Background：The expression of genes encoding proteins involved in triacyglyceride and fatty acid synthesis and storage in cattle muscle are correlated with intramuscular fat（IMF）%.Are the same genes also correlated ...Background：The expression of genes encoding proteins involved in triacyglyceride and fatty acid synthesis and storage in cattle muscle are correlated with intramuscular fat（IMF）%.Are the same genes also correlated with IMF%in sheep muscle,and can the same set of genes be used to estimate IMF%in both species？Results：The correlation between gene expression（microarray） and IMF%in the longissimus muscle（LM） of twenty sheep was calculated.An integrated analysis of this dataset with an equivalent cattle correlation dataset and a cattle differential expression dataset was undertaken.A total of 30 genes were identified to be strongly correlated with IMF%in both cattle and sheep.The overlap of genes was highly significant,8 of the 13 genes in the TAG gene set and 8 of the 13 genes in the FA gene set were in the top 100 and 500 genes respertively most correlated with IMF%in sheep,P-value = 0.Of the 30 genes,CIDEA,THRSP,ACSM1,DGAT2 and FABP4 had the highest average rank in both species.Using the data from two small groups of Brahman cattle（control and Hormone growth promotant-treated[known to decrease IMF%in muscle]） and 22 animals in total,the utility of a direct measure and different estimators of IMF%（ultrasound and gene expression） to differentiate between the two groups were examined.Directly measured IMF%and IMF%estimated from ultrasound scanning could not discriminate between the two groups.However,using gene expression to estimate IMF%discriminated between the two groups.Increasing the number of genes used to estimate IMF%from one to five significantly increased the discrimination power;but increasing the number of genes to 15 resulted in little further improvement.Conclusion：We have demonstrated the utility of a comparative approach to identify robust estimators of IMF%in the LM in cattle and sheep.We have also demonstrated a number of approaches（potentially applicable to much smaller groups of animals than conventional methods） to using gene expression to rank animals for IMF%within a single farm/treatment,or to estimate differences in IMF%between two farms/treatments.展开更多
Quercetin compounds have antioxidant,anti-inflammatory and anticancer pharmacological functions.Longterm exposure to acrylamide(AA)can cause liver injury and endanger human health.However,whether quercetin compounds c...Quercetin compounds have antioxidant,anti-inflammatory and anticancer pharmacological functions.Longterm exposure to acrylamide(AA)can cause liver injury and endanger human health.However,whether quercetin compounds can attenuate AA-induced liver injury and the specific mechanism are not clear.Here,we studied the mechanism and structure-activity relationship of quercetin compounds in reducing AA-induced hepatotoxicity in vivo and in vitro.In vivo studies found that quercetin-like compounds protect against AAinduced liver injury by reducing oxidative stress levels,activating the Akt/m TOR signaling pathway to attenuate autophagy,and improving mitochondrial apoptosis and endoplasmic reticulum stress-mediated apoptosis.In vitro studies found that quercetin compounds protected Hep G2 cells from AA by attenuating the activation of AA-induced autophagy,lowering reactive oxygen species(ROS)levels by exerting antioxidant effects and thus attenuating oxidative stress,increasing mitochondrial membrane potential(MMP),and improving apoptosis-related proteins,thus attenuating AA-induced apoptosis.Furthermore,the conformational differences between quercetin compounds correlated with their protective capacity against AA-induced hepatotoxicity,with quercetin showing the best protective capacity due to its strongest antioxidant activity.In conclusion,quercetin compounds can protect against AA-induced liver injury through multiple pathways of oxidative stress,autophagy and apoptosis,and their protective capacity correlates with antioxidant activity.展开更多
Dairy cows undergo tremendous changes in physiological, metabolism and the immune function from pregnancy to lac- tation that are associated with cows being susceptible to metabolic and infectious diseases. The object...Dairy cows undergo tremendous changes in physiological, metabolism and the immune function from pregnancy to lac- tation that are associated with cows being susceptible to metabolic and infectious diseases. The objective of this study is to investigate the changes of plasma proteome on 21 d before expected calving and 1 d after calving from dairy cows using an integrated proteomic approach consisting of minor abundance protein enrichment by ProteoMiner beads, protein labeling by isobaric tags for relative and absolute quantification, and protein identification by liquid chromatography coupled with tandem mass spectrometry. Nineteen proteins were changed around the time of calving. These proteins were asso- ciated with response to stress, including acute-phase response and defense response, based on the proteins annotation. In particular, three up-regulated proteins after calving including factor V, a2-antiplasmin and prothrombin were assigned into the complement and coagulation pathway. These results may provide new information in elucidating host response to lactation and parturition stress, and inflammatory-like conditions at the protein level. Differential proteins may serve as potential markers to regulate the lactation and parturition stress in periparturient dairy cows.展开更多
