Although coagulase-negative Staphylococcus(CNS),along with technological activities,plays a key role in fermented sausage flavour and nutrient production,the molecular mechanism of these activities remains elusive.In ...Although coagulase-negative Staphylococcus(CNS),along with technological activities,plays a key role in fermented sausage flavour and nutrient production,the molecular mechanism of these activities remains elusive.In this study,18 CNS strains with high proteolytic activity were isolated from Chinese Dong fermented pork(Nanx Wudl),and their technological and transcriptomic properties were investigated.After biochemical identification and genetic analysis,their technological properties,including nitrate reductase,catalase,antioxidant,and lipolytic activities and their growth under varying temperatures,salt concentrations,and p H levels were evaluated.Their aroma-producing potential was also determined in a model medium resembling fermented sausages.Transcriptomic analysis was performed using the most promising isolates.Biochemical identification and 16S rDNA sequencing revealed that the 18 Staphylococcus strains belonged to Staphylococcus xylosus,Staphylococcus saprophyticus,Staphylococcus carnosus,Staphylococcus sciuri,and Staphylococcus equorum.In terms of technological properties,16 strains showed a nitrate-reducing ability,while 11 strains had a lipolytic activity.All strains exhibited superoxide dismutase(SOD)and catalase activities;four strains displayed an SOD activity of>50%.They also tolerated 10%NaCl and 150 mg/kg of nitrite.They showed significant differences in ketone and acid production.The transcriptomic analysis of S.xylosus strains Sx3 and Sx6,which were selected because of their excellent enzymatic activities and aroma-producing ability,revealed the remarkable effect of genes related to pyruvate catabolism and amino acid metabolism on aroma generation.Therefore,this study provided valuable insights into the metabolic mechanisms underlying the technological properties of CNS and identified promising candidates as starter cultures in fermented sausage manufacturing.展开更多
In this study, two bacilli strains namely S2-3 and S4-5, isolated from Terasi, a traditional fermented seafood product of Indonesia, were studied in terms of their phenotypic and genotypic properties. Both strains are...In this study, two bacilli strains namely S2-3 and S4-5, isolated from Terasi, a traditional fermented seafood product of Indonesia, were studied in terms of their phenotypic and genotypic properties. Both strains are of great interests due to their high proteolytic activity. Initially, they were subjected to morphological determination and a series of biochemical tests. These bacteria were Gram-positive, endospore-forming bacilli. Based on 16S rRNA gene sequence analysis, the identities of the strains S2-3 and S4-5 were confirmed as Bacillus thuringiensis and B. subtilis, respectively. Additionally, the two strains were also evaluated for their antibiogram profiles. It was found that they were susceptible to chloramphenicol, erythromycin, kanamycin, tetracycline and vancomycin and resistant to ampicillin and intermediately susceptible to bacitracin.展开更多
In a number of renal disease tubular epithelial cells often display hypertrophy rather than hyperplasia. This hypertrophy, characterized by an increase in protein conten and cell size, as well as an accumulation of ex...In a number of renal disease tubular epithelial cells often display hypertrophy rather than hyperplasia. This hypertrophy, characterized by an increase in protein conten and cell size, as well as an accumulation of extracellular matrix, is a key process which may lead subsequently to tubulointerstitial fibrosis and end-stage renal failure.展开更多
The integral membrane,Kunitz-type serine protease inhibitors HAI-1 and HAI-2,can suppress the proteolytic activity of the type 2 transmembrane serine protease matriptase with high specificity and potency.High levels o...The integral membrane,Kunitz-type serine protease inhibitors HAI-1 and HAI-2,can suppress the proteolytic activity of the type 2 transmembrane serine protease matriptase with high specificity and potency.High levels of extracellular matriptase proteolytic activity have,however,been observed in some neoplastic B-cells with high levels of endogenous HAI-2,indicating that HAI-2 may be an ineffective matriptase inhibitor at the cellular level.The different effectiveness of the HAIs in the control of extracellular matriptase proteolytic activity is examined here.Upon inducing matriptase zymogen activation in the HAI Teton