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1.
PLoS One ; 15(8): e0236129, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760076

RESUMO

Salix matsudana, a member of Salicaceae, is an important ornamental tree in China. Because of its capability to tolerate high salt conditions, S. matsudana also plays an important ecological role when grown along Chinese coastal beaches, where the salinity content is high. Here, we aimed to elucidate the mechanism of higher salt tolerance in S. matsudana variety '9901' by identifying the associated genes through RNA sequencing and comparing differential gene expression between the S. matsudana salt-tolerant and salt-sensitive samples treated with 150 mM NaCl. Transcriptomic comparison of the roots of the two samples revealed 2174 and 3159 genes responsive to salt stress in salt-sensitive and salt-tolerant sample, respectively. Real-time polymerase chain reaction analysis of 9 of the responsive genes revealed a strong, positive correlation with RNA sequencing data. The genes were enriched in several pathways, including carbon metabolism pathway, plant-pathogen interaction pathway, and plant hormone signal transduction pathway. Differentially expressed genes (DEGs) encoding transcription factors associated with abiotic stress responses and salt stress response network were identified; their expression levels differed between the two samples in response to salt stress. Hub genes were also revealed by weighted gene co-expression network (WGCNA) analysis. For functional analysis of the DEG encoding sedoheptulose-1,7-bisphosphatase (SBPase), the gene was overexpressed in transgenic Arabidopsis, resulting in increased photosynthetic rates, sucrose and starch accumulation, and enhanced salt tolerance. Further functional characterization of other hub DEGs will reveal the molecular mechanism of salt tolerance in S. matsudana and allow the application of S. matsudana in coastal afforestation.


Assuntos
Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes/fisiologia , Salix/fisiologia , Tolerância ao Sal/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Fotossíntese/genética , Raízes de Plantas , Plantas Geneticamente Modificadas , RNA-Seq , Salinidade , Amido/metabolismo , Sacarose/metabolismo
2.
PLoS One ; 15(8): e0236249, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804964

RESUMO

BACKGROUND: The insect predator Coccinella septempunctata can effectively control many types of pests, such as aphids, whiteflies, and small lepidopteran larvae. We previously found that C. septempunctata fed an artificial diet showed diminished biological properties(e.g. fecundity, egg hatching rate, survival rate, etc.) compared with those fed natural prey (Aphis craccivora), likely due to different nutritional characteristics of the diet. In this study, we used transcriptome sequencing analysis to identify nutrition- and metabolism-related genes of C. septempunctata that were differentially expressed depending on diet. METHODOLOGY/PRINCIPAL FINDINGS: The Illumina HiSeq2000 was used to sequence 691,942,058 total clean reads from artificial diet-fed and A. craccivora-fed C. septempunctata libraries, and the clean reads were assembled using Trinity de novo software (Tabel 2). Comparison of transcriptome sequences revealed that expression of 38,315 genes was affected by the artificial diet, and 1,182 of these genes showed a significant change in expression levels (FDR ≤ 0.05,|log2FC|≥1, "FC" stands for "fold change"). These differentially expressed genes (DEGs) were likely associated with the decreased egg laying capacity, hatching rate, longevity, and increased sex ratio (♀:♂) of adult C. septempunctata observed in the group fed the artificial diet. Furthermore, in the most DEGs metabolic pathways for C. septempunctata feeding on the artificial diet accumulated amino acid metabolic pathways, lipid metabolic pathways, and starch and glucose metabolism were down-regulated. CONCLUSIONS/SIGNIFICANCE: We found some differentially expressed genes and metabolic pathways are related to nutrition, from which a more informative feedback for diet formulation was obtained and the artificial diet could be more efficiently optimized.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal/genética , Afídeos , Besouros/fisiologia , Genes de Insetos , Comportamento Predatório/fisiologia , Aminoácidos/metabolismo , Animais , Regulação para Baixo , Fertilidade/fisiologia , Perfilação da Expressão Gênica , Glucose/metabolismo , Metabolismo dos Lipídeos/genética , Longevidade/fisiologia , Redes e Vias Metabólicas/genética , Controle Biológico de Vetores/métodos , Razão de Masculinidade , Amido/metabolismo , Sequenciamento Completo do Exoma
3.
PLoS One ; 15(7): e0236185, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730344

