2024
Pacwa-Płociniczak, M.; Kumor, A.; Bukowczan, M.; Sinkkonen, A.; Roslund, M. I.; Płociniczak, T.
The potential of enhanced phytoremediation to clean up multi-contaminated soil – insights from metatranscriptomics Journal Article
In: Microbiological Research, vol. 284, 2024, ISSN: 09445013.
@article{2-s2.0-85191660822,
title = {The potential of enhanced phytoremediation to clean up multi-contaminated soil – insights from metatranscriptomics},
author = { M. Pacwa-Płociniczak and A. Kumor and M. Bukowczan and A. Sinkkonen and M.I. Roslund and T. Płociniczak},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85191660822&doi=10.1016%2fj.micres.2024.127738&partnerID=40&md5=8cf241c76fa93518298378a353af22cc},
doi = {10.1016/j.micres.2024.127738},
issn = {09445013},
year = {2024},
date = {2024-01-01},
journal = {Microbiological Research},
volume = {284},
publisher = {Elsevier GmbH},
abstract = {This study aimed to (i) investigate the potential for enhanced phytoremediation to remove contaminants from soil historically co-contaminated with petroleum hydrocarbons (PHs) and heavy metals (HMs) and (ii) analyze the expression of crucial bacterial genes and whole metatranscriptomics profiles for better understanding of soil processes during applied treatment. Phytoremediation was performed using Zea mays and supported by the Pseudomonas qingdaonensis ZCR6 strain and a natural biofertilizer: meat and bone meal (MBM). In previous investigations, mechanisms supporting plant growth and PH degradation were described in the ZCR6 strain. Here, ZCR6 survived in the soil throughout the experiment, but the efficacy of PH removal from all soils fertilized with MBM reached 32 % regardless of the bacterial inoculation. All experimental groups contained 2 % (w/w) MBM. The toxic effect of this amendment on plants was detected 30 days after germination, irrespective of ZCR6 inoculation. Among the 17 genes tested using the qPCR method, only expression of the acdS gene, encoding 1-aminocyclopropane-1-carboxylic acid deaminase, and the CYP153 gene, encoding cytochrome P450-type alkane hydroxylase, was detected in soils. Metatranscriptomic analysis of soils indicated increased expression of methane particulated ammonia monooxygenase subunit A (pmoA-amoA) by Nitrosomonadales bacteria in all soils enriched with MBM compared to the non-fertilized control. We suggest that the addition of 2 % (w/w) MBM caused the toxic effect on plants via the rapid release of ammonia, and this led to high pmoA-amoA expression. In parallel, due to its wide substrate specificity, enhanced bacterial hydrocarbon removal in MBM-treated soils was observed. The metatranscriptomic results indicate that MBM application should be considered to improve bioremediation of soils polluted with PHs rather than phytoremediation. However, lower concentrations of MBM could be considered for phytoremediation enhancement. From a broader perspective, these results indicated the superior capability of metatranscriptomics to investigate the microbial mechanisms driving various bioremediation techniques. © 2024 Elsevier GmbH},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This study aimed to (i) investigate the potential for enhanced phytoremediation to remove contaminants from soil historically co-contaminated with petroleum hydrocarbons (PHs) and heavy metals (HMs) and (ii) analyze the expression of crucial bacterial genes and whole metatranscriptomics profiles for better understanding of soil processes during applied treatment. Phytoremediation was performed using Zea mays and supported by the Pseudomonas qingdaonensis ZCR6 strain and a natural biofertilizer: meat and bone meal (MBM). In previous investigations, mechanisms supporting plant growth and PH degradation were described in the ZCR6 strain. Here, ZCR6 survived in the soil throughout the experiment, but the efficacy of PH removal from all soils fertilized with MBM reached 32 % regardless of the bacterial inoculation. All experimental groups contained 2 % (w/w) MBM. The toxic effect of this amendment on plants was detected 30 days after germination, irrespective of ZCR6 inoculation. Among the 17 genes tested using the qPCR method, only expression of the acdS gene, encoding 1-aminocyclopropane-1-carboxylic acid deaminase, and the CYP153 gene, encoding cytochrome P450-type alkane hydroxylase, was detected in soils. Metatranscriptomic analysis of soils indicated increased expression of methane particulated ammonia monooxygenase subunit A (pmoA-amoA) by Nitrosomonadales bacteria in all soils enriched with MBM compared to the non-fertilized control. We suggest that the addition of 2 % (w/w) MBM caused the toxic effect on plants via the rapid release of ammonia, and this led to high pmoA-amoA expression. In parallel, due to its wide substrate specificity, enhanced bacterial hydrocarbon removal in MBM-treated soils was observed. The metatranscriptomic results indicate that MBM application should be considered to improve bioremediation of soils polluted with PHs rather than phytoremediation. However, lower concentrations of MBM could be considered for phytoremediation enhancement. From a broader perspective, these results indicated the superior capability of metatranscriptomics to investigate the microbial mechanisms driving various bioremediation techniques. © 2024 Elsevier GmbH
2018
Pacwa-Płociniczak, M.; Płociniczak, T.; Yu, D.; Kurola, J. M.; Sinkkonen, A.; Piotrowska-Seget, Z.; Romantschuk, M.
