Plasma-activated water(PAW) indicated promising potential in controlling the biological contamination of Bacillus cereus,which eliminated its evolutionary endospore that improves its survival ability.However,the spore...Plasma-activated water(PAW) indicated promising potential in controlling the biological contamination of Bacillus cereus,which eliminated its evolutionary endospore that improves its survival ability.However,the spore inactivation mechanism by PAW at molecular level was not well understood.The mechanism of the B.cereus endospore against PAW at proteomic levels was demonstrated.The Tandem Mass Tag(TMT) labeling was performed.By comparing the treatment groups with control(including PAW and PAW added superoxide dismutase(SOD)),the expression of 251 proteins(with the number of 207 up-and 44 down-regulated) and 379 proteins(with the corresponding number of 238 and 141) were drastically affected,separately.The 6 categories based on the protein-protein interaction(PPI) networks included oxidation-reduction,transport,sporulation and DNA topological change,gene expression,metabolism,and others.The 3 dehydrogenases(genes hisD,BC_2176,and asd) in PAW while oxidoreductase(genes BC_0399 and BC_2529) in SOD were activated to maintain the antioxidation of spores.The proteins(BC_4271 and BC_2655) in SOD were dramatically activated,which were involved in the carbohydrate,amino acid,and energy-coupling transport.All the small,acid-soluble spore proteins were activated in both groups to protect the spores' DNA.In SOD,genes metG2 and rpmC also were considered important factors in translation while this role was played in gene groES but not rpmF in PAW.The PAW activated the biogenesis of cell wall/membrane/envelope and phosphorelay signal transduction system to contribute to the survival of spores whereas the SOD damaged these 2 processes as well as cell division,chromosome separation,organic acid phosphorylation,base-and nucleotide-excision repairs to lead to the death of spores.This would promise to lay the foundation for advancing the study of the intrinsic mechanism of spore killing against PAW and can also provide a reference for future verification.展开更多
Ice has been extensively employed as a general coolant or ingredient in the food industry.However,evident indicates that food-associated ice can be easily contaminated by pathogenic bacteria,such as Escherichia coli,S...Ice has been extensively employed as a general coolant or ingredient in the food industry.However,evident indicates that food-associated ice can be easily contaminated by pathogenic bacteria,such as Escherichia coli,Staphylococcus aureus,and Salmonella spp.,among others.The contamination sources are attributed to the use of unhygienic water,improper handling,and poor hygiene conditions of ice-making machines.The contaminated ice might be a vesicle for the transmission of pathogens to food and human,posing potential risks to public health.This review overviewed the microbial contamination of food-associated ice,including the microbial contamination levels and the main microbial contaminants.In addition,a systematical introduction was constructed on the recent advances and applications of state-of-the-art methods to manufacture safe ices,illustrating ozone,electrolyzed water,cold plasma,essential oils,and ultraviolet light-emitting diode irradiation.The validities and limitations of ice treated by these techniques on the food quality were then discussed in detail.Various studies were also organized to demonstrate the potential of the mentioned treated ice,for ensuring the microbial safety and control quality deterioration during the storage of aquatic products.Finally,the direction for future study was given.展开更多
Bacteria pretend to organize into complex,multicellular structures known as biofilms,which enable survival and adaptation in dynamic environments.Bacterial biofilms serve diverse functions,including providing structur...Bacteria pretend to organize into complex,multicellular structures known as biofilms,which enable survival and adaptation in dynamic environments.Bacterial biofilms serve diverse functions,including providing structural stability,directing metabolic adaptations,and facilitating bacterial expansion and nutrient acquisition.In natural environments,biofilms are predominantly formed by diverse multispecies bacteria.The formation of multispecies biofilms is a dynamic process shaped by intricate bacterial interactions,encompassing both cooperative and antagonistic behaviors.These interactions are mediated by signaling molecules that facilitate cell-to-cell communications,influenced by the spatiotemporal heterogeneity of the extracellular polymeric substance matrix and biofilm architecture.This review synthesizes recent advances in understanding bacterial interactions within biofilms,focusing on mediating metabolites,underlying mechanisms,and their implications for the process of biofilm development.These insights offer a foundation for developing strategies to manipulate microbial communities and control biofilm-related challenges.展开更多