Daudi Burkitt lymphoma cells,which naturally express matriptase with very low levels of HAI-2 and no HAI-1,nascent active matriptase was rapidly inhibited or shed as an enzymatically active enzyme.With increasing HAI-1 expression,cellular matriptase-HAI-1 complex increased,and extracellular active matriptase decreased proportionally.Increasing HAI-2 expression,however,resulted in cellular matriptase-HAI-2 complex levels reaching a plateau,while extracellular active matriptase remained high.In contrast to this differential effect,both HAI-1 and HAI-2,even at very low levels,were shown to promote the expression and cell-surface translocation of endogenous matriptase.The difference in the suppression of extracellular active matriptase by the two closely related serine protease inhibitors could result from the primarily cell surface expression of HAI-1 compared to the mainly intracellular localization of HAI-2.The HAIs,therefore,resemble one another with respect to promoting matriptase expression and surface translocation but differ in their effectiveness in the control of extracellular matriptase enzymatic activity.展开更多
The effect of a proteolytic starter culture isolated from Nanx Wudl,on microbiological,biochemical and organoleptic attributes of dry fermented sausages was investigated during processing.Based on preliminary screenin...The effect of a proteolytic starter culture isolated from Nanx Wudl,on microbiological,biochemical and organoleptic attributes of dry fermented sausages was investigated during processing.Based on preliminary screening,the combination of Staphylococcus xylosus SX16 and Lactobacillus plantarum CMRC6,showing excellent proteolytic activity in vitro,was selected as the multi-strain starter(starter LS).For comparison,the single-strain starter culture of L.plantarum CMRC6(starter LB)and non-inoculated control were also tested.During fermentation,lactic acid bacteria and staphylococci dominated the microbiota and suppressed the Enterobacteriaceae growth in LS-inoculated sausages.The addition of LS starter accelerated acidification and proteolysis during ripening,improving the contents of total free amino acids and several essential free amino acids(Phe,Ile and Leu).Volatile compounds analysis revealed that LS-fermented sausage showed the highest abundance of 3-methyl-1-butanol,probably due to the inoculated S.xylosus.The inoculation of LS starter improved the sensory properties of sausages,especially the flavor attribute.Therefore,S.xylosus SX16 and L.plantarum CMRC6 are promising candidates for inclusion as multi-strain starters in the manufacture of gourmet fermented dry sausage.展开更多
The Synechocystis sp. PCC 6803 genome harbours a Deg gene family consisting of three members, htrA （degP, slr1204）, hhoA （degQ, sll1679） and hhoB （degS, sll1427）. This work provided biochemical characterization ...The Synechocystis sp. PCC 6803 genome harbours a Deg gene family consisting of three members, htrA （degP, slr1204）, hhoA （degQ, sll1679） and hhoB （degS, sll1427）. This work provided biochemical characterization of HhoA, HtrA and HhoB from Synechocystis sp. PCC 6803. Firstly mature HhoA, HhoB and HtrA from Synechocystis sp. PCC 6803 were cloned and expressed as soluble recombinant his-tagged fusion protein in Escherichia coli. Then the proteolytic activity of HhoA, HhoB and HtrA was tested using casein, bovine serum albumin, five recombinant chromoproteins and cyanobacterial phycocyanin as substrates in vitro. The experimental results showed that HhoA and HtrA had proteolytic activity on casein, five recombinant chromoproteins and cyanobacterial phycocyanin. No proteolytic activity of HhoB was found using all substrates in vitro, indicating functional difference among Deg proteases from Synechocystis sp. PCC 6803. Therefore, the results indicated the biochemical properties of HhoA and HtrA on hydrolysis of proteins and phycobiliproteins in vitro, which implicated that they were proteases possibly involved in phycobiliprotein degradation in vivo.展开更多