Effect of Silene vulgaris and Heavy Metal Pollution on Soil Microbial Diversity in Long-Term Contaminated Soil Journal Article
In: Water, Air, and Soil Pollution, vol. 229, no. 1, 2018, ISSN: 00496979, (34).
@article{2-s2.0-85040236045,
title = {Effect of Silene vulgaris and Heavy Metal Pollution on Soil Microbial Diversity in Long-Term Contaminated Soil},
author = { M. Pacwa-Płociniczak and T. Płociniczak and D. Yu and J.M. Kurola and A. Sinkkonen and Z. Piotrowska-Seget and M. Romantschuk},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040236045&doi=10.1007%2fs11270-017-3655-3&partnerID=40&md5=c3554399dc403e2252677ae08796fad4},
doi = {10.1007/s11270-017-3655-3},
issn = {00496979},
year = {2018},
date = {2018-01-01},
journal = {Water, Air, and Soil Pollution},
volume = {229},
number = {1},
publisher = {Springer International Publishing},
abstract = {In this study, we analysed the impact of heavy metals and plant rhizodeposition on the structure of indigenous microbial communities in rhizosphere and bulk soil that had been exposed to heavy metals for more than 150 years. Samples of the rhizosphere of Silene vulgaris and non-rhizosphere soils 250 and 450 m from the source of emission that had different metal concentrations were collected for analyses. The results showed that soils were collected 250 m from the smelter had a higher number of Cd-resistant CFU compared with the samples that were collected from 450 m, but no significant differences were observed in the number of total and oligotrophic CFU or the equivalent cell numbers between rhizosphere and non-rhizosphere soils that were taken 250 and 450 m from the emitter. Unweighted pair group method with arithmetic mean (UPGMA) cluster analysis of the denaturing gradient gel electrophoresis (DGGE) profiles, as well as a cluster analysis that was generated on the phospholipid fatty acid (PLFA) profiles, showed that the bacterial community structure of rhizosphere soils depended more on the plant than on the distance and metal concentrations. The sequencing of the 16S rDNA fragments that were excised from the DGGE gel revealed representatives of the phyla Bacteroidetes, Acidobacteria, Gemmatimonadetes, Actinobacteria and Betaproteobacteria in the analysed soil with a predominance of the first three groups. The obtained results demonstrated that the presence of S. vulgaris did not affect the number of CFUs, except for those of Cd-resistant bacteria. However, the presence of S. vulgaris altered the soil bacterial community structure, regardless of the sampling site, which supported the thesis that plants have a higher impact on soil microbial community than metal contamination. © 2017, The Author(s).},
note = {34},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this study, we analysed the impact of heavy metals and plant rhizodeposition on the structure of indigenous microbial communities in rhizosphere and bulk soil that had been exposed to heavy metals for more than 150 years. Samples of the rhizosphere of Silene vulgaris and non-rhizosphere soils 250 and 450 m from the source of emission that had different metal concentrations were collected for analyses. The results showed that soils were collected 250 m from the smelter had a higher number of Cd-resistant CFU compared with the samples that were collected from 450 m, but no significant differences were observed in the number of total and oligotrophic CFU or the equivalent cell numbers between rhizosphere and non-rhizosphere soils that were taken 250 and 450 m from the emitter. Unweighted pair group method with arithmetic mean (UPGMA) cluster analysis of the denaturing gradient gel electrophoresis (DGGE) profiles, as well as a cluster analysis that was generated on the phospholipid fatty acid (PLFA) profiles, showed that the bacterial community structure of rhizosphere soils depended more on the plant than on the distance and metal concentrations. The sequencing of the 16S rDNA fragments that were excised from the DGGE gel revealed representatives of the phyla Bacteroidetes, Acidobacteria, Gemmatimonadetes, Actinobacteria and Betaproteobacteria in the analysed soil with a predominance of the first three groups. The obtained results demonstrated that the presence of S. vulgaris did not affect the number of CFUs, except for those of Cd-resistant bacteria. However, the presence of S. vulgaris altered the soil bacterial community structure, regardless of the sampling site, which supported the thesis that plants have a higher impact on soil microbial community than metal contamination. © 2017, The Author(s).
