Clementina Pozo | University of Granada (original) (raw)
Papers by Clementina Pozo
Applied Soil Ecology, Mar 1, 1998
The effects of Captan at rates of 2.0, 3.5, 5.0 and 10.0 kg ha y1 on microbial function were stud... more The effects of Captan at rates of 2.0, 3.5, 5.0 and 10.0 kg ha y1 on microbial function were studied in four agricultural soils under aerobic conditions. Parameters monitored included total culturable populations, numbers of aerobic N-fixing 2 bacteria, denitrifying bacteria, nitrifying bacteria and nitrogenase activity. Total culturable fungal populations, nitrifying bacteria, aerobic N-fixing bacteria and nitrogenase activity were significantly decreased at dose rates of 2.0 to 10.0 kg ha y1. 2 However, the presence of Captan enhanced denitrifying and total culturable bacteria, showing that some microbial groups can tolerate high doses of this fungicide. q 1998 Elsevier Science B.V.
Amino Acids, 1995
Interest of microbial production of amino acids has been increased greatly since development of b... more Interest of microbial production of amino acids has been increased greatly since development of biotechnological methods. These methods represent a perspective way applied in a future large-scale manufacture of inexpensive amino acids. In this context, the isolation of producing organisms that may be exploited in the desing of alternative methods for the production of amino acids could be of primary importance. In this review we will describe the liberation of amino acids (methionine, lysine, arginine, tryptophane and glutamic acid) by Azotobacter and Azospirillum during growth in culture media with different carbon sources under diazotrophic and adiazotrophic conditions. These organisms may be useful in developing new methods for the industrial production of amino acids.
Science of The Total Environment, Oct 1, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Applied Microbiology, Jun 1, 2002
A microorganism with the ability to release methionine from D,L-(2-methylthioethyl) hydantoin (st... more A microorganism with the ability to release methionine from D,L-(2-methylthioethyl) hydantoin (strain 245) was isolated from soil. The aim of this study was the identification of the strain and the adjustment of the conditions of growth and of the enzymatic reaction, in order to achieve high specific activities of bioconversion of the hydantoin. Methods and Results: Strain 245 was identified as Ochrobactrum anthropi. The strain grew at alkaline pH (up to 10AE0) and its hydantoinase activity was found to be inducible by the substrate D L D,L-(2-methylthioethyl) hydantoin. The enzyme is also alkalostable, with a pH optimum of 9AE0. Under these conditions, hydantoinase activity was significantly enhanced and its half life prolonged when 200 mmol l-1 ammonium and phosphate were added. The addition of Ca 2+ , Na + , Cu 2+ , Co 2+ , Mg 2+ , Zn 2+ or Fe 3+ (0AE5 mmol l-1) to the reaction mixture increased the hydantoinase activity of strain 245 up to tenfold after 24 h of incubation, compared with unamended controls. Conclusion: The adequate adjustment of some environmental parameters (pH, addition of inducer, presence of ammonium, phosphate, heavy metals and other ions) can considerably increase the D, L-hydantoinase activity of strain 245. Significance and Impact of the Study: The findings reported here set up the initial conditions for a further application of strain 245 in the production of methionine from hydantoine.
Ecotoxicology, Mar 1, 1994
A study was made of the effects of one selected acetanilide herbicide, alachlor, at concentration... more A study was made of the effects of one selected acetanilide herbicide, alachlor, at concentrations of 2.0-10.0 kg ha-' on bacterial populations, fungi, dinitrogen fixation bacteria, denitrifying bacteria, nitrifying bacteria, nitrogenase activity, acid and alkaline phosphatases, arylsulfatase and deshydrogenase. The presence of 2.0-10.0 kg ha-' of alachlor in the soil increased the total number of bacteria and fungi. The population of denitrifying bacteria increased significantly at concentrations of 5.0-10.0 kg ha-'. However, aerobic dinitrogen fixing bacteria and nitrogenase activity decreased at alachlor concentrations of 3.5-10.0 kg ha-'. Acid and alkaline phosphatases, arylsulfatase and dehydrogenase activity decreased significantly initially at concentrations of 5.0-10.0 kg ha-', but recovered to levels similar to those in the control. Nitrifying bacteria were not affected as a consequence of the addition of the herbicide to agricultural soil.
