scholarly journals Association of Microbial Community Composition and Activity with Lead, Chromium, and Hydrocarbon Contamination

2002 ◽  
Vol 68 (8) ◽  
pp. 3859-3866 ◽  
Author(s):  
W. Shi ◽  
J. Becker ◽  
M. Bischoff ◽  
R. F. Turco ◽  
A. E. Konopka
Keyword(s):  
Heavy Metals ◽  
Microbial Community ◽  
Microbial Biomass ◽  
Community Composition ◽  
Microbial Community Composition ◽  
Soil Samples ◽  
Hydrocarbon Contamination ◽  
Total Petroleum Hydrocarbons ◽  
Organic C ◽  
Microbial C

ABSTRACT Microbial community composition and activity were characterized in soil contaminated with lead (Pb), chromium (Cr), and hydrocarbons. Contaminant levels were very heterogeneous and ranged from 50 to 16,700 mg of total petroleum hydrocarbons (TPH) kg of soil−1, 3 to 3,300 mg of total Cr kg of soil−1, and 1 to 17,100 mg of Pb kg of soil−1. Microbial community compositions were estimated from the patterns of phospholipid fatty acids (PLFA); these were considerably different among the 14 soil samples. Statistical analyses suggested that the variation in PLFA was more correlated with soil hydrocarbons than with the levels of Cr and Pb. The metal sensitivity of the microbial community was determined by extracting bacteria from soil and measuring [3H]leucine incorporation as a function of metal concentration. Six soil samples collected in the spring of 1999 had IC50 values (the heavy metal concentrations giving 50% reduction of microbial activity) of approximately 2.5 mM for CrO4 2− and 0.01 mM for Pb2+. Much higher levels of Pb were required to inhibit [14C]glucose mineralization directly in soils. In microcosm experiments with these samples, microbial biomass and the ratio of microbial biomass to soil organic C were not correlated with the concentrations of hydrocarbons and heavy metals. However, microbial C respiration in samples with a higher level of hydrocarbons differed from the other soils no matter whether complex organic C (alfalfa) was added or not. The ratios of microbial C respiration to microbial biomass differed significantly among the soil samples (P < 0.05) and were relatively high in soils contaminated with hydrocarbons or heavy metals. Our results suggest that the soil microbial community was predominantly affected by hydrocarbons.

scholarly journals Ecostoichiometry Reveals the Separation of Microbial Adaptation Strategies in a Bamboo Forest in an Urban Wetland under Simulated Nitrogen Deposition

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 428 ◽  
Author(s):  
Weicheng Li ◽  
Haiyan Sheng ◽  
Yaoyao Liu ◽  
Rui Zhang ◽  
Desy Ekawati ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Biomass ◽  
Nitrogen Deposition ◽  
Community Composition ◽  
Microbial Community Composition ◽  
Adaptation Strategies ◽  
Moso Bamboo ◽  
Bamboo Forest ◽  
N Limitation ◽  
P Limitation

The effect of nitrogen (N) deposition on N limitation, phosphorus (P) limitation and the related soil and microbial stoichiometries remains unclear. A simulated nitrogen deposition (SND) experiment (control, ambient, medium and high) and molecular techniques (high-throughput sequencing of 16S and ITS) were conducted to examine the variations in abiotic and biotic properties and to describe the responses of microbial (bacteria and fungi) adaptation strategies in a moso bamboo (Phyllostachys edulis J. Houzeau) forest following SND. Soil water content (SWC) was positively correlated with the microbial community composition. Observed increases in total N and nitrate N contents and decreased ammonia N suggested that SND influenced nitrification. Chao1 and F:B showed that bacteria were more sensitive to SND than fungi. PCoA and linear discriminant analysis (LDA), coupled with effect size measurements (LefSe), confirmed that microbial community composition, including the subgroups (below class level), responded to SND by employing different adaptation strategies. Soil C:N indicated that the soil of the moso bamboo forest was under N limitation prior to SND. The increase in total P (TP), available P (AP) and microbial biomass P (MBP) suggested the acceleration of soil P cycling. Microbial biomass C (MBC) and microbial biomass N (MBN) were not affected by SND, which led to a significant shift in MBC:MBP and MBN:MBP, suggesting that P utilization per unit of C or N was promoted. There was a negative gradient correlation between the fungal community composition and MBC:MBP, while bacteria were positively correlated with MBN:MBP. The results illustrated that the response of fungi to MBC was more sensitive than that of bacteria in the process of accelerated P cycling, while bacteria were sensitive to MBN. Prior to P limitation, SND eliminated the soil N limitation and stimulated soil microorganisms to absorb more P, resulting in an increase in MBP, but did not alter MBC or MBN. This study contributes to our understanding of the adaptation strategies of fungi and bacteria and their responses to soil and microbial stoichiometries.

