Sweet potato is an important food crop that can also be used as an industrial raw material. Sucrose is the main form of long-distance carbohydrate transport in plants, and sucrose transporter (SUT) regulates the transmembrane transport and distribution of sucrose during plant growth and metabolism. Moreover, SUT plays a key role in phloem mediated source-to-sink sucrose transport and physiological activities, supplying sucrose for the sink tissues. In this study, the full-length cDNA sequences of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were obtained by rapid amplification of cDNA ends (RACE) cloning according to the transcripts of the two SUT coding genes which were differentially expressed in sweet potato storage roots with different starch properties. Phylogenetic analysis was performed to clarify the classification of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆. The subcellular localization of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ was determined by transient expression in Nicotiana benthamiana. The function of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in sucrose and hexose absorption and transport was identified using yeast functional complementarity system. The expression pattern of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in sweet potato organs were analyzed by real-time fluorescence quantitative PCR (RT-qPCR). Arabidopsis plants heterologous expressing IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ genes were obtained using floral dip method. The differences in starch and sugar contents between transgenic and wild-type Arabidopsis were compared. The results showed IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ encoded SUT proteins with a length of 505 and 521 amino acids, respectively, and both proteins belonged to the SUT1 subfamily. IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were located in the cell membrane and were able to transport sucrose, glucose and fructose in the yeast system. In addition, IbSUT₆₂₇₈₈ was also able to transport mannose. The expression of IbSUT₆₂₇₈₈ was higher in leaves, lateral branches and main stems, and the expression of IbSUT₈₁₆₁₆ was higher in lateral branches, stems and storage roots. After IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were heterologously expressed in Arabidopsis, the plants grew normally, but the biomass increased. The heterologous expression of IbSUT₆₂₇₈₈ increased the soluble sugar content, leaf size and 1 000-seed weight of Arabidopsis plants. Heterologous expression of IbSUT₈₁₆₁₆ increased starch accumulation in leaves and root tips and 1 000-seed weight of seeds, but decreased soluble sugar content. The results obtained in this study showed that IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ might be important genes regulating sucrose and sugar content traits in sweet potato. They might carry out physiological functions on cell membrane, such as transmembrane transport of sucrose, sucrose into and out of sink tissue, as well as transport and unloading of sucrose into phloem. The changes in traits result from their heterologous expression in Arabidopsis indicates their potential in improving the yield of other plants or crops. The results obtained in this study provide important information for revealing the functions of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in starch and glucose metabolism and formation mechanism of important quality traits in sweet potato.
Ipomoea batatas/metabolism* ; Arabidopsis/metabolism* ; Sucrose/metabolism* ; Saccharomyces cerevisiae/metabolism* ; DNA, Complementary ; Phylogeny ; Plants, Genetically Modified/genetics* ; Membrane Transport Proteins/metabolism* ; Starch/metabolism* ; Plant Proteins/metabolism* ; Gene Expression Regulation, Plant

In order to investigate the enzyme production mechanism of yak rumen-derived anaerobic fungus Orpinomyces sp. YF3 under the induction of different carbon sources, anaerobic culture tubes were used for in vitro fermentation. 8 g/L of glucose (Glu), filter paper (Flp) and avicel (Avi) were respectively added to 10 mL of basic culture medium as the sole carbon source. The activity of fiber-degrading enzyme and the concentration of volatile fatty acid in the fermentation liquid were detected, and the enzyme producing mechanism of Orpinomyces sp. YF3 was explored by transcriptomics. It was found that, in glucose-induced fermentation solution, the activities of carboxymethyl cellulase, microcrystalline cellulase, filter paper enzyme, xylanase and the proportion of acetate were significantly increased (P < 0.05), the proportion of propionate, butyrate, isobutyrate were significantly decreased (P < 0.05). The results of transcriptome analysis showed that there were 5 949 differentially expressed genes (DEGs) between the Glu group and the Flp group, 10 970 DEGs between the Glu group and the Avi group, and 6 057 DEGs between the Flp group and the Avi group. It was found that the DEGs associated with fiber degrading enzymes were significantly up-regulated in the Glu group. Gene ontology (GO) function enrichment analysis identified that DEGs were mainly associated with the xylan catabolic process, hemicellulose metabolic process, β-glucan metabolic process, cellulase activity, endo-1,4-β-xylanase activity, cell wall polysaccharide metabolic process, carbohydrate catabolic process, glucan catabolic process and carbohydrate metabolic process. Moreover, the differentially expressed pathways associated with fiber degrading enzymes enriched by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were mainly starch and sucrose metabolic pathways and other glycan degradation pathways. In conclusion, Orpinomyces sp. YF3 with glucose as carbon source substrate significantly increased the activity of cellulose degrading enzyme and the proportion of acetate, decreased the proportion of propionate, butyrate and isobutyrate. Furthermore, the degradation ability and energy utilization efficiency of fungus in the presence of glucose were improved by means of regulating the expression of cellulose degrading enzyme gene and participating in starch and sucrose metabolism pathway, and other glycan degradation pathways, which provides a theoretical basis for the application of Orpinomyces sp. YF3 in practical production and facilitates the application of Orpinomyces sp. YF3 in the future.
Animals ; Cattle ; Neocallimastigales/metabolism* ; Anaerobiosis ; Rumen/microbiology* ; Propionates/metabolism* ; Isobutyrates/metabolism* ; Cellulose/metabolism* ; Fungi ; Starch/metabolism* ; Glucose/metabolism* ; Acetates ; Sucrose/metabolism* ; Cellulases ; Cellulase

