Objective:To screen the bacteriocinogenic isolate from buffalo milk and to characterize it on physical,chemical and biological aspects for the application in biopreservation.Methods:Bacillus cereus(B.cereus)was isolat...Objective:To screen the bacteriocinogenic isolate from buffalo milk and to characterize it on physical,chemical and biological aspects for the application in biopreservation.Methods:Bacillus cereus(B.cereus)was isolated and assessed for its baceteriocinogenic activity.Bacteriocin was produced and purified by ammonium sulphate precipitation,dialysis and gel filtration chromatography.Purified bacteriocin was used to clieck its antimicrobial activity against food borne bacteria.Effect and stability of bacteripcin was determined with the respect to temperature,pH,enzymes,organic solvents and chemicals.Bacteriocin was also subjected to SDS PAGE analysis to determine its molecular weight.In addition,functional groups exist in the bacteriocin was determined by FTIR analysis.Results:B.cereus was identified by 16S rRNA sequence analysis.Bacteriocin showed increased activity against all the bacteria used and its activity unit was found to be 51,200 AU/mL.It was stable to high temperature(100℃)and wide range of pH(3-10),sensitive to proteolytic enzymes and resistant to nonprotcolytic enzymes.It was low molecular weight(3.5-6 kDa)protein and FTIR study revealed the presence of amide group and NH stretching,Conclusions:Bacteriocin produced in this study possesses the highest antimicrobial activity against both gram positive and gram negative bacteria thereby it has immense application as biopreservative agent.FTIR proved its peptide nature.展开更多
Objective:To develop allenualed slrains of Salmonella enterica serorar Typhi(S.typhi) for the candidate vaccine by osmolar stress.Mothods:S.typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in...Objective:To develop allenualed slrains of Salmonella enterica serorar Typhi(S.typhi) for the candidate vaccine by osmolar stress.Mothods:S.typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in Mamakkal,Tamil Nadu.India.Both strains were grown in LB(Luria Bertani) medium supplemented with various concentration of NaCl(0.1- 0.7M) respectively.The effecl of osmolar stress was determined at molecular level by PCR using MCR 06 and MCR07 primers corresponding to ompR with chromosomal DNA of S.typhi SS3 and SS5 strains.Attenuation by osmolar stress results in deletion mutation of the.S.typhi slrains was determined by agglutination assays,precipitation method.SDS PAGE analysis and by animal models.Results:The 799 bp amplified ompR gene product from wild type S.typhi SS3 and SS5 illustrate the presence of virulent gene.Interestingly,there was only a 282 bp amplified product from S.typhi SS3 and SS5 grown in the presence of 0.5.0.6 and 0.7 M NaCl.This illustrates the occurrence of deletion mutation in ompR gene al high concentration of NaCl.Furthermore,both the wildtype and mutant S.typhi outer membrane SDS-PAGF.profile reveals the differences in the expression of ompF.ompC and ompA proteins.In mice,wild type and mutant strains lethal dose(LD_(50)) were determined.The mice died within 72 h when both the wild type strains were injected intraperitoneally with 3 log CFU-mL^(-1).When the mice were injected with the mutants in same dosage,no clinical symptoms were observed;whereas the serum antibodv litre was elicited within two weeks indicated that the mutants have the ability to induce protective humoral immune response.These results suggest that S.typhi SS3 and SS5 may bo used as good candidate strains for the development of live attenuated vaccine against salmonellosis.Conclusions:This study demonstrates that the S.typhi strains were allenualed and could be good vaccine candidates in future.展开更多
基金Managemtent of Vivekananda Educational Inslitulions Tiruchengode, India for their support throughout the project
文摘Objective:To screen the bacteriocinogenic isolate from buffalo milk and to characterize it on physical,chemical and biological aspects for the application in biopreservation.Methods:Bacillus cereus(B.cereus)was isolated and assessed for its baceteriocinogenic activity.Bacteriocin was produced and purified by ammonium sulphate precipitation,dialysis and gel filtration chromatography.Purified bacteriocin was used to clieck its antimicrobial activity against food borne bacteria.Effect and stability of bacteripcin was determined with the respect to temperature,pH,enzymes,organic solvents and chemicals.Bacteriocin was also subjected to SDS PAGE analysis to determine its molecular weight.In addition,functional groups exist in the bacteriocin was determined by FTIR analysis.Results:B.cereus was identified by 16S rRNA sequence analysis.Bacteriocin showed increased activity against all the bacteria used and its activity unit was found to be 51,200 AU/mL.It was stable to high temperature(100℃)and wide range of pH(3-10),sensitive to proteolytic enzymes and resistant to nonprotcolytic enzymes.It was low molecular weight(3.5-6 kDa)protein and FTIR study revealed the presence of amide group and NH stretching,Conclusions:Bacteriocin produced in this study possesses the highest antimicrobial activity against both gram positive and gram negative bacteria thereby it has immense application as biopreservative agent.FTIR proved its peptide nature.
文摘Objective:To develop allenualed slrains of Salmonella enterica serorar Typhi(S.typhi) for the candidate vaccine by osmolar stress.Mothods:S.typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in Mamakkal,Tamil Nadu.India.Both strains were grown in LB(Luria Bertani) medium supplemented with various concentration of NaCl(0.1- 0.7M) respectively.The effecl of osmolar stress was determined at molecular level by PCR using MCR 06 and MCR07 primers corresponding to ompR with chromosomal DNA of S.typhi SS3 and SS5 strains.Attenuation by osmolar stress results in deletion mutation of the.S.typhi slrains was determined by agglutination assays,precipitation method.SDS PAGE analysis and by animal models.Results:The 799 bp amplified ompR gene product from wild type S.typhi SS3 and SS5 illustrate the presence of virulent gene.Interestingly,there was only a 282 bp amplified product from S.typhi SS3 and SS5 grown in the presence of 0.5.0.6 and 0.7 M NaCl.This illustrates the occurrence of deletion mutation in ompR gene al high concentration of NaCl.Furthermore,both the wildtype and mutant S.typhi outer membrane SDS-PAGF.profile reveals the differences in the expression of ompF.ompC and ompA proteins.In mice,wild type and mutant strains lethal dose(LD_(50)) were determined.The mice died within 72 h when both the wild type strains were injected intraperitoneally with 3 log CFU-mL^(-1).When the mice were injected with the mutants in same dosage,no clinical symptoms were observed;whereas the serum antibodv litre was elicited within two weeks indicated that the mutants have the ability to induce protective humoral immune response.These results suggest that S.typhi SS3 and SS5 may bo used as good candidate strains for the development of live attenuated vaccine against salmonellosis.Conclusions:This study demonstrates that the S.typhi strains were allenualed and could be good vaccine candidates in future.
