環境微生物（包括方興未艾的腸道微生物）在不同的系統中發揮著的生態作用逐漸被意識到，我們對環境微生物實際上仍舊知之甚少，其多樣性問題仍舊是一個非常基礎和重要的課題。這次讀的兩篇文章都是關于波蘭地區重金屬污染地區的土壤微生物研究。

文獻一： Chodak M., Go??biewski M., Morawska-P?oskonka J., Kuduk K. & Niklińska M. 2013. Diversity of microorganisms from forest soils differently polluted with heavy metals. Applied Soil Ecology. 64: 7–14.? 背景：

arge accumulation of heavy metals in organic layers of forest soils may adversely affect the structure?and diversity of microbial communities.

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實驗內容：

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The objective of this study was to assess the influence of different?soil chemical properties on structure and diversity of microbial communities in soils polluted with?different levels of heavy metals. The soil samples were taken at ten sites located in the vicinity of the?cities of Legnica and Olkusz, differently polluted with Cu, Zn and Pb.

The samples were measured for pH?and the contents of organic C (Corg), total N (Nt), total S (St) and total Zn, Cu and Pb. The measured gross?microbial properties included microbial biomass (Cmic) and soil respiration (RESP).

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The structure of soil?microbial communities was assessed using phospholipid fatty acid (PLFA) analysis and the structure of?soil bacterial communities using pyrosequencing of 16S rRNA genes.

To assess diversity of the bacterial?communities the Chao1 index was calculated based on the pyrosequencing data.

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結論：

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For Cmic and RESP the most important factors were Nt and Corg, respectively. The structure and diversity of soil microbial communities?revealed by PLFA profiles and pyrosequencing depended mainly on soil pH. The effect of high?heavy metal contents on soil microbial properties was weaker compared with other soil properties.

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High?

concentrations of heavy metals negatively affected RESP and the Chao1 diversity index. The heavy metal?

pollution altered the structure of microbial communities measured with PLFA analysis, but the effect of?

heavy metal pollution was not observed for the structure of soil bacteria measured by pyrosequencing. （PLFA比16S更敏感地反映環境對微生物群落結構的影響）

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最終結果：

The obtained results indicate that the use of soil microbial properties to study heavy metal effects may?be difficult due to confounding influences of other environmental factors.

主要數據分析手段：cca 文獻二： Go??biewski M., Deja-Sikora E., Cichosz M., Tretyn A. & Wróbel B. 2014. 16S rDNA Pyrosequencing Analysis of Bacterial Community in Heavy Metals Polluted Soils. Microb Ecol. 67: 635–647.? 背景：Soil contamination with heavy metals is a widespread?

problem, especially prominent on grounds lying in the?

vicinity of mines, smelters, and other industrial facilities.?

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試驗體系：Many such areas are located in Southern Poland; they are?

polluted mainly with Pb, Zn, Cd, or Cu, and locally also with?

Cr. As for now, little is

known about most bacterial species?

thriving in such soils and even less about a core bacterial?

community—a set of taxa common to polluted soils. Therefore,?

we wanted to answer the question if such a set could be?

found in samples differing physicochemically and?

phytosociologically. To answer the question, we analyzed?

bacterial communities in three soil samples contaminated with?

Pb and Zn and two contaminated with Cr and lower levels of?

Pb and Zn. The communities were assessed with 16S rRNA?gene fragments pyrosequencing.

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結論：

It was found that the samples?

differed significantly and Zn decreased both diversity and?

species richness at species and family levels, while plant?

species richness did not correlate with bacterial diversity. In?

spite of the differences between the samples, they shared?

many operational taxonomic units (OTUs) and it was possible?

to delineate the core microbiome of our sample set. The core?

set of OTUs comprised members of such taxa as?

Sphingomonas, Candidatus Solibacter, or Flexibacter showing?

that particular genera might be shared among sites ~40 km?

distant.

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總結：發表這兩篇文章的兩個期刊的IF（兩三個點）在生態學領域不是很低，但兩篇文章都是味同嚼蠟，基本上都是流水賬，在方法及結論上并沒有特別的亮點。一般而言，我跨領域半個小時能讀懂的論文（Nature級別的例外，大工不巧），我都不認為是好的論文。

第一篇文章，故事相對完整。主要是用主成份分析分析了不同環境因子對土壤微生物多樣性的影響，“PH是影響微生物群落結構的主要因素”這個觀點再次得到驗證；實驗用了兩種方法檢測微生物多樣性，其敏感性差異也是預料之中的。本論文的觀點是，在所研究區域其他環境因子對微生物群落結構的影響遮蔽了重金屬污染的作用。

第二篇文章，我則覺得屬于描述性論文，就是比較低等的論文。比較有意思的結論是，本文利用16s的方法檢測到了Zn污染對微生物多樣性的影響，而上一篇沒有檢測到這種影響，生態學上這樣的相反的結論很多，也很正常，關鍵能夠自圓其說，最終把結論推廣后實踐就更好了。另外，本文沒有檢測到植被植物豐富度的影響。

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生詞：

respiration 呼吸

vicinity附近

（備注：標黃色底色為實驗要點，紅色是運用比較好的動詞形容詞等，粗體是專業詞匯）

轉載于:https://www.cnblogs.com/liulele/p/6392351.html

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