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

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 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.

Impact of Fullerene (C60) on a Soil Microbial Community

“…In this study soil respiration was monitored 14 times over 30 days following treatment with either distilled water, C60, nC60, or THF-C and for simplicity is reported as cumulative CO2 production (Figure 1). A reduction in the rate of respiration compared to the control would be expected if soil populations were subjected to a highly toxic material (29)(30)(31). Noncumulative respiration data collected at each time point were subjected to Tukey's test for the treatments effects and showed no significant differences (P > 0.05) between any treatments and the control.…”

“…The impact of manufactured nanomaterials on soil microbial function was estimated using basal CO2 production (27,28) as it is an established method to determine the effects of anthropogenic chemicals on aerobic soil activity (29,30) and has been applied widely in studies of pollutants in soil (31). The implications of nanomaterials on the ability of the soil microbial community to respond to introduced substrates were evaluated using a modified substrate response protocol (30,32,33) following soil incubation with nanomaterials.…”

“…The implications of nanomaterials on the ability of the soil microbial community to respond to introduced substrates were evaluated using a modified substrate response protocol (30,32,33) following soil incubation with nanomaterials. The effects of nanomaterials on general soil processes and nutrient cycling were evaluated using four different enzyme activities.…”

Effects of Experimental Lead Pollution on the Microbial Communities Associated with Sphagnum fallax (Bryophyta)

“…However, most ecotoxicological studies on microorganisms have dealt only with bacteria using molecular (community structure profile: DGGE, PLFA) or microbial activity approaches [18,37]. Among the eukaryotic microorganisms, protozoa, especially ciliates [11,20,21], and microalgae, especially the genus Chlorella [38], have also been used as models for some investigations.…”

Bioprospecting fungal diversity from crude oil infiltrate soil of Assam, India’s Northeast

“…Increased fungal population may be due to high pH and moisture and their adaptability to the prevailing environmental conditions (Rahman et al 2002).The isolated fungal population might have the potentiality to assimilate petroleum hydrocarbon in the contaminated soil. The growing trend in the fungal population with the increase in petroleum hydrocarbon compounds has been also discussed by different researchers (Shi et al 2002). Similarly, in some of the earlier studies, large population of bacteria, actinomycetes and fungi were recorded from oil-spilled environment (Venkateswaran et al 1993, Wrenn & Venosa 1996, Cabello 1997.…”