Fungicide isopyrazam degradative response toward extrinsically added fungal and bacterial strains

• Published in: Journal of basic microbiology 2020-06, Vol.60 (6), p.484-493
• Main Authors: Ahmad, Khuram Shahzad, Gul, Palwasha
• Format: Article
• Language: English
• Subjects: bacteria; Bacteria - classification; Bacteria - metabolism; biodegradation; Biodegradation, Environmental; fungi; Fungi - classification; Fungi - metabolism; Fungicides, Industrial - chemistry; Fungicides, Industrial - metabolism; isopyrazam; Molecular Structure; Norbornanes - chemistry; Norbornanes - metabolism; pyrazole; Pyrazoles - chemistry; Pyrazoles - metabolism; Soil Microbiology; Species Specificity
• ISSN: 0233-111X; 1521-4028
• DOI: 10.1002/jobm.201900687

The current research is a pioneer in the evaluation of isopyrazam biodegradation, which has been performed utilizing soil‐isolated microbes. Biodisintegrative assays of pure fungal strains, namely Aspergillus flavus (AF), Penicillium chrysogenum (PC), Aspergillus niger (AN), Aspergillus terreus (AT), and Aspergillus fumigatus (AFu), and bacterial strains, namely Xanthomonas axonopodis (XA) and Pseudomonas syringae (PS), were utilized. Initial isopyrazam concentration (10 mg/L) was prepared with an individual microbial suspension and monitored for 35 days. Isopyrazam biotransformation was analyzed quantitatively and qualitatively by UV–visible spectrophotometery and gas chromatography–mass spectroscopy. P. syringae (R2 = 0.90) and X. axonopodis (R2 = 0.88) displayed maximal potential to metabolize the fungicide (86% and 80%, respectively) while forming intermediate metabolites, including 3‐difluoromethyl‐1‐methyl‐1H‐pyrazole‐4‐carboxylic acid ((S)‐9‐hydroxy‐9‐isopropyl‐1,2,3,4‐tetrahydro‐1,4‐methanonaphthalen‐5‐yl)‐amide, 3‐difluoromethyl‐1H‐pyrazole‐4‐carboxylic acid, and 3‐difluoromethyl‐1‐methyl‐1H‐pyrazole‐4‐amide. Isopyrazam degradation by all strains, AT, PC, AFu, AN, AF, XA, and PS, was found to be 11%, 18%, 21%, 21%, 18%, 30%, 80%, and 86%, respectively, after 35 days, elucidating the effectiveness of all the utilized strains in degrading isopyrazam at varying rates. The descending order of half‐lives (days) obtained is as follows: AT (56.8) > PC (44.7) > AFu (40.7) > AN (39.6) > AF (32.6) > XA (28.1) > PS (21) days. Current research can influence imperative and significant environment‐friendly bioremedial strategies for xenobiotic eradication from the ecological compartments.