两种绘制枯草芽孢杆菌和大肠杆菌生长曲线方法的比较

Comparison of Two Methods for Drawing the Growth Curve of Bacillus subtilis and Escherichia coli

利用分光光度法和活菌计数法对大肠杆菌O78和枯草芽孢杆菌CGMCC 1.504的生长曲线进行测定,并根据两种方法在细菌对数生长期的线性关系,筛选相关系数最大的吸光度。结果表明:大肠杆菌O78培养中0~2 h为迟缓期,2~12 h为对数生长期,12~20 h为稳定期,20 h以后进入衰亡期。枯草芽孢杆菌CGM培养中0~2 h为迟缓期,2~12 h为对数生长期,12~18 h为稳定期,18 h以后进入衰亡期。在两种细菌的对数生长期,分光光度计测出不同吸光度下的OD值和活菌计数法测得的细菌数都表现出一定的线性关系,且在吸光度为630 nm时,O78和CGM的OD值和活菌数相关系数最大(R^2_(O78)=0.991 2,R^2_(CGM)=0.990 4),相关程度最高。

Escherichia coli 078 and Bacillus subtilis CGMCC 1.504 growth curves were determined by spectrophotometric method and viable count method, using the linear relationship of two methods in logarithmic growth period of bacteria to select the absorbance maximum of the correlation coefficient. The results showed that 0-2 h was in the lag phase; 2-12 h was in logarithmic growth phase in the cultivation of Escherichia coli 078; 12-20 h was stable, after 20 h 078 entered into decline phase. In the cultivation of Bacil- lus subtilis CGM, 0-2 h was in the lag phase; 2-12 h was in logarithmic growth phase; 12-18 h was stable, after 18 h CGM entered into decline phase. In logarithmic growth phase of two germs, the number of bacteria was measured by OD value in different absorbance and the number of live bacteria measured by viable counting method showed a linear relationship. Besides, in absorbance of 630 nm, the OD value of 078 and CGM were related to the highest degree with live bacteria, and the correlation coefficient maintained maximum （R^2078 = 0.991 2, R^2CGM = 0.990 4）.