Crude enzyme extracts were prepared from leaves and stems of Linn. (Fabaceae) from Cameroon under optimized conditions. Proteolytic enzymes were precipitated with ammonium sulfate at 35% (w/v) saturation and assayed f...Crude enzyme extracts were prepared from leaves and stems of Linn. (Fabaceae) from Cameroon under optimized conditions. Proteolytic enzymes were precipitated with ammonium sulfate at 35% (w/v) saturation and assayed for enzyme activity. The effects of temperature, pH, incubation time and substrate specificity were studied. SDS-PAGE was used to determine molecular weight of precipitated protease. Results indicated that proteolytic activity of crude extract was 35.20 U/ml compared to 51.03 U/ml of partial purified extract. The optimum enzyme activity was found to be at 40°C, while 50% of activity was maintained at 60°C after 60 min incubation. Partial purified crude extract exhibited two optimum pH (2.75 and 9.0). The highest enzyme activity towards Bovine Serum Albumine (25.9 U/ml) was noted. SDS-PAGE gels exhibited molecular weight between 40 - 60 KDa. This result confirms that partial purified extract of A. precatorius contains proteases and could be a promising source for proteolytic enzyme extraction.展开更多
Pea,rice,hemp,and oat proteins at concentrations of 5%and 10%were modified using controlled hydrolysis by Alcalase^(®)(4%,g enzyme/g protein)during 30,60,120,and 300 min,and their solubility and surface propertie...Pea,rice,hemp,and oat proteins at concentrations of 5%and 10%were modified using controlled hydrolysis by Alcalase^(®)(4%,g enzyme/g protein)during 30,60,120,and 300 min,and their solubility and surface properties were measured.The degree of hydrolysis(DH%)gradually increased with hydrolysis time(R^(2)≥85%)and(R^(2)≥96%)at 5%and 10%protein concentrations,respectively.The protein profile of hydrolysates suggests that Alcalase^(®)cleaved the pea,rice,and oat proteins to smaller sizes up to 15 kDa and the hemp protein to larger polypeptides with exposure of basic subunits(20 kDa).All plant proteins at 5%and 10%protein concentrations were greatly solubilised after 30 min of hydrolysis(at pH 8.0 and temperature 50℃)compared with their unhydrolysed counterparts.Increasing the hydrolysis time to four,five,and ten times more than 30 min further increased protein solubility.The relative fluorescent intensity from the spectrofluorometer suggests that hydrophobic groups remained unchanged after hydrolysis in rice protein.This agrees with the low DH%of rice protein.Unhydrolysed pea had the highest hydrophobicity with values of 59.69±1.94 and 86.28±2.88 at 5%and 10%protein,respectively,which decreased through hydrolysis.On the other hand,hemp hydrolysates had the highest hydrophobicity compared with their unhydrolysed counterparts at both protein concentrations.Hydrolysis increased surface charge only in oat protein.Higher protein concentration led to lower protein solubility in oat and hemp proteins.These results showed that prolonged hydrolysis and higher protein concentration can affect the dynamic association and dissociation of proteins leading the functional groups previously exposed by hydrolysis to hide in the interior of the protein structure.展开更多
One of the most important physicochemical properties of meat is its tenderness.The impact of Leek (Allium ampeloprasum ) extract and ultrasound on meat quality and molecular weight distribution of Longissimus lumborum...One of the most important physicochemical properties of meat is its tenderness.The impact of Leek (Allium ampeloprasum ) extract and ultrasound on meat quality and molecular weight distribution of Longissimus lumborum muscles was studied.Samples have been treated with ultrasound (100 and 300 W during 10,20,and 30 min) and Leek-derived exogenous proteases (16.9 and 33.8U/g) simultaneously and separately.The combined effect of enzyme and ultrasound in 10 and 20 min increased the pH value.It was also increased the proteolytic activity of meat.Regarding meat quality,the filtering residues,cooking loss,shear force,and hardness were reduced;water-binding capacity,emulsion capacity,and emulsion stability were improved.The electrophoretic pattern of myofibrillar proteins showed the muscle fibers were severely degraded in the combined treatments.It can be concluded that this process could be used as an alternative to the chemical tenderizing agents in the meat industry.展开更多
Microorganisms such as Bacillus spp.,Propionibacterium spp.,Lactobacillus spp.,Citrobacter spp.,Enterobacter spp.,Klebsiella spp,and Aspergillus spp.play vital roles in fermenting macromolecules present in African leg...Microorganisms such as Bacillus spp.,Propionibacterium spp.,Lactobacillus spp.,Citrobacter spp.,Enterobacter spp.,Klebsiella spp,and Aspergillus spp.play vital roles in fermenting macromolecules present in African legumes,result-ing in beneficial derivatives with diverse bioactivities advantageous to human health.While fermentation of legumes is a common practice in Africa,yielding nutritious products rich in phenolic compounds,the specific contribution of peptides generated during this process to the health-promoting qualities of legumes remains underexplored.This review