Assessing the microbial activity of soil samples, its nutrient limitation and toxic effects of contaminants using a simple respiration test

doi:10.1016/S0045-6535(03)00556-3

Chemosphere

Volume 53, Issue 3, October 2003, Pages 269-275

https://doi.org/10.1016/S0045-6535(03)00556-3 Get rights and content

Abstract

Eight soil samples from five wells of a former gas plant site differing in the contamination with BTEX and PAHs as well as the nutrient content were investigated by soil respiration measurements. The basal, glucose as well as NH₄⁺ and PO₄³⁻ induced cumulative oxygen consumption and carbon dioxide production in 72 and 120 h were determined and additionally the maximal turnover rates and the limitation quotients were calculated. Without additional carbon source only one of five investigated samples was clearly nutrient limited. After glucose supplementation four of seven investigated samples showed nutrient limitation that was in accordance with the available ammonium and phosphorous content. BTEX and PAHs did not exhibit an inhibiting effect on the respiration rate. In contrast, BTEX containing samples exhibited the highest oxygen consumption indicating biodegradation of the contaminants. The results show that oxygen consumption and carbon dioxide production as well as the kinetic of these processes are all informative parameters characterizing the whole microbial respiration potential and their nutrient limitation in soil samples. Therefore this fast respirometric method can be used for the decision if further detailed studies of the bioremediation are useful and if nutrient supplementation is recommended to enhance natural attenuation.

Introduction

Among all remediation techniques available for contaminated sites, in situ bioremediation and natural attenuation is regarded as environmentally friendly because it preserves the soil structure and requires little energy input. In situ bioremediation usually relies on the stimulation and augmentation of the activity of indigenous microorganisms by supplying oxidants and nutrients in various compounds. However, implementation of bioremediation can only be performed if the sites fulfil a number of prerequisites such as accessibility of the site, absence of recalcitrant toxic compounds and the existence of degrading microorganisms. The experience during bioremediation of many contaminated sites showed that mostly microorganisms for mineralization of BTEX or hydrocarbons are available but the degradation activity is limited by the milieu parameters. Numerous studies have been published in which nitrogen and/or phosphorus addition stimulated pollutant degradation (Alexander, 1994; Bragg et al., 1994; Cleland et al., 1997; Breedveld and Sparrevik, 2000; Margesin et al., 2000). However, degradation rates have also been shown to be unaffected or decreased by nutrient addition (Morgan and Watkinson, 1992; Carmichael and Pfaender, 1997; Johnson and Scow, 1999).

Due to cost efficiency simple and fast methods are preferred to provide design criteria for an optimum bioremediation approach. Soil respiration measurements are used frequently as sensitive and easy analyzable microbial parameter for the characterization of soil samples. The respiration activity is close connected to other microbial parameters such as microbial biomass (Martens, 1995; Dilly, 2001). In addition, it is used for the assessment of ecotoxic effects in contaminated soils (Dott et al., 1995; Eisentraeger et al., 2000; Wilke et al., 2000). Hund and Schenk (1994) found a strong correlation between the quotient of the basal and substrate-induced respiration rate and the PAH concentration at a contaminated site during bioremediation. Margesin et al. (2000) used soil respiration as a monitoring instrument for the decontamination process of a mineral-oil-contaminated soil. In other studies hydrocarbon biodegradation rates could be calculated with a good accuracy from oxygen consumption and carbon dioxide formation (Baker et al., 2000; Miles and Doucette, 2001).

The aim of the study was to investigate if soil respiration measurements are useful for the first assessment if sufficient microbial activity is available and can be increased by nutrient addition or is depressed by toxic effects of contaminants at contaminated sites. Eight soil samples with different contamination level and different soil structure of a contaminated site were used to study the basal, substrate- and nutrient-induced respiration measuring oxygen consumption and carbon dioxide formation.