Starch is composed of glucose units linked by α-1, 4-glucoside bond and α-1, 6-glucoside bond. It is the main component of foods and the primary raw material for starch processing industry. Pullulanase can effectively hydrolyze the α-1, 6-glucoside bond in starch molecules. Combined with other starch processing enzymes, it can effectively improve the starch utilization rate. Therefore, it has been widely used in the starch processing industry. This paper summarized the screening of pullulanase-producing strain and its encoding genes. In addition, the effects of expression elements and fermentation conditions on the production of pullulanase were summarized. Moreover, the progress in crystal structure elucidation and molecular modification of pullulanase was discussed. Lastly, future perspectives on pullulanase research were proposed.
Glycoside Hydrolases/genetics* ; Starch/metabolism*

Production of biofuels such as ethanol from non-grain crops may contribute to alleviating the global energy crisis and reducing the potential threat to food security. Tobacco (Nicotiana tabacum) is a commercial crop with high biomass yield. Breeding of starch-rich tobacco plants may provide alternative raw materials for the production of fuel ethanol. We cloned the small subunit gene NtSSU of ADP-glucose pyrophosphorylase (NtAGPase), which controls starch biosynthesis in tobacco, and constructed a plant expression vector pCAMBIA1303-NtSSU. The NtSSU gene was overexpressed in tobacco upon Agrobacterium-mediated leaf disc transformation. Phenotypic analysis showed that overexpression of NtSSU gene promoted the accumulation of starch in tobacco leaves, and the content of starch in tobacco leaves increased from 17.5% to 41.7%. The growth rate and biomass yield of the transgenic tobacco with NtSSU gene were also significantly increased. The results revealed that overexpression of NtSSU gene could effectively redirect more photosynthesis carbon flux into starch biosynthesis pathway, which led to an increased biomass yield but did not generate negative effects on other agronomic traits. Therefore, NtSSU gene can be used as an excellent target gene in plant breeding to enrich starch accumulation in vegetative organs to develop new germplasm dedicated to fuel ethanol production.
Biomass ; Gene Expression Regulation, Plant ; Plant Breeding ; Plant Leaves/genetics* ; Plants, Genetically Modified/metabolism* ; Starch ; Tobacco/metabolism*

Obesity is a substantial public health challenge across the globe. The use of resistant starch has been proposed as a probable management strategy for complications of obesity. We investigated the effects of resistant starch intake on lipid profiles, glucose metabolism, antioxidant status, lipid peroxidation marker, blood pressure, and anthropometric variables in subjects with overweight or obesity. In this 12-week, randomized, double-blind, placebo-controlled, 2 × 2 crossover trial, 21 Participants (mean age, 35 ± 7.0 years; body mass index, 32.4 ± 3.5 kg/m²) were given 13.5 g Hi-Maize 260 or placebo daily for 4 weeks, separated by a 4-week washout period. Changes in total antioxidant status (p = 0.04) and serum concentrations of insulin in 52.4% participants with insulin levels above 16 µIU/mL at the baseline (p = 0.04) were significantly different in the three phases. In addition, the mean of serum high-density lipoprotein cholesterol after the intervention was significantly higher than after baseline value (p = 0.04). We found no significant differences in serum concentrations of total cholesterol, triacylglycerol, low-density lipoprotein cholesterol, fasting blood sugar, insulin, homeostatic model assessment of insulin resistance, quantitative insulin sensitivity check index, superoxide dismutase activity, malondialdehyde, blood pressure, and anthropometric variables in the three phases of baseline, after intervention with resistant starch and after placebo. Resistant starch consumption improved serum insulin concentrations, lipid profiles, and antioxidant status in subjects with overweight or obesity. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01992783
Adult ; Blood Glucose ; Blood Pressure ; Body Mass Index ; Cholesterol ; Dietary Fiber ; Fasting ; Glucose ; Humans ; Insulin ; Insulin Resistance ; Lipid Metabolism ; Lipid Peroxidation ; Lipoproteins ; Malondialdehyde ; Metabolism ; Obesity ; Overweight ; Oxidative Stress ; Public Health ; Starch ; Superoxide Dismutase ; Triglycerides