Sodium sulfate(Na2SO4)is a readily available chlorine-free source of sodium,which could be used to reduce sodium chloride to maintain the ratio between chlorine and sodium in poultry diets.Dietary supplementation with...Sodium sulfate(Na2SO4)is a readily available chlorine-free source of sodium,which could be used to reduce sodium chloride to maintain the ratio between chlorine and sodium in poultry diets.Dietary supplementation with excessive levels of Na2SO4 might be detrimental to bird's health and per-formance.A subchronic study was carried out to investigate the potential adverse effects of an accidental oversupply of Na2SO4 in the diets of laying hens.Four hundred and fifty 21-week-old Hy-Line White layers were randomly assigned to 5 treatments with 6 replicates.The birds were fed diets supplemented with 0(control),0.3%,0.6%,1.5%,and 3.0%Na2SO4 for 8 weeks.Laying perfor-mance,egg quality parameters,clinical blood parameters,histopathology,intestinal barrier func-tions,and intestinal microflora composition were measured.No clinical signs of intoxication or mortality were observed during the experimental period.The results of this study showed that the optimal levels of Na2SO4(0.3%to 0.6%)significantly improved the laying rates,average daily egg mass,and eggshell quality of hens compared to the control(P<0.05).However,3.0%Na2SO4 produced negative effects on laying performance,eggshell quality,blood biochemistry,and partic-ularly on liver and kidney pathology,and intestinal morphology and barrier functions compared with the controls.Although minor changes were observed in clinical blood parameters of hens receiving 1.5%Na2SO4,these were not considered to be of toxicological significance due to the absence of any organ pathological changes in hens.In conclusion,our results indicated that a Na2SO4 concentration of 1.5%was non-deleterious to laying hens after a daily administration for 56 d,namely that dietary supplementation of up to 5 times the maximum recommended dose is safely tolerated by laying hens.展开更多
This paper considers the problem of geolocating a target on the Earth surface whose altitude is known previously using the target signal time difference of arrival （TDOA） and frequency difference of arrival （FDOA）...This paper considers the problem of geolocating a target on the Earth surface whose altitude is known previously using the target signal time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements obtained at satellites. The number of satellites available for the geolocation task is more than sufficient and their locations are subject to random errors. This paper derives the constrained Cramor-Rao lower bound （CCRLB） of the target position, and on the basis of the CCRLB analysis, an approximately efficient constrained maximum likelihood estimator （CMLE） for geolocating the target is established. A new iterative algorithm for solving the CMLE is then proposed, where the updated target position estimate is shown to be the globally optimal solution to a generalized trust region sub-problem （GTRS） which can be found via a simple bisection search. First-order mean square error （MSE） analysis is conducted to quantify the performance degradation when the known target altitude is assumed to be precise but indeed has an unknown but deterministic error. Computer simulations are used to compare the performance of the proposed iterative geolocation technique with those of two benchmark algorithms. They verify the approximate efficiency of the proposed algorithm and the validity of the MSE analysis.展开更多
Pyrroloquinoline quinone （PQQ） plays a sig- nificant role as a redox cofactor in combination with dehydrogenases in bacteria. These dehydrogenases play key roles in the oxidation of important substrates for the biot...Pyrroloquinoline quinone （PQQ） plays a sig- nificant role as a redox cofactor in combination with dehydrogenases in bacteria. These dehydrogenases play key roles in the oxidation of important substrates for the biotechnology industry, such as vitamin C production. While biosynthesis of PQQ genes has been widely studied, PQQ-transport mechanisms used both two-dimensional remain unclear. Herein, we fluorescence-difference gel electrophoresis tandem mass spectrometry and RNA sequencing to investigate the effects ofpqqB overexpres- sion in an industrial strain of Gluconobacter oxydans WSH-003. We have identified 73 differentially expressed proteins and 99 differentially expressed genes, a majority of which are related to oxidation-reduction and transport processes by gene ontology analysis. We also described several putative candidate effectors that responded to increased PQQ levels resulting from pqqB overexpression. Furthermore, quantitative PCR was used to verify five putative PQQ-transport genes among different PQQ producing strains, and the results showed that ompW, B932 1930 and B932_2186 were upregulated in all conditions. Then the three genes were over-expressed in G. oxydans WSH-003 and PQQ production were detected. The results showed that extracellular PQQ of B932_1930 （a transporter） and B932_2186 （an ABC transporter perrnease） overexpression strains were enhanced by 1.77- fold and 1.67-fold, respectively. The results suggest that the proteins encoded by PqqB, B932_1930 and B932 2186 might enhance the PQQ secretion process.展开更多