RESUMO

Fluorescent markers are a powerful tool and have been widely applied in biology for different purposes. The genome sequence of Xanthomonas citri subsp. citri (X. citri) revealed that approximately 30% of the genes encoded hypothetical proteins, some of which could play an important role in the success of plant-pathogen interaction and disease triggering. Therefore, revealing their functions is an important strategy to understand the bacterium pathways and mechanisms involved in plant-host interaction. The elucidation of protein function is not a trivial task, but the identification of the subcellular localization of a protein is key to understanding its function. We have constructed an integrative vector, pMAJIIc, under the control of the arabinose promoter, which allows the inducible expression of red fluorescent protein (mCherry) fusions in X. citri, suitable for subcellular localization of target proteins. Fluorescence microscopy was used to track the localization of VrpA protein, which was visualized surrounding the bacterial outer membrane, and the GyrB protein, which showed a diffused cytoplasmic localization, sometimes with dots accumulated near the cellular poles. The integration of the vector into the amy locus of X. citri did not affect bacterial virulence. The vector could be stably maintained in X. citri, and the disruption of the α-amylase gene provided an ease screening method for the selection of the transformant colonies. The results demonstrate that the mCherry-containing vector here described is a powerful tool for bacterial protein localization in cytoplasmic and periplasmic environments.


Assuntos
Proteínas de Bactérias/metabolismo , Citoplasma/metabolismo , Periplasma/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Xanthomonas/metabolismo , Arabinose/farmacologia , Cromossomos Bacterianos/genética , Vetores Genéticos/metabolismo , Viabilidade Microbiana/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Amido/metabolismo , Frações Subcelulares/efeitos dos fármacos , Xanthomonas/patogenicidade
4.
Food Chem ; 331: 127315, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32593039

RESUMO

The effects of frying temperature on the properties of wheat starch were investigated, including the microstructure, weight-average molar mass (Mw), crystalline properties, functional groups, in vitro digestibility, static rheological properties, swelling power and solubility. SEM micrographs showed that the disc-shaped starch granules ruptured after being fried, and formed a continuous and dense gel structure. With the increasing frying temperature, the starch molecules underwent violent degradation, and the Mw decreased from 3.04 × 107 g/mol to 0.80 × 107 g/mol. The XRD and FTIR data indicated the formation of starch-lipid complexes during the frying process. In vitro digestion analysis revealed that the digestion rate of starch decreased, while the content of resistant starch (RS) increased after being fried. Besides, the shear stability of fried starch increased, whereas its swelling power and solubility decreased. These significant variations in physicochemical properties of starch could provide scientific basis for further improving the quality of instant noodles.


Assuntos
Culinária , Digestão , Reologia , Amido/química , Triticum/química , Lipídeos/química , Peso Molecular , Solubilidade , Amido/metabolismo , Temperatura
5.
PLoS One ; 15(6): e0234344, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32502191

RESUMO

Nitrogen (N) isotopic discrimination (i.e. the difference in natural 15N abundance between the animal proteins and the diet; Δ15N) is known to correlate with N use efficiency (NUE) and feed conversion efficiency (FCE) in ruminants. However, results from the literature are not always consistent across studies, likely due to isotopic discrimination pathways that may differ with the nature of diets. The objective of the present study was to assess at which level, from rumen to tissues, Δ15N originates and becomes related to NUE and FCE in fattening yearling bulls when they are fed two contrasted diets. Twenty-four Charolais yearling bulls were randomly divided into two groups and fed during 8 months, from weaning to slaughter, either 1) a high starch diet based on corn silage supplying a balanced N to energy ratio at the rumen level (starch) or 2) a high fiber diet based on grass silage supplying an excess of rumen degradable N (fiber). All animals were slaughtered and samples of different digestive pools (ruminal, duodenal, ileal and fecal contents), animal tissues (duodenum, liver and muscle), blood and urine were collected for each animal. Ruminal content was further used to isolate liquid-associated bacteria (LAB), protozoa and free ammonia, while plasma proteins were obtained from blood. All samples along with feed were analyzed for their N isotopic composition. For both diets, the digestive contribution (i.e. the N isotopic discrimination occurring before absorption) to the Δ15N observed in animal tissues accounted for 65 ± 11%, leaving only one third to the contribution of post-absorptive metabolism. Concerning the Δ15N in digestive pools, the majority of these changes occurred in the rumen (av. Δ15N = 2.12 ± 0.66‰), with only minor 15N enrichments thereafter (av. Δ15N = 2.24 ± 0.41‰), highlighting the key role of the rumen on N isotopic discrimination. A strong, significant overall relationship (n = 24) between Δ15N and FCE or NUE was found when using any post-absorptive metabolic pool (duodenum, liver, or muscle tissues, or plasma proteins; 0.52 < r < 0.73; P ≤ 0.01), probably as these pools reflect both digestive and post-absorptive metabolic phenomena. Fiber diet compared to starch diet had a lower feed efficiency and promoted higher (P ≤ 0.05) Δ15N values across all post-absorptive metabolic pools and some digestive pools (ruminal, duodenal, and ileal contents). The within-diet relationship (n = 12) between Δ15N and feed efficiency was not as strong and consistent as the overall relationship, with contrasted responses between the two diets for specific pools (diet x pool interaction; P ≤ 0.01). Our results highlight the contrasted use of N at the rumen level between the two experimental diets and suggests the need for different equations to predict FCE or NUE from Δ15N according to the type of diet. In conclusion, rumen digestion and associated microbial activity can play an important role on N isotopic discrimination so rumen effect related to diet may interfere with the relationship between Δ15N and feed efficiency in fattening yearling bulls.


