scholarly journals Microbial biomass dynamics after addition of EDTA into heavy metal contaminated soils

2009 ◽  
Vol 55 (No. 12) ◽  
pp. 544-550 ◽  
Author(s):  
G. Mühlbachová
Keyword(s):  
Heavy Metal ◽  
Microbial Biomass ◽  
Contaminated Soils ◽  
Soil Microorganisms ◽  
Organic Substrate ◽  
Microbial Biomass C ◽  
Microbial Activities ◽  
Arable Soils ◽  
Microbial Properties ◽  
Biomass Dynamics

An incubation experiment with addition of EDTA and alfalfa into soils contaminated with heavy metal over 200 years was carried out in order to evaluate the EDTA effects on microbial properties. Alfalfa was added to soils together with EDTA to examine its abilities to improve microbial activities affected by EDTA. The obtained results showed that the addition of EDTA led to a significant decrease of microbial biomass C during the first 24 days of incubation. At the end of the experiment the microbial biomass C significantly increased quite close to the original level. The EDTA amendment caused, probably due to the toxic effects, a significant increase in respiratory activities and of the metabolic quotient <i>q</i>CO<sub>2</sub>. An addition of alfalfa significantly improved the microbial biomass C contents in arable soils treated together with EDTA. Both, respiratory activities and <i>q</i>CO<sub>2</sub> significantly increased after the soil treatment with EDTA together with alfalfa. EDTA alone decreased the microbial biomass, alfalfa alone as organic substrate was mineralised and utilised by soil microorganisms for their metabolism.

scholarly journals Potential of the soil microbial biomass C to tolerate and degrade persistent organic pollutants

2008 ◽  
Vol 3 (No. 1) ◽  
pp. 12-20 ◽  
Author(s):  
G. Mühlbachová
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Contaminated Soil ◽  
Soil Microorganisms ◽  
Soil Microbial Biomass ◽  
Microbial Biomass C ◽  
Microbial Activities ◽  
Soil Microbial Biomass C ◽  
Soil Microbial

A 12-day incubation experiment with the addition of glucose to soils contaminated with persistent organic pollutants (POPs) was carried out in order to estimate the potential microbial activities and the potential of the soil microbial biomass C to degrade 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT), polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAHs). The microbial activities were affected in different ways depending on the type of pollutant. The soil organic matter also played an important role. The microbial activities were affected particularly by high concentrations of PAHs in the soils. Soil microorganisms in the PAHs contaminated soil used the added glucose to a lesser extent than in the non-contaminated soil, which in the contaminated soil resulted in a higher microbial biomass content during the first day of incubation. DDT, DDD and DDE, and PCB affected the soil microbial activities differently and, in comparison with control soils, decreased the microbial biomass C during the incubation. The increased microbial activities led to a significant decrease of PAH up to 44.6% in the soil long-term contaminated with PAHs, and up to 14% in the control soil after 12 days of incubation. No decrease of PAHs concentrations was observed in the soil which was previously amended with sewage sludges containing PAHs and had more organic matter from the sewage sludges. DDT and its derivates DDD and DDE decreased by about 10%, whereas the PCB contents were not affected at all by microbial activities. Studies on the microbial degradation of POPs could be useful for the development of methods focused on the remediation of the contaminated sites. An increase of soil microbial activities caused by addition of organic substrates can contribute to the degradation of pollutants in some soils. However, in situ biodegradation may be limited because of a complex set of environmental conditions, particularly of the soil organic matter. The degradability and availability of POPs for the soil microorganisms has to be estimated individually for each contaminated site.

scholarly journals The availability of Cd, Pb and Zn and their relationships with soil pH and microbial biomass in soils amended by natural clinoptilolite

2011 ◽  
Vol 51 (No. 1) ◽  
pp. 26-33 ◽  
Author(s):  
G. Mühlbachová ◽  
T. Šimon ◽  
M. Pechová
Keyword(s):  
Heavy Metal ◽  
Microbial Biomass ◽  
Contaminated Soils ◽  
Metal Availability ◽  
Maximum Increase ◽  
Glucose Addition ◽  
Soil Microbial ◽  
Significant Relationships ◽  
Metal Contents ◽  
Natural Clinoptilolite

The relationships among soil microbial biomass, pH and available of heavy metal fractions were evaluated in longterm contaminated soils during an incubation experiment with the amendment of zeolite (natural clinoptilolite) and the subsequent addition of glucose. The values of pH after the addition of glucose decreased during the first day of incubation approximately at about one unit and corresponded with the maximum increase of microbial biomass. The available heavy metal contents extracted by H<sub>2</sub>O, 1 mol/l NH<sub>4</sub>NO<sub>3</sub> and 0.005 mol/l DTPA increased during the first two days of incubation. Only a few significant relationships were found between the available metal contents and pH or microbial biomass. This fact could be ascribed to the different dynamics of the microbial biomass, pH and metal availability after glucose addition, when the highest metal contents during the incubation were usually reached one day later in respect to the greatest changes of pH and microbial activity. In comparison to soils without zeolite addition, the variants with natural clinoptilolite showed lower heavy metal contents in all used extractants with the exception of Cd which in H<sub>2</sub>O extracts tended to increase.

scholarly journals The impact of tall fescue (Festuca arundinacea) endophyte (Neotyphodium spp) on non target soil microorganisms

