A full-length cDNA encoding fructose-6-phosphate, 2-kinase/fructose-2,6-bisphosphatase from maize (Zea mays L.) was cloned by the methods of reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplifica...A full-length cDNA encoding fructose-6-phosphate, 2-kinase/fructose-2,6-bisphosphatase from maize (Zea mays L.) was cloned by the methods of reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE), and designated as mF2KP. The encoded protein is composed of two regions. Its COOH-terminal region is catalytic region and homologous to the enzymes from other eukaryotes; and its NH 2-terminal region is common and special region only in plant. A truncated fragment of mF2KP covering integrated catalytic region was expressed in Escherichia coli. The fusion protein had the activities of fructose-6-phosphate, 2-kinase as well as fructose-2,6-bisphosphatase. Northern blot showed that the transcript level of mF2KP in seedlings initiated from strong-vigor seeds is lower than that from weak-vigor seeds.展开更多
This study consolidates the efficacy of a non-starch polysaccharide （NSP）ase enzyme-concept in corn and wheat-based broiler diets. The NSP building blocks of corn, wheat and soybean meal （SBM, 44% protein） were st...This study consolidates the efficacy of a non-starch polysaccharide （NSP）ase enzyme-concept in corn and wheat-based broiler diets. The NSP building blocks of corn, wheat and soybean meal （SBM, 44% protein） were studied first. Cereal NSP primarily consists of arabinose, xylose and glucose molecules that form arabinoxylan, β-glucan and cellulose polysaccharides. In soybean meal （SBM）, glucose （cellulose） predominates, next to galactose and uronic acids that form “pectins”. Broiler performance progress using in-feed NSPase enzymes depends on the concentration, complexity and solubility of the substrate and the genetic potential of the animal, mainly. A dual NSPase enzyme-concept for cereal and SBM NSP, predominantly being arabinoxylan, β-glucan and cellulose, was developed. Methods for measuring enzyme activities （endo-1,4-β-xylanase （EC 3.2.1.8） and endo-1,3（4）-β-glucanase （EC 3.2.1.6）） were developed （AVEVE Biochem UNITS） and preparations thereof （XG） standardized to meet requirements for most challenging NSP （corn, barely soluble）. Feed intake （FI）, bodyweight gain （BWG） and feed：gain ratio （F：G） were assessed in three zootechnical studies, each using 160 Ross 308 broilers split in two feeding groups with 80 birds/group （10 replicates of eight） for 42 d （starter/grower period）. Respective corn-SBM, wheat-SBM and corn/wheat-SBM diets were used as negative control （NC） or added with the enzyme-concept （XG）. In the total period, XG ameliorated BWG and F：G compared to NC in each study, where BWG increased best in diets with corn and F：G lowered most in diets with wheat. The dual NSPase enzyme-concept offers ingredient flexibility in present setting by enhancing the nutritional content of corn, wheat and SBM, expectedly from cleaving major NSP target molecules. Thereby, broiler professionals increase feed formulation liberty and safety and production result simultaneously.展开更多
A 9-week feeding trial in floating freshwater cages(1.0 m×1.0 m×2.0 m) was conducted to study the effects of different dietary levels of protein and starch on growth,body composition,and gene expression of e...A 9-week feeding trial in floating freshwater cages(1.0 m×1.0 m×2.0 m) was conducted to study the effects of different dietary levels of protein and starch on growth,body composition,and gene expression of enzymes in common carp,Cyprinus carpio(mean body weight,36.12±1.18 g) to evaluate the protein-sparing effect of dietary carbohydrate.Four diets were formulated with corn starch as the carbohydrate source to obtain corn starch levels of 6.5%,13%,19.5%,or 26%and protein levels of 30.5%,28.2%,26.4%,and 24.2%.The results showed no differences in growth performance of fish fed the diets with different protein and corn starch levels,but body composition and glucose metabolic enzyme activity of carp were significantly affected by the different diets(P<0.05).Weight gain,specific growth rate,and the feed conversion ratio were not different in fish fed the different dietary treatments.Protein efficiency ratio increased significantly as corn starch level increased(P<0.05).Whole-body crude lipid composition increased with increasing dietary corn starch level(P<0.05).Glucokinase(GK),hexokinase,and pyruvate kinase(PK) activities increased significantly with increasing dietary corn starch level(P<0.05),whereas glucose-6-phosphate(G6Pase) activity decreased with increasing dietary corn starch level(P<0.05).GK gene expression was significantly higher in fish fed the high-corn starch diet than those fed the low-corn starch diet(P<0.05).G6 pase gene expression tended to decrease with increasing starch level(P>0.05).In summary,the results indicate a protein-sparing effect by substituting carbohydrate in the diet of common carp.展开更多
