分光光度法测定酿酒酵母细胞悬液浓度研究

采用分光光度法测定酿酒酵母(Saccharomyces cerevisiae)在不同生长条件、不同时间菌悬液OD600nm值,建立OD600nm在不同稀释区间的分段回归方程,利用OD600nm回归值绘制生长曲线,对比平板菌落计数法测得的生长曲线,研究在对数期与稳定期,OD600nm值与菌体数量以及稀释倍数的关系。结果表明,稀释前后OD600nm值在对应区间内呈线性关系,用OD600nm回归值绘制的生长曲线没有明显的衰亡期,其主要是由于在对数期以后OD600nm值与菌体数量不呈线性关系,而在稳定期以前两者线性良好;得到了OD600nm值在0.2~0.8范围内与细胞数量的对应关系,还发现实际OD600nm值与稀释倍数之间并不是简单的乘积关系,而呈幂函数关系。

Determination of Saccharomyces cerevisiae cell suspension concentration by spectrophotometry

The OD600nm values of Saccharomyces cerevisiae were measured by spectrophotometry under different growth time and condition. The piecewise regression equations of OD600nm values with different dilution ratio were established for obtaining growth curves. Comparing to the growth curve which acquired by the plate culture count method, the relation between OD600nm and cell number in log phase and stable phase were studied. Results showed that the OD600nm values were linear relation in corresponding interval before and after dilution. The growth curve had no obvious decline phase, mainly due to the relation between OD600nm, values and yeast cells number didn＇t show linear relation after log phase, but in linear relation before stable phase. The corresponding relation between OD600nm values in 0.2-0.8 range and cell number was gained and the relation on OD600nm values and dilution ratio was power function relationship rather than multiplication relation.