2017
Parajuli, A.; Grönroos, M.; Kauppi, S.; Płociniczak, T.; Roslund, M. I.; Galitskaya, P.; Laitinen, O. H.; Hyöty, H.; Jumpponen, A.; Strömmer, R.; Romantschuk, M.; Hui, N.; Sinkkonen, A.
The abundance of health-associated bacteria is altered in PAH polluted soils - Implications for health in urban areas? Journal Article
In: PLoS ONE, vol. 12, no. 11, 2017, ISSN: 19326203, (30).
@article{2-s2.0-85034604138,
title = {The abundance of health-associated bacteria is altered in PAH polluted soils - Implications for health in urban areas?},
author = { A. Parajuli and M. Grönroos and S. Kauppi and T. Płociniczak and M.I. Roslund and P. Galitskaya and O.H. Laitinen and H. Hyöty and A. Jumpponen and R. Strömmer and M. Romantschuk and N. Hui and A. Sinkkonen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85034604138&doi=10.1371%2fjournal.pone.0187852&partnerID=40&md5=daf04338cd62c181266837cb929913e3},
doi = {10.1371/journal.pone.0187852},
issn = {19326203},
year = {2017},
date = {2017-01-01},
journal = {PLoS ONE},
volume = {12},
number = {11},
publisher = {Public Library of Science},
abstract = {Long-term exposure to polyaromatic hydrocarbons (PAHs) has been connected to chronic human health disorders. It is also well-known that i) PAH contamination alters soil bacterial communities, ii) human microbiome is associated with environmental microbiome, and iii) alteration in the abundance of members in several bacterial phyla is associated with adverse or beneficial human health effects. We hypothesized that soil pollution by PAHs altered soil bacterial communities that had known associations with human health. The rationale behind our study was to increase understanding and potentially facilitate reconsidering factors that lead to health disorders in areas characterized by PAH contamination. Large containers filled with either spruce forest soil, pine forest soil, peat, or glacial sand were left to incubate or contaminated with creosote. Biological degradation of PAHs was monitored using GC-MS, and the bacterial community composition was analyzed using 454 pyrosequencing. Proteobacteria had higher and Actinobacteria and Bacteroidetes had lower relative abundance in creosote contaminated soils than in non-contaminated soils. Earlier studies have demonstrated that an increase in the abundance of Proteobacteria and decreased abundance of the phyla Actinobacteria and Bacteroidetes are particularly associated with adverse health outcomes and immunological disorders. Therefore, we propose that pollution-induced shifts in natural soil bacterial community, like in PAH-polluted areas, can contribute to the prevalence of chronic diseases. We encourage studies that simultaneously address the classic “adverse toxin effect” paradigm and our novel “altered environmental microbiome” hypothesis. © 2017 Parajuli et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.},
note = {30},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Long-term exposure to polyaromatic hydrocarbons (PAHs) has been connected to chronic human health disorders. It is also well-known that i) PAH contamination alters soil bacterial communities, ii) human microbiome is associated with environmental microbiome, and iii) alteration in the abundance of members in several bacterial phyla is associated with adverse or beneficial human health effects. We hypothesized that soil pollution by PAHs altered soil bacterial communities that had known associations with human health. The rationale behind our study was to increase understanding and potentially facilitate reconsidering factors that lead to health disorders in areas characterized by PAH contamination. Large containers filled with either spruce forest soil, pine forest soil, peat, or glacial sand were left to incubate or contaminated with creosote. Biological degradation of PAHs was monitored using GC-MS, and the bacterial community composition was analyzed using 454 pyrosequencing. Proteobacteria had higher and Actinobacteria and Bacteroidetes had lower relative abundance in creosote contaminated soils than in non-contaminated soils. Earlier studies have demonstrated that an increase in the abundance of Proteobacteria and decreased abundance of the phyla Actinobacteria and Bacteroidetes are particularly associated with adverse health outcomes and immunological disorders. Therefore, we propose that pollution-induced shifts in natural soil bacterial community, like in PAH-polluted areas, can contribute to the prevalence of chronic diseases. We encourage studies that simultaneously address the classic “adverse toxin effect” paradigm and our novel “altered environmental microbiome” hypothesis. © 2017 Parajuli et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
2016
Płociniczak, T.; Sinkkonen, A.; Romantschuk, M.; Sułowicz, S.; Piotrowska-Seget, Z.
