In order to evaluate the safety and functional characteristics of two potential meat starter cultures,Staphylococcus simulans HZ01(OM758216)and Staphylococcus simulans HZ02(OM758217),we performed the whole genome sequ...In order to evaluate the safety and functional characteristics of two potential meat starter cultures,Staphylococcus simulans HZ01(OM758216)and Staphylococcus simulans HZ02(OM758217),we performed the whole genome sequences,and then investigated their effects on nitrosomyoglobin formation based on nitric oxide synthase(NOS)catalysis.The results revealed that the two strains did not possess any virulence genes.The gene annotation indicated the gene function is mainly due to translation,ribosomal structure and biogenesis,and amino acid transport and metabolism.Both strains possess nos gene.The phylogenetic tree based on nos gene indicated the two strains formed an independent evolutionary branch.Subsequently,NOS was found to be expressed in both HZ01 and HZ02.NOS activity was higher in HZ01 than in HZ02,whereas NO production in inoculated groups changed considerably with increasing culture time.In the model system,nitrosomyoglobin formed in S.simulans inoculated groups,and the derivatives had absorption peaks at 545 nm and 580 nm.The secondary structure of these derivatives exhibited differences inβ-turn proportion andα-helix proportion.Physicochemical properties of fermented sausages inoculated groups indicated that S.simulans HZ01 and HZ02 can significantly improve the color of sausages with no addition of nitrite/nitrate.This result confirmed that the two S.simulans strains can improve the nitrosomyoglobin formation based on the NOS pathway,which contributes to the color of fermented sausages,without the requirement of nitrite or nitrate.Nevertheless,the contribution of the NOS pathway in fermented meat products should be further evaluated.展开更多
基金supported by the National Natural Science Foundation of China[grant no.32302037]a Key research and development project of“vanguard”and“leading goose”in Zhejiang Province,China[grant no.2022C02060].
文摘In order to evaluate the safety and functional characteristics of two potential meat starter cultures,Staphylococcus simulans HZ01(OM758216)and Staphylococcus simulans HZ02(OM758217),we performed the whole genome sequences,and then investigated their effects on nitrosomyoglobin formation based on nitric oxide synthase(NOS)catalysis.The results revealed that the two strains did not possess any virulence genes.The gene annotation indicated the gene function is mainly due to translation,ribosomal structure and biogenesis,and amino acid transport and metabolism.Both strains possess nos gene.The phylogenetic tree based on nos gene indicated the two strains formed an independent evolutionary branch.Subsequently,NOS was found to be expressed in both HZ01 and HZ02.NOS activity was higher in HZ01 than in HZ02,whereas NO production in inoculated groups changed considerably with increasing culture time.In the model system,nitrosomyoglobin formed in S.simulans inoculated groups,and the derivatives had absorption peaks at 545 nm and 580 nm.The secondary structure of these derivatives exhibited differences inβ-turn proportion andα-helix proportion.Physicochemical properties of fermented sausages inoculated groups indicated that S.simulans HZ01 and HZ02 can significantly improve the color of sausages with no addition of nitrite/nitrate.This result confirmed that the two S.simulans strains can improve the nitrosomyoglobin formation based on the NOS pathway,which contributes to the color of fermented sausages,without the requirement of nitrite or nitrate.Nevertheless,the contribution of the NOS pathway in fermented meat products should be further evaluated.
