Abstract:In order to study the dominant spoilage bacteria of Micropterus salmoides, the 16S rDNA gene sequencing technique was used to isolate and identify the spoilage bacteria. The sensory properties, pH, total volatile base nitrogen (TVBN) value and yield factor (YTVBN/cfu) were used as indicators for systematic evaluation of the spoilage ability of the bacterium strains. The results showed that 9 strains were isolated from the sample of Micropterus salmoides, including Providencia, Hafnia, Aeromonas, Acinetobacter, Enterococcus, Staphylococcus, Shewanella, and Megasphaera. Among them, three were Gram-positive whilst six were Gram-negative. The results of spoilage ability evaluation revealed that it only took 1.5 h for the sample containing Staphylococcus pasteuri from the high quality level to where sensory rejection occurred. After a 24-h culture, the pH value and TVBN value of the sample containing Staphylococcus pasteuri samples could reach the highest (7.35±0.33 and 160.02±0.28 mg/100 g), with a yield factor YTVBN/cfu of 227.32±1.08 (10-9 mg TVBN/cfu) (which was significantly (p<0.05) higher than those for the samples containing other strains. In summary, Staphylococcus pasteuri has strong spoilage and protein decomposition abilities and is the dominant spoilage bacteria of Micropterus salmoides meat.