bioRxiv (Cold Spring Harbor Laboratory), May 23, 2023
Hydraulic retention time drives changes in energy production and the anodic microbiome of a micro... more Hydraulic retention time drives changes in energy production and the anodic microbiome of a microbial fuel cell (MFC)
Social Science Research Network, 2023
Environmental Toxicology and Chemistry, 1996
The effects of 10, 50, 100, 200, and 300 g simazine per gram of soil was studied under aerobic co... more The effects of 10, 50, 100, 200, and 300 g simazine per gram of soil was studied under aerobic conditions. Compared with control soil, the herbicide simazine did not affect bacterial populations, fungi, aerobic dinitrogen-fixing bacteria, denitrifying bacteria, and nitrogenase activity. However, nitrifying bacteria were decreased at concentrations of 50 to 300 g/g. The negative effects observed on nitrifying bacteria in soil amended with simazine were particularly evident after a second application of herbicide, showing that these microorganisms cannot tolerate certain concentrations of simazine.
Journal of Microbiology and Biotechnology, May 1, 2007
Amino Acids, Sep 22, 2004
Five strains of Rhizobium spp, one strain of Mesorhizobium loti and two strains of Sinorhizobium ... more Five strains of Rhizobium spp, one strain of Mesorhizobium loti and two strains of Sinorhizobium meliloti were tested for their ability to grow in chemically-defined medium lacking growth factor. Qualitative and quantitative production of aspartic acid, serine, glutamic acid, glycine, histidine, threonine, arginine, alanine, proline, cysteine, tyrosine, valine, methionine, lysine, isoleucine, leucine, and phenylalanine was determined by the use of mannitol as sole carbon source. Strains of Rhizobium spp. and Sinorhizobium sp. produced all the amino acids analysed with the exception of cysteine and high biological levels of serine, glycine and alanine were detected after 2 days of culture in mineral medium. Strain U226 of M. loti only produced small amounts of amino acids and glutamic acid, histidine, arginine, cysteine, methionine, lysine and phenylalanine was not liberated into the media.
Science of The Total Environment, Jul 1, 2021
Abstract The Aznalcollar accident, which occurred in 1998, spilled 36 × 105 m3 of pyritic sludge ... more Abstract The Aznalcollar accident, which occurred in 1998, spilled 36 × 105 m3 of pyritic sludge and 9 × 105 m3 of acidic water around an area of 43 km2 in the south of Spain. This spill is considered one of the most important metal-mining associated accidents worldwide. In this study, two soil remediation techniques were evaluated: the addition of marble sludge (liming treatment, LS) and the mixing of recovered soils (RC) with contaminated soils (CT) (biopile treatment, BS). Both LS and BS significantly reduce the solubility of Cu, Zn, As, and Pb mainly due to the increase in pH and organic matter content, respectively. Soil basal respiration rate and the seed germination and root elongation bioassay with Lactuca sativa were used to evaluate the toxicity of the potential pollution in the sampled soils. Both bioassays showed that the CT soils exhibited the highest toxicity with a significant reduction in the toxicity of the amended soils (LS and BS). The abundance and structure of microbial communities in the soils were determined by qPCR and Illumina 16S rRNA sequencing, respectively. The absolute abundances of total bacterial and archaeal populations, ammonium oxidising bacteria, and denitrifiers in the CT soils were statistically lower than these found in the other three soils. Similarly, the structure of the bacterial community was highly different in the CT soils. Our results underline the persistence of the detrimental effect of pollutants in CT soils compared to the recuperated (RC) and amended soils (LS and BS). We also highlight the uses of liming or biopile as remediation techniques as satisfactory tools to reduce the impact of heavy metals in the contaminated Aznalcollar soils.
