Metabolic profiling reveals coordinated switches in primary carbohydrate metabolism in grape berry (Vitis vinifera L.), a non-climacteric fleshy fruit

Changes in carbohydrate metabolism during grape berry development play a central role in shaping the final composition of the fruit. The present work aimed to identify metabolic switches during grape development and to provide insights into the timing of developmental regulation of carbohydrate metabolism. Metabolites from central carbon metabolism were measured using high-pressure anion-exchange chromatography coupled to tandem mass spectrometry and enzymatic assays during the development of grape berries from either field-grown vines or fruiting cuttings grown in the greenhouse. Principal component analysis readily discriminated the various stages of berry development, with similar trajectories for field-grown and greenhouse samples. This showed that each stage of fruit development had a characteristic metabolic profile and provided compelling evidence that the fruit-bearing cuttings are a useful model system to investigate regulation of central carbon metabolism in grape berry. The metabolites measured showed tight coordination within their respective pathways, clustering into sugars and sugar-phosphate metabolism, glycolysis, and the tricarboxylic acid cycle. In addition, there was a pronounced shift in metabolism around veraison, characterized by rapidly increasing sugar levels and decreasing organic acids. In contrast, glycolytic intermediates and sugar phosphates declined before veraison but remained fairly stable post-veraison. In summary, these detailed and comprehensive metabolite analyses revealed the timing of important switches in primary carbohydrate metabolism, which could be related to transcriptional and developmental changes within the berry to achieve an integrated understanding of grape berry development. The results are discussed in a meta-analysis comparing metabolic changes in climacteric versus non-climacteric fleshy fruits

Characterization of botryococcus sp. and identification of carbohydrates metabolic related enzymes toward lipid production

The advancement of microalgal biofuels is faced with challenges among which is low strain performance in lipid production. Alternatively, the carbohydrate production in microalgal cells could be manipulated to increase the lipid content thereby maximizing the overall biofuel production. This work is aimed at determining metabolic pathway and enzymes involved in carbohydrate metabolism of Botryococcus sp. The B. sp. from Taman Negara Johor Endau Rompin was isolated and identified. Some relevant intracellular metabolites were extracted and quantified through HPLC and GC-MS analysis while extracellular metabolites excreted into the Bold basal medium were also analysed and identified through GC-MS. Enzymes involved in carbohydrate metabolism leading to lipid production in B. sp. under natural conditions were also identified through one-dimensional gel electrophoresis followed by proteomic mass spectrometry (LC-MS) and database searching. Finally, the carbohydrate to lipid metabolic pathway of B. sp. cultivated under natural conditions was determined. The total carbohydrate content was found to be 23 % per milligram biomass dry weight with monomeric sugars galactose, glucose, mannose, and arabinose. Total protein estimated for the microalgae B. sp. is 16.22 % and the lipid content was found to be 60.69 %. The extracellular metabolites constitute majorly cyclohydrocarbons, nitrogenated hydrocarbons, siloxanes, phenols and phenol derivatives. A glycolytic enzyme ‘Enolase ’which can generate phosphoenolpyruvate (PEP) and then convert it into pyruvate was identified in this study. Enolase which helps in high lipid metabolism was found in the cytoplasm and was used to construct the alternative pathway. Enolase was found to export fixed carbon (3PGA) to the cytoplasm, hence providing a shorter route to lipid production than the normal process via the plastid leading to the production of more lipid in Botryococcus

Fuel utilization during exercise after 7 days of bed rest

Energy yield from carbohydrate, fat, and protein during physical activity is partially dependent on an individual's fitness level. Prolonged exposure to microgravity causes musculoskeletal and cardiovascular deconditioning; these adaptations may alter fuel utilization during space flight. Carbohydrate and fat metabolism during exercise were analyzed before and after 7 days of horizontal bed rest

Diabetes Mellitus : Insulin use

Insulin is required for normal carbohydrate, protein and fat metabolism. Patients with Type I diabetes depend on exogenous insulin for their survival while Type II diabetics may require insulin at a later stage of their disease.peer-reviewe

Medium-term carbohydrate tolerance improves and then deteriorates with advancing pregnancy in urban Nigerian women

