Study on the possibility of pre-cooked beef fluid nitrogen as a medium to explore

ZHANG Xiao-yong,LUO Ai-ping,TANG Hui-zhou(College of Life Sciences,Guizhou University,Guiyang 550025,China)

pre-cooked beef fluid;total nitrogen;culture media;beef immersion

Pre-cooked beef liquid to centrifugation and filtration etc,was concentrated to the original volume of its 75%,50%,mainly determination of total nitrogen,amino nitrogen content. Staphylococcus aureus,E. coli,Salmonella strains for quality control,testing of three different concentrations of pre-cooked beef broth liquid alternative to ordinary sensitivity,and to observe the three kinds of quality control strains were pre-cooked beef at different concentrations of nutrient agar solution prepared on the growth of colony morphology. The results showed that:the original pre-cooked beef liquid,concentrated to the original volume of 75%,50% concentrated liquid TN contents were 2.044,3.066,4.088mg/mL,amino acid nitrogen contents were 0.945,1.425,1.890mg/mL. Phosphate test,alkaline precipitation test,pigment-producing testing and sensitivity met the media requirements. Three kinds of quality control strains of colony morphology,colony size,pigment-producing strains were in line with the growth characteristics. Concentrated solution in 50% of the pre-cooked beef liquid nutrient broth prepared to cultivate 24h sensitivity can reach 10-9,the sensitivity of the strongest. Therefore TN,amino nitrogen content were up to 4.088,1.890mg/mL can be alternative to the concentrated solution of three quality control strains used for this culture of beef extract.