Environmental Toxicology and Chemistry, Jul 1, 1996
Environmental Toxicology and Chemistry, Vol. 15, No. 7, pp. 11151118, 1996 ... 1996 SETAC Printe... more Environmental Toxicology and Chemistry, Vol. 15, No. 7, pp. 11151118, 1996 ... 1996 SETAC Printed in the USA 0730-7268/96 $6.00 .00 ... STUDIES ON THE EFFECTS OF THE HERBICIDE SIMAZINE ON MICROFLORA OF FOUR AGRICULTURAL SOILS
Journal of environmental chemical engineering, Aug 1, 2021
Abstract The goal of this research was to study the operation of an integrated fixed-film activat... more Abstract The goal of this research was to study the operation of an integrated fixed-film activated sludge system (IFAS), in anaerobic/anoxic/aerobic (A2O) configuration for the elimination of emerging pollutants, in particular of 27 pharmaceutical active compounds (PhACs) (eight anti-inflammatory and/or analgesic pharmaceuticals (AIAPs), six antibiotics, four b-blockers, two antihypertensives/diuretics, three lipid regulators-bezafibrate and four psychiatric medications). Different operational conditions were analyzed in the biological reactor, controlling at all times both the amount of suspended and fixed biomass present. The A2O-IFAS system has obtained similar or higher removal efficiency (RE) in the elimination of organic matter, and especially of nutrients, nitrogen (N) and phosphorous (P), with respect to the conventional A2O system, working however with very low values of the sludge retention time (SRT) (4.0 days) and mix liquid suspended solid (MLSS) in the reactor (1822 mg L-1). In general, conventional activated sludge (CAS) and IFAS processes show the importance of operating at high SRT and MLSS concentration, that give low food/microorganisms (F/M) ratio, to increase the RE of several PhACs. However, the A2O-IFAS system, operating with low mixed liquor SRT and MLSS has achieved similar or better RE of PhACs, obtaining the highest average REs values (>80%) for fenofibrate, acetaminophen, ibuprofen, naproxen, clarithromycin and atenolol. According to the results obtained, due to the affordable cost and well-demonstrated performance, IFAS systems become one of the most promising technology for conventional wastewater treatment plants (WWTP) upgrading.
Environmental Science and Pollution Research, May 30, 2009
Background, aim, and scope Linear alkylbenzene sulfonate (LAS) is the most used anionic surfactan... more Background, aim, and scope Linear alkylbenzene sulfonate (LAS) is the most used anionic surfactant in a worldwide scale and is considered a high-priority pollutant. LAS is regarded as a readily biodegradable product under aerobic conditions in aqueous media and is mostly removed in wastewater treatment plants, but an important fraction (20-25%) is immobilized in sewage sludge and persists under anoxic conditions. Due to the application of the sludge as a fertilizer, LAS reaches agricultural soil, and therefore, microbial toxicity tests have been widely used to evaluate the influence of LAS on soil microbial ecology. However, molecular-based community-level analyses have been seldom applied in studies regarding the effects of LAS on natural or engineered systems, and, to our knowledge, there are no reports of their use for such appraisals in agricultural soil. In this study, a microcosm system is used to evaluate the effects of a commercial mixture of LAS on the community structure of Alphaproteobacteria, Actinobacteria, and Acidobacteria in an agricultural soil. Material and methods The microcosms consisted of agricultural soil columns (800 g) fed with sterile water (8 ml h −1) added of different concentration of LAS (10 or 50 mg l −1) for periods of time up to 21 days. Sterile water was added to control columns for comparison. The structures of Alphaproteobacteria, Actinobacteria, and Acidobacteria communities were analyzed by a cultivation independent method (temperature gradient gel electrophoresis (TGGE) separation of polymerase chain reaction (PCR)-amplified partial 16S rRNA genes). Relevant populations were identified by subsequent reamplification, DNA sequencing, and database comparisons. Results Cluster analysis of the TGGE fingerprints taking into consideration both the number of bands and their relative intensities revealed that the structure of the Alphaproteobacteria community was significantly changed in the presence of LAS, at both concentrations tested. The average number of bands was significantly lower in the microcosms receiving 50 mg l −1 LAS and in the lower portion of soil cores. The clear differentiation of the samples of the upper portion of the soil columns amended with LAS was specifically related to the presence and intensity of a distinctive major band (named band class 7). There was a statistically significant positive correlation between the concentrations of LAS detected in soil portions taken from LAS 10 mg l −1 and LAS 50 mg l −1 microcosms and the relative intensity of band class 7 in the corresponding TGGE profiles. Prevalent Alphaproteobacteria populations in the soil microcosms had close similarity (>99%) to cultivated species affiliated to genera of the Rhizobiaceae, Methylocystaceae, Hyphomicrobiaceae, Rhodospirillaceae, Brucellaceae, Bradyrhizobiaceae, and Caulobacteraceae families. The population represented by band class 7 was found closely related to the genus
Journal of Fungi
Multi-contamination by organic pollutants and toxic metals is common in anthropogenic and industr... more Multi-contamination by organic pollutants and toxic metals is common in anthropogenic and industrial environments. In this study, the five fungal strains Chaetomium jodhpurense (MH667651.1), Chaetomium maderasense (MH665977.1), Paraconiothyrium variabile (MH667653.1), Emmia lacerata, and Phoma betae (MH667655.1), previously isolated in Tunisia, were investigated for the simultaneous removal and detoxification of phenanthrene (PHE) and benzo[a]anthracene (BAA), as well as heavy metals (HMs) (Cu, Zn, Pb and Ag) in Kirk’s media. The removal was analysed using HPLC, ultra-high performance liquid chromatography (UHPLC) coupled to a QToF mass spectrometer, transmission electron microscopy, and toxicology was assessed using phytotoxicity (Lepidium sativum seeds) and Microtox® (Allivibrio fisherii) assays. The PHE and BAA degradation rates, in free HMs cultures, reached 78.8% and 70.7%, respectively. However, the addition of HMs considerably affected the BAA degradation rate. The highest de...