Rhizospheric bacterial strain brevibacterium casei MH8a colonizes plant tissues and enhances Cd, Zn, Cu phytoextraction by white mustard Journal Article
In: Frontiers in Plant Science, vol. 7, no. FEB2016, 2016, ISSN: 1664462X, (38).
@article{2-s2.0-84960129136,
title = {Rhizospheric bacterial strain brevibacterium casei MH8a colonizes plant tissues and enhances Cd, Zn, Cu phytoextraction by white mustard},
author = { T. Płociniczak and A. Sinkkonen and M. Romantschuk and S. Sułowicz and Z. Piotrowska-Seget},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84960129136&doi=10.3389%2ffpls.2016.00101&partnerID=40&md5=e5f857a1ee07a62caa63d2653e3266aa},
doi = {10.3389/fpls.2016.00101},
issn = {1664462X},
year = {2016},
date = {2016-01-01},
journal = {Frontiers in Plant Science},
volume = {7},
number = {FEB2016},
publisher = {Frontiers Media S.A.},
abstract = {Environmental pollution by heavy metals has become a serious problem in the world. Phytoextraction, which is one of the plant-based technologies, has attracted the most attention for the bioremediation of soils polluted with these contaminants. The aim of this study was to determine whether the multiple-tolerant bacterium, Brevibacterium casei MH8a isolated from the heavy metal-contaminated rhizosphere soil of Sinapis alba L., is able to promote plant growth and enhance Cd, Zn, and Cu uptake by white mustard under laboratory conditions. Additionally, the ability of the rifampicin-resistant spontaneous mutant of MH8a to colonize plant tissues and its mechanisms of plant growth promotion were also examined. In order to assess the ecological consequences of bioaugmentation on autochthonous bacteria, the phospholipid fatty acid (PLFA) analysis was used. The MH8a strain exhibited the ability to produce ammonia, 1-amino-cyclopropane-1-carboxylic acid deaminase, indole 3-acetic acid and HCN but was not able to solubilize inorganic phosphate and produce siderophores. Introduction of MH8a into soil sigNificantly increaSed S. alba biomass and the accumulation of Cd (208%), Zn (86%), and Cu (39%) in plant shoots in comparison with those grown in non-inoculated soil. Introduced into the soil, MH8a was able to enter the plant and was found in the roots and leaves of inoculated plants thus indicating its endophytic features. PLFA analysis revealed that the MH8a that was introduced into soil had a temporary influence on the structure of the autochthonous bacterial communities. The plant growth-promoting features of the MH8a strain and its ability to enhance the metal uptake by white mustard and its long-term survival in soil as well as its temporary impact on autochthonous microorganisms make the strain a suitable candidate for the promotion of plant growth and the efficiency of phytoextraction. © 2016, Płociniczak, Sinkkonen, Romantschuk, Sułowicz and Piotrowska-Seget.},
note = {38},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Environmental pollution by heavy metals has become a serious problem in the world. Phytoextraction, which is one of the plant-based technologies, has attracted the most attention for the bioremediation of soils polluted with these contaminants. The aim of this study was to determine whether the multiple-tolerant bacterium, Brevibacterium casei MH8a isolated from the heavy metal-contaminated rhizosphere soil of Sinapis alba L., is able to promote plant growth and enhance Cd, Zn, and Cu uptake by white mustard under laboratory conditions. Additionally, the ability of the rifampicin-resistant spontaneous mutant of MH8a to colonize plant tissues and its mechanisms of plant growth promotion were also examined. In order to assess the ecological consequences of bioaugmentation on autochthonous bacteria, the phospholipid fatty acid (PLFA) analysis was used. The MH8a strain exhibited the ability to produce ammonia, 1-amino-cyclopropane-1-carboxylic acid deaminase, indole 3-acetic acid and HCN but was not able to solubilize inorganic phosphate and produce siderophores. Introduction of MH8a into soil sigNificantly increaSed S. alba biomass and the accumulation of Cd (208%), Zn (86%), and Cu (39%) in plant shoots in comparison with those grown in non-inoculated soil. Introduced into the soil, MH8a was able to enter the plant and was found in the roots and leaves of inoculated plants thus indicating its endophytic features. PLFA analysis revealed that the MH8a that was introduced into soil had a temporary influence on the structure of the autochthonous bacterial communities. The plant growth-promoting features of the MH8a strain and its ability to enhance the metal uptake by white mustard and its long-term survival in soil as well as its temporary impact on autochthonous microorganisms make the strain a suitable candidate for the promotion of plant growth and the efficiency of phytoextraction. © 2016, Płociniczak, Sinkkonen, Romantschuk, Sułowicz and Piotrowska-Seget.
