Abstract: The spoilage potential of Shewanella putrefaciens and Pseudomonas fluorescens to Pacific white shrimp and their interaction were evaluated by inoculating pure and mixed cultures into sterile shrimp juice. Changes in total bacterial count, total volatile basic nitrogen (TVB-N), and the contents of amino acids, biogenic amines, myogen and volatile compounds were monitored during 8 days of culture at (4 ± 1) ℃. A control was prepared by adding sterile water into shrimp broth. The results showed that the maximum viable counts of S. putrefaciens and P. fluorescens in co-culture were 8.85 and 8.26 (lg(CFU/mL)), respectively, which were higher than their monocultures. The results of spoilage capacity showed that higher TVB-N content and putrescine production were observed in the co-culture when compared with the single cultures. It is concluded that S. putrefaciens grew well than P. fluorescens and that both bacteria could mutually enhance growth and accelerate the spoilage of Pacific white shrimp juice.

Key words: Shewanella putrefaciens, Pseudomonas fluorescens, Pacific white shrimps juice, interaction, spoilage potential