scholarly journals Spatial gradients in the characteristics of soil-carbon fractions are associated with abiotic features but not microbial communities

2019 ◽  
Vol 16 (19) ◽  
pp. 3911-3928 ◽  
Author(s):  
Aditi Sengupta ◽  
Julia Indivero ◽  
Cailene Gunn ◽  
Malak M. Tfaily ◽  
Rosalie K. Chu ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Organic Compounds ◽  
Community Composition ◽  
Microbial Community Composition ◽  
Water Soluble ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Organic C ◽  
Shallow Soils

Abstract. Coastal terrestrial–aquatic interfaces (TAIs) are dynamic zones of biogeochemical cycling influenced by salinity gradients. However, there is significant heterogeneity in salinity influences on TAI soil biogeochemical function. This heterogeneity is perhaps related to unrecognized mechanisms associated with carbon (C) chemistry and microbial communities. To investigate this potential, we evaluated hypotheses associated with salinity-associated shifts in organic C thermodynamics; biochemical transformations; and nitrogen-, phosphorus-, and sulfur-containing heteroatom organic compounds in a first-order coastal watershed on the Olympic Peninsula of Washington, USA. In contrast to our hypotheses, thermodynamic favorability of water-soluble organic compounds in shallow soils decreased with increasing salinity (43–867 µS cm−1), as did the number of inferred biochemical transformations and total heteroatom content. These patterns indicate lower microbial activity at higher salinity that is potentially constrained by accumulation of less-favorable organic C. Furthermore, organic compounds appeared to be primarily marine- or algae-derived in forested floodplain soils with more lipid-like and protein-like compounds, relative to upland soils that had more lignin-, tannin-, and carbohydrate-like compounds. Based on a recent simulation-based study, we further hypothesized a relationship between C chemistry and the ecological assembly processes governing microbial community composition. Null modeling revealed that differences in microbial community composition – assayed using 16S rRNA gene sequencing – were primarily the result of limited exchange of organisms among communities (i.e., dispersal limitation). This results in unstructured demographic events that cause community composition to diverge stochastically, as opposed to divergence in community composition being due to deterministic selection-based processes associated with differences in environmental conditions. The strong influence of stochastic processes was further reflected in there being no statistical relationship between community assembly processes (e.g., the relative influence of stochastic assembly processes) and C chemistry (e.g., heteroatom content). This suggests that microbial community composition does not have a mechanistic or causal linkage to C chemistry. The salinity-associated gradient in C chemistry was, therefore, likely influenced by a combination of spatially structured inputs and salinity-associated metabolic responses of microbial communities that were independent of community composition. We propose that impacts of salinity on coastal soil biogeochemistry need to be understood in the context of C chemistry, hydrologic or depositional dynamics, and microbial physiology, while microbial composition may have less influence.

scholarly journals Investigating the Impact of Storage Conditions on Microbial Community Composition in Soil Samples

PLoS ONE ◽  
2013 ◽  
Vol 8 (7) ◽  
pp. e70460 ◽  
Author(s):  
Benjamin E. R. Rubin ◽  
Sean M. Gibbons ◽  
Suzanne Kennedy ◽  
Jarrad Hampton-Marcell ◽  
Sarah Owens ◽  
...  
Keyword(s):  
Microbial Community ◽  
Community Composition ◽  
Microbial Community Composition ◽  
Storage Conditions ◽  
Soil Samples ◽  
The Impact

Shifts in soil microbial community biomass and resource utilization along a Canadian glacier chronosequence

2013 ◽  
Vol 93 (3) ◽  
pp. 305-318 ◽  
Author(s):  
Aria S. Hahn ◽  
Sylvie A. Quideau
Keyword(s):  
Microbial Community ◽  
Microbial Biomass ◽  
Community Composition ◽  
Resource Utilization ◽  
Soil Microbial Community ◽  
Microbial Community Composition ◽  
Soil Microbial ◽  
Community Biomass ◽  
Plfa Analysis ◽  
Soil Microbial Community Composition