aims to demonstrate the possibility of the occurrence of bioactive peptides in fermented African legume prod-ucts by investigating the intricate processes underlying microbial conversion of proteins into peptides and explaining the structure–activity relationship governing their bioactivity.The review also evaluates the stability of bioactive pep-tides during digestion in the human gastrointestinal tract,shedding light on their potential health benefits.African fermented legume products could be utilized in various food systems such as condiments,meat binders and compo-nents of high-protein snacks,as sources of bioactive compounds in the production of functional foods and nutraceu-ticals.In summary,this comprehensive examination not only summarizes our understanding of the health-promoting qualities of fermented African legume products but also underscores their potential as sustainable food sources for commercial utilization in diverse food industries.展开更多
Sterol-regulatory element binding proteins(SREBPs)are the key transcriptional regulators of lipid metabolism.The activation of SREBP requires translocation of the SREBP precursor from the endoplasmic reticulum to the ...Sterol-regulatory element binding proteins(SREBPs)are the key transcriptional regulators of lipid metabolism.The activation of SREBP requires translocation of the SREBP precursor from the endoplasmic reticulum to the Golgi,where it is sequentially cleaved by site-1 protease(S1P)and site-2 protease and releases a nuclear form to modulate gene expression.To search for new genes regulating cholesterol metabolism,we perform a genome-wide CRISPR/Cas9 knockout screen and find that partner of site-1 protease(POSH),encoded by C120RF49,is critically involved in the SREBP signaling.Ablation of POSH decreases the generation of nuclear SREBP and reduces the expression of SREBP target genes.POSH binds S1P,which is synthesized as an inactive protease(form A)and becomes fully mature via a two-step autocatalytic process involving forms B/B and C/C.POSH promotes the generation of the functional S1P-C/C from S1P-B/B(canonical cleavage)and,notably,from S1P-A directly(non-canonical cleavage)as well.This POSH-mediated S1P activation is also essential for the cleavages of other S1P substrates including ATF6,CREB3 family members and the a/p-subunit precursor of N-acetylglucosamine-1-phospho-transferase.Together,we demonstrate that POSH is a cofactor controlling S1P maturation and plays important roles in lipid homeostasis,unfolded protein response,lipoprotein metabolism and lysosome biogenesis.展开更多
基金the financial support of the National Natural Science Foundation of China(32102016)the Taishan Industrial Experts Program。
文摘Although coagulase-negative Staphylococcus(CNS),along with technological activities,plays a key role in fermented sausage flavour and nutrient production,the molecular mechanism of these activities remains elusive.In this study,18 CNS strains with high proteolytic activity were isolated from Chinese Dong fermented pork(Nanx Wudl),and their technological and transcriptomic properties were investigated.After biochemical identification and genetic analysis,their technological properties,including nitrate reductase,catalase,antioxidant,and lipolytic activities and their growth under varying temperatures,salt concentrations,and p H levels were evaluated.Their aroma-producing potential was also determined in a model medium resembling fermented sausages.Transcriptomic analysis was performed using the most promising isolates.Biochemical identification and 16S rDNA sequencing revealed that the 18 Staphylococcus strains belonged to Staphylococcus xylosus,Staphylococcus saprophyticus,Staphylococcus carnosus,Staphylococcus sciuri,and Staphylococcus equorum.In terms of technological properties,16 strains showed a nitrate-reducing ability,while 11 strains had a lipolytic activity.All strains exhibited superoxide dismutase(SOD)and catalase activities;four strains displayed an SOD activity of>50%.They also tolerated 10%NaCl and 150 mg/kg of nitrite.They showed significant differences in ketone and acid production.The transcriptomic analysis of S.xylosus strains Sx3 and Sx6,which were selected because of their excellent enzymatic activities and aroma-producing ability,revealed the remarkable effect of genes related to pyruvate catabolism and amino acid metabolism on aroma generation.Therefore,this study provided valuable insights into the metabolic mechanisms underlying the technological properties of CNS and identified promising candidates as starter cultures in fermented sausage manufacturing.
