A Prelimilary Research For The Effect Of LuxI?luxR Gene On Quorum-sensing In Hafnia Alvei

Hafnia alvei commonly in spoiled food,that could growth at low temperature,which will shorten the shelf life.Hafnia alvei was isolated from spoilage sea cucumber that is one quorum sensing strain,which produced AHL?s?.The spoilage ability of Hafnia alvei isolates from spoilage sea cucumber was detected and also investigated the effect of quorum-sensing gene luxI,luxR and quorum-sensing molecules acylated homoserine?AHL?from Hafnia alvei on the bioLogical characteristics.This study wants to know the role of quorum sensing mechanism in food spoilage,and to provide new ideas to extend the shelf life.This article explored the spoilage ability of Hafnia alvei and the effect of quorum sensing gene luxI,luxR on the spoilage ability.The results showed that Hafnia alvei play a role in microbial food spoilage,quorum sensing gene luxI,luxR could effect the TVB-N in sea cucumber.Adding different kind of Hafnia alvei into sea cucumber was stored in 20?.After 15 day,the strains number of WT,?luxI,?luxR and?luxI/R is 8.55 Log?CFU/mL??8.52Log?CFU/mL??8.39 Log?CFU/mL?and 8.76 Log?CFU/mL?,the TVB-N is 15.05mg/100g,6.12 mg/100g,8.01 mg/100g and 3.45 mg/100g?In this study,we explored the effect of quorum sensing gene luxI?luxR on the biological characteristics in Hafnia alvei.The results showed that quorum sensing gene luxI?luxR don't effect the growth of Hafnia alvei,and they can control the AHL production.Hafnia alvei can produce C₆-HSL,and the highest concentration of C₆-HSL was observed after 16 hour culture.There no C₆-HSL was detected from cultures of the Hafnia alvei luxI mutant when using the HPLC.The quorum sensing gene luxI?luxR could effect the swarming ability and biofilm formation.In addition,the effect of quorum-sensing molecules acylated homoserine?AHL?from Hafnia alvei on the biological characteristics was detected.When adding C₆-HSL,the bacteria growth was not significantly affected,and the swarming was promoted.As a consequence,biofilm formation of Hafnia alvei was inhibited by the presence of C₆-HSL.