Abstract:The growth of spoilage bacteria and the rate of production of metabolite for sterile Pseudosciaena crocea tissue blocks inoculated Shewanella putrefaciens and Pseudomonas spp. stored aerobically at 5 ℃ were respectively assayed. The yield factor for production of metabolite and the cell concentration determined at the time of off-odour detection were used as quantitative measurements of microbial spoilage ability. At spoilage point,the logarithm counts of the Ns (minimum number of spoilage bacteria) of Shewanella putrefaciens and Pseudomonas spp. were 9.14 lg cfu/g and 9.25 lg cfu/g,respectively. Adopting Gompertz regression equation to describe the growth curve of Shewanella putrefaciens and Pseudomonas spp.,we gained growth kinetics model parameters of both spoilage bacteria. The μmax (maximum specific growth rate) of Shewanella putrefaciens and Pseudomonas spp. were 0.071 4 and 0.070 0,the logarithm counts of the Nmax (maximum number of bacteria) of them were 9.45 lg cfu/g and 9.37 lg cfu/g,respectively. The results showed that their μmax were basically the same and both of Nmax were more than Ns of them,suggesting both spoilage organisms could be responsible for spoilage of Pseudosciaena crocea. The YTVBN/cfu and YTMA/cfu of Shewanella putrefaciens were 1.38×10-10 mg-N TVBN/cfu and 1.31×10-10 mg-N TMA/cfu,respectively. The YTVBN/cfu of Pseudomonas spp. was 1.18×10-10 mg-N TVBN/cfu. The quantitative results indicated that the spoilage ability of both spoilage bacteria was equivalent. Because Shewanella putrefaciens and Pseudomonas spp. were the dominant spoilage bacteria when Pseudosciaena crocea was stored aerobically at low temperature,also based on the concept of SSO (Specific spoilage organism),Shewanella putrefaciens was the most dominant spoilage bacterium in the specific spoilage organisms,followed by Pseudomonas spp.