Background: It has been reported that carbohydrate metabolism does not deteriorate in pregnancy in the African, an observation at variance with general teaching. Objective: To determine the effect of pregnancy on medium term carbohydrate metabolism Methods: Medium term carbohydrate metabolism was evaluated in pregnant and non-pregnant Nigerian women using changes in Glycoted Plasma Proteins (GPP) as a surrogate for medium-term carbohydrate metabolism. Study subjects included women in all three trimesters of pregnancy, a group of non-pregnant women with normal carbohydrate metabolism and another group of women with confirmed diabetes already on treatment but not pregnant. Fasting plasma glucose was determined by the glucose oxidase method while GPP was determined using a modification of the thiobarbituric method with correction for levels of total plasma proteins (TPP). Average values are presented as mean (SD) while relationship between variables were determined using Pearson product moment correlation coefficients. Significance of p values of determinations is set at

Muscle protein and glycogen responses to recovery from hypogravity and unloading by tail-cast suspension

Previous studies in this laboratory using the tail-bast hindlimb suspension model have shown that there are specific changes in protein and carbohydrate metabolism in the soleus muscle due to unloading. For example, 6 days of unloading caused a 27% decrease in mass and a 60% increase in glycogen content in the soleus muscle, while the extensor digitorum longus muscle was unaffected. Also, fresh tissue tyrosine and its in vitro release from the muscle are increased in the unloaded soleus, indicating that this condition causes a more negative protein balance. With these results in mind, studies to investigate the effect of hypogravity on protein and carbohydrate metabolism in a number of rat hindlimb muscles were carried out

Carbohydrate metabolism after one year of using a gestodene containing monophasic oral contraceptive

Aim: To prospectively evaluate the effects of an oral contraceptive containing the progestin gestodene on carbohydrate metabolism in ordinary Turkish women Material / Method: Carbohydrate metabolism was prospectively evaluated in 53 normal women prior to and during their use of monophasic oral contraceptive containing the progestin gestodene plus ethinyl estradiol for one year. The women had a two hour oral glucose tolerance test using 75 gram glucose load, measuring serum glucose and insulin level, performed at the beginning of the contraceptive therapy and after one year. Results: The results demonstrate no significant changes in either of carbohydrate metabolic indices between the two tests.  Conclusion: The progestin containing contraceptive pill can be safely used in consideration of the carbohydrate metabolism

Microalgae cultivation for lipids and carbohydrates production

Microalgae are photoautotrophic microorganisms that can produce energy both by using sunlight, water and CO2 (phototrophic metabolism) and by using organic sources such as glucose (heterotrophic metabolism). Heterotrophic growth is a key factor in microalgae research, due to its increased productivity and the lower capital and operative costs compared to photoautotrophic growth in photobioreactors. Carbohydrate production from microalgae is usually investigated for the production of biofuels (e.g. bioethanol) by successive fermentation, but also other applications can be envisaged in biopolymers. In this work an increment in carbohydrate purity after lipid extraction was found. Protein hydrolysis for different microalgae strains (Scenedesmus sp. and Chlorella sp.) was investigated. Microalgae were cultivated under photoautotrophic or heterotrophic conditions, collecting biomass at the end of the growth. Biomass samples were dried or freeze dried and used for carbohydrate and lipid extraction tests. Lipid extraction was achieved using different organic solvents (methanol-chloroform and hexane-2propanol). Basic protein hydrolysis has been carried out testing different temperatures and NaOH concentrations values. Lipids were spectrophotometrically quantified, while residual biomass was saccharificated and the total amount of sugars was measured. Significant differences about the purity of extracted carbohydrates were found comparing dried with freeze dried biomass. However, not a very promising purification of carbohydrates was achieved after protein hydrolysis, asking for further analysis. © Copyright 2017, AIDIC Servizi S.r.l

Oxidation of glucose by iodine in the presence of insulin

This investigation was undertaken with the purpose of determining whether insulin, alone or in the presence of certain animal fluids, has any influence upon glucose in vitro. The establishment of such an influence might have much significance in relation both to the study of carbohydrate metabolism and to the development of methods of assaying insulin