Preservative and Fresh-keeping Effects of Fermented Products by Two strains of Bacillus subtilis on Mutton
In order to obtain a novel green and safe bio-preservative for mutton,two strains of Bacillus subtilis were screened from the laboratory-preserved Bacillus spp.Using the Oxford cup method,and both strains were found to have good inhibitory effects on four strains of mutton spoilage bacteria.Through the observation of colony characteristics and 16S rDNA sequence analysis and the construction of phylogenetic tree,the two strains were initially identified as Bacillus subtilis,named RG-3 and SH-7,respectively,and were fermented using LB and Landy medium,respectively,and it was determined that the SH-7 strain had a better inhibitory activity with the active substance obtained by using Landy medium,and RG-3 strain had a better inhibitory activity with fermentation using LB medium.Fermentation of RG-3 strain with LB medium had better bacteriostatic activity.In order to further verify its preservative and fresh-keeping effect,after treating mutton with Bacillus subtilis fermentation extracts,the preservative and fresh-keeping effect was tested by four methods,namely,microbial colony counting,sensory evaluation,pH test,and globulin precipitation test,and the results showed that,mutton treated with fermentation extracts from two strains was compared to the control,the number of spoilage colonies of the treated mutton was significantly less,the sensory scores were higher,and the changes in pH were moderated,less precipitation in the globulin test.It indicates that the fermented extracts of the two strains of Bacillus subtilis have a better effect on the preservation of mutton.The results provide a new resouece for the developing new biological preservatives and applying them to the preservation of mutton.
Bacillus subtilislow temperature muttonbacteriostatic activitypreservative and fresh-keeping
NETL
NSTL
万方数据
