Degradation of forchlorfenuron by nitrification and denitrification reactions in the gut and shell biofilm of Limnoperna fortunei
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The capacity and mechanism of Limnoperna fortunei to reduce the concentration of forchlorfenuron [or 1-(2-chloropyridin-4-yl)-3-phenylurea (CPPU)] in water has been studied under laboratory conditions. Firstly, the evasive response of mussels to CPPU (10, 20, 40 and 60 mg L−1) was evaluated, and a toxicity test was carried out at these concentrations. Secondly, the effect of two different sizes of mussels on CPPU concentrations was investigated in a 24-day experiment. Thirdly, the role of intact mussels and valvae only were respectively evaluated in another 24-day experiment. The CPPU concentration decreased by about 40 % in the presence of large mussels and about 20 % in the presence of valvae only. Finally, nucleic acid extracts from the gut and biofilm microbial communities of L. fortunei were analyzed, and the number of copies of the bacterial genes amoA, nirK and nirS were determined. Based on these results, we propose possible mechanisms for CPPU degradation involving bacteria-associated nitrification and denitrification reactions. In summary, we found that the CPPU half-life depended on the presence of mussels, their size and their associated microorganisms.
KeywordsForchlorfenuron Limnoperna fortunei Microorganism Denitrification Nitrification Freshwater
The authors would like to acknowledge the financial support for this work provided by the National Natural Science Foundation of China (Grants No. 51378217 and No. U1360101), Guangdong Provincial Department of Science and Technology Department (No. 2012A010800006) and Guangdong Natural Science and Foundation (No. S2012020010887).
Conflict of Interest
The authors declare that they have no conflict of interest.
- Arima Y, Oshima K, Shudo K (1995) Evolution of a novel urea-type cytokinin: horticultural uses of forchlorfenuron. Acta Hortic 394:75–84Google Scholar
- Burlakova LE, Karatayev A, Padilla DK (2005) Functional changes in benthic freshwater communities after Dreissena Polymorpha (Pallas) invasion and consequences for filtration. In: The comparative roles of suspension-feeders in ecosystems. Springer, Dordrecht, pp 263-275Google Scholar
- Muyzer G, De Waal ED, Uitierlinden AG (1993) Profiling of complex microbial populations by denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified genes coding for 16S rRNA. Appl Environ Microbiol 59:695–700Google Scholar
- Suárez-Pantaleón C, Esteve-Turrillas FA, Mercader JV, Agulló C, Abad-Somovilla A, Abad-Fuentes A (2012) Development and validation of a direct competitive monoclonal antibody-based immunoassay for the sensitive and selective analysis of the phytoregulator forchlorfenuron. Anal Bioanal Chem 403:2019–2026CrossRefGoogle Scholar
- Svenningsen NB, Heisterkampb IM, Sigby-Clausena M, Larsena LH, Nielsena LP, Stiefb P, Schramma A (2012) Shell biofilm nitrification and gut denitrification contribute to emission of nitrous oxide by the invasive freshwater mussel Dreissena polymorpha (Zebra Mussel). Appl Environ Microbiol 78(12):4505–4509CrossRefGoogle Scholar
- Taylor JD, Layman M (1972) The mechanical properties of bivalve (Mollusca) shell structures. Paleontology 15(1):73–87Google Scholar
- United States Environmental Protection Agency (2004–2009) Pesticide fact sheet: forchlorfenuron [R/OL]. http://www.epa.gov/opprd001/factsheets/forchlorfenuron.pdf. Accessed 14 Sep 2011
- Zhang R, Cui B, Huang S (2014) Algae consumption and nitrate removal in raw water transport system by Limnoperna fortunei and its associated microorganisms. Water Environ Res (in press)Google Scholar
- Zumft WG (1997) Cell biology and molecular basis of denitrification. Microbiol Mol Biol Rev 61:533–616Google Scholar