Soil enzymatic activities and microbial community structure with different application rates of Cd and Pb

Khan, Sardar; Cao, Qing; Hesham, Abd El-Latif; Xia, Yue; He, Ji‐Zheng

doi:10.1016/s1001-0742(07)60139-9

Cited by 174 publications

(59 citation statements)

References 45 publications

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“…Similarly, Wang et al (2008) has also reported that the bacterial community structure was changed in the soils amended with Cu and cultivated with different plants. In our previous work, microbial community structure was also changed in heavy metal-amended soils (Khan et al 2007). Furthermore, a great community change of indigenous microbes in this study, particularly at a high level of contamination of Cd, Pb, and Cd/Pb mix, was probably a result of metal toxicity and also unavailability of nutrients because no nutrients were supplied during the whole incubation period.…”

Section: Discussionmentioning

confidence: 87%

“…The experimental set up of this pot experiment was also the same as that used in our previous work (Khan et al 2007). Briefly, the sieved soil sample was added with Cd and Pb using the CdSO 4 and Pb(NO 3 ) 2 solutions at the following application rates (in milligrams per kilogram): (a) Cd as Cd 1 =1.5, Cd 2 =3, and Cd 3 =5; (b) Pb as Pb 1 =150, Pb 2 = 300, and Pb 3 =500; and (c) both Cd/Pb as Cd 1 /Pb 1 =1.5/ 150, Cd 2 /Pb 2 =3/300, and Cd 3 /Pb 3 =5/500g.…”

Section: Experimental Set Upmentioning

confidence: 99%

“…Soil biological characteristics are recognized as bioindicators of soil quality because they are more dynamic and more sensitive than the soil physicochemical properties (Brookes 1995;Hinojosa et al 2004). Previously, literature has revealed that both short-term and long-term exposures to heavy metals result in the reduction of soil microbial community diversity and activities (Lasat 2002;McGrath et al 2001;Khan et al 2007).…”

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confidence: 99%

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Effects of Cd and Pb on soil microbial community structure and activities

Khan

Hesham

Qiao

et al. 2009

Environ Sci Pollut Res

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329

132

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Background, aim, and scope Soil contamination with heavy metals occurs as a result of both anthropogenic and natural activities. Heavy metals could have long-term hazardous impacts on the health of soil ecosystems and adverse influences on soil biological processes. Soil enzymatic activities are recognized as sensors towards any natural and anthropogenic disturbance occurring in the soil ecosystem. Similarly, microbial biomass carbon (MBC) is also considered as one of the important soil biological activities frequently influenced by heavy metal contamination. The polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) has recently been used to investigate changes in soil microbial community composition in response to environmental stresses. Soil microbial community structure and activities are difficult to elucidate using single monitoring approach; therefore, for a better insight and complete depiction of the soil microbial situation, different approaches need to be used. This study was conducted in a greenhouse for a period of 12 weeks to evaluate the changes in indigenous microbial community structure and activities in the soil amended with different application rates of Cd, Pb, and Cd/Pb mix. In a field environment, soil is contaminated with single or mixed heavy metals; so that, in this research, we used the selected metals in both single and mixed forms at different application rates and investigated their toxic effects on microbial community structure and activities, using soil enzyme assays, plate counting, and advanced molecular DGGE technique. Soil microbial activities, including acid phosphatase (ACP), urease (URE), and MBC, and microbial community structure were studied. Materials and methods A soil sample (0-20 cm) with an unknown history of heavy metal contamination was collected and amended with Cd, Pb, and Cd/Pb mix using the CdSO 4 and Pb(NO 3 ) 2 solutions at different application rates. The amended soils were incubated in the greenhouse at 25±4°C and 60% water-holding capacity for 12 weeks. During the incubation period, samples were collected from each pot at 0, 2, 9, and 12 weeks for enzyme assays, MBC, numeration of microbes, and DNA extraction. Fumigationextraction method was used to measure the MBC, while plate counting techniques were used to numerate viable heterotrophic bacteria, fungi, and actinomycetes. Soil DNAs were extracted from the samples and used for DGGE analysis. Results ACP, URE, and MBC activities of microbial community were significantly lower (p <0.05) in the metal-amended samples than those in the control. The enzyme inhibition extent was obvious between different incubation periods and varied as the incubation proceeded, and the highest rate was detected in the samples after 2 weeks. However, the lowest values of ACP and URE activities (35.6% and 36.6% of the control, respectively) were found in the Cd 3 /Pb 3 -treated sample after 2 weeks. Similarly, MBC was strongly decreased in both Cd/Pbamended samples and highest reduction (52.4%) was Envir...

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Section: Discussionmentioning

confidence: 87%

Section: Experimental Set Upmentioning

confidence: 99%

mentioning

confidence: 99%

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Effects of Cd and Pb on soil microbial community structure and activities

Khan

Hesham

Qiao

et al. 2009

Environ Sci Pollut Res

Self Cite

329

132

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“…In previous studies, Winding et al (2005) reported that soil respiration is a good indicator to distinguish different soil types and land use management. Khan et al (2007) observed that soil respiration significantly reduced by organic and inorganic pollutants. In the present study, lower BSR but higher metabolic quotient (q-CO 2 ) values observed in R3 soil was in agreement with the above observations, which indicated pollution induced stress on soil microbial populations.…”

Section: Discussionmentioning

confidence: 97%

“…Soil microbial activity and diversity are highly sensitive to soil contamination by organic and inorganic pollutants, including heavy metals (Zhang et al 2010a, b;Thavamani et al 2012;Subrahmanyam et al 2014a). It was found that both short-term and long-term exposures to heavy metals resulted in the reduction of soil microbial activity and diversity (Khan et al 2007;Sheik et al 2012). Heavy metals adversely affect the activity and diversity of soil microbial communities associating with elemental cycling (Wang et al 2007;Subrahmanyam et al 2014a, c).…”

Section: Introductionmentioning

confidence: 99%

Effect of long-term industrial waste effluent pollution on soil enzyme activities and bacterial community composition

Subrahmanyam

Shen

Liu

et al. 2016

Environ Monit Assess

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Although numerous studies have addressed the influence of exogenous pollutants on microorganisms, the effect of long-term industrial waste effluent (IWE) pollution on the activity and diversity of soil bacteria was still unclear. Three soil samples characterized as uncontaminated (R1), moderately contaminated (R2), and highly contaminated (R3) receiving mixed organic and heavy metal pollutants for more than 20 years through IWE were collected along the Mahi River basin, Gujarat, western India. Basal soil respiration and in situ enzyme activities indicated an apparent deleterious effect of IWE on microbial activity and soil function. Community composition profiling of soil bacteria using 16S rRNA gene amplification and denaturing gradient gel electrophoresis (DGGE) method indicated an apparent bacterial community shift in the IWE-affected soils. Cloning and sequencing of DGGE bands revealed that the dominated bacterial phyla in polluted soil were affiliated with Firmicutes, Acidobacteria, and Actinobacteria, indicating that these bacterial phyla may have a high tolerance to pollutants. We suggested that specific bacterial phyla along with soil enzyme activities could be used as relevant biological indicators for longterm pollution assessment on soil quality.

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