Mechanisms of Humic Acids Degradation by White Rot Fungi Explored Using 1H NMR Spectroscopy and FTICR Mass Spectrometry

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• 作者：Tzafrir Grinhut ; Norbert Hertkorn ; Philippe Schmitt-Kopplin ; Yitzhak Hadar ; Yona Chen
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：April 1, 2011
• 年：2011
• 卷：45
• 期：7
• 页码：2748-2754
• 全文大小：915K
• 年卷期：v.45,no.7(April 1, 2011)
• ISSN：1520-5851

文摘

Enzymatic activities involved in decay processes of natural aromatic macromolecules, such as humic acids (HA) and lignin by white rot fungi, have been widely investigated. However, the physical and chemical analysis of degradation products of these materials has not been intensively explored. Fourier transform cyclotron resonance mass spectrometry (FTICR MS) and ¹H NMR as well as CHNOS and size exclusion chromatography were employed to study the mechanisms of HA degradation by Trametes sp. M23 and Phanerochaete sp. Y6. Size exclusion chromatography analyses demonstrate and provide evidence for HA breakdown into low MW compounds. The ¹H NMR analysis revealed oxidation, a decrease in the aromatic content, and an indication of demethylation of the HA during biodegradation. Evidence for oxidation was also obtained using CHNOS. Analysis of FTICR MS results using a new software program developed by our group (David Mass Sort) revealed consecutive series of masses suggesting biochemical degradation trends such as oxidation, aromatic cleavage, and demethylation. These results are in agreement with the ¹H NMR analysis and with the suggested role of the ligninolytic system leading to HA degradation.