Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, United States.
J Microbiol Methods. 2013 Jun;93(3):161-7. doi: 10.1016/j.mimet.2013.03.005. Epub 2013 Mar 21.
In this study, we introduce a Bayesian approach to address uncertainty of microbial recoveries from hollow-fiber ultrafilters (HFUF) and to determine any sources of uncertainty. Microbial recoveries were measured under twenty conditions, including two types of water, two types of ultrafilters, and five types of microorganisms. The probability distributions of the recoveries were approximated using Bayesian statistics with Markov chain Monte Carlo sampling after integrating the likelihood function of the recovery data and prior information about the data. Then a variance-decomposition method was used for examining influential factors on microbial recovery by HFUF. The results revealed that HFUF efficiently recovered Escherichia coli KO11, E. coli O157:H7 and bacteriophage MS2, but recoveries for Bacillus atrophaeus spores and adenovirus 41 were markedly different between source and treated waters. The uncertainty analysis indicated that the probability distributions for recoveries had dissimilar patterns under different conditions. Among these test factors, the type of microorganisms and associated interaction effects had great impacts on the recovery. To sum up, the Bayesian approach to uncertainty analysis shows advantages in evaluating the recovery of HFUF by providing its full probability distribution.
在这项研究中，我们引入了一种贝叶斯方法来解决中空纤维超滤器（HFUF）中微生物回收的不确定性问题，并确定任何不确定性的来源。在二十种条件下测量了微生物的回收率，包括两种水、两种超滤器和五种微生物。在将回收数据的似然函数和数据的先验信息集成后，使用贝叶斯统计和马尔可夫链蒙特卡罗抽样来近似回收率的概率分布。然后，使用方差分解方法来检查 HFUF 对微生物回收的影响因素。结果表明，HFUF 能够有效地回收大肠杆菌 KO11、E. coli O157:H7 和噬菌体 MS2，但枯草芽孢杆菌孢子和腺病毒 41 的回收率在原水和处理水中有明显的差异。不确定性分析表明，在不同条件下，回收率的概率分布模式不同。在这些测试因素中，微生物的类型及其相关的相互作用对回收有很大的影响。总之，贝叶斯不确定性分析方法在评估 HFUF 的回收方面具有优势，因为它提供了回收率的完整概率分布。
