Changes in bacterial diversity and catabolic gene abundance during the removal of dimethylphenol isomers in laboratory-scale constructed wetlands
Constructed wetlands (CWs) are well-established wastewater treatment technologies and applied for bioremediation of contaminated water. Despite the optimal performance of CWs, the understanding of the bacterial processes in the rhizosphere, where mainly microbial degradation processes take place, is still limited. In the present study, laboratory-scale CWs planted with Juncus effusus and running under controlled conditions were studied in order to evaluate removal efficiency of dimethylphenols (DMPs), also in comparison to an unplanted bed. Next to removal rates, the bacterial community structure, diversity, and distribution, their correlation with physiochemical parameters, and abundance of the phenol hydroxylase gene were determined. As a result, better removal performance of DMP isomers (3,4-, 3,5-, and 2,6-DMP added as singles compounds or in mixtures) and ammonium loads, together with a higher diversity index, bacterial number, and phenol hydroxylase gene abundance in Juncus effusus CW in comparison with the non-planted CW, indicates a clear rhizosphere effect in the experimental CWs. An enhancement in the DMP removal and the recovery of the phenol hydroxylase gene were found during the fed with the DMP mixture. In addition, the shift of bacterial community in CWs was found to be DMP isomer dependent. Positive correlations were found between the bacteria harboring the phenol hydroxylase gene and communities present with 3,4-DMP and 3,5-DMP isomers, but not with the community developed with 2,6-DMP. These results indicate that CWs are highly dynamic ecosystems with rapid changes in bacterial communities harboring functional catabolic genes.
KeywordsConstructed wetlands Xylenols Biodegradation Phenol hydroxylase Rhizosphere effect Bacterial community
We thank the Department of Environmental Microbiology-UFZ for the collaboration with the equipment for the community analysis. Special thanks to Uwe Kappelmeyer for his suggestions during the conception of the study, the critical reading with the improvements in the manuscript. We also thank Roisin Murtagh for the improvement of the English language. We would also like to thank Dr. Sabine Kleinsteuber and Dr. Athaydes Francisco Leite Junior for their support for script management for n-MDS analysis.
Mónica A. Vásquez Piñeros received sustaining grant for Doctoral studies from COLCIENCIAS Departamento de Ciencia, Tecnología e Innovación- República de Colombia
Compliance with ethical standards
Human and animal studies
This article does not contain any studies with human or animals performed by any of the authors.
Conflict of interest
The authors declare that they have no conflict of interest.
- Abdo Z, Schuette UM, Bent SJ, Williams CJ, Forney LJ, Joyce P (2006) Statistical methods for characterizing diversity of microbial communities by analysis of terminal restriction fragment length polymorphisms of 16S rRNA genes. Environ Microbiol 8(5):929–938. https://doi.org/10.1111/j.1462-2920.2005.00959.x CrossRefPubMedGoogle Scholar
- Adrados B, Sanchez O, Arias CA, Becares E, Garrido L, Mas J, Brix H, Morato J (2014) Microbial communities from different types of natural wastewater treatment systems: vertical and horizontal flow constructed wetlands and biofilters. Water Res 55:304–312. https://doi.org/10.1016/j.watres.2014.02.011 CrossRefPubMedGoogle Scholar
- Arenghi FL, Berlanda D, Galli E, Sello G, Barbieri P (2001b) Organization and regulation of meta cleavage pathway genes for toluene and o-xylene derivative degradation in Pseudomonas stutzeri OX1. Appl Environ Microbiol 67(7):3304–3308. https://doi.org/10.1128/AEM.67.7.3304-3308.2001 CrossRefPubMedPubMedCentralGoogle Scholar
- Chang JJ, Wu SQ, Liang K, Wu Z, Liang W (2015) Comparative study of microbial community structure in integrated vertical-flow constructed wetlands for treatment of domestic and nitrified wastewaters. Environ Sci Pollut Res Int 22(5):3518–3527. https://doi.org/10.1007/s11356-014-3594-0 CrossRefPubMedGoogle Scholar