Journal of Water Process Engineering
Science of The Total Environment, 2021
Abstract The Aznalcollar accident, which occurred in 1998, spilled 36 × 105 m3 of pyritic sludge ... more Abstract The Aznalcollar accident, which occurred in 1998, spilled 36 × 105 m3 of pyritic sludge and 9 × 105 m3 of acidic water around an area of 43 km2 in the south of Spain. This spill is considered one of the most important metal-mining associated accidents worldwide. In this study, two soil remediation techniques were evaluated: the addition of marble sludge (liming treatment, LS) and the mixing of recovered soils (RC) with contaminated soils (CT) (biopile treatment, BS). Both LS and BS significantly reduce the solubility of Cu, Zn, As, and Pb mainly due to the increase in pH and organic matter content, respectively. Soil basal respiration rate and the seed germination and root elongation bioassay with Lactuca sativa were used to evaluate the toxicity of the potential pollution in the sampled soils. Both bioassays showed that the CT soils exhibited the highest toxicity with a significant reduction in the toxicity of the amended soils (LS and BS). The abundance and structure of microbial communities in the soils were determined by qPCR and Illumina 16S rRNA sequencing, respectively. The absolute abundances of total bacterial and archaeal populations, ammonium oxidising bacteria, and denitrifiers in the CT soils were statistically lower than these found in the other three soils. Similarly, the structure of the bacterial community was highly different in the CT soils. Our results underline the persistence of the detrimental effect of pollutants in CT soils compared to the recuperated (RC) and amended soils (LS and BS). We also highlight the uses of liming or biopile as remediation techniques as satisfactory tools to reduce the impact of heavy metals in the contaminated Aznalcollar soils.
Science of The Total Environment, 2019
Biodegradation and toxicity reduction of nonylphenol, 4-tert-octylphenol and 2,4-dichlorophenol b... more Biodegradation and toxicity reduction of nonylphenol, 4-tert-octylphenol and 2,4-dichlorophenol by the ascomycetous fungus Thielavia sp HJ22: Identification of fungal metabolites and proposal of a putative pathway
Ecotoxicology and environmental safety, Jan 30, 2018
Four different laccase-producing strains were isolated from arid soils and used for bisphenol A (... more Four different laccase-producing strains were isolated from arid soils and used for bisphenol A (BPA) degradation. These strains were identified as Chaetomium strumarium G5I, Thielavia arenaria CH9, Thielavia arenaria HJ22 and Thielavia arenaria SM1(III) by internal transcribed spacer 5.8 S rDNA analysis. Residual BPA was evaluated by HPLC analysis during 48 h of incubation. A complete removal of BPA was observed by the whole cell fungal cultures within different times, depending on each strain. C. strumarium G5I was the most efficient degrader, showing 100% of removal within 8 h of incubation. The degradation of BPA was accompanied by the production of laccase and dye decolorizing peroxidase (DyP) under degradation conditions. The presence of aminobenzotriazole (ABT) as an inhibitor of cytochrome P450s monooxygenases (CYP) demonstrated a slight decrease in BPA removal rate, suggesting the effective contribution of CYP in the conversion. The great involvement of laccase in BPA trans...
