Abstract:

To address the current problems of Micrococcus lysodeikticus Fleming (turbidity) method for the determination of Lysozyme activity，such as not unified measurement conditions, poor repeatability, four main influence factors have been studied which were respectively the range of Lysozyme activity, substrate suspension absorbance value range, measuring temperature and cell preparation in this paper. Ultimately, the study expected to be the best test conditions and substrate preparation method. The results were as follows: (1) the Lysozyme activity curves had good linear relation when the Lysozyme active range of 75 to 250 U/mL and substrate suspension absorptance value range of 0.45-0.77 (wavelength 450 nm)，in general accord with the GBT 25879-2010; (2) In measuring temperature 25~50℃, substrate suspensions of absorbance difference (△OD450) increased with the rise of temperature. Appropriate to improve the measuring temperature can improve the measuring accuracy, which is needed to be further studied; (3) For large-scale sample test, frozen bacteria was selected as the optimum substrate, which had good linear relation, better repeatability and storage stability.