In order to meet the increasing demands for the development of large varieties of new molecules for discovering new drugs and materials, organic chemists are developing many novel multifunctional building blocks, whic...In order to meet the increasing demands for the development of large varieties of new molecules for discovering new drugs and materials, organic chemists are developing many novel multifunctional building blocks, which are assembled rationally to create ‘nature-like＇ and yet unnatural organic molecules with well-defined structures and useful properties. Sugar amino acids（SAAs）, the carbohydrate derivatives bearing both amino and carboxylic acid functional groups, are important ones of these multifunctional building blocks, which can be used to create novel materials with potential applications as glycomimetics and peptidomimetics. This review will focus on recent synthetic strategies of SAAs and their applications in creating large number of structurally diverse glycomimetics and peptidomimetics.展开更多
In cold regions,heating is necessary to maintain the continuous and steady year-round operation of biogas fermentation.In this study,changes in the liquid composition,biogas production,and microbial diversity in heate...In cold regions,heating is necessary to maintain the continuous and steady year-round operation of biogas fermentation.In this study,changes in the liquid composition,biogas production,and microbial diversity in heated-and unheated-phase samples were evaluated in a production-scale biogas plant that was fed continuously with cattle manure as a mono-substrate in Heilongjiang province in northeastern China.The volatile solid(VS)and volatile fatty acid(VFA)contents both gradually decreased in the heated and unheated fermentation processes.The chemical oxygen demand(COD)removal efficiency in the unheated phase sampled on June 15(s-6-15)and October 15(a-10-15)and in the heated phase sampled on January 15(w-1-15)was 63.35%,44.2%and 44.0%,respectively.The biogas production yields were in agreement with the results obtained for the VS and VFA contents and COD removal efficiency.The performance of the reactor in the heated phase was less efficient than that in the unheated phase,and the biogas production efficiency in June-August was higher than that in the other months.However,the CH4 content in the biogas remained similar all year.Moreover,ARDRA(Amplified Ribosomal DNA Restriction Analysis)was used to study the microbial community composition in the fermentation process.The results showed that the methanogenic archaeal consortium consisted mainly of members of the genera Methanomicrobiales and Methanosarcinales.In the heated phase,hydrogenotrophic methanogens represented the dominant methanogen in w-1-15 feedstock.After fermentation,the strict aceticlastic methanogen Methanosaeta became the dominant methanogen.In the unheated phase,the hydrogenotrophic methanogens and aceticlastic methanogens were equivalent in s-6-15 feedstock and effluent,and aceticlastic methanogens were dominant in both a-10-15 feedstock and effluent.Assessments of the bacteria diversity of the microbial communities revealed that the common strains in the feed and effluent of the three samples included the rumen bacteria,Bacteroides,Clostridium,Ruminococcaceae and Proteobacteria.展开更多
Coix seed is a nutritious food with the effect of reducing uric acid.Few studies have been performed on the relevant active compounds.In this study,uric-acid-lowering active compounds were isolated and screened from C...Coix seed is a nutritious food with the effect of reducing uric acid.Few studies have been performed on the relevant active compounds.In this study,uric-acid-lowering active compounds were isolated and screened from Coix seed,and their structures were identified using NMR and mass spectrometry.The study showed that Coix seed effectively reduced serum uric acid and creatinine levels,suppressed liver xanthine oxidase activity,and improved kidney damage in mice due to hyperuricemia.Two major anti-hyperuricemic compounds were identified,namely,1-phenyl-1,3,3-propanetriamine(compound 1)and dihydroferulic acid(compound 2),among which compound 1 was a new compound,and compound 2 was separated from Coix seed for the first time.Two compounds showed potent inhibitory activity in vitro against xanthine oxidase,with IC_(50) values of 230.48 and 373.09μM,respectively.Furthermore,the molecular docking results indicated that the compounds could inhibit enzyme activity by interacting with residues within the active pocket of xanthine oxidase.This study provided a new alternative for the development of uric acid-lowering medications by identifying an anti-hyperuricemic alkaloid from Coix seed.展开更多