2013
Sinkkonen, A.; Kauppi, S.; Pukkila, V.; Nan, H.; Płociniczak, T.; Kontro, M.; Strömmer, R.; Romantschuk, M.
Previous exposure advances the degradation of an anthropogenic s-triazine regardless of soil origin Journal Article
In: Journal of Soils and Sediments, vol. 13, no. 8, pp. 1430-1438, 2013, ISSN: 14390108, (10).
@article{2-s2.0-84881492403,
title = {Previous exposure advances the degradation of an anthropogenic s-triazine regardless of soil origin},
author = { A. Sinkkonen and S. Kauppi and V. Pukkila and H. Nan and T. Płociniczak and M. Kontro and R. Strömmer and M. Romantschuk},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84881492403&doi=10.1007%2fs11368-013-0742-y&partnerID=40&md5=ba682c40b00a106b5fee8ec28c23f2a5},
doi = {10.1007/s11368-013-0742-y},
issn = {14390108},
year = {2013},
date = {2013-01-01},
journal = {Journal of Soils and Sediments},
volume = {13},
number = {8},
pages = {1430-1438},
abstract = {Purpose: Previous investigations-field samplings and laboratory experiments-support the hypothesis that the degradation of s-triazines is enhanced in previously exposed as compared to pristine soils in terrestrial environments. Despite this, bottlenecks of soil sampling and various soil modification practices in microcosm studies have made it difficult to guarantee that previous contamination history enhances contaminant degradation regardless of soil origin in terrestrial ecosystems. We test the hypothesis that the degradation of simazine (2-chloro-4;6-bis(ethylamino)-s-triazine) is enhanced in previously exposed soils as compared to pristine soils in 10 l buckets at the mesocosm scale. Materials and methods: We collected soil at three separate sites consisting of a previously exposed and a pristine field. At every field, soil was collected at three separate plots and simazine degradation (days 0 and 65) and the response to atzB degrader gene primers (days 0 and 110) were followed. We analyzed the results using analysis of covariance (ANCOVA). Previous exposure and field site were assessed as fixed factors and initial simazine concentration and abiotic soil conditions as covariates. Results and discussion: After the 65-day exposure, remaining simazine concentrations depended on previous exposure but not on collection site. The response to atzB gene primers was positive in all mesocosms where simazine degradation had been rapid. Soil moisture, pH, and organic matter content were insignificant. If soil moisture was not included in the ANCOVA model, previous exposure did not appear as a significant factor. Conclusions: The results support the hypothesis that simazine is degraded more rapidly in previously exposed soils as compared to pristine environments, provided that degradation genes are available. Previously exposed soil might be used to enhance the degradation of simazine in recently contaminated terrestrial soils, supposing that the central requirements for microbial growth are adequate. © 2013 Springer-Verlag Berlin Heidelberg.},
note = {10},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Purpose: Previous investigations-field samplings and laboratory experiments-support the hypothesis that the degradation of s-triazines is enhanced in previously exposed as compared to pristine soils in terrestrial environments. Despite this, bottlenecks of soil sampling and various soil modification practices in microcosm studies have made it difficult to guarantee that previous contamination history enhances contaminant degradation regardless of soil origin in terrestrial ecosystems. We test the hypothesis that the degradation of simazine (2-chloro-4;6-bis(ethylamino)-s-triazine) is enhanced in previously exposed soils as compared to pristine soils in 10 l buckets at the mesocosm scale. Materials and methods: We collected soil at three separate sites consisting of a previously exposed and a pristine field. At every field, soil was collected at three separate plots and simazine degradation (days 0 and 65) and the response to atzB degrader gene primers (days 0 and 110) were followed. We analyzed the results using analysis of covariance (ANCOVA). Previous exposure and field site were assessed as fixed factors and initial simazine concentration and abiotic soil conditions as covariates. Results and discussion: After the 65-day exposure, remaining simazine concentrations depended on previous exposure but not on collection site. The response to atzB gene primers was positive in all mesocosms where simazine degradation had been rapid. Soil moisture, pH, and organic matter content were insignificant. If soil moisture was not included in the ANCOVA model, previous exposure did not appear as a significant factor. Conclusions: The results support the hypothesis that simazine is degraded more rapidly in previously exposed soils as compared to pristine environments, provided that degradation genes are available. Previously exposed soil might be used to enhance the degradation of simazine in recently contaminated terrestrial soils, supposing that the central requirements for microbial growth are adequate. © 2013 Springer-Verlag Berlin Heidelberg.