Overweight or obesity has become a serious public health problem in the world, scientists are concentrating their efforts on exploring novel ways to treat obesity. Nowadays, the availabilities of bariatric surgery and pharmacotherapy have enhanced obesity treatment, but it should has support from diet, physical exercise and lifestyle modification, especially the functional food. Resistant starch, an indigestible starch, has been studied for years for its beneficial effects on regulating blood glucose level and lipid metabolism. The aim of this review is to summarize the effect of resistant starch on weight loss and the possible mechanisms. According to numerous previous studies it could be concluded that resistant starch can reduce fat accumulation, enhance insulin sensitivity, regulate blood glucose level and lipid metabolism. Recent investigations have focused on the possible associations between resistant starch and incretins as well as gut microbiota. Resistant starch seems to be a promising dietary fiber for the prevention or treatment of obesity and its related diseases.
Dietary Carbohydrates ; metabolism ; Dietary Fiber ; metabolism ; therapeutic use ; Gastrointestinal Tract ; microbiology ; physiology ; Microbiota ; Obesity ; diet therapy ; prevention & control ; Starch ; metabolism ; Weight Loss

In order to explore reasonable artificial cultivation pattern of Thesium chinense, the biological characteristics and nutrients change in the process of winter dormancy of T. chinense was studied. The phenological period of T. chinense was observed by using fixed-point notation and the starch grains changes were determined dynamically by PAS-vanadium iron hematoxylin staixjing method. Soluble sugar and starch content were measured by anthrone-sulfuric acid method and amylase activity was determined by DN'S method. The results showed that the normal life cycle of T. chinense was two years. T. chinense was growing by seed in the first year, but growing by the root neck bud in the second year. During the process of dormancy, starch and soluble sugar could mutual transformation in different periods. T. chinense had sufficient carbohydrate to maintain growth and also a lot of small molecules to improve their ability to fight against adversity.
Plant Dormancy ; Plant Leaves ; chemistry ; growth & development ; metabolism ; Plant Roots ; chemistry ; growth & development ; metabolism ; Plant Stems ; chemistry ; growth & development ; metabolism ; Santalaceae ; chemistry ; growth & development ; metabolism ; Seasons ; Starch ; analysis ; metabolism

OBJECTIVETo explore the effects of resuscitation with different kinds of colloids on oxygen metabolism of swine during shock stage of burn injury.

METHODSEighteen Guangxi Bama miniature swine were inflicted with 40% TBSA full-thickness burn on the back. And then they were divided into succinylated gelatin group (S) , hydroxyethyl starch group (H), and allogeneic plasma group (A) according to the random number table, with 6 swine in each group. The fluid resuscitation was begun at post injury hour (PIH) 2. The colloids used in groups S, H, and A were respectively succinylated gelatin, 60 g/L hydroxyethyl starch 130/0.4, and allogeneic plasma. The blood pressure, urine volume, heart rate, and central venous pressure (CVP) were recorded before injury and at the first and second PIH 24. The volume of resuscitation fluid was recorded at the first and second PIH 24. The changes in oxygen delivery., oxygen consumption, oxygen extraction ratio and D-lactate were determined and calculated before injury and at PIH 4, 8, 24, and 48. Data were processed with analysis of variance of repeated measurement, one-way analysis of variance and LSD test.