基金Supported by Mae Fah Luang University(MFU)(57101010027)
文摘In this study, two bacilli strains namely S2-3 and S4-5, isolated from Terasi, a traditional fermented seafood product of Indonesia, were studied in terms of their phenotypic and genotypic properties. Both strains are of great interests due to their high proteolytic activity. Initially, they were subjected to morphological determination and a series of biochemical tests. These bacteria were Gram-positive, endospore-forming bacilli. Based on 16S rRNA gene sequence analysis, the identities of the strains S2-3 and S4-5 were confirmed as Bacillus thuringiensis and B. subtilis, respectively. Additionally, the two strains were also evaluated for their antibiogram profiles. It was found that they were susceptible to chloramphenicol, erythromycin, kanamycin, tetracycline and vancomycin and resistant to ampicillin and intermediately susceptible to bacitracin.
文摘In a number of renal disease tubular epithelial cells often display hypertrophy rather than hyperplasia. This hypertrophy, characterized by an increase in protein conten and cell size, as well as an accumulation of extracellular matrix, is a key process which may lead subsequently to tubulointerstitial fibrosis and end-stage renal failure.
基金This study was supported by Cancer Institute Grant R01 CA 123223(to MDJ and CYL)Grant(MAB-108-079)from the Ministry of Defense Medical Affairs Bureau+2 种基金Grants(CMNDMC10705,CMNDMC10813)from Chi-Mei Medical Center(to J.-K.Wang)Grant(TSGH-E-109213-003)from Tri-Service General Hospital(to Y.-Y.Wu)Grants(108-2311-B-016-001-,109-2320-B-016-004-)from Ministry of Science and Technology(to Y.-L.Chiu).
文摘The integral membrane,Kunitz-type serine protease inhibitors HAI-1 and HAI-2,can suppress the proteolytic activity of the type 2 transmembrane serine protease matriptase with high specificity and potency.High levels of extracellular matriptase proteolytic activity have,however,been observed in some neoplastic B-cells with high levels of endogenous HAI-2,indicating that HAI-2 may be an ineffective matriptase inhibitor at the cellular level.The different effectiveness of the HAIs in the control of extracellular matriptase proteolytic activity is examined here.Upon inducing matriptase zymogen activation in the HAI Teton Daudi Burkitt lymphoma cells,which naturally express matriptase with very low levels of HAI-2 and no HAI-1,nascent active matriptase was rapidly inhibited or shed as an enzymatically active enzyme.With increasing HAI-1 expression,cellular matriptase-HAI-1 complex increased,and extracellular active matriptase decreased proportionally.Increasing HAI-2 expression,however,resulted in cellular matriptase-HAI-2 complex levels reaching a plateau,while extracellular active matriptase remained high.In contrast to this differential effect,both HAI-1 and HAI-2,even at very low levels,were shown to promote the expression and cell-surface translocation of endogenous matriptase.The difference in the suppression of extracellular active matriptase by the two closely related serine protease inhibitors could result from the primarily cell surface expression of HAI-1 compared to the mainly intracellular localization of HAI-2.The HAIs,therefore,resemble one another with respect to promoting matriptase expression and surface translocation but differ in their effectiveness in the control of extracellular matriptase enzymatic activity.
基金the National Key R&D Program of China(grant no.2018YFD0400404).
