Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1016/j.envpol.2018.07.049 |
| Title (Primary) | Unraveling microbial turnover and non-extractable residues of bromoxynil in soil microcosms with 13C-isotope probing |
| Author | Nowak, K.M.; Telscher, M.; Seidel, E.; Miltner, A.
|
| Journal | Environmental Pollution |
| Year | 2018 |
| Department | UBT |
| Volume | 242 |
| Page From | 769 |
| Page To | 777 |
| Language | englisch |
| Keywords | Herbicide; Microbial activity; Biodegradation; Bound residues; Biogenic residues |
| Abstract | Bromoxynil is a widely used nitrile herbicide applied to maize and other cereals in many countries. To date, still little is known about bromoxynil turnover and the structural identity of bromoxynil non-extractable residues (NER) which are reported to occur in high amounts. Therefore, we investigated the microbial turnover of 13C-labeled bromoxynil for 32 days. A focus was laid on the estimation of biogenic NER based on the turnover of 13C into amino acids (AA). At the end, 25% of 13C6-bromoxynil equivalents were mineralized, 2% assigned to extractable residues and 72.5% to NER. Based on 12% in the 13C-total AA and an assumed share of AA of 50% in microbial biomass we arrived at 24% of total 13C-biogenic NER. About 33% of the total 13C-NER could thus be explained by 13C-biogenic NER; 67% was unknown and by definition xenobiotic NER with potential for toxicity. The 13C label from 13C6-bromoxynil was mainly detected in the humic acids (28.5%), but significant amounts were also found in non-humics (17.6%), fulvic acids (13.2%) and humins (12.7%). The 13C-total amino acids hydrolyzed from humic acids, humins and fulvic acids amounted to 5.2%, 6.1% and 1.2% of 13C6-bromoxynil equivalents, respectively, corresponding to total 13C-biogenic NER amounts of 10.4%, 12.2% and 2.4%. The humins contained mostly 13C-biogenic NER, whereas the humic and fulvic acids may be dominated by the xenobiotic NER. Due to the high proportion of unknown 13C-NER and particularly in the humic and fulvic acids, future studies should focus on the detailed characterization of these fractions. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=20804 |
| Nowak, K.M., Telscher, M., Seidel, E., Miltner, A. (2018): Unraveling microbial turnover and non-extractable residues of bromoxynil in soil microcosms with 13C-isotope probing Environ. Pollut. 242 , 769 - 777 |
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