Applied Soil Ecology, Mar 1, 1998
The effects of Captan at rates of 2.0, 3.5, 5.0 and 10.0 kg ha y1 on microbial function were stud... more The effects of Captan at rates of 2.0, 3.5, 5.0 and 10.0 kg ha y1 on microbial function were studied in four agricultural soils under aerobic conditions. Parameters monitored included total culturable populations, numbers of aerobic N-fixing 2 bacteria, denitrifying bacteria, nitrifying bacteria and nitrogenase activity. Total culturable fungal populations, nitrifying bacteria, aerobic N-fixing bacteria and nitrogenase activity were significantly decreased at dose rates of 2.0 to 10.0 kg ha y1. 2 However, the presence of Captan enhanced denitrifying and total culturable bacteria, showing that some microbial groups can tolerate high doses of this fungicide. q 1998 Elsevier Science B.V.
Amino Acids, 1995
Interest of microbial production of amino acids has been increased greatly since development of b... more Interest of microbial production of amino acids has been increased greatly since development of biotechnological methods. These methods represent a perspective way applied in a future large-scale manufacture of inexpensive amino acids. In this context, the isolation of producing organisms that may be exploited in the desing of alternative methods for the production of amino acids could be of primary importance. In this review we will describe the liberation of amino acids (methionine, lysine, arginine, tryptophane and glutamic acid) by Azotobacter and Azospirillum during growth in culture media with different carbon sources under diazotrophic and adiazotrophic conditions. These organisms may be useful in developing new methods for the industrial production of amino acids.
Science of The Total Environment, Oct 1, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Applied Microbiology, Jun 1, 2002
A microorganism with the ability to release methionine from D,L-(2-methylthioethyl) hydantoin (st... more A microorganism with the ability to release methionine from D,L-(2-methylthioethyl) hydantoin (strain 245) was isolated from soil. The aim of this study was the identification of the strain and the adjustment of the conditions of growth and of the enzymatic reaction, in order to achieve high specific activities of bioconversion of the hydantoin. Methods and Results: Strain 245 was identified as Ochrobactrum anthropi. The strain grew at alkaline pH (up to 10AE0) and its hydantoinase activity was found to be inducible by the substrate D L D,L-(2-methylthioethyl) hydantoin. The enzyme is also alkalostable, with a pH optimum of 9AE0. Under these conditions, hydantoinase activity was significantly enhanced and its half life prolonged when 200 mmol l-1 ammonium and phosphate were added. The addition of Ca 2+ , Na + , Cu 2+ , Co 2+ , Mg 2+ , Zn 2+ or Fe 3+ (0AE5 mmol l-1) to the reaction mixture increased the hydantoinase activity of strain 245 up to tenfold after 24 h of incubation, compared with unamended controls. Conclusion: The adequate adjustment of some environmental parameters (pH, addition of inducer, presence of ammonium, phosphate, heavy metals and other ions) can considerably increase the D, L-hydantoinase activity of strain 245. Significance and Impact of the Study: The findings reported here set up the initial conditions for a further application of strain 245 in the production of methionine from hydantoine.
Ecotoxicology, Mar 1, 1994
A study was made of the effects of one selected acetanilide herbicide, alachlor, at concentration... more A study was made of the effects of one selected acetanilide herbicide, alachlor, at concentrations of 2.0-10.0 kg ha-' on bacterial populations, fungi, dinitrogen fixation bacteria, denitrifying bacteria, nitrifying bacteria, nitrogenase activity, acid and alkaline phosphatases, arylsulfatase and deshydrogenase. The presence of 2.0-10.0 kg ha-' of alachlor in the soil increased the total number of bacteria and fungi. The population of denitrifying bacteria increased significantly at concentrations of 5.0-10.0 kg ha-'. However, aerobic dinitrogen fixing bacteria and nitrogenase activity decreased at alachlor concentrations of 3.5-10.0 kg ha-'. Acid and alkaline phosphatases, arylsulfatase and dehydrogenase activity decreased significantly initially at concentrations of 5.0-10.0 kg ha-', but recovered to levels similar to those in the control. Nitrifying bacteria were not affected as a consequence of the addition of the herbicide to agricultural soil.