Section snippets

Study site and samples

The soil samples were received by drilling of five wells (W64–W70) distributed over the site “Testfeld Süd” that is located in the south-west of Germany in the Neckar valley. Till the 1970’s the gasworks produced city gas, thus, there is a contamination by products of coal gas and the following processes like tar distillation and gas washing. A heterogeneous contamination, consisting of aliphatic and aromatic hydrocarbons (BTEX, indane, indene, biphenyls, PAHs, etc.), heterocyclic aromatic

Characterisation of the soil samples

The physico-chemical data and bacterial counts of the soil samples are summarized in Table 1. The BTEX and PAH concentrations of the eight soil samples received from the drilling of five wells differed to a large extent (Table 1). Well 69 and 70 are not located within the plume and therefore the soils were only low polluted, although PAHs were found in the lower mg/kg range. The samples of well 64 contained mainly PAHs caused by the well position next to a former tar oil pit. Well 65 is located

Conclusions

The described fast and inexpensive respirometer tests enable an assessment of the available microbial activity and the nutrient limitation of soil samples. Oxygen consumption and carbon dioxide production are both informative parameters showing the whole microbial respiration activity and the comparison of both values gives hints of nitrifying processes or incomplete oxidation of carbon sources. In addition an inhibition of the microbial activity by the contaminants or even the degradation of

Acknowledgments

This paper represents a publication of the Priority Program 546 “Geochemical processes with long-term effects in anthropogenically affected seepage- and groundwater”. Financial support was provided by Deutsche Forschungsgemeinschaft. The authors wish to thank U. Kaufmann for his technical assistance as well as R. Güttes and A. Eisenträger for helpful discussion.

References (23)

K. Althoff et al.
Microcosms-experiments to assess the potential for natural attenuation of contaminated groundwater
Water Res.
(2001)
R.J. Baker et al.
Estimation of hydrocarbon biodegradation rates in gasoline-contaminated sediment from measured respiration rates
J. Contam. Hydrol.
(2000)
O. Dilly
Microbial respiratory quotient during basal metabolism and after glucose amendment in soils and litter
Soil Biol. Biochem.
(2001)
A. Eisentraeger et al.
A stepwise procedure for assessment of the microbial respiratory activity of soil samples contaminated with organic compounds
Ecotoxicol. Environ. Saf.
(2000)
K. Hund et al.
The microbial respiration quotient as indicator for bioremediation processes
Chemosphere
(1994)
C. Lutermann et al.
Combined modifier/in situ derivatization effects on supercritical fluid extraction of polycyclic aromatic hydrocarbons from soil
J. Chromatogr. A
(1998)
R. Margesin et al.
Monitoring of bioremediation by soil biological activities
Chemosphere
(2000)
R.A. Miles et al.
Assessing the aerobic biodegradability of 14 hydrocarbons in two soils using a simple microcosm/respiration method
Chemosphere
(2001)
P. Morgan et al.
Factors limiting the supply and efficiency of nutrient and oxygen supplements for the in situ biotreatment of contaminated soil and groundwater
Water Res.
(1992)
M.B. Müller et al.
Sample cleanup and reversed-phase high-performance liquid chromatographic analysis of polar aromatic compounds in groundwater samples from a former gas plant
J. Chromatogr. A
(1999)

D. Zamfirescu et al.

Occurrence and attenuation of specific organic compounds in the groundwater plume at a former gasworks site

J. Contam. Hydrol.

(2001)

Cited by (51)