Hahn, A. S. and Quideau, S. A. 2013. Shifts in soil microbial community biomass and resource utilization along a Canadian glacier chronosequence. Can. J. Soil Sci. 93: 305–318. We aimed to describe soil microbial community composition and functional diversity as well as determine the influence of Engelmann spruce (Picea engelmannii Parry) and yellow mountain avens (Dryas drummondii Rich.) on soil microbial community succession along a Canadian glacier chronosequence. Soil microbial composition and functional activity were assessed using phospholipid fatty acid (PLFA) analysis, substrate-induced respiration and enzyme activity analysis. To the best of our knowledge, this is the first study investigating peroxidase and phenol oxidase activities, indicators of fungal activity, along any glacial chronosequence. While no difference in soil microbial community composition along the chronosequence was detected from the PLFA analysis, both total microbial biomass and fungal activity increased with time since deglaciation. Yellow mountain avens, a plant known to support microbial nitrogen fixation in mid- and late successional stages, increased soil microbial biomass, although this effect took 40 yr after deglaciation to emerge. Additionally, significant correlations between microbial respiration of N-acetyl-glucosamine, protocatechuic acid, glucose and percent soil N were found along the chronosequence, indicating that the soil microbial community was influencing changes in the soil environment.

scholarly journals Effect of Litter-Derived Dissolved Organic Carbon Addition on Forest Soil Microbial Community Composition

2021 ◽  
Vol 1 ◽  
Author(s):  
Min Wang ◽  
Qiuxiang Tian ◽  
Chang Liao ◽  
Rudong Zhao ◽  
Feng Liu
Keyword(s):  
Microbial Community ◽  
Microbial Biomass ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Community Composition ◽  
Soil Microbial Biomass ◽  
Microbial Community Composition ◽  
Soil Microbial ◽  
Significant Difference ◽  
Microbial Groups

The input of dissolved organic carbon (DOC) into soil affects soil organic carbon mineralization and microbial community composition by changing carbon availability. However, up to now, there is little knowledge about the microbial groups that utilize the added DOC and how the incorporation process may vary over time. In this study, we added 13C-labeled litter-derived DOC (treatment) or pure water (control) to a forest soil from different layers to investigate the effects of DOC addition on soil microbial biomass and community composition in a 180-d laboratory incubation experiment. Soil microbial phospholipid fatty acid (PLFA) were measured to assess changes in the microbial community composition. The 13C incorporation into microbial biomass and PLFAs was analyzed to trace the microbial utilization of litter-derived DOC. Our results indicated that DOC addition increased the biomass of gram-negative bacteria, gram-positive bacteria, fungi, and actinomycetes, but the microbial community composition manifested a similar trend for both treatment and control soils at the end of incubation. Proportions of added DOC in different depths of soil microbial PLFAs had no significant difference. Moreover, 17:0 cy and 15:0 PLFAs which are described as the bacterial biomarkers had a greater amount of 13C incorporation than other PLFAs for the topsoil, which indicated that 13C-labeled litter-derived DOC was more easily assimilated by some specific bacterial community. Soil microbial biomass and the incorporation of 13C into PLFA reached its maximum around 30 days after DOC addition and then rapidly reduced to the level comparable to control. Overall, this study demonstrated that the incorporation of 13C-labeled litter-derived DOC into PLFA in different depth soil had no significant difference, and the incorporation of 13C by bacteria was higher than other microbial groups.

Changes in soil microbial biomass and community composition along vegetation zonation in a coastal sand dune

Soil Research ◽  
2008 ◽  
Vol 46 (4) ◽  
pp. 390 ◽  
Author(s):  
Shinpei Yoshitake ◽  
Takayuki Nakatsubo
Keyword(s):  
Microbial Community ◽  
Microbial Biomass ◽  
Community Composition ◽  
Sand Dune ◽  
Phospholipid Fatty Acid ◽  
Microbial Community Composition ◽  
Coastal Sand Dune ◽  
Vegetation Zonation ◽  
Soil Microbial ◽  
Coastal Sand

We used phospholipid fatty acid (PLFA) analysis to examine the relation of microbial biomass and community composition to vegetation zonation on a coastal sand dune. Soil samples were collected along 3 line transects established from the shoreline to the inland bush. Total PLFA content and PLFA composition of soils were used as indices of total microbial biomass and community composition, respectively. The microbial biomass was much higher in the inland Vitex rotundifolia zone than in the seaside plots. The microbial community composition also differed among the vegetation zones, with a higher contribution of fungal biomarkers in the inland plots. The microbial biomass increased significantly with increasing soil organic matter (SOM) content, but was not correlated with soil salinity. These results suggest that microbial biomass in the coastal sand dune was controlled primarily by the accumulation of SOM. The microbial community composition also changed with SOM content in the seaside plots, but SOM had little effect in the inland plots. These results suggest that the factors limiting the microbial community composition differed with location on the dune.

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