicos , Concentração de Íons de Hidrogênio , Amido , Eliminação de Resíduos Líquidos
16.
Chemosphere ; 244: 125515, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32050331

RESUMO

Stable and long-term power output is a prerequisite for the application of the energy recovered from microbial fuel cells (MFCs). In this study, a novel fuel supplying strategy based on slow-release carbon embedded in polymer gels was attempted in MFCs aimed to achieve a sustainable power generation. Polymer gels containing starch acetate as the carbon source (40% (w/w)) were prepared, and the effects of its loading dosage on power generation and microbial community structure were investigated. Results showed that the MFCs once fed with 20.0 g/L, 37.5 g/L and 55.0 g/L polymer gels attained a long-term power generation periods of 110, 140 and 170 days, respectively, with a maximum power density of 386-427 mW/m2. The MFC with a medium loading dosage (37.5 g/L polymer gels) performed best. MFCs fed with the slow-release carbon enriched a distinct microbial community comparing to the control MFC with acetate as the carbon source, with the genera Geobacter, Sphaerochaeta, Christensenellaceae, Aminiphilus and Proteiniphilum significantly enriched on the anode electrode, and Sphaerochaeta, Proteiniphilum and Bacteroidetes in the anolyte. This carbon source providing method will promote the application of MFCs as a sustainable and stable power source for environmental monitoring and remediation.


Assuntos
Fontes de Energia Bioelétrica , Acetatos , Bactérias , Carbono , Eletricidade , Eletrodos , Polímeros , Amido/análogos & derivados
18.
Animal ; 14(S1): s17-s28, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32024574

RESUMO

Pregastric fermentation along with production practices that are dependent on high-energy diets means ruminants rely heavily on starch and protein assimilation for a substantial portion of their nutrient needs. While the majority of dietary starch may be fermented in the rumen, significant portions can flow to the small intestine. The initial phase of small intestinal digestion requires pancreatic α-amylase. Numerous nutritional factors have been shown to influence pancreatic α-amylase secretion with starch producing negative effects and casein, certain amino acids and dietary energy having positive effects. To date, manipulation of α-amylase secretion has not resulted in substantial changes in digestibility. The second phase of digestion involves the actions of the brush border enzymes sucrase-isomaltase and maltase-glucoamylase. Genetically, ruminants appear to possess these enzymes; however, the absence of measurable sucrase activity and limited adaptation with changes in diet suggests a reduced capacity for this phase of digestion. The final phase of carbohydrate assimilation is glucose transport. Ruminants possess Na+-dependent glucose transport that has been shown to be inducible. Because of the nature of pregastric fermentation, ruminants see a near constant flow of microbial protein to the small intestine. This results in a nutrient supply, which places a high priority on protein digestion and utilization. Comparatively, little research has been conducted describing protein assimilation. Enzymes and processes appear consistent with non-ruminants and are likely not limiting for efficient digestion of most feedstuffs. The mechanisms regulating the nutritional modulation of digestive function in the small intestine are complex and coordinated via the substrate, neural and hormonal effects in the small intestine, pancreas, peripheral tissues and the pituitary-hypothalamic axis. More research is needed in ruminants to help unravel the complexities by which small intestinal digestion is regulated with the aim of developing approaches to enhance and improve the efficiency of small intestinal digestion.


Assuntos
Aminoácidos/metabolismo , Carboidratos da Dieta/metabolismo , Ingestão de Energia , Proteínas/metabolismo , Ruminantes/metabolismo , Amido/metabolismo , Animais , Caseínas/metabolismo , Dieta/veterinária , Digestão , Fermentação , Intestino Delgado/metabolismo , Pâncreas/enzimologia , Rúmen/metabolismo , alfa-Amilases/metabolismo
19.
Food Chem ; 317: 126452, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32106008

RESUMO

A new water-soluble resistant dextrin (WSRD), fabricated by thermal-acid treatment following amylase hydrolysis from corn starch, was expected to strengthen the dietary fibers intake of flour products. This study was to investigate the effects of WSRD on flour processing quality, and further dissect its improvement mechanisms by farinographic and rheological analysis, SDS-PAGE, Fourier transform infrared spectroscopy, texture analyzer, etc. Results showed that WSRD greatly improved the viscoelasticity and strength of dough, which was predominantly contributed by its formation of gel-like networks. Meanwhile, the WSRD-induced increase of gluten aggregates and ß-sheet conformation provided the structural basis for enhancing dough quality. Notably, WSRD greatly promoted the sensory appearance and crumb quality of baked breads. Moreover, the WSRD-treated breads resisted the hydrolysis of digestive fluid and enzymes. Therefore, WSRD can strengthen the processing qualities and nutritional values of flour products, which will broaden the application of the novel dietary fiber in flour industry.


Assuntos
Pão , Dextrinas/química , Fibras na Dieta , Farinha , Amilases/química , Qualidade dos Alimentos , Glutens/química , Hidrólise , Valor Nutritivo , Reologia , Solubilidade , Amido/química , Viscosidade , Água
20.
Food Chem ; 316: 126263, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32045812

RESUMO

In this study, starch was isolated from 13 genotypes of 12 Lycoris species, and the morphology, granule size distribution and physicochemical properties, including apparent amylose content (AAC), Rapid Visco Analyzer (RVA) pasting properties, textural properties, thermal and retrogradation properties were characterized. The majority of starch granules of the 13 Lycoris genotypes were oval in shape, and granule size followed a normal distribution with a mean diameter of 20-30 µm. Contrary to previously published findings, the XRD results revealed that lycoris starches had either C-type or CA-type crystallinity. All lycoris starches showed high AAC varying from 25.6% to 32.7%, and low gelatinization temperature (GT) ranging from 58.8 to 69.7℃. Inter-relationships among 18 starch quality traits were analyzed based on correlation analysis. The present study provides information on lycoris starch characteristics which should serve as a useful guide for later studies on lycoris starch utilization in food and non-food industries.


Assuntos
Lycoris/química , Amido/química , Amilose/química , Fenômenos Químicos , Genótipo , Lycoris/genética , Amido/isolamento & purificação , Temperatura
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