The Application Of PCR Technique In Microbial Distribution Detection And Dentification Analysis Of Yogurt Workshop

The purity of the production environment is directly related to the quality problem of the yogurt. A yogurt workshop was used as the object for studying in this paper. In order to monitor the quality change of sanitation, we did an sedimentation experiment in pretreatment section, filling process and storage area of air environment weekly, with smearing experiment of equipment and personnel hands’ surface. We amplified the 16 s rDNA of the isolated bacteria and sequenced. According to the classification of the sequence for each status, we determined the dominant of each area in yogurt workshop. At the same time, the contaminant microorganisms in samples were separated and identified, with the traceability was analyzed.The results were as follows:(1) Among the pretreatment section, filling process and storage section, the worst air environment was the storage areas, and the best was the filling room. The air quality in all areas were dligibled.In the pretreatment section, the air was the most vulnerable to pollution in May and July,followed by April and November. In filling process, the air cleanliness is poorer in October,November and December. The air quality was more cleanner in the first and third quarter than the second and forth quarter. In milk collection, the air environment was the worst in September and October. And in burdening room, the air environment of was the worst in December,. the air environment of dosing area was the worst in Novembet. The population of microorganisms on the surface of equipment and hands were least in April and May, with better cleanliness, and the cleanliness was worse relatively in November and December, with higher pupolation.(2) In environmental hygiene and cleanliness monitoring, the dominant population of whole workshop were Moraxella spp., Kocuria spp., Acinetobacter spp., Bacillus spp. and Staphylococcus spp.. So each respectively, Bacillus spp., Moraxella spp., Acinetobacter spp.and Kocuria spp. were the dominant population in the air. And Lactococcus lactis subsp.Lactis, Streptococcus thermophiles and Staphylococcus spp. were the dominant population on the surface of equipment. The dominant population on the hands were Staphylococcus epidermidis and Staphylococcus warneri.(3) Cross contamination of Staphylococcus spp. were occurred between waiting zone and filling room, and also between hands and surface of filling machine. The strain isolated from polluted samples was Staphylococcus warneri. It was similar with the genus from personal hand. It can be used to predict that the contaminant microorganism may be brought by the hands of filing workers. And the filling process was the important source of secondary pollution.