Assuntos
Ração Animal/análise , Dieta/métodos , Nitrogênio/metabolismo , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Animais , Bovinos , Carboidratos da Dieta/metabolismo , Fibras na Dieta/metabolismo , Digestão/fisiologia , Fezes/química , Masculino , Rúmen/microbiologia , Ruminantes/metabolismo , Amido/metabolismo
6.
Food Chem ; 330: 127313, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32569932

RESUMO

Starch granule-surface proteins (SGSPs) and granule-channel proteins (SGCPs) are granule-associated proteins (SGAPs), which have been found to be distributed on the surface and channels of starch granules, respectively. To investigate the impacts of SGAPs on α-amylase hydrolysis of starch, SGCPs or SGAPs of waxy, low and high amylose rice starches were removed. Removal of SGAPs or SGCPs greatly increased hydrolysis rate of rice starches. Meanwhile, these granules incurred a greater number and size of pores on their surfaces during hydrolysis. Compared to low and high amylose starches, waxy starch before and after removing SGAPs exhibited a higher hydrolysis rate. Rice starch hydrolysis began with enlargement of cavity and channels both horizontally and vertically. XRD analysis revealed that removal of SGAPs decreased relative crystallinity (RC) of starch and advanced changes in RC during hydrolysis process. This study provides new information about the role of SGAPs in the mechanisms of α-amylase hydrolysis.


Assuntos
Oryza/química , Proteínas de Plantas/química , Amido/química , alfa-Amilases/metabolismo , Amilose/metabolismo , Hidrólise , Oryza/metabolismo , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Amido/metabolismo , Amido/farmacocinética , Difração de Raios X , alfa-Amilases/química
7.
Food Chem ; 330: 127328, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32569940

RESUMO

Granular protein is an important structural feature in determining starch digestibility. High-amylose wheat starch (HAWS) with >80% amylose content contains more granular protein than wild-type starch. As analyzed by mass spectrometry-based proteomics, granular-bound starch synthase (GBSS) is the major granular protein in isolated starch materials. GBSS content increases with amylose content (Spearman's correlation, p < 0.05), whereas the abundance relative to other proteins is similar among starches. Multiple amylase inhibitors were also identified. From Michaelis-Menten analysis, HAWS has a similar Km (Michaelis constant) as wild type, suggesting initial enzymatic binding is similar. After the pre-digestion of proteins, wild type had a greater change in starch digestibility than HAWS, probably due to the latter having 'thicker' granular-protein layers and higher enzymatic resistance of substrate per se. Overall, the study suggests that the greater granular protein content in HAWS is a factor that contributes to slower amylolysis compared to wild type.


Assuntos
Amilose/metabolismo , Proteínas de Plantas/metabolismo , Sintase do Amido/metabolismo , Amido/química , Triticum/química , Amilose/análise , Amilose/química , Digestão , Hidrólise , Cinética , Proteínas de Plantas/análise , Amido/metabolismo , Sintase do Amido/análise , Espectrometria de Massas em Tandem , Triticum/metabolismo , alfa-Amilases/química , alfa-Amilases/metabolismo
8.
Food Chem ; 326: 126845, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32438226

RESUMO

Dry cultivation of high-yielding or drought-resistant rice cultivars relieves the current pressure on rice cultivation systems. However, the metabolites and metabolic pathways that affect rice quality in high-yield or drought-resistant rice cultivars under dry cultivation have not yet been explored. A field experiment was conducted in 2017 to explore the effects of flooding irrigation (F) and dry cultivation (D) of high-yield and -quality cultivars (Huanghuazhan, HH; Yueyou9113, YY) and a drought-resistant cultivar (Hanyou73, HY) on rice quality traits using metabolomic analysis. Treatment DHH maintained higher head rice yield, amylose content, protein content, and breakdown values and a lower whiteness index and setback value than other cultivars under dry cultivation. These rice quality traits were related to 16 metabolites and 8 metabolic pathways. DHH showed decreases in stress response metabolites (m72, m98, m127, m165, m167, m213, m297, and m298) but maintained stress resistance (m29, m30, m39, m48, and m58) and sucrose (m150) accumulation in grains to support head rice yields and a low whiteness index. Raising the lactose, choline, and nicotinoylcholine levels in rice grains improved their protein content and cooking quality. DHH also adjusted the glycine, serine and threonine metabolism, galactose metabolism, and starch and sucrose metabolism of rice. This affected the biosynthesis of anthocyanin, phenylpropanoid, and flavonoid, supporting protein biosynthesis and starch accumulation in the endosperm. These findings provide further possibilities for improving rice quality traits of high-yield and -quality rice cultivars under dry cultivation.