An improved process of hydrolysis of corn starch was adopted in the production of itaconic acid （IA）, the aim was to decrease the unfermentable reducing sugar （RS） in the medium from the beginning of the fermentat...An improved process of hydrolysis of corn starch was adopted in the production of itaconic acid （IA）, the aim was to decrease the unfermentable reducing sugar （RS） in the medium from the beginning of the fermentation and to increase the crystallization efficiency of IA from the fermentation broth. The glucose （GS） syrups saccharified by several combinations of glucoamylase and pullulanase were investigated and used as the carbohydrate source of the fermentation medium for the spore-initiated submerged fermentations experiments. Compared with the conventional process （with pullulanase controlled）, the improved process decreased th.e RS residue in the fermentation broth from 3.01g/L to 1.35g/L and from 4.25g/L to 3.25g/L when the original RS of the medium were 100 and 120g/L, respectively. The crystallization efficiency of IA increased from 65% to 78.8% and from 69.58% to 82.81% with the original RS being 100 and 120g/L, respectively.展开更多
[Objective] To accurately determine the components and content of fermentable sugars in wort. [Method] The components and content of fermentable sugars in wort made from degermed corn extruded at low temperature as be...[Objective] To accurately determine the components and content of fermentable sugars in wort. [Method] The components and content of fermentable sugars in wort made from degermed corn extruded at low temperature as beer adjunct were determined by HPLC. [Result] The contents of sugar components were shown as below: fructose was 3.8 g/L, glucose was 7.4 g/L, sucrose was 4.2 g/L, maltose was 53.8 g/L and maltotriose was 10.6 g/L.The content of the five fermentable sugars had good linear relation within their peak area in the determination range, the correlation coefficient was 0.977 6-0.990 7, the recoveries of samples were >96%, the standard deviation was 1.27%-3.26%. [Conclusion] The method is simple and rapid with high sensitivity and good reproducibility, it provides reliable and accurate analytic method for determining the components of fermentable sugars in wort made from degermed corn extruded at low temperature as beer adjunct.展开更多
In this paper three methods(dilute acid pretreatment, aqueous ammonia/dilute acid pretreatment and alkaline pretreatment) were used to study the hydrolysis of corn stover and characteristics of each method were compar...In this paper three methods(dilute acid pretreatment, aqueous ammonia/dilute acid pretreatment and alkaline pretreatment) were used to study the hydrolysis of corn stover and characteristics of each method were compared. The results showed that the lignin removal rate was 71.8% when the corn stover was treated with a caustic soda solution containing 1.5% of NaOH, at a temperature of 75 ℃ for 90 min with an initial solid-liquid ratio of 1:8(w/v). Hydrolysis yield of the NaOH pretreated sample reached 78.5%, which was much higher than other control groups. These results are useful for evaluation of pretreatment technologies, and identification of key factors that limit cellulose hydrolysis, and can also serve as a basis for designing and screening appropriate pretreatment technologies.展开更多
Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% （w/v） chitosan solutions at 15 ...Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% （w/v） chitosan solutions at 15 ℃ on the growth and physiological changes were investigated using two maize （Zea rnays L.） inbred lines, HuangC （chilling-tolerant） and Mo17 （chilling-sensitive）. While seed priming with chitosan had no significant effect on germination percentage under low temperature stress, it enhanced germination index, reduced the mean germination time （MGT）, and increased shoot height, root length, and shoot and root dry weights in both maize lines. The decline of malondialdehyde （MDA） content and relative permeability of the plasma membrane and the increase of the concentrations of soluble sugars and proline, peroxidase （POD） activity, and catalase （CAT） activity were detected both in the chilling-sensitive and chilling-tolerant maize seedlings after priming with the three concentrations of chitosan. HuangC was less sensitive to responding to different concentrations of chitosan. Priming with 0.50% chitosan for about 60-64 h seemed to have the best effects. Thus, it suggests that seed priming with chitosan may improve the speed of germination of maize seed and benefit for seedling growth under low temperature stress.展开更多
文摘A full-length cDNA encoding fructose-6-phosphate, 2-kinase/fructose-2,6-bisphosphatase from maize (Zea mays L.) was cloned by the methods of reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE), and designated as mF2KP. The encoded protein is composed of two regions. Its COOH-terminal region is catalytic region and homologous to the enzymes from other eukaryotes; and its NH 2-terminal region is common and special region only in plant. A truncated fragment of mF2KP covering integrated catalytic region was expressed in Escherichia coli. The fusion protein had the activities of fructose-6-phosphate, 2-kinase as well as fructose-2,6-bisphosphatase. Northern blot showed that the transcript level of mF2KP in seedlings initiated from strong-vigor seeds is lower than that from weak-vigor seeds.