bioRxiv (Cold Spring Harbor Laboratory), May 23, 2023
Hydraulic retention time drives changes in energy production and the anodic microbiome of a micro... more Hydraulic retention time drives changes in energy production and the anodic microbiome of a microbial fuel cell (MFC)
Social Science Research Network, 2023
Environmental Toxicology and Chemistry, 1996
The effects of 10, 50, 100, 200, and 300 g simazine per gram of soil was studied under aerobic co... more The effects of 10, 50, 100, 200, and 300 g simazine per gram of soil was studied under aerobic conditions. Compared with control soil, the herbicide simazine did not affect bacterial populations, fungi, aerobic dinitrogen-fixing bacteria, denitrifying bacteria, and nitrogenase activity. However, nitrifying bacteria were decreased at concentrations of 50 to 300 g/g. The negative effects observed on nitrifying bacteria in soil amended with simazine were particularly evident after a second application of herbicide, showing that these microorganisms cannot tolerate certain concentrations of simazine.
Journal of Microbiology and Biotechnology, May 1, 2007
Amino Acids, Sep 22, 2004
Five strains of Rhizobium spp, one strain of Mesorhizobium loti and two strains of Sinorhizobium ... more Five strains of Rhizobium spp, one strain of Mesorhizobium loti and two strains of Sinorhizobium meliloti were tested for their ability to grow in chemically-defined medium lacking growth factor. Qualitative and quantitative production of aspartic acid, serine, glutamic acid, glycine, histidine, threonine, arginine, alanine, proline, cysteine, tyrosine, valine, methionine, lysine, isoleucine, leucine, and phenylalanine was determined by the use of mannitol as sole carbon source. Strains of Rhizobium spp. and Sinorhizobium sp. produced all the amino acids analysed with the exception of cysteine and high biological levels of serine, glycine and alanine were detected after 2 days of culture in mineral medium. Strain U226 of M. loti only produced small amounts of amino acids and glutamic acid, histidine, arginine, cysteine, methionine, lysine and phenylalanine was not liberated into the media.
Science of The Total Environment, Jul 1, 2021
Abstract The Aznalcollar accident, which occurred in 1998, spilled 36 × 105 m3 of pyritic sludge ... more Abstract The Aznalcollar accident, which occurred in 1998, spilled 36 × 105 m3 of pyritic sludge and 9 × 105 m3 of acidic water around an area of 43 km2 in the south of Spain. This spill is considered one of the most important metal-mining associated accidents worldwide. In this study, two soil remediation techniques were evaluated: the addition of marble sludge (liming treatment, LS) and the mixing of recovered soils (RC) with contaminated soils (CT) (biopile treatment, BS). Both LS and BS significantly reduce the solubility of Cu, Zn, As, and Pb mainly due to the increase in pH and organic matter content, respectively. Soil basal respiration rate and the seed germination and root elongation bioassay with Lactuca sativa were used to evaluate the toxicity of the potential pollution in the sampled soils. Both bioassays showed that the CT soils exhibited the highest toxicity with a significant reduction in the toxicity of the amended soils (LS and BS). The abundance and structure of microbial communities in the soils were determined by qPCR and Illumina 16S rRNA sequencing, respectively. The absolute abundances of total bacterial and archaeal populations, ammonium oxidising bacteria, and denitrifiers in the CT soils were statistically lower than these found in the other three soils. Similarly, the structure of the bacterial community was highly different in the CT soils. Our results underline the persistence of the detrimental effect of pollutants in CT soils compared to the recuperated (RC) and amended soils (LS and BS). We also highlight the uses of liming or biopile as remediation techniques as satisfactory tools to reduce the impact of heavy metals in the contaminated Aznalcollar soils.