Objectives:To assess the variations in hypertonic tolerance among Salmonella enterica serovar Newport(S.Newport)strains isolated from diverse sources and investigate the mechanism underlying the tolerance differences ...Objectives:To assess the variations in hypertonic tolerance among Salmonella enterica serovar Newport(S.Newport)strains isolated from diverse sources and investigate the mechanism underlying the tolerance differences between the sensitive and tolerant strain.Materials and Methods:In this work,various S.Newport strains were cultured in 5%and 10%NaCl solutions(hypertonic stress),and the most sensitive and tolerant strains were selected using a Weibull model.The regulatory mechanisms underlying the hypertonic tolerance differences of S.Newport were preliminarily investigated in the aspects of cell phenotype,intracellular solute concentration,and gene expression level.Results:With prolonged hypertonic stress time,the leakage of nucleic acids and proteins of S.Newport increased gradually,and the membrane potential of S.Newport declined after increasing.Compared with the sensitive strain,the tolerant counterpart exhibited the ability to maintain the integrity of the cell membrane and sustain a high membrane potential level.The expression levels of the upstream genes proV and otsB in the tolerant strain were signifcantly lower than those in the sensitive strain;but the Kdp and Trk systems and downstream genes proX,proW,and otsA were highly expressed in the tolerant strain compared with the sensitive strain,leading to higher concentrations of intracellular K+and trehalose,enabling better survival in a hypertonic environment.Conclusions:The fndings of this work offer valuable insights into pathogen survival mechanisms under hypertonic stress and contribute to the development of strategies for mitigating microbiological risks during long-term processing and storage in the cured food industry.展开更多
Objectives:This work aimed to investigate and compare the physicochemical properties and bacterial diversity of traditionally pickled mustard tuberfromdifferentregions in China.Materials and Methods:Pickles were obtai...Objectives:This work aimed to investigate and compare the physicochemical properties and bacterial diversity of traditionally pickled mustard tuberfromdifferentregions in China.Materials and Methods:Pickles were obtained from Ningbo(NB),Nei Mongol(NMG),and Harbin(HEB).The pH was monitored by a pH meter.Titratable acidity and salinity were determined via titrimetric analysis.Nitrite content was measured using N-(1-naphthyl)-ethylenediamine dihydrochloride spectrophotometric method.Organic acids were detected by liquid chromatography-tandem mass spectrometry(LC-MS/MS).Bacterial diversity was conducted through the Illumina high-throughput sequencing platform.Results:There were significant differences in the physicochemical properties of pickled mustard tuber from various locations,with the NB pickles having the highest pH,salinity,and nitrite content and the lowest titratable acidity.Importantly,pickles with higher titratable acidity levels had relatively lower nitrite and salinity contents.A total of 63 organic acids were detected,with lactic acid and succinic acid being the most prevalent.Moreover,the organic acid compositions of the NMG and HEB samples were more similar than those of the NB pickles.Additionally.bioinformatic analysis revealed that Firmicutes and Proteobacteria were the predominant bacterial phyla in all the samples.Among these,Lactobacillus was the major genus.The most abundant bacteria were found in the HEB pickles.Further correlation analysis revealed a strong correlation between bacterial community and 11 internal physicochemical parameters.Conclusions:This study could contribute to a better understanding of the physicochemical characteristics and bacterial diversity of pickled mustard tuber from different locations.展开更多
基金supported by the Zhejiang Provincial Natural Science Foundation of China (LR21C200002)。
文摘Plasma-activated water(PAW) indicated promising potential in controlling the biological contamination of Bacillus cereus,which eliminated its evolutionary endospore that improves its survival ability.However,the spore inactivation mechanism by PAW at molecular level was not well understood.The mechanism of the B.cereus endospore against PAW at proteomic levels was demonstrated.The Tandem Mass Tag(TMT) labeling was performed.By comparing the treatment groups with control(including PAW and PAW added superoxide dismutase(SOD)),the expression of 251 proteins(with the number of 207 up-and 44 down-regulated) and 379 proteins(with the corresponding number of 238 and 141) were drastically affected,separately.The 6 categories based on the protein-protein interaction(PPI) networks included oxidation-reduction,transport,sporulation and DNA topological change,gene expression,metabolism,and others.The 3 dehydrogenases(genes hisD,BC_2176,and asd) in PAW while oxidoreductase(genes BC_0399 and BC_2529) in SOD were activated to maintain the antioxidation of spores.The proteins(BC_4271 and BC_2655) in SOD were dramatically activated,which were involved in the carbohydrate,amino acid,and energy-coupling transport.All the small,acid-soluble spore proteins were activated in both groups to protect the spores' DNA.In SOD,genes metG2 and rpmC also were considered important factors in translation while this role was played in gene groES but not rpmF in PAW.The PAW activated the biogenesis of cell wall/membrane/envelope and phosphorelay signal transduction system to contribute to the survival of spores whereas the SOD damaged these 2 processes as well as cell division,chromosome separation,organic acid phosphorylation,base-and nucleotide-excision repairs to lead to the death of spores.This would promise to lay the foundation for advancing the study of the intrinsic mechanism of spore killing against PAW and can also provide a reference for future verification.
基金This research was supported by the Natural Science Foundation of Zhejiang Province,China(LR21C200002)the project funded by China Postdoctoral Science Foundation(2021M702862)China National Center for Food Safety Risk Assessment(CFSA).
