两篇波兰地区重金属污染地区土壤微生物多样性的研究

Posted 2020-08-31

环境微生物（包括方兴未艾的肠道微生物）在不同的系统中发挥着的生态作用逐渐被意识到，我们对环境微生物实际上仍旧知之甚少，其多样性问题仍旧是一个非常基础和重要的课题。这次读的两篇文章都是关于波兰地区重金属污染地区的土壤微生物研究。

文献一：

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.

 

 

实验内容：

 

 

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).

 

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.

 

 

结论：

 

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.

 

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更敏感地反映环境对微生物群落结构的影响）

 

 

最终结果：

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.

主要数据分析手段：cca

 

文献二：

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. 

 

 

试验体系：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.

 

 

结论：

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.

 

 

总结：发表这两篇文章的两个期刊的IF（两三个点）在生态学领域不是很低，但两篇文章都是味同嚼蜡，基本上都是流水账，在方法及结论上并没有特别的亮点。一般而言，我跨领域半个小时能读懂的论文（Nature级别的例外，大工不巧），我都不认为是好的论文。

第一篇文章，故事相对完整。主要是用主成份分析分析了不同环境因子对土壤微生物多样性的影响，“PH是影响微生物群落结构的主要因素”这个观点再次得到验证；实验用了两种方法检测微生物多样性，其敏感性差异也是预料之中的。本论文的观点是，在所研究区域其他环境因子对微生物群落结构的影响遮蔽了重金属污染的作用。

第二篇文章，我则觉得属于描述性论文，就是比较低等的论文。比较有意思的结论是，本文利用16s的方法检测到了Zn污染对微生物多样性的影响，而上一篇没有检测到这种影响，生态学上这样的相反的结论很多，也很正常，关键能够自圆其说，最终把结论推广后实践就更好了。另外，本文没有检测到植被植物丰富度的影响。

 

生词：

respiration 呼吸

vicinity附近

（备注：标黄色底色为实验要点，红色是运用比较好的动词形容词等，粗体是专业词汇）