Phospholipids have been recognized as significant functional lipids related to nutrition,while they were complex and multiple,and their sources were various.Bioactive functions of phospholipids in skeletal muscle were...Phospholipids have been recognized as significant functional lipids related to nutrition,while they were complex and multiple,and their sources were various.Bioactive functions of phospholipids in skeletal muscle were given serious attention;however,studies on dietary phospholipid profiles with functions on skeletal muscle were rarely reported.Here,we analyzed phospholipid profiles of four kinds of dietary phospholipids(including yolk phospholipid,soybean phospholipid,perilla seed phospholipid and krill oil phospholipid)and compared their composition differences using UPLC-Q-TOF-MS.Lipidomics emphasized significant differences in compositions.Krill oil phospholipid rich inω-3 long-chain polyunsaturated fatty acids(ω-3 LCPUFAs)showed the most excellent effect in skeletal muscle protection.Compared with triglyceride-type lipid(fish oil),phospholipids had higher bioavailability.Besides,as for a higher degree of unsaturation of phospholipid,they did not always perform better effects,which might be related to being more susceptible to suffering from oxidative stress.Overall,four representative phospholipids were analyzed and compared for their bioactive function in skeletal muscle,providing a reference for better understanding relationships between structures and functional applications of phospholipids.展开更多
Quantitative real-time PCR is widely used to determine absolute abundance of microbes in food fermentation.However,it remains challenges in the application for quantification at the species level due to the difficulty...Quantitative real-time PCR is widely used to determine absolute abundance of microbes in food fermentation.However,it remains challenges in the application for quantification at the species level due to the difficulty in designing species-specific primer sets.This work,using Lactobacillaceae,a dominant family within the lactic acid bacteria that involved in diversity food fermentations,as a case,presents an extendable strategy to design species-specific primer sets for microbial quantita-tive analysis.136,257 species-specific genes were obtained from all 307 species within Lactobacillaceae family through comparative genomics analysis.A total of 130,521 primer sets were designed using species-specific genes.Among them,81,710 primer sets had 100%interspecific specificity and 100%intraspecific coverage,and were reserved to quantify all 307 individual Lactobacillaceae species.These primer sets had uniform melting temperature(57–63℃)and product size(100–300 bp),that allowed simultaneously quantify different Lactobacillaceae species with the same qPCR condition.We then established a Lactobacillaceae species quantitation primer database(LSQP-DB,http://lsqp-db.com)containing all 81,710 species-specific primer sets.The database would facilitate a fast and easy absolute quantitation analysis of all indi-vidual Lactobacillaceae species.This work represented the first ever large-scale integration of species-specific primer sets for microorganism,it can be extended to other bacterial and fungal genera to advance development of microbial absolute quantification.展开更多
By heterologous expression of a gene from Palaeococcus ferrophilus,a novel recombinant enzyme designated AMPf was obtained and proved to be an amylolytic enzyme with unique catalytic characteristics.The optimal temper...By heterologous expression of a gene from Palaeococcus ferrophilus,a novel recombinant enzyme designated AMPf was obtained and proved to be an amylolytic enzyme with unique catalytic characteristics.The optimal temperature and pH of AMPf were 50℃ and 7.0 respectively.Although sequence analysis and acarbose hydrolysis ability indicated that AMPf belongs to the subfamily GH13_20,interestingly,this enzyme hardly acts on cyclodextrins and pullulan distinguishing it from most enzymes in this subfamily.AMPf hydrolyzes starches to glucose,maltose,maltotriose,and maltotetrose as main products.AMPf mainly liberates glucose from starch with the concentration of 1%(w/v),while it shows malto-oligosaccharide forming ability with higher starch concentration of 4%(w/v).Also,the 4,6-ethylidene-4-nitrophenyl-maltoheptaose hydrolysis ability further indicates the unique combination endo-acting and glucose releasing exo-acting activtity of AMPf.AMPf could utilize maltose and maltotriose to produce malto-oligosaccharides by transglycosylation activity.It was proven AMPf has application protential in malto-oligosaccharides production.展开更多
基金partially supported by the CRC for Beef Genetic Technologies