文摘This study consolidates the efficacy of a non-starch polysaccharide （NSP）ase enzyme-concept in corn and wheat-based broiler diets. The NSP building blocks of corn, wheat and soybean meal （SBM, 44% protein） were studied first. Cereal NSP primarily consists of arabinose, xylose and glucose molecules that form arabinoxylan, β-glucan and cellulose polysaccharides. In soybean meal （SBM）, glucose （cellulose） predominates, next to galactose and uronic acids that form “pectins”. Broiler performance progress using in-feed NSPase enzymes depends on the concentration, complexity and solubility of the substrate and the genetic potential of the animal, mainly. A dual NSPase enzyme-concept for cereal and SBM NSP, predominantly being arabinoxylan, β-glucan and cellulose, was developed. Methods for measuring enzyme activities （endo-1,4-β-xylanase （EC 3.2.1.8） and endo-1,3（4）-β-glucanase （EC 3.2.1.6）） were developed （AVEVE Biochem UNITS） and preparations thereof （XG） standardized to meet requirements for most challenging NSP （corn, barely soluble）. Feed intake （FI）, bodyweight gain （BWG） and feed：gain ratio （F：G） were assessed in three zootechnical studies, each using 160 Ross 308 broilers split in two feeding groups with 80 birds/group （10 replicates of eight） for 42 d （starter/grower period）. Respective corn-SBM, wheat-SBM and corn/wheat-SBM diets were used as negative control （NC） or added with the enzyme-concept （XG）. In the total period, XG ameliorated BWG and F：G compared to NC in each study, where BWG increased best in diets with corn and F：G lowered most in diets with wheat. The dual NSPase enzyme-concept offers ingredient flexibility in present setting by enhancing the nutritional content of corn, wheat and SBM, expectedly from cleaving major NSP target molecules. Thereby, broiler professionals increase feed formulation liberty and safety and production result simultaneously.
基金Supported by the Key Technology R&D Program of Tianjin(No.13ZCZDNC00900)the Tianjin Research Program of Application Foundation and Advanced Technology(No.14JCQNJC15100)+2 种基金the Tianjin Innovative Research Team(No.TD12-5018)the Tianjin Key Laboratory of Animal and Plant Resistancethe National Natural Science Foundation of China(No.31402313)
文摘A 9-week feeding trial in floating freshwater cages(1.0 m×1.0 m×2.0 m) was conducted to study the effects of different dietary levels of protein and starch on growth,body composition,and gene expression of enzymes in common carp,Cyprinus carpio(mean body weight,36.12±1.18 g) to evaluate the protein-sparing effect of dietary carbohydrate.Four diets were formulated with corn starch as the carbohydrate source to obtain corn starch levels of 6.5%,13%,19.5%,or 26%and protein levels of 30.5%,28.2%,26.4%,and 24.2%.The results showed no differences in growth performance of fish fed the diets with different protein and corn starch levels,but body composition and glucose metabolic enzyme activity of carp were significantly affected by the different diets(P<0.05).Weight gain,specific growth rate,and the feed conversion ratio were not different in fish fed the different dietary treatments.Protein efficiency ratio increased significantly as corn starch level increased(P<0.05).Whole-body crude lipid composition increased with increasing dietary corn starch level(P<0.05).Glucokinase(GK),hexokinase,and pyruvate kinase(PK) activities increased significantly with increasing dietary corn starch level(P<0.05),whereas glucose-6-phosphate(G6Pase) activity decreased with increasing dietary corn starch level(P<0.05).GK gene expression was significantly higher in fish fed the high-corn starch diet than those fed the low-corn starch diet(P<0.05).G6 pase gene expression tended to decrease with increasing starch level(P>0.05).In summary,the results indicate a protein-sparing effect by substituting carbohydrate in the diet of common carp.