Assuntos
Grão Comestível/metabolismo , Oryza/metabolismo , Amilose/metabolismo , Culinária , Secas , Endosperma/metabolismo , Metabolômica , Amido/metabolismo
9.
PLoS One ; 15(5): e0232689, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32384105

RESUMO

Bacteria residing in the gastrointestinal tract of mammals are crucial for the digestion of dietary nutrients. Bacterial community composition is modified by age and diet in other species. Although horses are adapted to consuming fibre-based diets, high-energy, often high-starch containing feeds are increasingly used. The current study assessed the impact of age on the faecal bacteriome of ponies transitioning from a hay-based diet to a high-starch diet. Over two years, 23 Welsh Section A pony mares were evaluated (Controls, 5-15 years, n = 6/year, 12 in total; Aged, ≥19 years, n = 6 Year 1; n = 5 Year 2, 11 in total). Across the same 30-week (May to November) period in each year, animals were randomly assigned to a 5-week period of study and were individually fed the same hay to maintenance (2% body mass as daily dry matter intake) for 4-weeks. During the final week, 2g starch per kg body mass (micronized steam-flaked barley) was incorporated into the diet (3-day transition and 5 days at maximum). Faecal samples were collected for 11 days (final 3 days hay and 8 days hay + barley feeding). Bacterial communities were determined using Ion Torrent Sequencing of amplified V1-V2 hypervariable regions of 16S rRNA. Age had a minimal effect on the bacteriome response to diet. The dietary transition increased Candidatus Saccharibacteria and Firmicutes phyla abundance and reduced Fibrobactres abundance. At the genera level, Streptococcus abundance was increased but not consistently across individual animals. Bacterial diversity was reduced during dietary transition in Streptococcus 'responders'. Faecal pH and VFA concentrations were modified by diet but considerable inter-individual variation was present. The current study describes compositional changes in the faecal bacteriome associated with the transition from a fibre-based to a high-starch diet in ponies and emphasises the individual nature of dietary responses, which may reflect functional differences in the bacterial populations present in the hindgut.


Assuntos
Ração Animal , Carboidratos da Dieta/metabolismo , Microbioma Gastrointestinal , Cavalos/fisiologia , Amido/metabolismo , Envelhecimento , Ração Animal/análise , Animais , Carboidratos da Dieta/análise , Fibras na Dieta/análise , Fibras na Dieta/metabolismo , Fezes/microbiologia , Glucose/metabolismo , Insulina/metabolismo , Amido/análise
10.
J Food Sci ; 85(6): 1717-1724, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32406950

RESUMO

This study evaluated the influence of different fluidized-bed drying temperatures (20, 60, and 100 °C) on the cooking properties, in vitro starch digestibility, and phenolic bioaccessibility of black rice. The results indicated that the formation of fissures in the grains dried at or above 60 °C reduced the physical integrity of the grains after cooking, increasing the starch digestion and the rehydration ratio, and reduced the cooking time, the hardness and adhesiveness. Due to the higher digestibility of grains dried at higher temperatures, an increase in the bioaccessibility of ferulic acid, which was previously associated with the polysaccharides, was observed. Caffeic acid was the only phenolic compound whose levels decreased when the drying temperature increased. At high temperatures and in the gastric phase, cyanidin chalcones were formed due to the deglycosylation of cyanidin-3-O-glucoside. PRACTICAL APPLICATION: The results of this study provide information to the food industry about the effects of different fluidized-bed drying temperatures on the rice structure after cooking and that, consequently, affect the availability of bioactive compounds after digestion and the glycemic index of black rice.


Assuntos
Dessecação/métodos , Oryza/química , Fenóis/química , Amido/química , Antocianinas/química , Antocianinas/metabolismo , Culinária , Digestão , Manipulação de Alimentos , Glucosídeos/química , Glucosídeos/metabolismo , Índice Glicêmico , Humanos , Modelos Biológicos , Oryza/metabolismo , Fenóis/metabolismo , Amido/metabolismo , Temperatura
11.
J Anim Sci ; 98(5)2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32255481

