scholarly journals Soil Bacterial Diversity and Its Relationship with Soil CO2 and Mineral Composition: A Case Study of the Laiwu Experimental Site

Author(s):  
Hongying Zhang ◽  
Zongjun Gao ◽  
Mengjie Shi ◽  
Shaoyan Fang

To better understand the characteristics of soil bacterial diversity in different environments, the Laiwu Qilongwan experimental site was selected as it is of great significance for the study of geochemical cycles. The soil CO2, mineral composition and bacterial community were analyzed by an EGM-4 portable environmental gas detector, an X-ray diffractometer and 16S rDNA high-throughput sequencing, and soil bacterial diversity and the relationship between soil bacterial diversity and environmental factors were studied. The results showed that with increasing soil depth, the CO2 content increased, the feldspar and amphibole contents increased, the quartz content decreased, the richness of the soil bacterial community increased, the relative richness of Nitrospirae increased, and Chloroflexi decreased. The dominant bacteria were Proteobacteria, Actinobacteria and Acidobacteria. There were slight differences in soil CO2, mineral composition and dominant bacterial flora at the same depth. Actinobacteria, Proteobacteria and Firmicutes were the dominant phyla of L02. The CO2 was lowest in bare land, and the quartz and K-feldspar contents were the highest. Soil CO2 mainly affected the deep bacterial diversity, while shallow soil bacteria were mainly affected by mineral components (quartz and K-feldspar). At the same depth, amphibole and clay minerals had obvious effects on the bacterial community, while CO2 had obvious effects on subdominant bacteria.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiaxin Wang ◽  
Xuening Lu ◽  
Jiaen Zhang ◽  
Guangchang Wei ◽  
Yue Xiong

Abstract It has been shown that the golden apple snail (GAS, Pomacea canaliculata), which is a serious agricultural pest in Southeast Asia, can provide a soil amendment for the reversal of soil acidification and degradation. However, the impact of GAS residue (i.e., crushed, whole GAS) on soil bacterial diversity and community structure remains largely unknown. Here, a greenhouse pot experiment was conducted and 16S rRNA gene sequencing was used to measure bacterial abundance and community structure in soils amended with GAS residue and lime. The results suggest that adding GAS residue resulted in a significant variation in soil pH and nutrients (all P < 0.05), and resulted in a slightly alkaline (pH = 7.28–7.75) and nutrient-enriched soil, with amendment of 2.5–100 g kg−1 GAS residue. Soil nutrients (i.e., NO3-N and TN) and TOC contents were increased (by 132–912%), and some soil exocellular enzyme activities were enhanced (by 2–98%) in GAS residue amended soil, with amendment of 1.0–100 g kg−1 GAS residue. Bacterial OTU richness was 19% greater at the 2.5 g kg−1 GAS residue treatment than the control, while it was 40% and 53% lower at 100 g kg−1 of GAS residue and 50 g kg−1 of lime amended soils, respectively. Firmicutes (15–35%) was the most abundant phylum while Bacterioidetes (1–6%) was the lowest abundant one in GAS residue amended soils. RDA results suggest that the contents of soil nutrients (i.e., NO3-N and TN) and soil TOC explained much more of the variations of bacterial community than pH in GAS residue amended soil. Overuse of GAS residue would induce an anaerobic soil environment and reduce bacterial OTU richness. Soil nutrients and TOC rather than pH might be the main factors that are responsible for the changes of bacterial OTU richness and bacterial community structure in GAS residue amended soil.


2021 ◽  
Vol 9 (1) ◽  
pp. 139
Author(s):  
Quanchao Zeng ◽  
Shaoshan An

High-throughput sequencing is commonly used to study soil microbial communities. However, different primers targeting different 16S rRNA hypervariable regions often generate different microbial communities and result in different values of diversity and community structure. This study determined the consequences of using two bacterial primers (338f/806r, targeting the V3-V4 region, and 520f/802r, targeting the V4 region) to assess bacterial communities in the soils of different land uses along a latitudinal gradient. The results showed that the variations in the soil bacterial diversity in different land uses were more evident based on the former pair. The statistical results showed that land use had no significant impact on soil bacterial diversity when primer pair 520f/802r was used. In contrast, when primer pair 338f/806r was used, the cropland and orchard soils had significantly higher operational taxonomic units (OTUs) and Shannon diversity index values than those of the shrubland and grassland soils. Similarly, the soil bacterial diversity generated by primer pair 338f/806r was significantly impacted by mean annual precipitation, soil total phosphorus (TP), soil total nitrogen (TN), and soil available phosphorus (AVP), while the soil bacterial diversity generated by primer pair 520f/802r showed no significant correlations with most of these environmental factors. Multiple regression models indicated that soil pH and soil organic carbon (SOC) shaped the soil bacterial community structure on the Loess Plateau regardless of what primer pair was used. Climatic conditions mainly affected the diversity of rare bacteria. Abundant bacteria are more sensitive than rare bacteria to environmental changes. Very little of the variation in the rare bacterial community was explained by environmental factors or geographic distance, suggesting that the communities of rare bacteria are unpredictable. The distributions of the abundant taxa were mainly determined by variations in environmental factors.