文摘Background：The expression of genes encoding proteins involved in triacyglyceride and fatty acid synthesis and storage in cattle muscle are correlated with intramuscular fat（IMF）%.Are the same genes also correlated with IMF%in sheep muscle,and can the same set of genes be used to estimate IMF%in both species？Results：The correlation between gene expression（microarray） and IMF%in the longissimus muscle（LM） of twenty sheep was calculated.An integrated analysis of this dataset with an equivalent cattle correlation dataset and a cattle differential expression dataset was undertaken.A total of 30 genes were identified to be strongly correlated with IMF%in both cattle and sheep.The overlap of genes was highly significant,8 of the 13 genes in the TAG gene set and 8 of the 13 genes in the FA gene set were in the top 100 and 500 genes respertively most correlated with IMF%in sheep,P-value = 0.Of the 30 genes,CIDEA,THRSP,ACSM1,DGAT2 and FABP4 had the highest average rank in both species.Using the data from two small groups of Brahman cattle（control and Hormone growth promotant-treated[known to decrease IMF%in muscle]） and 22 animals in total,the utility of a direct measure and different estimators of IMF%（ultrasound and gene expression） to differentiate between the two groups were examined.Directly measured IMF%and IMF%estimated from ultrasound scanning could not discriminate between the two groups.However,using gene expression to estimate IMF%discriminated between the two groups.Increasing the number of genes used to estimate IMF%from one to five significantly increased the discrimination power;but increasing the number of genes to 15 resulted in little further improvement.Conclusion：We have demonstrated the utility of a comparative approach to identify robust estimators of IMF%in the LM in cattle and sheep.We have also demonstrated a number of approaches（potentially applicable to much smaller groups of animals than conventional methods） to using gene expression to rank animals for IMF%within a single farm/treatment,or to estimate differences in IMF%between two farms/treatments.
基金supported by the National Natural Science Foundation of China(32072142,31972099)Guangxi Science and Technology Base and Talent Special Projects(Guike AD21220004)。
文摘Quercetin compounds have antioxidant,anti-inflammatory and anticancer pharmacological functions.Longterm exposure to acrylamide(AA)can cause liver injury and endanger human health.However,whether quercetin compounds can attenuate AA-induced liver injury and the specific mechanism are not clear.Here,we studied the mechanism and structure-activity relationship of quercetin compounds in reducing AA-induced hepatotoxicity in vivo and in vitro.In vivo studies found that quercetin-like compounds protect against AAinduced liver injury by reducing oxidative stress levels,activating the Akt/m TOR signaling pathway to attenuate autophagy,and improving mitochondrial apoptosis and endoplasmic reticulum stress-mediated apoptosis.In vitro studies found that quercetin compounds protected Hep G2 cells from AA by attenuating the activation of AA-induced autophagy,lowering reactive oxygen species(ROS)levels by exerting antioxidant effects and thus attenuating oxidative stress,increasing mitochondrial membrane potential(MMP),and improving apoptosis-related proteins,thus attenuating AA-induced apoptosis.Furthermore,the conformational differences between quercetin compounds correlated with their protective capacity against AA-induced hepatotoxicity,with quercetin showing the best protective capacity due to its strongest antioxidant activity.In conclusion,quercetin compounds can protect against AA-induced liver injury through multiple pathways of oxidative stress,autophagy and apoptosis,and their protective capacity correlates with antioxidant activity.
基金supported by the National Key Technology R&D Program of China (2012BAD12B02-5)the Research Program of the State Key Laboratory of Animal Nutrition, China (2004DA125184G1103)the Synergetic Innovation Center of Food Safety and Nutrition, China
文摘Dairy cows undergo tremendous changes in physiological, metabolism and the immune function from pregnancy to lac- tation that are associated with cows being susceptible to metabolic and infectious diseases. The objective of this study is to investigate the changes of plasma proteome on 21 d before expected calving and 1 d after calving from dairy cows using an integrated proteomic approach consisting of minor abundance protein enrichment by ProteoMiner beads, protein labeling by isobaric tags for relative and absolute quantification, and protein identification by liquid chromatography coupled with tandem mass spectrometry. Nineteen proteins were changed around the time of calving. These proteins were asso- ciated with response to stress, including acute-phase response and defense response, based on the proteins annotation. In particular, three up-regulated proteins after calving including factor V, a2-antiplasmin and prothrombin were assigned into the complement and coagulation pathway. These results may provide new information in elucidating host response to lactation and parturition stress, and inflammatory-like conditions at the protein level. Differential proteins may serve as potential markers to regulate the lactation and parturition stress in periparturient dairy cows.
