Louisiana State University, Department of Biological Sciences, 202 Life Sciences Building, Baton Rouge, LA 70803, USA.
Appl Environ Microbiol. 2010 Apr;76(7):2212-7. doi: 10.1128/AEM.01861-09. Epub 2010 Feb 5.
Isolation of multiple carbon monoxide (CO)-oxidizing Burkholderia strains and detection by culture-independent approaches suggest that Burkholderia may be an important component of CO-oxidizing communities in Hawaiian volcanic deposits. The absolute and relative abundance of the bacteria in these communities remains unknown, however. In this study, a quantitative PCR (Q-PCR) approach has been developed to enumerate Burkholderia coxL genes (large subunit of carbon monoxide dehydrogenase). This represents the first attempt to enumerate coxL genes from CO oxidizers in environmental samples. coxL copy numbers have been determined for samples from three sites representing a vegetation gradient on a 1959 volcanic deposit that included unvegetated cinders (bare), edges of vegetated sites (edge), and sites within tree stands (canopy). Q-PCR has also been used to estimate copy numbers of Betaproteobacteria 16S rRNA gene copy numbers and total Bacteria 16S rRNA. coxL genes could not be detected in the bare site (detection limit, > or = 4.7 x 10(3) copies per reaction) but average 1.0 x 10(8) + or - 2.4 x 10(7) and 8.6 x 10(8) + or - 7.6 x 10(7) copies g(-1) (dry weight) in edge and canopy sites, respectively, which differ statistically (P = 0.0007). Average Burkholderia coxL gene copy numbers, expressed as a percentage of total Bacteria 16S rRNA gene copy numbers, are 6.2 and 0.7% for the edge and canopy sites, respectively. Although the percentage of Burkholderia coxL is lower in the canopy site, significantly greater gene copy numbers demonstrate that absolute abundance of coxL increases in vegetated sites and contributes to the expansion of CO oxidizer communities during biological succession on volcanic deposits.
从多个一氧化碳 (CO)-氧化伯克霍尔德氏菌菌株的分离以及非培养方法的检测结果来看，伯克霍尔德氏菌可能是夏威夷火山沉积物中 CO 氧化群落的一个重要组成部分。然而，这些群落中细菌的绝对和相对丰度仍然未知。在这项研究中，开发了一种定量 PCR (Q-PCR) 方法来计数伯克霍尔德氏菌 coxL 基因（一氧化碳脱氢酶大亚基）。这是首次尝试从环境样品中的 CO 氧化菌中计数 coxL 基因。已经确定了代表植被梯度的三个地点的样品中的 coxL 拷贝数，这些地点包括无植被的火山渣（裸露）、植被区的边缘（边缘）和树冠内的地点（树冠）。Q-PCR 还用于估计贝塔变形菌 16S rRNA 基因拷贝数和总细菌 16S rRNA 的拷贝数。在裸露地点无法检测到 coxL 基因（检测限，≥4.7 x 10(3) 个拷贝/反应），但平均分别为 1.0 x 10(8) +或-2.4 x 10(7)和 8.6 x 10(8) +或-7.6 x 10(7)个拷贝 g(-1)（干重）在边缘和树冠地点，这些差异具有统计学意义（P = 0.0007）。边缘和树冠地点的伯克霍尔德氏菌 coxL 基因拷贝数分别以总细菌 16S rRNA 基因拷贝数的百分比表示，平均值为 6.2%和 0.7%。尽管树冠地点的伯克霍尔德氏菌 coxL 百分比较低，但基因拷贝数的显著增加表明，在植被区，coxL 的绝对丰度增加，并促进了 CO 氧化菌群落在火山沉积物生物演替过程中的扩展。
