College of Enology, Northwest A&F University, Yangling, Shaanxi, China.
Lett Appl Microbiol. 2010 Mar;50(3):283-8. doi: 10.1111/j.1472-765X.2009.02789.x. Epub 2009 Dec 15.
Microbial biomass is an important biotechnological parameter. The traditional method for its determination involves an oven-drying step and equilibration to room temperature before weighing, and it is tedious and time consuming. This work studied the utilisation of a moisture analyser consisting of an efficient infrared-heating module and an analytical balance for the determination of microbial biomass by dry weight.
The method duration depended on the sample volume and was between 7 and 40 min for sample volumes of 1-10 ml. The method precision depended on the total dry weight analysed - 10 mg of total dry weight being sufficient to achieve coefficients of variation of 5% or less. Comparison with the conventional oven method provided a correlation coefficient r(2) of 0.99. The recovery of an internal standard ranged between 94.2 and 106.4% with a precision of 1.39-4.53%CV.
Validation revealed sufficient method accuracy, precision and robustness and was successfully applied to the study of yeast and bacterial growth kinetics. Techniques are discussed that allow for increased method precision at low biomass concentrations, and equations are provided to estimate required drying time and method precision based on sample volume and total sample dry weight, respectively.
This work presents a rapid method for the determination of microbial biomass, allowing for the timely implementation of biomass-based information in biotechnological and laboratory protocols.
微生物生物量是一个重要的生物技术参数。传统的测定方法需要经过烘干和平衡至室温后称重，过程繁琐且耗时。本研究利用高效的红外加热模块和分析天平的水分分析仪，通过干重法来测定微生物生物量。
方法的持续时间取决于样品的体积，对于 1-10ml 的样品体积，其时间在 7 至 40 分钟之间。方法的精密度取决于分析的总干重-总干重 10mg 足以使变异系数达到 5%或以下。与传统的烘箱法相比，相关系数 r²为 0.99。内部标准的回收率在 94.2%至 106.4%之间，精密度为 1.39%至 4.53%CV。
验证结果表明该方法具有足够的准确性、精密度和稳健性，并成功应用于酵母和细菌生长动力学的研究。讨论了可以提高低生物质浓度下方法精密度的技术，并提供了根据样品体积和总样品干重分别估算所需干燥时间和方法精密度的公式。
本研究提出了一种快速测定微生物生物量的方法，可及时将基于生物量的信息应用于生物技术和实验室方案中。