Responsiveness change of biochemistry and micro-ecology in alkaline soil under PAHs contamination with or without heavy metal interaction
2020, Environmental Pollution
Co-presence of organic pollutants and heavy metals in soil is causing increasing concerns, but the lack of knowledge of relation between soil ecology and pollutant fate is limiting the developing of specific control strategy. This study investigated soil change under pyrene stress and its interaction with cadmium (Cd). Soil physicochemical properties were not seriously influenced. However, pollutants’ presence easily varied soil microbial activity, quantity, and diversity. Under high-level pyrene, Cd presence contributed to soil indigenous microorganisms’ adaption and soil microbial community structure stability. Soils with both pyrene and Cd presented 7.11–12.0% higher pyrene degradation compared with single pyrene treatment. High-throughput sequencing analysis indicated the proportion of Mycobacterium sp., a commonly known PAHs degrader, increased to 25.2–48.5% in treatments from 0.52% in control. This phenomenon was consistent with the increase of PAHs probable degraders (the ratio increased to 2.86–6.57% from 0.24% in control). Higher Cd bioavailability was also observed in soils with both pollutants than that with Cd alone. And Cd existence caused the elevation of Cd resistant bacterium Limnobacter sp. (increased to 12.2% in CdCK from 2.06% in control). Functional gene prediction also indicated that abundance of genes related to nutrient metabolism decreased dramatically with pollutants, while the abundances of energy metabolism, lipid metabolism, secondary metabolites biosynthesis-related genes increased (especially for aromatic compound degradation related genes). These results indicated the mutual effect and internal-interaction existed between pollutants and soils resulted in pollutants’ fate and soil microbial changes, providing further information regarding pollutants dissipation and transformation under soil microbial response.
Responses of soil fungal and archaeal communities to environmental factors in an ongoing antimony mine area
2019, Science of the Total Environment
Citation Excerpt :
A significant correlation between the basal respiration and the concentration of Sb by regression analysis revealed a high concentration of Sb stimulated soil basal respiration. Soil basal respiration is the sum of all metabolic processes that produce CO2 (Lu et al., 2013) and is accredited as an indirect indicator of total soil microbial activity (Hollender et al., 2003). As far as we know, the ecotoxicity of various heavy metals on soil microbial activity has been reported widely.
Microorganisms are vital to biogeochemical cycles. However, heavy metal contamination has been implicated in altering the microbial community. Antimony (Sb) and arsenic (As) in soils can alter soil bacterial community composition in previous studies and, therefore, may have effects on soil fungal and archaeal community composition. The aim of this study was to assess the microbial activity and fungal and archaeal community composition in long-term Sb and As contamination areas. We analyzed soil respiration rates from 247.91 μg C/kg SDW h to 1372.93 μg C/kg SDW h, which revealed a positive correlation with concentrations of antimony (r = 0.79). The microbial diversity indices (Shannon and Simpson indices) showed that the abundances of the fungal and archaeal communities were more sensitive to As. Redundancy analysis (RDA) revealed that soil properties and contamination are drivers controlling the fungal and archaeal community. All of these two microbial groups responded strongly to pH. However, the dominant drivers for fungal and archaeal community composition were very different. These differences were related to limiting conditions for different species, with fungal community composition affected strongly by pH, TC, TSb, RI and Sb_DGT, while archaeal community composition was mainly affected by the pH, As_DGT and TAs. Furthermore, soil respiration showed a very strong relationship with fungal community composition with r² = 0,60, p < 0.01. These results showed that microbial responses to contamination gradients of Sb and As were heterogeneous due to the limiting environmental conditions of different microbial taxa.
Long term effects of olive mill wastewaters application on soil properties and phenolic compounds migration under arid climate
2019, Agricultural Water Management
The principal objective of the present study has been to investigate the long term application effects of olive mill wastewaters (OMWW) on the main properties of a Mediterranean soil under arid climate. In addition the migration dynamic and evolution of phenolic compounds in the different soil layers over time and according to the OMWW amount added have been studied.
Results have showed that the irrigation of sandy soils by different doses of OMWW has influenced the soil physicochemical and microbiological characteristics. However, a slight change in the granulometric composition of soil treated with OMWW has been distinguished. The study of the phenolic compounds dynamic has showed the migration of these compounds further than 120 cm soil depth. The comparison of the different spectra obtained by the high pressure liquid chromatography (HPLC) technique has explained that the high molecular weight polyphenols which have been retained in the upper soil layers. However, the low molecular weight phenolic compounds have been detected in depth. All the results obtained have proved that the dose of 50 m³ ha⁻¹ has been the most suitable for the soil studied.
Agro-physiological and biochemical responses of Sorghum bicolor in soil amended by olive mill wastewater
2019, Agricultural Water Management
Produced in huge quantities, olive mill wastewater (OMW) causes serious environmental problems in the Mediterranean basin, where olive growing is concentrated.
