Yu Chang-Ping, Chu Kung-Hui
Zachry Department of Civil Engineering, Texas A&M University, College Station, Texas 77843-3136, USA.
Environ Sci Technol. 2005 Dec 15;39(24):9611-9. doi: 10.1021/es051024e.
A comprehensive culture-independent assay, called Q-FAST, was developed for concurrent identification and quantification of active microorganisms involved a specific function in a given microbial community. The development of Q-FAST was achieved by integrating the concept of stable isotope probing technique into a new quantitative fingerprinting assay called real-time-t-RFLP for microbial community structure analysis. The Q-FAST was successfully validated by using a three-member artificial microbial community containing a known naphthalene-utilizing bacterium (Pseudomonas putida G7) and two nonnaphthalene-degrading bacteria (Escherichia coli and Bacillus thuringiensis). The application of Q-FAST to identify and quantify a guild of naphthalene-utilizing microorganisms in soils revealed the involvement of eight members, with six members relating to several phylogenetic groups of eubacteria (three in beta-proteobacteria, two in gamma-proteobacteria, and one in genera Intrasporangium of Gram-positive bacteria) and two members showing no close phylogenetic affiliation to any known bacterial sequences deposited in GenBank. The quantity of three members belonging to beta-proteobacteria accounted for 34% of total 16S rDNA copies measured from the "heavier" fraction of DNA that was contributed from the DNA of microorganisms capable of incorporating 13C-labeled naphthalene into their genetic biomarkers. The other five members composed 66% of total 16S rDNA copies of active naphthalene-utilizing populations measured. Offering a powerful tool for studying microbial ecology, Q-FAST thus opens a new avenue for deeper exploration of microbial-mediated processes, mainly the quantitative relationship between microbial diversity and microbial activity in a given environment.
一种名为Q-FAST的全面的非培养分析方法被开发出来，用于同时鉴定和定量参与特定功能的活性微生物，这些微生物存在于给定的微生物群落中。Q-FAST的开发是通过将稳定同位素探测技术的概念整合到一种名为实时t-RFLP的新型定量指纹分析方法中实现的，该方法用于微生物群落结构分析。通过使用一个由三种细菌组成的人工微生物群落对Q-FAST进行了成功验证，该群落包含一种已知的萘利用细菌（恶臭假单胞菌G7）和两种非萘降解细菌（大肠杆菌和苏云金芽孢杆菌）。将Q-FAST应用于鉴定和定量土壤中利用萘的微生物群落，结果显示其中有八个成员，其中六个成员与真细菌的几个系统发育组有关（三个属于β-变形菌纲，两个属于γ-变形菌纲，一个属于革兰氏阳性菌中的孢囊杆菌属），另外两个成员与GenBank中任何已知细菌序列的亲缘关系都不紧密。属于β-变形菌纲的三个成员的数量占从“较重”DNA组分中测得的16S rDNA总拷贝数的34%，该“较重”DNA组分来自能够将13C标记的萘纳入其遗传生物标志物的微生物的DNA。其他五个成员占所测活性萘利用种群16S rDNA总拷贝数的66%。Q-FAST为研究微生物生态学提供了一个强大的工具，从而为更深入地探索微生物介导的过程开辟了一条新途径，主要是探索给定环境中微生物多样性与微生物活性之间的定量关系。