文摘Ice has been extensively employed as a general coolant or ingredient in the food industry.However,evident indicates that food-associated ice can be easily contaminated by pathogenic bacteria,such as Escherichia coli,Staphylococcus aureus,and Salmonella spp.,among others.The contamination sources are attributed to the use of unhygienic water,improper handling,and poor hygiene conditions of ice-making machines.The contaminated ice might be a vesicle for the transmission of pathogens to food and human,posing potential risks to public health.This review overviewed the microbial contamination of food-associated ice,including the microbial contamination levels and the main microbial contaminants.In addition,a systematical introduction was constructed on the recent advances and applications of state-of-the-art methods to manufacture safe ices,illustrating ozone,electrolyzed water,cold plasma,essential oils,and ultraviolet light-emitting diode irradiation.The validities and limitations of ice treated by these techniques on the food quality were then discussed in detail.Various studies were also organized to demonstrate the potential of the mentioned treated ice,for ensuring the microbial safety and control quality deterioration during the storage of aquatic products.Finally,the direction for future study was given.
基金supported by the Natural Science Foundation of Zhejiang Province,China(No.ZCLTGN24C2001).
文摘Bacteria pretend to organize into complex,multicellular structures known as biofilms,which enable survival and adaptation in dynamic environments.Bacterial biofilms serve diverse functions,including providing structural stability,directing metabolic adaptations,and facilitating bacterial expansion and nutrient acquisition.In natural environments,biofilms are predominantly formed by diverse multispecies bacteria.The formation of multispecies biofilms is a dynamic process shaped by intricate bacterial interactions,encompassing both cooperative and antagonistic behaviors.These interactions are mediated by signaling molecules that facilitate cell-to-cell communications,influenced by the spatiotemporal heterogeneity of the extracellular polymeric substance matrix and biofilm architecture.This review synthesizes recent advances in understanding bacterial interactions within biofilms,focusing on mediating metabolites,underlying mechanisms,and their implications for the process of biofilm development.These insights offer a foundation for developing strategies to manipulate microbial communities and control biofilm-related challenges.
基金supported by the National Natural Science Foundation of China(Nos.32302271 and 32272431).
文摘Objectives:To assess the variations in hypertonic tolerance among Salmonella enterica serovar Newport(S.Newport)strains isolated from diverse sources and investigate the mechanism underlying the tolerance differences between the sensitive and tolerant strain.Materials and Methods:In this work,various S.Newport strains were cultured in 5%and 10%NaCl solutions(hypertonic stress),and the most sensitive and tolerant strains were selected using a Weibull model.The regulatory mechanisms underlying the hypertonic tolerance differences of S.Newport were preliminarily investigated in the aspects of cell phenotype,intracellular solute concentration,and gene expression level.Results:With prolonged hypertonic stress time,the leakage of nucleic acids and proteins of S.Newport increased gradually,and the membrane potential of S.Newport declined after increasing.Compared with the sensitive strain,the tolerant counterpart exhibited the ability to maintain the integrity of the cell membrane and sustain a high membrane potential level.The expression levels of the upstream genes proV and otsB in the tolerant strain were signifcantly lower than those in the sensitive strain;but the Kdp and Trk systems and downstream genes proX,proW,and otsA were highly expressed in the tolerant strain compared with the sensitive strain,leading to higher concentrations of intracellular K+and trehalose,enabling better survival in a hypertonic environment.Conclusions:The fndings of this work offer valuable insights into pathogen survival mechanisms under hypertonic stress and contribute to the development of strategies for mitigating microbiological risks during long-term processing and storage in the cured food industry.
基金funded by the Key Research and Development Project of Ningbo City,Zhejiang Province(No.2022Z176)the National Natural Science Foundation of China(Nos.32001710 and 31871904)the Natural Science Foundation of Zhejiang Province(Nos.LY23C200008 and LZ23C200004),China.
文摘Objectives:This work aimed to investigate and compare the physicochemical properties and bacterial diversity of traditionally pickled mustard tuberfromdifferentregions in China.Materials and Methods:Pickles were obtained from Ningbo(NB),Nei Mongol(NMG),and Harbin(HEB).The pH was monitored by a pH meter.Titratable acidity and salinity were determined via titrimetric analysis.Nitrite content was measured using N-(1-naphthyl)-ethylenediamine dihydrochloride spectrophotometric method.Organic acids were detected by liquid chromatography-tandem mass spectrometry(LC-MS/MS).Bacterial diversity was conducted through the Illumina high-throughput sequencing platform.Results:There were significant differences in the physicochemical properties of pickled mustard tuber from various locations,with the NB pickles having the highest pH,salinity,and nitrite content and the lowest titratable acidity.Importantly,pickles with higher titratable acidity levels had relatively lower nitrite and salinity contents.A total of 63 organic acids were detected,with lactic acid and succinic acid being the most prevalent.Moreover,the organic acid compositions of the NMG and HEB samples were more similar than those of the NB pickles.Additionally.bioinformatic analysis revealed that Firmicutes and Proteobacteria were the predominant bacterial phyla in all the samples.Among these,Lactobacillus was the major genus.The most abundant bacteria were found in the HEB pickles.Further correlation analysis revealed a strong correlation between bacterial community and 11 internal physicochemical parameters.Conclusions:This study could contribute to a better understanding of the physicochemical characteristics and bacterial diversity of pickled mustard tuber from different locations.
