Abstract:

A dominant spoilage bacterium designated as CMRC BC-1 from emulsified sausages sterilized at medium
temperature was isolated and identified. The inhibitory potency of 7 common preservatives on the spoilage bacterium was
evaluated by cylinder-plate method and microtiter plate assay. The results showed that the aerobic plate count of emulsified
sausages sterilized at medium temperature had exceeded the relevant national standards on the 25th day of storage at 25 ℃.
The isolate was identified as Bacillus coagulans according to the results of morphological, physiological and biochemical
tests and 16S rDNA sequence alignment. The percent inhibition of the strain by 0.1 g/L nisin was 99.05%, demonstrating that
nisin had a remarkable inhibitory activity on the strain. Six other preservatives except potassium sorbate also had definite
inhibitory effect on the strain with the maximum addition, respectively.

Key words: medium-temperature sterilization, emulsified sausages, spoilage bacteria, isolation and identification, characteristics