scholarly journals Evaluation of functional diversity of soil microbial communities – a case study

2011 ◽  
Vol 50 (No. 4) ◽  
pp. 141-148 ◽  
Author(s):  
J. Hofman ◽  
J. Švihálek ◽  
I. Holoubek

In our case study, we measured the functional diversity of the microbial communities of twelve soils from the small natural area to assess if this assay is suitable for routine monitoring of soil biological quality. We found the BIOLOG assay meets especially practical benefits in routine monitoring of soils being simple and quick assay. However, we confirmed the ambiguity about the most appropriate analysis of the BIOLOG multivariate data and about the best parameter, which can be derived from the assay. The different analyses of the data were examined and various parameters derived from the BIOLOG assay were comparatively used to contribute to the discussion of how the data should be evaluated. We showed that not-normalized raw absorbances or trapezoid areas should be used for calculation of diversity index if the inoculum was standardized. There was no single answer to what parameter provided more correct results in the multivariate statistical analysis. Evaluating at least one not-normalized (e.g. trapezoid area) and one normalized parameter (e.g. absorbances read in fixed AWCD) was strongly suggested keeping in mind that they reveal different information.

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 532 ◽  
Author(s):  
Chaoqun Wang ◽  
Lin Xue ◽  
Yuhong Dong ◽  
Yihui Wei ◽  
Ruzhen Jiao

The structure and function of forest ecosystems are directly or indirectly affected by their stand density. However, what effect the density of Chinese fir plantations has on the functional diversity of the soil microbial community remains unclear. The microbial metabolic functional diversity of soils sampled at the topsoil (0–20 cm) of 35-year-old Chinese fir plantations of five initial densities (D1: 1667 stems∙hm−2, D2: 3333 stems∙hm−2, D3: 5000 stems∙hm−2, D4: 6667 stems∙hm−2, and D5: 10,000 stems∙hm−2) was studied by using Biolog ECO technology. The results showed that the soil pH, oxidizable organic carbon (SOOC), available N (AN), available P (AP), and available K (AK) contents all showed a gradual increase from D1 to D4 and a decrease from D4 to D5, while the number of culturable bacteria and total microorganisms, the average well color development (AWCD) values for the single carbon substrate and six types of carbon sources used by the microbial community, as well as the Shannon-Wiener diversity index (H’), Pielou evenness index (J), and McIntosh Diversity Index (U), were the opposite, suggesting that low-densities favored C and N mineralization and the nutrient cycle. The density of Chinese fir plantations had a significant effect on the use of carbohydrates, amino acids, carboxylic acids, and phenolic acids by the soil microbial community, but it had no significant effect on the use of polymers (p < 0.05). Principal component analysis (PCA) revealed that carbohydrates, polymers, and phenolic acids were sensitive carbon sources that caused differences in the metabolic functions of soil microbial communities in Chinese fir plantations. Redundancy analysis (RDA) showed that physicochemical factors have a significant influence on the metabolic function of soil microbial communities (RDA1 and RDA2 explained >85% variance). The changes in density affected the soil physicochemical properties, the composition, and the metabolic functional diversity of microbial communities in Chinese fir plantations, which is certainly useful for the stand density regulation of Chinese fir plantations.


2021 ◽  
Vol 49 (4) ◽  
pp. 12532
Author(s):  
Ali I. MALLANO ◽  
Xianli ZHAO ◽  
Yanling SUN ◽  
Guangpin JIANG ◽  
Huang CHAO

Continuous cropping systems are the leading cause of decreased soil biological environments in terms of unstable microbial population and diversity index. Nonetheless, their responses to consecutive peanut monocropping cycles have not been thoroughly investigated. In this study, the structure and abundance of microbial communities were characterized using pyrosequencing-based approach in peanut monocropping cycles for three consecutive years. The results showed that continuous peanut cultivation led to a substantial decrease in soil microbial abundance and diversity from initial cropping cycle (T1) to later cropping cycle (T3). Peanut rhizosphere soil had Actinobacteria, Protobacteria, and Gemmatimonadetes as the major bacterial phyla. Ascomycota, Basidiomycota were the major fungal phylum, while Crenarchaeota and Euryarchaeota were the most dominant phyla of archaea. Several bacterial, fungal and archaeal taxa were significantly changed in abundance under continuous peanut cultivation. Bacterial orders, Actinomycetales, Rhodospirillales and Sphingomonadales showed decreasing trends from T1>T2>T3. While, pathogenic fungi Phoma was increased and beneficial fungal taxa Glomeraceae decreased under continuous monocropping. Moreover, Archaeal order Nitrososphaerales observed less abundant in first two cycles (T1&T2), however, it increased in third cycle (T3), whereas, Thermoplasmata exhibit decreased trends throughout consecutive monocropping. Taken together, we have shown the taxonomic profiles of peanut rhizosphere communities that were affected by continuous peanut monocropping. The results obtained from this study pave ways towards a better understanding of the peanut rhizosphere soil microbial communities in response to continuous cropping cycles, which could be used as bioindicator to monitor soil quality, plant health and land management practices.


2008 ◽  
Vol 16 (2) ◽  
pp. 166 ◽  
Author(s):  
Xu Huaqin ◽  
Xiao Runlin ◽  
Song Tongqing ◽  
Luo Wen ◽  
Ren Quan ◽  
...  

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