Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany.
Environ Microbiol Rep. 2009 Oct;1(5):393-7. doi: 10.1111/j.1758-2229.2009.00044.x. Epub 2009 Jul 14.
Despite numerous studies on methanotrophs, virtually nothing is known about their spatial heterogeneity in nature. These patterns, however, have strong influences on the interpretations made from analysing microbial processes and community structure. Here we report the first use of geostatistics to analyse the spatial heterogeneity of methanotrophs in a rice field soil (Vercelli, Italy). We used the gene encoding the particulate methane monooxygenase, pmoA, for terminal restriction fragment length polymorphism (T-RFLP) analysis. The profiles obtained were compared using a pseudo-variogram analysis to study autocorrelation as a function of distance. We demonstrated that there was no large-scale spatial structure at this study site, but a micro-scale spatial structure could not be excluded. A species accumulation curve with all terminal restriction fragments revealed that even 75 samples were insufficient to cover the diversity of methanotrophs in a rice field. However, a species accumulation curve of methanotrophs defined as operational taxonomic units validated from a clone library with 90% coverage demonstrated saturation after approximately 15 samples. The results of this study have consequences for studying the diversity and function of methanotrophs. In this agroecosystem population structure showed no spatial pattern implying that both a systematic and random sampling design would be adequate.
尽管已经有许多关于甲烷营养菌的研究，但实际上对于它们在自然界中的空间异质性几乎一无所知。然而，这些模式对从分析微生物过程和群落结构中得出的结论有很大的影响。在这里，我们首次报道了使用地质统计学分析稻田土壤（意大利韦尔切利）中甲烷营养菌空间异质性的方法。我们使用编码颗粒状甲烷单加氧酶（pmoA）的基因进行末端限制性片段长度多态性（T-RFLP）分析。通过伪变异函数分析比较获得的图谱，以研究距离的相关性。我们证明在该研究地点不存在大规模的空间结构，但不能排除微尺度的空间结构。所有末端限制性片段的物种积累曲线表明，即使使用 75 个样本也不足以覆盖稻田中甲烷营养菌的多样性。然而，当使用覆盖率为 90%的克隆文库验证定义为操作分类单位的甲烷营养菌的物种积累曲线时，大约 15 个样本后就达到了饱和。本研究的结果对研究甲烷营养菌的多样性和功能具有重要意义。在这个农业生态系统中，种群结构没有表现出空间模式，这意味着系统和随机抽样设计都是足够的。
