Details zur Publikation

Referenztyp Zeitschriften
DOI / URL Link
Titel (primär) Unraveling microbial turnover and non-extractable residues of bromoxynil in soil microcosms with 13C-isotope probing
Autor Nowak, K.M.; Telscher, M.; Seidel, E.; Miltner, A.;
Journal / Serie Environmental Pollution
Erscheinungsjahr 2018
Department UBT;
Band/Volume 242
Sprache englisch;
POF III (gesamt) T41;
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.
ID 20804
dauerhafte UFZ-Verlinkung 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