2021 ◽  
Author(s):  
Wenjuan Liu ◽  
Yufeng Guo ◽  
Guoli Chai ◽  
Wenbo Deng

Abstract Graphene (GR) has huge industrial and biomedical potential, and its adverse effect on soil microorganisms has been evaluated in some ecotoxicological studies. These studies focus on a single exposure to GR, but repeated exposures are more likely to occur in soil. In this study, we compared the impact of single and repeated exposures (one, two and three exposures that resulted in the same final concentration) of GR on structure, abundance and function of soil bacterial community based on soil enzyme activity and high-throughput sequencing. The activities of urease and fluorescein diacetate esterase and alpha diversity demonstrate that repeated exposure to GR increase the diversity of soil bacterial diversity after 4 days of incubation following the last application of GR to soil. And the PCoA and sample level clustering tree showed single exposure to GR after 4 days alter the soil bacterial community to some extent, but the difference has been narrowed with the extension of time. During the entire incubation process, no matter what kind of exposure scenarios to GR, the majority of bacterial phylotypes remained unchanged except for Proteobacteria and Actinobacteria according to the relative abundance of phylotypes.


2021 ◽  
Author(s):  
Shangdong Yang ◽  
Jian Xiao ◽  
Ziyue Huang ◽  
Renliu Qin ◽  
Weizhong He ◽  
...  

Abstract Aims Sugarcane intercropping with soybean (Glycine max (Linn.) Merr.), mung bean (Vignaradiata (Linn.) Wilczek) and peanut (Arachishypogaea Linn.) as well as a sugarcane monoculture were conducted to study the impacts of intercropping on soil biological characteristics and bacterial diversity. Methods The soil samples were collected from twelve random sites and mixed well at the experimental farm of the Guangxi South Sub-tropical Agricultural Science Research Institute, Longzhou, China. Traditional analysis methods and modern high-throughput sequencing technology was used to compare and analyze the soil enzyme activity, microbial biomass, soil cultivable microorganisms and other biological traits and bacterial diversity.Results The results showed that soil cultivable microorganisms, the activities of soil enzymes and microbial biomass carbon, nitrogen, and phosphorus were all significantly improved by intercropping with soybean and mung bean. Additionally, soil bacterial diversity and richness in sugarcane fields were also significantly enhanced by intercropping with soybean and mung bean. In addition, soil bacterial community structures in sugarcane fields can be altered by intercropping with different legumes. Proteobacteria, a high-nutrient-tolerant bacterial assemblage, became the dominant bacteria in the sugarcane-soybean and sugarcane-mung bean intercropped soils. Twenty four, 28, 26 and 27 dominant soil bacterial genera were found after the sugarcane-soybean, sugarcane-mung bean, sugarcane-peanut and sugarcane monoculture treatments, respectively.Conclusions Sugarcane-mung bean intercropping suggested to be the most promising system for regaining and improving soil fertility and soil heath and facilitate agriculture intensification of sugarcane.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12176
Author(s):  
Micaela Schagen ◽  
Jason Bosch ◽  
Jenny Johnson ◽  
Robbert Duker ◽  
Pedro Lebre ◽  
...  

This study examines the soil bacterial diversity in the Portulacaria afra-dominated succulent thicket vegetation of the Albany Subtropical Thicket biome; this biome is endemic to South Africa. The aim of the study was to compare the soil microbiomes between intact and degraded zones in the succulent thicket and identify environmental factors which could explain the community compositions. Bacterial diversity, using 16S amplicon sequencing, and soil physicochemistry were compared across three zones: intact (undisturbed and vegetated), degraded (near complete removal of vegetation due to browsing) and restored (a previously degraded area which was replanted approximately 11 years before sampling). Amplicon Sequence Variant (ASV) richness was similar across the three zones, however, the bacterial community composition and soil physicochemistry differed across the intact and degraded zones. We identified, via correlation, the potential drivers of microbial community composition as soil density, pH and the ratio of Ca to Mg. The restored zone was intermediate between the intact and degraded zones. The differences in the microbial communities appeared to be driven by the presence of plants, with plant-associated taxa more common in the intact zone. The dominant taxa in the degraded zone were cosmopolitan organisms, that have been reported globally in a wide variety of habitats. This study provides baseline information on the changes of the soil bacterial community of a spatially restricted and threatened biome. It also provides a starting point for further studies on community composition and function concerning the restoration of degraded succulent thicket ecosystems.


2021 ◽  
Vol 11 (3) ◽  
pp. 918
Author(s):  
Lingzi Mo ◽  
Augusto Zanella ◽  
Xiaohua Chen ◽  
Bin Peng ◽  
Jiahui Lin ◽  
...  

Continuing nitrogen (N) deposition has a wide-ranging impact on terrestrial ecosystems. To test the hypothesis that, under N deposition, bacterial communities could suffer a negative impact, and in a relatively short timeframe, an experiment was carried out for a year in an urban area featuring a cover of Bermuda grass (Cynodon dactylon) and simulating environmental N deposition. NH4NO3 was added as external N source, with four dosages (N0 = 0 kg N ha−2 y−1, N1 = 50 kg N ha−2 y−1, N2 = 100 kg N ha−2 y−1, N3 = 150 kg N ha−2 y−1). We analyzed the bacterial community composition after soil DNA extraction through the pyrosequencing of the 16S rRNA gene amplicons. N deposition resulted in soil bacterial community changes at a clear dosage-dependent rate. Soil bacterial diversity and evenness showed a clear trend of time-dependent decline under repeated N application. Ammonium nitrogen enrichment, either directly or in relation to pH decrease, resulted in the main environmental factor related to the shift of taxa proportions within the urban green space soil bacterial community and qualified as a putative important driver of bacterial diversity abatement. Such an impact on soil life induced by N deposition may pose a serious threat to urban soil ecosystem stability and surrounding areas.


Sign in / Sign up

Export Citation Format

Share Document