RESULTSThere were no statistically significant differences among the three groups in blood pressure, urine volume, heart rate, and CVP at each time point (with P values above 0. 05). There were no statistically significant differences in resuscitation fluid volume among the three groups at the first and second PIH 24 (with F values respectively 0. 239 and 2. 023, P values respectively 0. 790 and 0. 167). The oxygen consumption of swine in group S was (201 ± 38) L · min(-1) · m(-2) at PIH 48, which was significantly higher than that in group A [(150 ± 37) L · min(-1) · m(-2), P < 0.05], and the oxygen consumption was similar among the three groups at the rest time points (with P values above 0.05). The oxygen delivery of swine in group S was (484 ± 63) L · min(-1) · m(-2) at PIH 8, and it was significantly lower than that in group A [(652 ± 65) L(-1) min(-1) · m(-2), P < 0.01]. The oxygen delivery of swine in group S reached (903 ± 132) and (1,028 ± 98) L · min(-1) · m(-2) at PIH 24 and 48, respectively, and they were significantly higher than those in group A [(686 ± 72) and (720 ± 75) L · min(-1) · M(-2), with P values below 0.01]. Oxygen delivery in group H was similar to that of group A at each time point (with P values above 0.05). The oxygen extraction ratio in group S or group H was close to that of group A at each time point (with P values above 0.05). The D-lactate level in group S was (69 ± 9) mmol/L, and it was significantly higher than that in group A [(52 ± 4) mmol/L, P < 0.01] at PIH 48. The D-lactate level was similar among the three groups at the rest time points (with P values above 0.05).

CONCLUSIONSAccording to the changes in oxygen metabolism of swine during shock stage of burn injury resuscitated with different kinds of colloids, it is found that allogeneic plasma is better than artificial colloid, and 60 g/L hydroxyethyl starch 130/0.4 is superior to succinylated gelatin.

Animals ; Blood Pressure ; Burns ; China ; Colloids ; administration & dosage ; pharmacology ; Fluid Therapy ; Hydroxyethyl Starch Derivatives ; Oxygen ; metabolism ; Resuscitation ; methods ; Shock ; Swine

The dynamic changes of germination percentage, germination potential, thousand-seed weight, antioxidase activity in Desmodium styracifolium seeds with different storage time were tested, and electrical conductivity, contents of soluble sugar, soluble protein, starch in seed leach liquor were also determined in order to reveal the mechanism of seed deterioration. The results as the following. (1) The germination percentage, germination potential and thousand-seed weight of D. styracifolium seeds declined, while the seed coat color darkened with the extension of storage time. (2) The activities of superoxide dismutase (SOD) and peroxidase (POD) decreased with the prolongation of storage period. The SOD activity declined fastest in 1,095-1,185 d of storage, while the POD activity declined significantly in 365-395 d of storage. (3) The electrical conductivity and the contents of soluble sugar, starch in seed leach liquor increased, while the content of soluble protein declined with the extension of storage time. (4) Correlation analysis indicated that the germination percentage, germination potential and thousand-seed weight of D. styracifolium seeds have a significantly positive correlation with SOD and POD activity, while have a significantly negative correlation with the electrical conductivity, contents of soluble sugar and starch. It can be concluded that during the storage of D. styracifolium seeds, physiological and biochemical changes including decrease in antioxidase activity, rise in electrical conductivity, degradation effluent of soluble sugar and starch, degradation of soluble protein were the main factors leading to the seed deterioration.
Color ; Fabaceae ; chemistry ; enzymology ; growth & development ; metabolism ; Germination ; Peroxidases ; metabolism ; Plant Proteins ; metabolism ; Seeds ; chemistry ; enzymology ; growth & development ; metabolism ; Starch ; metabolism ; Superoxide Dismutase ; metabolism ; Time Factors

Production of bioethanol using starch as raw material has become a very prominent technology. However, phytate in the raw material not only decreases ethanol production efficiency, but also increases phosphorus discharge. In this study, to decrease phytate content in an ethanol fermentationprocess, Saccharomyces cerevisiae was engineered forheterologous expression of phytase on the cell surface. The phy gene encoding phytase gene was fused with the C-terminal-half region of α-agglutinin and then inserted downstream of the secretion signal gene, to produce a yeast surface-display expression vector pMGK-AG-phy, which was then transformed into S. cerevisiae. The recombinant yeast strain, PHY, successfully displayed phytase on the surface of cells producing 6.4 U/g wet cells and its properties were further characterized. The growthrate and ethanol production of the PHY strain were faster than the parent S. cerevisiae strain in the fermentation medium by simultaneous saccharification and fermentation. Moreover, the phytate concentration decreased by 91% in dry vinasse compared to the control. In summary, we constructed recombinant S. cerevisiae strain displaying phytase on the cell surface, which could effectively reduce the content of phytate, improve the utilization value of vinasse and reduce the discharge of phosphorus. The strain reported here represents a useful novel engineering platform for developing an environment-friendly system for bioethanol production from a corn substrate.
6-Phytase ; metabolism ; Biofuels ; Ethanol ; chemistry ; Fermentation ; Industrial Microbiology ; Saccharomyces cerevisiae ; metabolism ; Starch ; chemistry ; Zea mays ; chemistry