RESUMO

A study was conducted to determine effects of reducing hindgut pH through dietary inclusion of high-amylose cornstarch (HA-starch) on growth performance, organ weights relative to live body weight (BW), blood thyroid hormone levels, and glucosinolate degradation products of nursery pigs fed cold-pressed canola cake (CPCC). A total of 240 pigs (initial BW: 7.1 kg), which had been weaned at 21 d of age, were housed in 40 pens (6 pigs per pen) and fed 4 diets (10 pens per diet) in a randomized complete block design for 28 d. Four diets were a basal diet with CPCC at 0 or 40%, and with HA-starch at 0 or 40% in a 2 × 2 factorial arrangement. The diets were fed in two phases: Phase 1 from day 0 to 14 and Phase 2 from day 14 to 28 and were formulated to have the same net energy, standardized ileal digestible AA, Ca, and standardized total tract digestible P contents. Dietary inclusion of CPCC and HA-starch was achieved by a partial or complete replacement of corn, soybean meal, and soy protein. At the end of the study, one pig from each pen was euthanized to determine organ weights, blood parameters, hindgut pH, and glucosinolate degradation products. Dietary CPCC reduced (P < 0.05) overall average daily gain (ADG) by 15%; increased (P < 0.05) relative weights of liver and thyroid gland by 27% and 64%, respectively; and reduced (P < 0.05) serum tetraiodothyronine (T4) level from 30.3 to 17.8 ng/mL. Heart, kidney, and gastrointestinal tract weights; serum triiodothyronine level; and hindgut pH of pigs were unaffected by dietary CPCC. Dietary HA-starch reduced (P < 0.05) overall ADG, relative weight of thyroid gland, cecal, and colonic pH; but increased (P < 0.05) relative weight of colon; tended to increase (P = 0.062) serum T4 level. Dietary CPCC and HA-starch interacted (P = 0.024) on relative weight of thyroid gland such that dietary CPCC increased (P < 0.05) weight of thyroid gland for HA-starch-free diet (120 vs. 197 mg/kg of BW) but not for HA-starch-containing diet (104 vs. 130 mg/kg of BW). Dietary CPCC and HA-starch interacted (P = 0.001) on cecal isothiocyanate content such that dietary CPCC increased (P < 0.05) level of isothiocyanates for HA-starch-containing diet but not for HA-starch-free diet. In conclusion, dietary CPCC reduced growth performance, increased liver, size and interfered with thyroid gland functions of pigs. However, the negative effects of dietary CPCC on thyroid gland functions of nursery pigs were alleviated by dietary HA-starch.


Assuntos
Ração Animal/análise , Brassica napus/química , Glucosinolatos/toxicidade , Amido/metabolismo , Suínos/fisiologia , Animais , Ceco/efeitos dos fármacos , Ceco/fisiologia , Dieta/veterinária , Feminino , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/fisiologia , Fígado/efeitos dos fármacos , Fígado/fisiologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Tamanho do Órgão/fisiologia , Soja , Zea mays
12.
Food Chem ; 324: 126855, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32344341

RESUMO

To develop a 1,4-α-glucan branching enzyme (BE) without homology to known allergens, the glgB gene from Bifidobacterium longum was overexpressed under the control of BLMA promoter in Escherichia coli. B. longum BE (BlBE) had a molecular weight of 86.1 kDa and a specific activity of more than 18.5U/mg protein at 25-35 °C and pH 5.5-7.0, and exhibited 30% of the maximum activity at 10 °C. The cold-active BlBE preferred to transfer maltohexaose and introduced DP 4-36 branches into amylose. BlBE also increased the proportion of DP 2-10 branches in amylopectin and decreased its Mw from 1.39 × 106 to 1.16 × 105 g/mol. As the BlBE concentration increased from 0.0 to 0.5U/mg substrate, the retrogradation enthalpy of BlBE-modified wheat starch decreased from 4.50 to 1.83 J/g (p < 0.05) at day 14 and the slowly digestible starch content increased from 2.10% to 17.39% (p < 0.05).


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Bifidobacterium longum/enzimologia , Amido/metabolismo , Triticum/metabolismo , Enzima Ramificadora de 1,4-alfa-Glucana/classificação , Enzima Ramificadora de 1,4-alfa-Glucana/genética , Sequência de Aminoácidos , Amilopectina/metabolismo , Escherichia coli/metabolismo , Concentração de Íons de Hidrogênio , Peso Molecular , Filogenia , Alinhamento de Sequência , Temperatura , Termodinâmica
13.
J Dairy Sci ; 103(6): 5090-5101, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32229110