基金the National Key Research and Development Program of China(grant no.2013BAD20B02)Feed Quality and Safety Supervision Project of Ministry of Agriculture,Beijing,China.
文摘Sodium sulfate(Na2SO4)is a readily available chlorine-free source of sodium,which could be used to reduce sodium chloride to maintain the ratio between chlorine and sodium in poultry diets.Dietary supplementation with excessive levels of Na2SO4 might be detrimental to bird's health and per-formance.A subchronic study was carried out to investigate the potential adverse effects of an accidental oversupply of Na2SO4 in the diets of laying hens.Four hundred and fifty 21-week-old Hy-Line White layers were randomly assigned to 5 treatments with 6 replicates.The birds were fed diets supplemented with 0(control),0.3%,0.6%,1.5%,and 3.0%Na2SO4 for 8 weeks.Laying perfor-mance,egg quality parameters,clinical blood parameters,histopathology,intestinal barrier func-tions,and intestinal microflora composition were measured.No clinical signs of intoxication or mortality were observed during the experimental period.The results of this study showed that the optimal levels of Na2SO4(0.3%to 0.6%)significantly improved the laying rates,average daily egg mass,and eggshell quality of hens compared to the control(P<0.05).However,3.0%Na2SO4 produced negative effects on laying performance,eggshell quality,blood biochemistry,and partic-ularly on liver and kidney pathology,and intestinal morphology and barrier functions compared with the controls.Although minor changes were observed in clinical blood parameters of hens receiving 1.5%Na2SO4,these were not considered to be of toxicological significance due to the absence of any organ pathological changes in hens.In conclusion,our results indicated that a Na2SO4 concentration of 1.5%was non-deleterious to laying hens after a daily administration for 56 d,namely that dietary supplementation of up to 5 times the maximum recommended dose is safely tolerated by laying hens.
基金co-supported by the National Natural Science Foundation of China (Nos. 61304264 and 61305017)the Innovation Foundation of Industry, Education and Research of Jiangsu Province (No. BY2014023-25)
文摘This paper considers the problem of geolocating a target on the Earth surface whose altitude is known previously using the target signal time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements obtained at satellites. The number of satellites available for the geolocation task is more than sufficient and their locations are subject to random errors. This paper derives the constrained Cramor-Rao lower bound （CCRLB） of the target position, and on the basis of the CCRLB analysis, an approximately efficient constrained maximum likelihood estimator （CMLE） for geolocating the target is established. A new iterative algorithm for solving the CMLE is then proposed, where the updated target position estimate is shown to be the globally optimal solution to a generalized trust region sub-problem （GTRS） which can be found via a simple bisection search. First-order mean square error （MSE） analysis is conducted to quantify the performance degradation when the known target altitude is assumed to be precise but indeed has an unknown but deterministic error. Computer simulations are used to compare the performance of the proposed iterative geolocation technique with those of two benchmark algorithms. They verify the approximate efficiency of the proposed algorithm and the validity of the MSE analysis.
基金This work was supported by grants from the National High Technology Research and Development Program of China （863 Program, 2012AA022103）, the National Basic Research Program of China （973 Program, 2013CB733602, 2014CB745100）, the Major Program of National Natural Science Foundation of China （Grant No. 21390204）, the Program for New Century Excellent Talents in University （NCET-12-0876）, the Foundation for the Author of National Excellent Doctoral Dissertation of China （FANEDD, 201256）, the Priority Academic Program Development of Jiangsu Higher Education Institutions, and the 111 Project （111-2-06）.
文摘Pyrroloquinoline quinone （PQQ） plays a sig- nificant role as a redox cofactor in combination with dehydrogenases in bacteria. These dehydrogenases play key roles in the oxidation of important substrates for the biotechnology industry, such as vitamin C production. While biosynthesis of PQQ genes has been widely studied, PQQ-transport mechanisms used both two-dimensional remain unclear. Herein, we fluorescence-difference gel electrophoresis tandem mass spectrometry and RNA sequencing to investigate the effects ofpqqB overexpres- sion in an industrial strain of Gluconobacter oxydans WSH-003. We have identified 73 differentially expressed proteins and 99 differentially expressed genes, a majority of which are related to oxidation-reduction and transport processes by gene ontology analysis. We also described several putative candidate effectors that responded to increased PQQ levels resulting from pqqB overexpression. Furthermore, quantitative PCR was used to verify five putative PQQ-transport genes among different PQQ producing strains, and the results showed that ompW, B932 1930 and B932_2186 were upregulated in all conditions. Then the three genes were over-expressed in G. oxydans WSH-003 and PQQ production were detected. The results showed that extracellular PQQ of B932_1930 （a transporter） and B932_2186 （an ABC transporter perrnease） overexpression strains were enhanced by 1.77- fold and 1.67-fold, respectively. The results suggest that the proteins encoded by PqqB, B932_1930 and B932 2186 might enhance the PQQ secretion process.