文摘The effect of a proteolytic starter culture isolated from Nanx Wudl,on microbiological,biochemical and organoleptic attributes of dry fermented sausages was investigated during processing.Based on preliminary screening,the combination of Staphylococcus xylosus SX16 and Lactobacillus plantarum CMRC6,showing excellent proteolytic activity in vitro,was selected as the multi-strain starter(starter LS).For comparison,the single-strain starter culture of L.plantarum CMRC6(starter LB)and non-inoculated control were also tested.During fermentation,lactic acid bacteria and staphylococci dominated the microbiota and suppressed the Enterobacteriaceae growth in LS-inoculated sausages.The addition of LS starter accelerated acidification and proteolysis during ripening,improving the contents of total free amino acids and several essential free amino acids(Phe,Ile and Leu).Volatile compounds analysis revealed that LS-fermented sausage showed the highest abundance of 3-methyl-1-butanol,probably due to the inoculated S.xylosus.The inoculation of LS starter improved the sensory properties of sausages,especially the flavor attribute.Therefore,S.xylosus SX16 and L.plantarum CMRC6 are promising candidates for inclusion as multi-strain starters in the manufacture of gourmet fermented dry sausage.
基金Funded by the National Natural Science Foundation of China (Nos.30870541,30870519)
文摘The Synechocystis sp. PCC 6803 genome harbours a Deg gene family consisting of three members, htrA （degP, slr1204）, hhoA （degQ, sll1679） and hhoB （degS, sll1427）. This work provided biochemical characterization of HhoA, HtrA and HhoB from Synechocystis sp. PCC 6803. Firstly mature HhoA, HhoB and HtrA from Synechocystis sp. PCC 6803 were cloned and expressed as soluble recombinant his-tagged fusion protein in Escherichia coli. Then the proteolytic activity of HhoA, HhoB and HtrA was tested using casein, bovine serum albumin, five recombinant chromoproteins and cyanobacterial phycocyanin as substrates in vitro. The experimental results showed that HhoA and HtrA had proteolytic activity on casein, five recombinant chromoproteins and cyanobacterial phycocyanin. No proteolytic activity of HhoB was found using all substrates in vitro, indicating functional difference among Deg proteases from Synechocystis sp. PCC 6803. Therefore, the results indicated the biochemical properties of HhoA and HtrA on hydrolysis of proteins and phycobiliproteins in vitro, which implicated that they were proteases possibly involved in phycobiliprotein degradation in vivo.
文摘Crude enzyme extracts were prepared from leaves and stems of Linn. (Fabaceae) from Cameroon under optimized conditions. Proteolytic enzymes were precipitated with ammonium sulfate at 35% (w/v) saturation and assayed for enzyme activity. The effects of temperature, pH, incubation time and substrate specificity were studied. SDS-PAGE was used to determine molecular weight of precipitated protease. Results indicated that proteolytic activity of crude extract was 35.20 U/ml compared to 51.03 U/ml of partial purified extract. The optimum enzyme activity was found to be at 40°C, while 50% of activity was maintained at 60°C after 60 min incubation. Partial purified crude extract exhibited two optimum pH (2.75 and 9.0). The highest enzyme activity towards Bovine Serum Albumine (25.9 U/ml) was noted. SDS-PAGE gels exhibited molecular weight between 40 - 60 KDa. This result confirms that partial purified extract of A. precatorius contains proteases and could be a promising source for proteolytic enzyme extraction.
文摘Pea,rice,hemp,and oat proteins at concentrations of 5%and 10%were modified using controlled hydrolysis by Alcalase^(®)(4%,g enzyme/g protein)during 30,60,120,and 300 min,and their solubility and surface properties were measured.The degree of hydrolysis(DH%)gradually increased with hydrolysis time(R^(2)≥85%)and(R^(2)≥96%)at 5%and 10%protein concentrations,respectively.The protein profile of hydrolysates suggests that Alcalase^(®)cleaved the pea,rice,and oat proteins to smaller sizes up to 15 kDa and the hemp protein to larger polypeptides with exposure of basic subunits(20 kDa).All plant proteins at 5%and 10%protein concentrations were greatly solubilised after 30 min of hydrolysis(at pH 8.0 and temperature 50℃)compared with their unhydrolysed counterparts.Increasing the hydrolysis time to four,five,and ten times more than 30 min further increased protein solubility.The relative fluorescent intensity from the spectrofluorometer suggests that hydrophobic groups remained unchanged after hydrolysis in rice protein.This agrees with the low DH%of rice protein.Unhydrolysed pea had the highest hydrophobicity with values of 59.69±1.94 and 86.28±2.88 at 5%and 10%protein,respectively,which decreased through hydrolysis.On the other hand,hemp hydrolysates had the highest hydrophobicity compared with their unhydrolysed counterparts at both protein concentrations.Hydrolysis increased surface charge only in oat protein.Higher protein concentration led to lower protein solubility in oat and hemp proteins.These results showed that prolonged hydrolysis and higher protein concentration can affect the dynamic association and dissociation of proteins leading the functional groups previously exposed by hydrolysis to hide in the interior of the protein structure.