RESUMO

The objective of this study was to evaluate the effects of a commercially available fermentation by-product in a diet containing adequate rumen-degradable protein (RDP) on milk performance, intake, and total-tract nutrient digestion in lactating dairy cattle. Primiparous (n = 48) and multiparous (n = 144) lactating dairy cattle were stratified by milk production and randomly allocated into 12 pens containing 4 primiparous and 12 multiparous animals each. Cattle averaged 118 d in milk and 712 kg of body weight at trial start. Treatment diets, on a dry matter (DM) basis, consisted of 42% corn silage, 13% alfalfa hay and silage, 20% grain corn, and 25% protein premix containing either soybean meal, wheat middlings, and urea (SBM+U), soybean meal and fermentation by-product (SBM+F), or soybean meal and rumen-protected soybean meal (RP-SBM). All 3 diets provided a similar level (DM basis) of neutral detergent fiber analyzed using α-amylase and sodium sulfite and corrected for ash content (31%), crude protein (CP, 14.9%), starch (26%), and metabolizable energy (2.7 Mcal/kg), and differed in sources of RDP. The trial consisted of a 2-wk adaptation and covariate period during which all cows were fed the RP-SBM diet and covariate measurements were taken. Pens were then randomly allocated to treatments, and weekly measurements of milk production, intake, body weight, and condition score were taken for 10 wk. All data were analyzed using the Proc Mixed procedure in SAS (SAS Institute Inc., Cary, NC). Increased DM intake was observed for cows fed SBM+F compared with cows fed SBM+U and RP-SBM (28.3 vs. 26.9 and 26.7 kg/d, respectively). Cows fed SBM+F produced more energy-corrected milk (45.3 kg/d) compared with cows fed SBM+U and RP-SBM (43.6 and 43.7 kg/d, respectively). Milk protein yield was also increased in cows fed SBM+F. No differences were observed with body weight or condition score gain throughout the trial. Apparent total-tract digestibility of fiber was decreased in cows fed SBM+F, likely as a result of increased intake. Responses are consistent with previous research in our laboratory that demonstrated a decrease in ruminal CP degradation, leading to an increase in metabolizable protein supply in the small intestine. The fermentation by-product might be useful in diets containing adequate amounts of RDP from soybean meal or alfalfa. The results from this experiment demonstrate beneficial milk performance responses to fermentation by-product when fed with a source of RDP.


Assuntos
Bovinos/crescimento & desenvolvimento , Digestão , Leite , Rúmen/metabolismo , Animais , Bovinos/metabolismo , Dieta/veterinária , Fibras na Dieta/metabolismo , Feminino , Fermentação , Lactação , Medicago sativa , Proteínas do Leite/metabolismo , Nutrientes , Silagem , Soja , Amido/metabolismo , Triticum , Ureia , Zea mays
14.
J Dairy Sci ; 103(6): 5647-5653, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32307179

RESUMO

The objective was to investigate the effects of species (cow vs. goat) and of various dietary lipid supplements, known to modulate milk fat content, on selected metabolites and enzymes in milk and to explore their correlations with performance traits. Twelve Holstein cows and 12 Alpine goats, all multiparous and nonpregnant, and at 86 ± 24.9 and 61 ± 1.8 DIM, respectively, were fed a basal diet (45% forage + 55% concentrate) not supplemented (CTL) or supplemented with corn oil plus wheat starch [COS, 5% of diet dry matter (DM)], marine algae powder (MAP, 1.5% of diet DM), or hydrogenated palm oil (HPO, 3% of diet DM) in a replicated 4 × 4 Latin square design with 28-d experimental periods. Intake, milk production and composition, milk fatty acid profile, and plasma metabolite concentrations were previously reported. Concentrations of 9 milk metabolites [ß-hydroxybutyrate (BHB), glucose, glucose-6-phosphate, isocitrate, choline, glutamate, urea, cholesterol, and free amino groups] and 2 milk enzyme activities (alkaline phosphatase and lactate dehydrogenase) were measured on d 24 of each experimental period. Dairy performance data showed marked species and diet effects on milk fat content. Irrespective of diet, cow milk was richer in alkaline phosphatase and glucose compared with goat milk (16 and 3 times more, respectively), whereas goat milk had greater urea and glucose-6-phosphate concentrations compared with cow milk (1.9 and 5.3 times more, respectively). In cows, COS decreased milk BHB and choline (-25 and -43%, respectively) compared with CTL, whereas no effects were observed in goats. The COS and MAP diets increased milk isocitrate compared with CTL in cows, but COS decreased isocitrate concentrations in goat milk. Milk choline was correlated with milk fat content in cows (Spearman r, rS = +0.73) and goats (rs = +0.58), and lactate dehydrogenase activity was correlated with milk somatic cell count (rs = +0.66) in cows but not in goats. We provide evidence of different milk metabolite responses according to species and diets. Metabolites and enzymes secreted in milk may be indicators of specificities of lipid metabolism among ruminant species and may contribute to a better understanding of mechanisms regulating milk fat secretion. Changes in the concentrations of some metabolites considered minor components of milk may be valuable diagnostic tools of mammary gland and animal metabolism as well as of milk processing characteristics.