2004 ◽  
Vol 57 ◽  
pp. 329-336 ◽  
Author(s):  
S. Sayer ◽  
G. Burch ◽  
S.U. Sarathchandra
Keyword(s):  
Microbial Biomass ◽  
Functional Diversity ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Soil Microorganisms ◽  
Soil Microbial Biomass ◽  
Rhizosphere Soil ◽  
Microbial Biomass C ◽  
Soil Microbial ◽  
The Impact

The impact of two strains of the tall fescue (Festuca arundinacea) endophyte (Neotyphodium spp) (E) on the rhizoplane and rhizosphere soil microorganisms was examined at two sites (Lincoln endophytefree (E) and the endophyte strain AR501; and Aorangi E AR501 and a second strain AR542) Rhizosphere and rhizoplane populations of bacteria and fungi functional diversity root fungi and soil microbial biomass carbon and nitrogen were measured Most characteristics measured showed no differences between E and E samples indicating that the presence of endophytes had no impact on nontarget soil microorganisms At Aorangi soil microbial biomass C and N were significantly greater (Plt;005) in AR542 than E1 and AR501 soils Culturable fungal populations from both the rhizoplane and rhizosphere soil were significantly greater (Plt;005) in the E than the AR501 samples at Lincoln but not at Aorangi There were no differences in the functional diversity of rhizoplane microorganisms due to endophyte

scholarly journals Soil microbial properties of subalpine steppe soils at different grazing intensities in the Chinese Altai Mountains

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sven Goenster-Jordan ◽  
Mariko Ingold ◽  
Ramia Jannoura ◽  
Andreas Buerkert ◽  
Rainer Georg Joergensen
Keyword(s):  
Microbial Biomass ◽  
Soil Properties ◽  
Block Design ◽  
Stocking Density ◽  
Grazing Intensity ◽  
Microbial Biomass C ◽  
Altai Mountains ◽  
Microbial Properties ◽  
Soil Microbial ◽  
Soil Microbial Properties

AbstractLong-term provision of ecosystem services by grasslands is threatened by increasing stocking densities. The functions of grassland ecosystems depend on a mutual relationship between aboveground and belowground biota. While the effects of increasing stocking density on plant biomass are well studied, little is known about its impact on soil microbial properties. To fill this knowledge gap a grazing experiment was conducted on a summer pasture in the Chinese Altai Mountains during the summers of 2014 and 2015 using a randomized block design with stocking densities of 0, 8, 16, and 24 sheep ha−1 replicated four times. After two summer grazing periods (each 56 days), topsoil samples (1–7 cm) were taken in September 2015 and analyzed for major physical, chemical, and microbial soil properties. Except for the metabolic quotient (qCO2; p < 0.05), the examined soil properties remained unaffected by the increasing stocking densities, likely due to high spatial variability. The qCO2 declined from 13.5 mg CO2–C g−1 microbial biomass C d−1 at zero grazing to 12.2 mg CO2–C g−1 microbial biomass C d−1 at a stocking density of 24 sheep ha−1. Low values of qCO2 indicate an aged and dormant microbial community that diverts less soil organic carbon (SOC) to catabolic processes within their cells, characteristic for C limiting conditions. The aboveground biomass affected by grazing intensity correlated positively with SOC (rs = 0.60, p = 0.015) and ergosterol (rs = 0.76, p = 0.001) pointing indirectly to the effect of stocking density. Additionally to the relatively high values of qCO2, highest values of SOC (39.2 mg g−1 soil), ergosterol (6.01 µg g−1 soil), and basal respiration (10.7 µg g−1 soil d−1) were observed at a stocking density of 8 sheep ha−1 indicating that a low grazing intensity is recommendable to avoid soil degradation.

scholarly journals Effects of zeolite amendment on microbial biomass and respiratory activity in heavy metal contaminated soils

2011 ◽  
Vol 49 (No. 12) ◽  
pp. 536-541 ◽  
Author(s):  
G. Mühlbachová ◽  
T. Šimon
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Microbial Biomass ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Respiratory Activity ◽  
Metabolic Quotient ◽  
Incubation Experiment ◽  
Laboratory Incubation ◽  
Microbial Characteristics

A&nbsp;laboratory incubation experiment with zeolite and glucose was performed to evaluate the effects of zeolite amendment in heavy metal contaminated soils from two smelter areas on some microbial characteristics [Kremikovtzi (K1, K2) in Bulgariaand Př&iacute;bram (P1, P2) in the CzechRepublic]. The content of microbial biomass showed a&nbsp;tendency to decrease in Kremikovtzi soils whereas in Př&iacute;bram soils no significant effects were found after zeolite amendment. Respiratory activity and metabolic quotient (qCO2) decreased on the second and third day in Kremikovtzi soils amended with zeolite, no effects were observed in Př&iacute;bram soils. Heavy metals decreased the content of microbial biomass in Kremikovtzi soils whereas the contaminated soil from Př&iacute;bram area had the highest microbial biomass compared to non-contaminated soil during incubation, probably due to lower mineralization of carbon. The respiratory activity did not show any significant effects of zeolites on the evolution of CO2&nbsp;and qCO2&nbsp;in heavy metal contaminated Př&iacute;bram soil. The respiratory activity in non-contaminated Př&iacute;bram soil remained during the experiment lower in comparison to contaminated one, however the addition of zeolite increased qCO2.

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