基金gratitude sincerely to the Semnan Universtiy for funding this project.
文摘One of the most important physicochemical properties of meat is its tenderness.The impact of Leek (Allium ampeloprasum ) extract and ultrasound on meat quality and molecular weight distribution of Longissimus lumborum muscles was studied.Samples have been treated with ultrasound (100 and 300 W during 10,20,and 30 min) and Leek-derived exogenous proteases (16.9 and 33.8U/g) simultaneously and separately.The combined effect of enzyme and ultrasound in 10 and 20 min increased the pH value.It was also increased the proteolytic activity of meat.Regarding meat quality,the filtering residues,cooking loss,shear force,and hardness were reduced;water-binding capacity,emulsion capacity,and emulsion stability were improved.The electrophoretic pattern of myofibrillar proteins showed the muscle fibers were severely degraded in the combined treatments.It can be concluded that this process could be used as an alternative to the chemical tenderizing agents in the meat industry.
基金supported by the University of Pretoria for SM.Moyo and OY Famuyide under the UP postdoctoral fellowship programme.Grant Source:DRI-Cost Centre:A0X 816.
文摘Microorganisms such as Bacillus spp.,Propionibacterium spp.,Lactobacillus spp.,Citrobacter spp.,Enterobacter spp.,Klebsiella spp,and Aspergillus spp.play vital roles in fermenting macromolecules present in African legumes,result-ing in beneficial derivatives with diverse bioactivities advantageous to human health.While fermentation of legumes is a common practice in Africa,yielding nutritious products rich in phenolic compounds,the specific contribution of peptides generated during this process to the health-promoting qualities of legumes remains underexplored.This review aims to demonstrate the possibility of the occurrence of bioactive peptides in fermented African legume prod-ucts by investigating the intricate processes underlying microbial conversion of proteins into peptides and explaining the structure–activity relationship governing their bioactivity.The review also evaluates the stability of bioactive pep-tides during digestion in the human gastrointestinal tract,shedding light on their potential health benefits.African fermented legume products could be utilized in various food systems such as condiments,meat binders and compo-nents of high-protein snacks,as sources of bioactive compounds in the production of functional foods and nutraceu-ticals.In summary,this comprehensive examination not only summarizes our understanding of the health-promoting qualities of fermented African legume products but also underscores their potential as sustainable food sources for commercial utilization in diverse food industries.
文摘Sterol-regulatory element binding proteins(SREBPs)are the key transcriptional regulators of lipid metabolism.The activation of SREBP requires translocation of the SREBP precursor from the endoplasmic reticulum to the Golgi,where it is sequentially cleaved by site-1 protease(S1P)and site-2 protease and releases a nuclear form to modulate gene expression.To search for new genes regulating cholesterol metabolism,we perform a genome-wide CRISPR/Cas9 knockout screen and find that partner of site-1 protease(POSH),encoded by C120RF49,is critically involved in the SREBP signaling.Ablation of POSH decreases the generation of nuclear SREBP and reduces the expression of SREBP target genes.POSH binds S1P,which is synthesized as an inactive protease(form A)and becomes fully mature via a two-step autocatalytic process involving forms B/B and C/C.POSH promotes the generation of the functional S1P-C/C from S1P-B/B(canonical cleavage)and,notably,from S1P-A directly(non-canonical cleavage)as well.This POSH-mediated S1P activation is also essential for the cleavages of other S1P substrates including ATF6,CREB3 family members and the a/p-subunit precursor of N-acetylglucosamine-1-phospho-transferase.Together,we demonstrate that POSH is a cofactor controlling S1P maturation and plays important roles in lipid homeostasis,unfolded protein response,lipoprotein metabolism and lysosome biogenesis.