基金the National Natural Science Foundatioo of China(No.30670566)the International S&T Cooperation Program of China(No.2006DFA33150)
文摘An improved process of hydrolysis of corn starch was adopted in the production of itaconic acid （IA）, the aim was to decrease the unfermentable reducing sugar （RS） in the medium from the beginning of the fermentation and to increase the crystallization efficiency of IA from the fermentation broth. The glucose （GS） syrups saccharified by several combinations of glucoamylase and pullulanase were investigated and used as the carbohydrate source of the fermentation medium for the spore-initiated submerged fermentations experiments. Compared with the conventional process （with pullulanase controlled）, the improved process decreased th.e RS residue in the fermentation broth from 3.01g/L to 1.35g/L and from 4.25g/L to 3.25g/L when the original RS of the medium were 100 and 120g/L, respectively. The crystallization efficiency of IA increased from 65% to 78.8% and from 69.58% to 82.81% with the original RS being 100 and 120g/L, respectively.
基金Supported by Shandong Natural Foundation(Y2008B10)
文摘[Objective] To accurately determine the components and content of fermentable sugars in wort. [Method] The components and content of fermentable sugars in wort made from degermed corn extruded at low temperature as beer adjunct were determined by HPLC. [Result] The contents of sugar components were shown as below: fructose was 3.8 g/L, glucose was 7.4 g/L, sucrose was 4.2 g/L, maltose was 53.8 g/L and maltotriose was 10.6 g/L.The content of the five fermentable sugars had good linear relation within their peak area in the determination range, the correlation coefficient was 0.977 6-0.990 7, the recoveries of samples were >96%, the standard deviation was 1.27%-3.26%. [Conclusion] The method is simple and rapid with high sensitivity and good reproducibility, it provides reliable and accurate analytic method for determining the components of fermentable sugars in wort made from degermed corn extruded at low temperature as beer adjunct.
基金Financial support provided by the SINOPEC Research Program(No.S213070)
文摘In this paper three methods(dilute acid pretreatment, aqueous ammonia/dilute acid pretreatment and alkaline pretreatment) were used to study the hydrolysis of corn stover and characteristics of each method were compared. The results showed that the lignin removal rate was 71.8% when the corn stover was treated with a caustic soda solution containing 1.5% of NaOH, at a temperature of 75 ℃ for 90 min with an initial solid-liquid ratio of 1:8(w/v). Hydrolysis yield of the NaOH pretreated sample reached 78.5%, which was much higher than other control groups. These results are useful for evaluation of pretreatment technologies, and identification of key factors that limit cellulose hydrolysis, and can also serve as a basis for designing and screening appropriate pretreatment technologies.
基金Project supported by the Major Science and Technology Special Project (priority subject) of Zhejiang Province (No. 2008C12005-1)the Key Project of Education Department of Zhejiang Province (No. 20070147), China
文摘Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% （w/v） chitosan solutions at 15 ℃ on the growth and physiological changes were investigated using two maize （Zea rnays L.） inbred lines, HuangC （chilling-tolerant） and Mo17 （chilling-sensitive）. While seed priming with chitosan had no significant effect on germination percentage under low temperature stress, it enhanced germination index, reduced the mean germination time （MGT）, and increased shoot height, root length, and shoot and root dry weights in both maize lines. The decline of malondialdehyde （MDA） content and relative permeability of the plasma membrane and the increase of the concentrations of soluble sugars and proline, peroxidase （POD） activity, and catalase （CAT） activity were detected both in the chilling-sensitive and chilling-tolerant maize seedlings after priming with the three concentrations of chitosan. HuangC was less sensitive to responding to different concentrations of chitosan. Priming with 0.50% chitosan for about 60-64 h seemed to have the best effects. Thus, it suggests that seed priming with chitosan may improve the speed of germination of maize seed and benefit for seedling growth under low temperature stress.