Assuntos
Bovinos , Dieta/veterinária , Suplementos Nutricionais , Cabras , Leite/química , Óleo de Palmeira/administração & dosagem , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Óleo de Milho/metabolismo , Gorduras na Dieta/metabolismo , Ácidos Graxos/metabolismo , Feminino , Lactação/fisiologia , Metabolismo dos Lipídeos , Lipídeos , Leite/metabolismo , Amido/metabolismo
15.
J Anim Sci ; 98(5)2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32271920

RESUMO

The objectives of this study were to compare ruminal total tract digestibility, bacterial communities, and eating and rumination activity between Holstein and Angus steers fed grain- or forage-based diets. Six Holstein steers (average body weight [BW] = 483 ± 23 kg) and six Angus steers (average BW = 507 ± 29 kg), previously fitted with rumen cannulae, were fed in a crossover design with a 2 × 2 factorial arrangement of four treatments: 1) Holsteins fed a grain-based diet, 2) Holsteins fed a forage-based diet, 3) Angus fed a grain-based diet, and 4) Angus fed a forage-based diet. Each period was 35 d with 26 d of diet adaptation and 9 d of sample collection. On days 1 and 2 of collection, feeding activity was recorded for 48 h. On day 3, rumen contents were sampled to measure ruminal pH at 0, 3, 6, 12, and 18 h after feeding. A portion of the strained ruminal fluid was subsampled at 0, 3, and 6 h for volatile fatty acids (VFA) analysis. Rumen contents were subsampled at 3 h for analysis of bacterial communities. From day 4 to 8, total fecal excretion, feed, and refusals samples were collected and analyzed for dry matter (DM), neutral detergent fiber (NDF), and starch. On days 8 and 9 (0 and 3 h post-feeding, respectively), total reticulorumen evacuation was conducted and contents were weighed. Data were analyzed using the MIXED procedures in SAS (v9.4 SAS Inst. Inc., Cary, NC). Repeated measures were used to analyze changes in ruminal pH and VFA over time. There were no interactions of diet × breed (P ≥ 0.07). While the main effects of diet were expected, unique to these data is the fact that bacterial diversity and richness were reduced (P < 0.01) in cattle fed grain-based diets. There was no main effect (P > 0.34) of breed on total tract DM, organic matter, and starch digestibility, but Angus cattle had greater (P = 0.01) NDF digestibility than Holsteins. The increased NDF digestibility may be associated with a numerical (P = 0.08) increased numbers of bacterial species in Angus steers compared with Holstein steers. Holstein steers also spent more time (P ≤ 0.05) ruminating than Angus steers. There was no effect (P > 0.80) of breed on reticulorumen content at feeding time; however, Holstein steers had greater (P = 0.04) reticulorumen content on a wet basis 3 h post-feeding. Although Holstein steers spent more time ruminating, Angus steers were better able to digest NDF when compared with Holsteins, regardless of basal diet, and this improvement may be related to changes in bacterial communities in the rumen or to rumination activity.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Fibras na Dieta/metabolismo , Ácidos Graxos Voláteis/análise , Microbioma Gastrointestinal , Animais , Peso Corporal , Cruzamento , Bovinos/microbiologia , Estudos Cross-Over , Dieta/veterinária , Digestão , Ingestão de Alimentos , Grão Comestível , Fermentação , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/fisiologia , Masculino , Rúmen/microbiologia , Rúmen/fisiologia , Amido/metabolismo
16.
Int J Mol Sci ; 21(2)2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32284503

RESUMO

Allotriploid poplar has a prominent vegetative growth advantage that impacts dramatically on lumber yield. The growth regulation is complex which involves abundant genes, metabolic and signaling pathways, while the information about the functional control process is very little. We used high-throughput sequencing and physiological index measurement to obtain a global overview of differences between allotriploid and diploid Populus. The genes related to plant growth advantage show a higher expression compared to diploid, and most of them are revolved around hormones, photosynthesis and product accumulation. Thus, allotriploid Populus showed more efficient photosynthesis, carbon fixation, sucrose and starch synthesis, and metabolism as well as augmented biosynthesis of auxin, cytokinin, and gibberellin. These data enable the connection of metabolic processes, signaling pathways, and specific gene activity, which will underpin the development of network models to elucidate the process of triploid Populus advantage growth.


Assuntos
Fotossíntese/genética , Reguladores de Crescimento de Planta/metabolismo , Populus/genética , Transdução de Sinais , Ciclo do Carbono/genética , Citocininas/metabolismo , Perfilação da Expressão Gênica , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala , Ácidos Indolacéticos/metabolismo , Folhas de Planta , Populus/crescimento & desenvolvimento , Populus/fisiologia , Populus/ultraestrutura , Amido/metabolismo , Sacarose/metabolismo , Triploidia
17.
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
18.
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
19.
J Biotechnol ; 313: 39-47, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32198062