Environmental Toxicology and Chemistry, Jul 1, 1996
Environmental Toxicology and Chemistry, Vol. 15, No. 7, pp. 11151118, 1996 ... 1996 SETAC Printe... more Environmental Toxicology and Chemistry, Vol. 15, No. 7, pp. 11151118, 1996 ... 1996 SETAC Printed in the USA 0730-7268/96 $6.00 .00 ... STUDIES ON THE EFFECTS OF THE HERBICIDE SIMAZINE ON MICROFLORA OF FOUR AGRICULTURAL SOILS
Journal of environmental chemical engineering, Aug 1, 2021
Abstract The goal of this research was to study the operation of an integrated fixed-film activat... more Abstract The goal of this research was to study the operation of an integrated fixed-film activated sludge system (IFAS), in anaerobic/anoxic/aerobic (A2O) configuration for the elimination of emerging pollutants, in particular of 27 pharmaceutical active compounds (PhACs) (eight anti-inflammatory and/or analgesic pharmaceuticals (AIAPs), six antibiotics, four b-blockers, two antihypertensives/diuretics, three lipid regulators-bezafibrate and four psychiatric medications). Different operational conditions were analyzed in the biological reactor, controlling at all times both the amount of suspended and fixed biomass present. The A2O-IFAS system has obtained similar or higher removal efficiency (RE) in the elimination of organic matter, and especially of nutrients, nitrogen (N) and phosphorous (P), with respect to the conventional A2O system, working however with very low values of the sludge retention time (SRT) (4.0 days) and mix liquid suspended solid (MLSS) in the reactor (1822 mg L-1). In general, conventional activated sludge (CAS) and IFAS processes show the importance of operating at high SRT and MLSS concentration, that give low food/microorganisms (F/M) ratio, to increase the RE of several PhACs. However, the A2O-IFAS system, operating with low mixed liquor SRT and MLSS has achieved similar or better RE of PhACs, obtaining the highest average REs values (>80%) for fenofibrate, acetaminophen, ibuprofen, naproxen, clarithromycin and atenolol. According to the results obtained, due to the affordable cost and well-demonstrated performance, IFAS systems become one of the most promising technology for conventional wastewater treatment plants (WWTP) upgrading.
Environmental Science and Pollution Research, May 30, 2009
Background, aim, and scope Linear alkylbenzene sulfonate (LAS) is the most used anionic surfactan... more Background, aim, and scope Linear alkylbenzene sulfonate (LAS) is the most used anionic surfactant in a worldwide scale and is considered a high-priority pollutant. LAS is regarded as a readily biodegradable product under aerobic conditions in aqueous media and is mostly removed in wastewater treatment plants, but an important fraction (20-25%) is immobilized in sewage sludge and persists under anoxic conditions. Due to the application of the sludge as a fertilizer, LAS reaches agricultural soil, and therefore, microbial toxicity tests have been widely used to evaluate the influence of LAS on soil microbial ecology. However, molecular-based community-level analyses have been seldom applied in studies regarding the effects of LAS on natural or engineered systems, and, to our knowledge, there are no reports of their use for such appraisals in agricultural soil. In this study, a microcosm system is used to evaluate the effects of a commercial mixture of LAS on the community structure of Alphaproteobacteria, Actinobacteria, and Acidobacteria in an agricultural soil. Material and methods The microcosms consisted of agricultural soil columns (800 g) fed with sterile water (8 ml h −1) added of different concentration of LAS (10 or 50 mg l −1) for periods of time up to 21 days. Sterile water was added to control columns for comparison. The structures of Alphaproteobacteria, Actinobacteria, and Acidobacteria communities were analyzed by a cultivation independent method (temperature gradient gel electrophoresis (TGGE) separation of polymerase chain reaction (PCR)-amplified partial 16S rRNA genes). Relevant populations were identified by subsequent reamplification, DNA sequencing, and database comparisons. Results Cluster analysis of the TGGE fingerprints taking into consideration both the number of bands and their relative intensities revealed that the structure of the Alphaproteobacteria community was significantly changed in the presence of LAS, at both concentrations tested. The average number of bands was significantly lower in the microcosms receiving 50 mg l −1 LAS and in the lower portion of soil cores. The clear differentiation of the samples of the upper portion of the soil columns amended with LAS was specifically related to the presence and intensity of a distinctive major band (named band class 7). There was a statistically significant positive correlation between the concentrations of LAS detected in soil portions taken from LAS 10 mg l −1 and LAS 50 mg l −1 microcosms and the relative intensity of band class 7 in the corresponding TGGE profiles. Prevalent Alphaproteobacteria populations in the soil microcosms had close similarity (>99%) to cultivated species affiliated to genera of the Rhizobiaceae, Methylocystaceae, Hyphomicrobiaceae, Rhodospirillaceae, Brucellaceae, Bradyrhizobiaceae, and Caulobacteraceae families. The population represented by band class 7 was found closely related to the genus
Journal of Fungi
Multi-contamination by organic pollutants and toxic metals is common in anthropogenic and industr... more Multi-contamination by organic pollutants and toxic metals is common in anthropogenic and industrial environments. In this study, the five fungal strains Chaetomium jodhpurense (MH667651.1), Chaetomium maderasense (MH665977.1), Paraconiothyrium variabile (MH667653.1), Emmia lacerata, and Phoma betae (MH667655.1), previously isolated in Tunisia, were investigated for the simultaneous removal and detoxification of phenanthrene (PHE) and benzo[a]anthracene (BAA), as well as heavy metals (HMs) (Cu, Zn, Pb and Ag) in Kirk’s media. The removal was analysed using HPLC, ultra-high performance liquid chromatography (UHPLC) coupled to a QToF mass spectrometer, transmission electron microscopy, and toxicology was assessed using phytotoxicity (Lepidium sativum seeds) and Microtox® (Allivibrio fisherii) assays. The PHE and BAA degradation rates, in free HMs cultures, reached 78.8% and 70.7%, respectively. However, the addition of HMs considerably affected the BAA degradation rate. The highest de...