基金supported by the National Science Foundation for Young Scientists of China(No.21302068)the Natural Science Foundation of Jiangsu Province,China(No.BK20130127)+2 种基金Jiangsu Province‘‘Six Summit Talent’’Foundation(No.2012-SWYY-009)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20120093120002)the Fundamental Research Funds for the Central Universities(Nos.JUSRP51319B,JUSRP51411B)
文摘In order to meet the increasing demands for the development of large varieties of new molecules for discovering new drugs and materials, organic chemists are developing many novel multifunctional building blocks, which are assembled rationally to create ‘nature-like＇ and yet unnatural organic molecules with well-defined structures and useful properties. Sugar amino acids（SAAs）, the carbohydrate derivatives bearing both amino and carboxylic acid functional groups, are important ones of these multifunctional building blocks, which can be used to create novel materials with potential applications as glycomimetics and peptidomimetics. This review will focus on recent synthetic strategies of SAAs and their applications in creating large number of structurally diverse glycomimetics and peptidomimetics.
基金the National Key Technology R&D Program of China(2012BAD12B05,2013BAD21B01)Key Project of Science and Technology Agency of Heilongjiang Province(GC12B306)Program of Science and Technology Innovation Team in Heilongjiang Province(2012TD 006).
文摘In cold regions,heating is necessary to maintain the continuous and steady year-round operation of biogas fermentation.In this study,changes in the liquid composition,biogas production,and microbial diversity in heated-and unheated-phase samples were evaluated in a production-scale biogas plant that was fed continuously with cattle manure as a mono-substrate in Heilongjiang province in northeastern China.The volatile solid(VS)and volatile fatty acid(VFA)contents both gradually decreased in the heated and unheated fermentation processes.The chemical oxygen demand(COD)removal efficiency in the unheated phase sampled on June 15(s-6-15)and October 15(a-10-15)and in the heated phase sampled on January 15(w-1-15)was 63.35%,44.2%and 44.0%,respectively.The biogas production yields were in agreement with the results obtained for the VS and VFA contents and COD removal efficiency.The performance of the reactor in the heated phase was less efficient than that in the unheated phase,and the biogas production efficiency in June-August was higher than that in the other months.However,the CH4 content in the biogas remained similar all year.Moreover,ARDRA(Amplified Ribosomal DNA Restriction Analysis)was used to study the microbial community composition in the fermentation process.The results showed that the methanogenic archaeal consortium consisted mainly of members of the genera Methanomicrobiales and Methanosarcinales.In the heated phase,hydrogenotrophic methanogens represented the dominant methanogen in w-1-15 feedstock.After fermentation,the strict aceticlastic methanogen Methanosaeta became the dominant methanogen.In the unheated phase,the hydrogenotrophic methanogens and aceticlastic methanogens were equivalent in s-6-15 feedstock and effluent,and aceticlastic methanogens were dominant in both a-10-15 feedstock and effluent.Assessments of the bacteria diversity of the microbial communities revealed that the common strains in the feed and effluent of the three samples included the rumen bacteria,Bacteroides,Clostridium,Ruminococcaceae and Proteobacteria.
基金This work was supported by Fundamental Research Funds for the Central Universities(JUSRP21127).
文摘Coix seed is a nutritious food with the effect of reducing uric acid.Few studies have been performed on the relevant active compounds.In this study,uric-acid-lowering active compounds were isolated and screened from Coix seed,and their structures were identified using NMR and mass spectrometry.The study showed that Coix seed effectively reduced serum uric acid and creatinine levels,suppressed liver xanthine oxidase activity,and improved kidney damage in mice due to hyperuricemia.Two major anti-hyperuricemic compounds were identified,namely,1-phenyl-1,3,3-propanetriamine(compound 1)and dihydroferulic acid(compound 2),among which compound 1 was a new compound,and compound 2 was separated from Coix seed for the first time.Two compounds showed potent inhibitory activity in vitro against xanthine oxidase,with IC_(50) values of 230.48 and 373.09μM,respectively.Furthermore,the molecular docking results indicated that the compounds could inhibit enzyme activity by interacting with residues within the active pocket of xanthine oxidase.This study provided a new alternative for the development of uric acid-lowering medications by identifying an anti-hyperuricemic alkaloid from Coix seed.