RESUMO

Cold-adapted pullulanase with high catalytic activity and stability is of special interest for its wide application in cold starch hydrolysis, but few pullulanases displaying excellent characteristics at ambient temperature and acidic pH have hitherto been reported. Here, a novel pullulanase from Bacillus methanolicus PB1 was successfully expressed in Escherichia coli BL21 (DE3) and determined to be a cold-adapted type I pullulanase (PulPB1) with maximum activity at 50 °C and pH 5.5. The recombinant PulPB1 showed great stability, its half-life at 50 °C was 137 h. PulPB1 can efficiently hydrolyze pullulan and amylopectin, with activities of 292 and 184 U/mg at 50 °C and pH 5.5, respectively. Moreover, the N-terminal domain of PulPB1 was found to significantly affect the enzymatic performance. Following truncation of the N-terminal domain, the activity towards pullulan decreased markedly from 292 to 141 U/mg and the half-life at 50 °C decreased from 137 to 10 h. Compared to the hydrolysis system with amyloglucosidase alone, the catalytic efficiency showed a 2.4-fold increase on combining PulPB1 with amyloglucosidase for amylopectin hydrolysis at 40 °C. This demonstrates that PulPB1 is promising for development as a superior candidate for cold amylopectin hydrolysis.


Assuntos
Amilopectina/metabolismo , Bacillus/enzimologia , Glicosídeo Hidrolases/metabolismo , Bacillus/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Temperatura Baixa , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Glucanos/metabolismo , Glicosídeo Hidrolases/genética , Concentração de Íons de Hidrogênio , Hidrólise , Proteínas Recombinantes , Amido/metabolismo
20.
Pol J Microbiol ; 69(1): 109-120, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32189481

RESUMO

Hydrogen produced from lignocellulose biomass is deemed as a promising fuel of the future. However, direct cellulose utilization remains an issue due to the low hydrogen yields. In this study, the long-term effect of inoculum (anaerobic sludge) heat pretreatment on hydrogen production from untreated cellulose and starch was evaluated during repeated batch processes. The inoculum pretreatment at 90°C was not sufficient to suppress H2 consuming bacteria, both for starch and cellulose. Although hydrogen was produced, it was rapidly utilized with simultaneous accumulation of acetic and propionic acid. The pretreatment at 100°C (20 min) resulted in the successful enrichment of hydrogen producers on starch. High production of hydrogen (1.2 l H2/lmedium) and H2 yield (1.7 mol H2/molhexose) were maintained for 130 days, with butyric (1.5 g/l) and acetic acid (0.65 g/l) as main byproducts. On the other hand, the process with cellulose showed lower hydrogen production (0.3 l H2/lmedium) with simultaneous high acetic acid (1.4 g/l) and ethanol (1.2 g/l) concentration. Elimination of sulfates from the medium led to the efficient production of hydrogen in the initial cycles - 0.97 mol H2/molhexose (5.93 mmol H2/gcellulose). However, the effectiveness of pretreatment was only temporary for cellulose, because propionic acid accumulation (1.5 g/l) was observed after 25 days, which resulted in lower H2 production. The effective production of hydrogen from cellulose was also maintained for 40 days in a repeated fed-batch process (0.63 mol H2/molhexose).Hydrogen produced from lignocellulose biomass is deemed as a promising fuel of the future. However, direct cellulose utilization remains an issue due to the low hydrogen yields. In this study, the long-term effect of inoculum (anaerobic sludge) heat pretreatment on hydrogen production from untreated cellulose and starch was evaluated during repeated batch processes. The inoculum pretreatment at 90°C was not sufficient to suppress H2 consuming bacteria, both for starch and cellulose. Although hydrogen was produced, it was rapidly utilized with simultaneous accumulation of acetic and propionic acid. The pretreatment at 100°C (20 min) resulted in the successful enrichment of hydrogen producers on starch. High production of hydrogen (1.2 l H2/lmedium) and H2 yield (1.7 mol H2/molhexose) were maintained for 130 days, with butyric (1.5 g/l) and acetic acid (0.65 g/l) as main byproducts. On the other hand, the process with cellulose showed lower hydrogen production (0.3 l H2/lmedium) with simultaneous high acetic acid (1.4 g/l) and ethanol (1.2 g/l) concentration. Elimination of sulfates from the medium led to the efficient production of hydrogen in the initial cycles ­ 0.97 mol H2/molhexose (5.93 mmol H2/gcellulose). However, the effectiveness of pretreatment was only temporary for cellulose, because propionic acid accumulation (1.5 g/l) was observed after 25 days, which resulted in lower H2 production. The effective production of hydrogen from cellulose was also maintained for 40 days in a repeated fed-batch process (0.63 mol H2/molhexose).


Assuntos
Celulose/metabolismo , Fermentação , Hidrogênio/metabolismo , Consórcios Microbianos , Amido/metabolismo , Ácido Acético/metabolismo , Bactérias/metabolismo , Técnicas de Cultura Celular por Lotes , Biomassa , Temperatura Alta , Propionatos/metabolismo
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