Journal of Water Process Engineering
Science of The Total Environment, 2021
Abstract The Aznalcollar accident, which occurred in 1998, spilled 36 × 105 m3 of pyritic sludge ... more Abstract The Aznalcollar accident, which occurred in 1998, spilled 36 × 105 m3 of pyritic sludge and 9 × 105 m3 of acidic water around an area of 43 km2 in the south of Spain. This spill is considered one of the most important metal-mining associated accidents worldwide. In this study, two soil remediation techniques were evaluated: the addition of marble sludge (liming treatment, LS) and the mixing of recovered soils (RC) with contaminated soils (CT) (biopile treatment, BS). Both LS and BS significantly reduce the solubility of Cu, Zn, As, and Pb mainly due to the increase in pH and organic matter content, respectively. Soil basal respiration rate and the seed germination and root elongation bioassay with Lactuca sativa were used to evaluate the toxicity of the potential pollution in the sampled soils. Both bioassays showed that the CT soils exhibited the highest toxicity with a significant reduction in the toxicity of the amended soils (LS and BS). The abundance and structure of microbial communities in the soils were determined by qPCR and Illumina 16S rRNA sequencing, respectively. The absolute abundances of total bacterial and archaeal populations, ammonium oxidising bacteria, and denitrifiers in the CT soils were statistically lower than these found in the other three soils. Similarly, the structure of the bacterial community was highly different in the CT soils. Our results underline the persistence of the detrimental effect of pollutants in CT soils compared to the recuperated (RC) and amended soils (LS and BS). We also highlight the uses of liming or biopile as remediation techniques as satisfactory tools to reduce the impact of heavy metals in the contaminated Aznalcollar soils.
Science of The Total Environment, 2019
Biodegradation and toxicity reduction of nonylphenol, 4-tert-octylphenol and 2,4-dichlorophenol b... more Biodegradation and toxicity reduction of nonylphenol, 4-tert-octylphenol and 2,4-dichlorophenol by the ascomycetous fungus Thielavia sp HJ22: Identification of fungal metabolites and proposal of a putative pathway
Ecotoxicology and environmental safety, Jan 30, 2018
Four different laccase-producing strains were isolated from arid soils and used for bisphenol A (... more Four different laccase-producing strains were isolated from arid soils and used for bisphenol A (BPA) degradation. These strains were identified as Chaetomium strumarium G5I, Thielavia arenaria CH9, Thielavia arenaria HJ22 and Thielavia arenaria SM1(III) by internal transcribed spacer 5.8 S rDNA analysis. Residual BPA was evaluated by HPLC analysis during 48 h of incubation. A complete removal of BPA was observed by the whole cell fungal cultures within different times, depending on each strain. C. strumarium G5I was the most efficient degrader, showing 100% of removal within 8 h of incubation. The degradation of BPA was accompanied by the production of laccase and dye decolorizing peroxidase (DyP) under degradation conditions. The presence of aminobenzotriazole (ABT) as an inhibitor of cytochrome P450s monooxygenases (CYP) demonstrated a slight decrease in BPA removal rate, suggesting the effective contribution of CYP in the conversion. The great involvement of laccase in BPA trans...