Płociniczak, T.; Sinkkonen, A.; Romantschuk, M.; Piotrowska-Seget, Z.
Characterization of Enterobacter intermedius MH8b and its use for the enhancement of heavy metals uptake by Sinapis alba L. Journal Article
In: Applied Soil Ecology, vol. 63, pp. 1-7, 2013, ISSN: 09291393, (47).
@article{2-s2.0-84871021485,
title = {Characterization of Enterobacter intermedius MH8b and its use for the enhancement of heavy metals uptake by Sinapis alba L.},
author = { T. Płociniczak and A. Sinkkonen and M. Romantschuk and Z. Piotrowska-Seget},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84871021485&doi=10.1016%2fj.apsoil.2012.09.009&partnerID=40&md5=9d1ed1c9a279c2356085e1ec5be702a4},
doi = {10.1016/j.apsoil.2012.09.009},
issn = {09291393},
year = {2013},
date = {2013-01-01},
journal = {Applied Soil Ecology},
volume = {63},
pages = {1-7},
abstract = {The aim of this study was to test whether the multiple-tolerant bacterium Enterobacter intermedius MH8b isolated from metal-contaminated soil is able to promote plant growth and enhance Zn, Cd and Cu uptake by Sinapis alba L. under laboratory conditions. Additionally, the mechanisms of the plant growth promotion and the ecological consequences of bioaugmentation were examined. MH8b exhibited the ability to produce 1-amino-cyclopropane-1-carboxylic acid deaminase, indole 3-acetic acid and hydrocyanic acid and was also able to solubilize inorganic phosphate. Soil inoculation with MH8b significantly increased plant biomass as well as the accumulation of Zn (32%) and Cd (94%) in plant shoots. DGGE and PLFA analysis revealed that the introduced MH8b had only a short-term influence on the structure of indigenous microbial communities. The plant growth-promoting properties of MH8b and its ability to increase the metal uptake connected with its long-term survival and its short-term impact on autochthonous microflora make the strain a good candidate for the promotion of plant growth and phytoremediation efficiency. © 2012 Elsevier B.V.},
note = {47},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The aim of this study was to test whether the multiple-tolerant bacterium Enterobacter intermedius MH8b isolated from metal-contaminated soil is able to promote plant growth and enhance Zn, Cd and Cu uptake by Sinapis alba L. under laboratory conditions. Additionally, the mechanisms of the plant growth promotion and the ecological consequences of bioaugmentation were examined. MH8b exhibited the ability to produce 1-amino-cyclopropane-1-carboxylic acid deaminase, indole 3-acetic acid and hydrocyanic acid and was also able to solubilize inorganic phosphate. Soil inoculation with MH8b significantly increased plant biomass as well as the accumulation of Zn (32%) and Cd (94%) in plant shoots. DGGE and PLFA analysis revealed that the introduced MH8b had only a short-term influence on the structure of indigenous microbial communities. The plant growth-promoting properties of MH8b and its ability to increase the metal uptake connected with its long-term survival and its short-term impact on autochthonous microflora make the strain a good candidate for the promotion of plant growth and phytoremediation efficiency. © 2012 Elsevier B.V.