基金supported by the National Natural Science Foundation of China(Grant No.31972037)the National Key Research and Development Project(Grant No.2021YFC2103800).
文摘Phospholipids have been recognized as significant functional lipids related to nutrition,while they were complex and multiple,and their sources were various.Bioactive functions of phospholipids in skeletal muscle were given serious attention;however,studies on dietary phospholipid profiles with functions on skeletal muscle were rarely reported.Here,we analyzed phospholipid profiles of four kinds of dietary phospholipids(including yolk phospholipid,soybean phospholipid,perilla seed phospholipid and krill oil phospholipid)and compared their composition differences using UPLC-Q-TOF-MS.Lipidomics emphasized significant differences in compositions.Krill oil phospholipid rich inω-3 long-chain polyunsaturated fatty acids(ω-3 LCPUFAs)showed the most excellent effect in skeletal muscle protection.Compared with triglyceride-type lipid(fish oil),phospholipids had higher bioavailability.Besides,as for a higher degree of unsaturation of phospholipid,they did not always perform better effects,which might be related to being more susceptible to suffering from oxidative stress.Overall,four representative phospholipids were analyzed and compared for their bioactive function in skeletal muscle,providing a reference for better understanding relationships between structures and functional applications of phospholipids.
基金supported by the National Natural Science Foundation of China(32172175)National First-Class Discipline Program of Light Industry Technology and Engineering(LITE2018-12)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions,the 111 Project(No.111-2-06)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21-2029).
文摘Quantitative real-time PCR is widely used to determine absolute abundance of microbes in food fermentation.However,it remains challenges in the application for quantification at the species level due to the difficulty in designing species-specific primer sets.This work,using Lactobacillaceae,a dominant family within the lactic acid bacteria that involved in diversity food fermentations,as a case,presents an extendable strategy to design species-specific primer sets for microbial quantita-tive analysis.136,257 species-specific genes were obtained from all 307 species within Lactobacillaceae family through comparative genomics analysis.A total of 130,521 primer sets were designed using species-specific genes.Among them,81,710 primer sets had 100%interspecific specificity and 100%intraspecific coverage,and were reserved to quantify all 307 individual Lactobacillaceae species.These primer sets had uniform melting temperature(57–63℃)and product size(100–300 bp),that allowed simultaneously quantify different Lactobacillaceae species with the same qPCR condition.We then established a Lactobacillaceae species quantitation primer database(LSQP-DB,http://lsqp-db.com)containing all 81,710 species-specific primer sets.The database would facilitate a fast and easy absolute quantitation analysis of all indi-vidual Lactobacillaceae species.This work represented the first ever large-scale integration of species-specific primer sets for microorganism,it can be extended to other bacterial and fungal genera to advance development of microbial absolute quantification.
基金financially supported by National Natural Science Foundation of China(32072268)The Science&Technology Pillar Program of Jiangsu Province(BE2018304)+3 种基金National First class Discipline Program of Food Science and Technology(JUFSTR20180203)National Natural Science Foundation of China(32072164)National Key Research and Development Program of China(2020YFC1606804)National Natural Science Foundation of China(32101990).
文摘By heterologous expression of a gene from Palaeococcus ferrophilus,a novel recombinant enzyme designated AMPf was obtained and proved to be an amylolytic enzyme with unique catalytic characteristics.The optimal temperature and pH of AMPf were 50℃ and 7.0 respectively.Although sequence analysis and acarbose hydrolysis ability indicated that AMPf belongs to the subfamily GH13_20,interestingly,this enzyme hardly acts on cyclodextrins and pullulan distinguishing it from most enzymes in this subfamily.AMPf hydrolyzes starches to glucose,maltose,maltotriose,and maltotetrose as main products.AMPf mainly liberates glucose from starch with the concentration of 1%(w/v),while it shows malto-oligosaccharide forming ability with higher starch concentration of 4%(w/v).Also,the 4,6-ethylidene-4-nitrophenyl-maltoheptaose hydrolysis ability further indicates the unique combination endo-acting and glucose releasing exo-acting activtity of AMPf.AMPf could utilize maltose and maltotriose to produce malto-oligosaccharides by transglycosylation activity.It was proven AMPf has application protential in malto-oligosaccharides production.
