Screening of siderophore-producing Vibrio vulnificus and optimization of induction conditions using response surface methodology

Vibrio vulnificus is an important pathogen.When eating infected fish,human will suffer from serious disease.To date,many potential virulence factors of Vibrio vulnificus have been identified. Among the reported factors,Siderophore is a well-known crucial virulence factor.In this study,the siderophore- producing strains were screened by using MKB( Modified King B)medium which isolated from the seawater.MKB- CAS( Chrome azuorl S) overlay plate method and UV- VIS Spectrophotometer were used for the screening of high yield siderophore- producing strain and detection of SU( siderphore units) respectively.V.vulnificus Y8 strain was optimized which had the highest siderophore- producing capacity. The optimization of significant factors on SU including the initial p H,medium capacity and nitrogen ratio( C / N) was determined by response surface methodology. These results indicated that the value of SU was expected to 90.7404% under the optimum condition of initial pH7.84,medium capacity of 81.53 m L and C / N of 3.06.Three parallel verification results indicated that the maximum SU value was consistent with the mean SU value and the optimized SU value was increased by 23.73% compared to the previously measured value. The best optimization conditions was obtained by using response surface methodology which would lay the foundation of the further study in the future.