分光光度法测定W135群脑膜炎奈瑟菌生物量

Determination of bacterial biomass of serogroup W135 Neissria meningitidis by spectrophotometry

目的建立快速准确测量W135群脑膜炎奈瑟菌(Neissria meningitidis)生物量的紫外分光光度法。方法取W135群脑膜炎奈瑟菌发酵液进行系列浓度稀释,利用紫外-可见光分光光度法在最适吸收波长处测定各稀释度发酵液的A值,同时测定各浓度下细菌数、菌体干湿重,建立W135群脑膜炎奈瑟菌A值与菌体干湿重、细菌数间的关系曲线,利用所建立的回归方程计算细菌生物量。取4组不同浓度的W135群脑膜炎奈瑟菌培养液,采用建立的方法测量细菌生物量并与实际测量值对比,验证该方法的准确性。结果 W135群脑膜炎奈瑟菌A_(450)值与菌体干湿重、细菌数呈线性关系,R^2分别为0.990、0.980和0.926。利用所建立的回归方程得到的生物量结果与实际测量结果无统计学差异(P>0.05)。结论利用所建立的A值与生物量的关系方程可快速简便地检测到W135群脑膜炎奈瑟菌生物量的变化。

Objective To develop a ultraviolet（UV）-visible spectrophotometry for rapid and accurate determination of bacterial biomass of serogroup W135 Neissria meningitidis. Methods The fermentation liquid of serogroup W135 N. meningitides was diluted serially, and determined for A value at optimal absorption wavelength. Meanwhile, the bacterial counts and wet/dry weights in the fermentation liquids at various concentrations were determined to plot a relation curve of A values against the wet/dry weights and bacterial counts. The bacterial biomass was calculated by the established regression equation. Another four groups of culture liquid of serogroup W135 N. meningitides at various concentrations were determined for bacterial biomass by the developed method, and the result was compared with that of actual determination to verify the accuracy of the developed method. Results The A_（450） value of serogroup W135 N. meningitidis showed linear relationship to the wet weight, dry weight and bacterial count, with R^2 values of 0. 990,0. 980 and 0. 926 respectively. The determination results of bacterial biomass obtained by the developed regression equation showed no significant difference with the actual determination result（P 0. 05）. Conclusion The developed relation equation between A value and biomass may be used for rapid and convenient determination of bacterial biomass of serogroup W135 N. meningitidis.