Detection and Analysis of Dominant Bacillus in Different Milk Powder
To study the total bacterial count and the composition of Bacillus species in milk powder and analyze the risk bacteria during the transportation,sales and storage of milk powder,in this study,with six kinds of milk powder from different places of origin of a domestic brand as the research object,the total bacterial count and the number of Bacillus in six kinds of milk powder are statistically analyzed by traditional plate culture method combined with non-heat treatment and heat treatment,and the dominant Bacillus in the samples is identified by morphology,Gram staining microscopy combined with 16S rDNA.The total bacterial count in the six samples is mainly in the range of 102～103 CFU/g,which is all less than the national standard of 5.0 × 104 CFU/g,and meets the safety range of GB 19644-2010.Bacillus is detected in all the six samples,with the detection value in the range of 101～102 CFU/g.According to morphological observation,seven kinds of Gram-positive Bacillus are classified.After 16S rDNA and BLAST comparison,Bacillus is identified as Bacillus licheniformis,Bacillus amyloliquefaciens,Bacillus circulans,Bacillus paramycoides,Bacillus subtilis,Bacillus velezensis and Bacillus cereus respectively.The total bacterial count of different milk powder meets the requirements of national standards,but there are many kinds of Bacillus,which are the main dominant bacteria in milk powder.This study has provided data support for supervision and monitoring of milk powder quality in China and scientific basis for safety risk assessment of milk powder.
milk powdertotal bacterial countBacillus16S rDNAseparation and identification
万方数据
维普