The purpose of this study has been to evaluate the short term effects of various OMW quantities application on several Sorghum bicolor agro-physiological and biochemical parameters as well as the effects on the main properties of the amended soils. Four doses of OMW (25, 50, 75 and 100 m³ haˉ¹) have been applied in comparison to control soil not treated with OMW.
Results have showed an improvement of the organic matter, total nitrogen and minerals contents in soils treated with OMW proportionally to the increase of the doses applied. Moreover, soils microbiological activities have been strongly enhanced in comparison with control soil. Furthermore, the study of the effects of OMW on the Sorghum bicolor seeds germination has showed that raw OMW has blocked germination seeds. However, various effects on Sorghum bicolor seeds germination have been observed for the OMW amended soils extracts related to quantities applied. An improvement of the main agro-physiological and biochemical parameters as stems height, stems thickness, leaves number, leaves circumferences’, roots lengths, plant productivity, proteins content and essential minerals elements rates for the plants growing in soil treated with 25 m³ ha⁻¹ OMW dose has been reported. Nevertheless, clear inhibitions have been observed for the highest OMW doses applied as 75 and 100 m³ ha⁻¹.
Changes in the microbial community during bioremediation of gasoline-contaminated soil
2017, Brazilian Journal of Microbiology
We aimed to verify the changes in the microbial community during bioremediation of gasoline-contaminated soil. Microbial inoculants were produced from successive additions of gasoline to municipal solid waste compost (MSWC) previously fertilized with nitrogen-phosphorous. To obtain Inoculant A, fertilized MSWC was amended with gasoline every 3 days during 18 days. Inoculant B received the same application, but at every 6 days. Inoculant C included MSWC fertilized with N–P, but no gasoline. The inoculants were applied to gasoline-contaminated soil at 10, 30, or 50 g/kg. Mineralization of gasoline hydrocarbons in soil was evaluated by respirometric analysis. The viability of the inoculants was evaluated after 103 days of storage under refrigeration or room temperature. The relative proportions of microbial groups in the inoculants and soil were evaluated by FAME. The dose of 50 g/kg of inoculants A and B led to the largest CO₂ emission from soil. CO₂ emissions in treatments with inoculant C were inversely proportional to the dose of inoculant. Heterotrophic bacterial counts were greater in soil treated with inoculants A and B. The application of inoculants decreased the proportion of actinobacteria and increased of Gram-negative bacteria. Decline in the density of heterotrophic bacteria in inoculants occurred after storage. This reduction was bigger in inoculants stored at room temperature. The application of stored inoculants in gasoline-contaminated soil resulted in a CO₂ emission twice bigger than that observed in uninoculated soil. We concluded that MSWC is an effective material for the production of microbial inoculants for the bioremediation of gasoline-contaminated soil.
Limited recovery of soil microbial activity after transient exposure to gasoline vapors
2016, Environmental Pollution
Citation Excerpt :
The BTEX compounds (especially toluene and xylenes) were most abundant among the quantified analytes (Fig. 1). The highest average total BTEX concentration (0.13 g kg−1) was recorded for the G100 treatment towards the end of the passive dosing phase, whereas 8–14 fold higher BTEX levels have been recorded for field contaminated sites (Griffiths et al., 2001; Hollender et al., 2003). No hydrocarbons were detected in control soils (G0).
During gasoline spills complex mixtures of toxic volatile organic compounds (VOCs) are released to terrestrial environments. Gasoline VOCs exert baseline toxicity (narcosis) and may thus broadly affect soil biota. We assessed the functional resilience (i.e. resistance and recovery of microbial functions) in soil microbial communities transiently exposed to gasoline vapors by passive dosing via headspace for 40 days followed by a recovery phase of 84 days. Chemical exposure was characterized with GC-MS, whereas microbial activity was monitored as soil respiration (CO₂ release) and soil bacterial growth ([³H]leucine incorporation). Microbial activity was strongly stimulated and inhibited at low and high exposure levels, respectively. Microbial growth efficiency decreased with increasing exposure, but rebounded during the recovery phase for low-dose treatments. Although benzene, toluene, ethylbenzene and xylene (BTEX) concentrations decreased by 83–97% during the recovery phase, microbial activity in high-dose treatments did not recover and numbers of viable bacteria were 3–4 orders of magnitude lower than in control soil. Re-inoculation with active soil microorganisms failed to restore microbial activity indicating residual soil toxicity, which could not be attributed to BTEX, but rather to mixture toxicity of more persistent gasoline constituents or degradation products. Our results indicate a limited potential for functional recovery of soil microbial communities after transient exposure to high, but environmentally relevant, levels of gasoline VOCs which therefore may compromise ecosystem services provided by microorganisms even after extensive soil VOC dissipation.

View all citing articles on Scopus

View full text

Assessing the microbial activity of soil samples, its nutrient limitation and toxic effects of contaminants using a simple respiration test

Abstract

Introduction

Section snippets

Study site and samples

Characterisation of the soil samples

Conclusions

Acknowledgments

Water Res.

J. Contam. Hydrol.

Soil Biol. Biochem.

Ecotoxicol. Environ. Saf.

Chemosphere

J. Chromatogr. A

Chemosphere

Chemosphere

Water Res.

J. Chromatogr. A

J. Contam. Hydrol.