Objectives:Cronobacter sakazakii,formerly Enterobacter sakazakii,is an emerging ubiquitous and opportunistic foodborne pathogen with a high mortality rate.It has been implicated in cases of meningitis,septicaemia,and ...Objectives:Cronobacter sakazakii,formerly Enterobacter sakazakii,is an emerging ubiquitous and opportunistic foodborne pathogen with a high mortality rate.It has been implicated in cases of meningitis,septicaemia,and necrotizing enterocolitis among infants worldwide in association with powdered infant formula(PIF).This study was an insilico designed peptide base kit framework,using immunoinformatic techniques for quick detection of C.sakazakii in PIF.Materials and Methods:In the present study,a peptide-based kit was designed with a bioinformatic technique to rapidly identify C.sakazakii in PIF using fhE,secY,and bcsC,which are genes responsible for its bioflm formation,as target genes.The antigenicity,membrane topology,and the presence of signal peptides of the target genes were analysed using VaxiJen,DeepTMHMM,and SignalP servers.To provide stability and fexibility to the multiple-epitope construct,the linear B cells and helper T cells(IL-4(interleukin 4)and IL-10(interleukin 10)inducing epitopes)were linked with a GSGSG linker followed by the addition of protein disulphide bonds.To ascertain specifcity,the multi-epitope construct was molecularly docked against genes from sources other than PIF,like alfalfa,and the environment,with PIF being the highest:–328.48.Finally,the codons were modifed using the pET28a(+)vector,and the resultant multi-epitope construct was successfully cloned in silico.Results:The fnal construct had a length of 486 bp,an instability index of 23.26,a theoretical pI of 9.34,a molecular weight of 16.5 kDa,and a Z-score of–3.41.Conclusions:The multi-epitope peptide construct could be a conceptual framework for creating a C.sakazakii peptide-based detection kit,which has the potential to provide fast and effcient detection.However,there is a need for additional validation through the in vitro and in vivo techniques.展开更多
Wall sticking,which greatly reduces productivity and product quality,has been a big challenge of spray drying.Structure of drying tower and atomizer,as well as drying conditions are the main influencing factors.This r...Wall sticking,which greatly reduces productivity and product quality,has been a big challenge of spray drying.Structure of drying tower and atomizer,as well as drying conditions are the main influencing factors.This research explored the possibility to reduce wall sticking by optimizing drying conditions and components to obtain higher recovery rate of powdered infant formula milk(PIFM).Response surface experimental results indicated that inlet air temperature(T),feed concentration(C),feeding speed(S),as well as interaction term of TC and quadratic terms of C^(2) and S^(2) had significant influences on recovery rate for determined milk formula.According to mixture experiments at optimized drying conditions,whey protein(P),fat(F)and lactose(L)contents,as well as interaction term FL had significant effects on recovery rate.Positive effects were observed for F and L contents on recovery rate,while negative effects were observed for P and FL.Under the optimized drying condition of 136℃,19.80%and 4.07 mL/min,respectively,for T,C and S,the maximum recovery rate of 58.98%was obtained for PIFM with P,F and L content of 18%,31%and 51%,respectively.Wall sticking phenomena could be reduced by optimizing drying conditions and mildly adjusting components of infant formula milk.展开更多
文摘Objectives:Cronobacter sakazakii,formerly Enterobacter sakazakii,is an emerging ubiquitous and opportunistic foodborne pathogen with a high mortality rate.It has been implicated in cases of meningitis,septicaemia,and necrotizing enterocolitis among infants worldwide in association with powdered infant formula(PIF).This study was an insilico designed peptide base kit framework,using immunoinformatic techniques for quick detection of C.sakazakii in PIF.Materials and Methods:In the present study,a peptide-based kit was designed with a bioinformatic technique to rapidly identify C.sakazakii in PIF using fhE,secY,and bcsC,which are genes responsible for its bioflm formation,as target genes.The antigenicity,membrane topology,and the presence of signal peptides of the target genes were analysed using VaxiJen,DeepTMHMM,and SignalP servers.To provide stability and fexibility to the multiple-epitope construct,the linear B cells and helper T cells(IL-4(interleukin 4)and IL-10(interleukin 10)inducing epitopes)were linked with a GSGSG linker followed by the addition of protein disulphide bonds.To ascertain specifcity,the multi-epitope construct was molecularly docked against genes from sources other than PIF,like alfalfa,and the environment,with PIF being the highest:–328.48.Finally,the codons were modifed using the pET28a(+)vector,and the resultant multi-epitope construct was successfully cloned in silico.Results:The fnal construct had a length of 486 bp,an instability index of 23.26,a theoretical pI of 9.34,a molecular weight of 16.5 kDa,and a Z-score of–3.41.Conclusions:The multi-epitope peptide construct could be a conceptual framework for creating a C.sakazakii peptide-based detection kit,which has the potential to provide fast and effcient detection.However,there is a need for additional validation through the in vitro and in vivo techniques.
基金supported by the National Natural Science Foundation of China(31301563)Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment&Technology(FM-2014).
文摘Wall sticking,which greatly reduces productivity and product quality,has been a big challenge of spray drying.Structure of drying tower and atomizer,as well as drying conditions are the main influencing factors.This research explored the possibility to reduce wall sticking by optimizing drying conditions and components to obtain higher recovery rate of powdered infant formula milk(PIFM).Response surface experimental results indicated that inlet air temperature(T),feed concentration(C),feeding speed(S),as well as interaction term of TC and quadratic terms of C^(2) and S^(2) had significant influences on recovery rate for determined milk formula.According to mixture experiments at optimized drying conditions,whey protein(P),fat(F)and lactose(L)contents,as well as interaction term FL had significant effects on recovery rate.Positive effects were observed for F and L contents on recovery rate,while negative effects were observed for P and FL.Under the optimized drying condition of 136℃,19.80%and 4.07 mL/min,respectively,for T,C and S,the maximum recovery rate of 58.98%was obtained for PIFM with P,F and L content of 18%,31%and 51%,respectively.Wall sticking phenomena could be reduced by optimizing drying conditions and mildly adjusting components of infant formula milk.