- Chen Z, Kuschk P, Reiche N, Borsdorf H, Kastner M, Koser H (2012) Comparative evaluation of pilot scale horizontal subsurface-flow constructed wetlands and plant root mats for treating groundwater contaminated with benzene and MTBE. J Hazard Mater 209-210:510–515. https://doi.org/10.1016/j.jhazmat.2012.01.067 CrossRefPubMedGoogle Scholar
- Gkorezis P, Daghio M, Franzetti A, Van Hamme JD, Sillen W, Vangronsveld J (2016) The interaction between plants and bacteria in the remediation of petroleum hydrocarbons: an environmental perspective. Front Microbiol 7:1836. https://doi.org/10.3389/fmicb.2016.01836 CrossRefPubMedPubMedCentralGoogle Scholar
- Jeong JJ (2003) 3- and 4-alkylphenol degradation pathway in Pseudomonas sp. strain KL28: genetic organization of the lap gene cluster and substrate specificities of phenol hydroxylase and catechol 2,3-dioxygenase. Microbiology 149(11):3265–3277. https://doi.org/10.1099/mic.0.26628-0 CrossRefPubMedGoogle Scholar
- Kahru A, Pollumaa L, Reiman R, Ratsep A, Liiders M, Maloveryan A (2000) The toxicity and biodegradability of eight main phenolic compounds characteristic to the oil-shale industry wastewaters: a test battery approach. Environ Toxicol 15(5):431–442. https://doi.org/10.1002/1522-7278(2000)15:5<431::Aid-Tox11>3.0.Co;2-T CrossRefGoogle Scholar
- Long Y, Yi H, Chen S, Zhang Z, Cui K, Bing Y, Zhuo Q, Li B, Xie S, Guo Q (2016) Influences of plant type on bacterial and archaeal communities in constructed wetland treating polluted river water. Environ Sci Pollut Res Int 23(19):19570–19579. https://doi.org/10.1007/s11356-016-7166-3 CrossRefPubMedGoogle Scholar
- Marschner P, Crowley D, Yang CH (2004) Development of specific rhizosphere bacterial communities in relation to plant species, nutrition and soil type. Plant Soil 261(1–2):199–208. https://doi.org/10.1023/B:Plso.0000035569.80747.C5 CrossRefGoogle Scholar
- Mulling BT, Soeter AM, van der Geest HG, Admiraal W (2014) Changes in the planktonic microbial community during residence in a surface flow constructed wetland used for tertiary wastewater treatment. Sci Total Environ 466-467:881–887. https://doi.org/10.1016/j.scitotenv.2013.07.103 CrossRefPubMedGoogle Scholar
- Oksanen J, Blanchet FG, Kindt R, Legendre P, Minchin PR, O’Hara RB, Simpson GL, Solymos P, Stevens MHH, Wagner H (2015) Vegan: community ecology package. R package vegan, vers:2.2–2.1Google Scholar
- Rosenkranz F, Cabrol L, Carballa M, Donoso-Bravo A, Cruz L, Ruiz-Filippi G, Chamy R, Lema JM (2013) Relationship between phenol degradation efficiency and microbial community structure in an anaerobic SBR. Water Res 47(17):6739–6749. https://doi.org/10.1016/j.watres.2013.09.004 CrossRefPubMedGoogle Scholar
- Schultze-Nobre L, Wiessner A, Wang DD, Bartsch C, Kappelmeyer U, Paschke H, Mattusch J, Kuschk P (2015) Removal of dimethylphenols from an artificial wastewater in a laboratory-scale wetland system planted with Juncus effusus. Ecol Eng 80:151–155. https://doi.org/10.1016/j.ecoleng.2014.11.056 CrossRefGoogle Scholar
- Semple KT, Cain RB (1997) Degradation of phenol and its methylated homologues by Ochromonas danica. FEMS Microbiol Lett 152(1):133–139. https://doi.org/10.1111/j.1574-6968.1997.tb10419.x CrossRefGoogle Scholar
- Shi JY, Yuan XF, Lin HR, Yang YQ, Li ZY (2011) Differences in soil properties and bacterial communities between the rhizosphere and bulk soil and among different production areas of the medicinal plant Fritillaria thunbergii. Int J Mol Sci 12(6):3770–3785. https://doi.org/10.3390/ijms12063770 CrossRefPubMedPubMedCentralGoogle Scholar
- Stottmeister U, Wiessner A, Kuschk P, Kappelmeyer U, Kastner M, Bederski O, Muller RA, Moormann H (2003) Effects of plants and microorganisms in constructed wetlands for wastewater treatment. Biotechnol Adv 22(1–2):93–117. https://doi.org/10.1016/j.biotechadv.2003.08.010 CrossRefPubMedGoogle Scholar
- Vasquez-Pineros MA, Martinez-Lavanchy PM, Jehmlich N, Pieper DH, Rincon CA, Harms H, Junca H, Heipieper HJ (2018) Delftia sp. LCW, a strain isolated from a constructed wetland shows novel properties for dimethylphenol isomers degradation. BMC Microbiol 18(1):108. https://doi.org/10.1186/s12866-018-1255-z CrossRefPubMedPubMedCentralGoogle Scholar