Biodegradation of the Fungicide Iprodione by Zygosaccharomyces rouxii Strain DBVPG 6399

Abstract

Iprodione is a contact fungicide used to control several pathogens such as Botrytis cinerea, Monilia, and Sclerotinia. This paper reports the ability of an iprodione-resistant strain of Zygosaccharomyces rouxii to degrade iprodione at a concentration of 1 mg L(-1). The yeast Z. rouxii was chosen also for its ability to grow at high osmolarity. Also of note is that in bioremediation situations and in the food industry such resistance could be important. The kinetic and metabolic behaviors of the fungicide in the media are described. The results show a new transformation pathway of iprodione by the yeast leading to the formation of N-(3,5-dichlorophenyl)-2,4-dioxoimidazoline, 3-isopropylhydantoin, and 3,5-dichloroaniline. These compounds were identified by 1H NMR, 13C NMR, and GC-MS analyses. This study provides a basis to employ yeast strains in biodegradation studies in relation to their ability in the disappearance and degradation of xenobiotics into simpler molecules.

Blame It on the Metabolite: 3,5-Dichloroaniline Rather than the Parent Compound Is Responsible for the Decreasing Diversity and Function of Soil Microorganisms

“…S7). The limited formation of 3,5-DCA could be attributed either to the presence in the soil of a pool of efficient 3,5-DCA-degrading microorganisms, which actively degraded 3,5-DCA as soon as it was formed, keeping its levels low during the study, or to the operation of alternative metabolic pathways where 3,5-DCA does not constitute a major TP (27). Direct application of 3,5-DCA in soil B, at concentration levels equivalent to those formed in soil A upon application of 1, 10, and 100 times the recommended dose of iprodione, induced a significant reduction in nitrification activity, as determined by measurements of PN and NH 3 -N/NO 3…”

Snow cover has variable effects on persistence of fungicides and their suppression of microdochium patch on amenity turfgrass

“…The decline in iprodione residues coincided with prolonged soil and air temperatures greater than 0°C, suggesting that any such additional factors may be influenced by temperature. It is well established that both iprodione (Walker, 1987;Mercadier et al, 1997;Zadra et al, 2006) and chlorothalonil (Motonaga et al, 1998;Singh et al, 2002) are rapidly degraded by microorganisms in the soil. Less research has been conducted on phyllosphere impacts on fungicide persistence and the results of those studies have often been conflicting (Lukens & Ou, 1976;Frederick et al, 1996;Sigler et al, 2003).…”

“…and Zygosaccharomyces spp. have been identified as organisms that readily metabolize iprodione to its primary metabolite, 3,5-dichloroaniline (Mercadier et al, 1997;Zadra et al, 2006). A number of studies suggest that repeated applications of iprodione may lead to increased degradation rates in the soil, presumably due to the build-up of organisms that rapidly metabolize the parent compound (Walker, 1987;Mercadier et al, 1997;Garcia-Cazorla & Xirau-Vayreda, 1998).…”

Evolution of tebuconazole residues through the winemaking process of Mencía grapes

“…Reducing sugars were assayed by the 3,5-dinitrosalicylic acid (DNS) method (Bernfeld, 1951) with glucose as standard, and ethanol and glycerol were measured by a high-performance liquid chromatograph equipped with a RI-150 Spectra System refractive index detector (Thermo Separation Products) and a column model ION-300 (Transgenomic, San Jose, CA) eluted with 0.0085 M H 2 SO 4 at 35°C and a flow rate of 0.4 mL/min during 40 min. On the other hand, a 30 mL aliquot of the culture medium (experiments A 0 and C 0 ) was centrifuged to quantify free tebuconazole and tebuconazole degradation products in the supernatant, while the biomass was washed twice with water, re-suspended in 0.5 M CaCl 2 , incubated in an orbital shaker for 60 min at 200 rpm to extract the fungicide residues adsorbed on yeast cells, and centrifuged to obtain the supernatant for quantifying the adsorbed fungicide, according to Zadra and co-workers (Zadra, Cardinali, Corte, Fatichenti, & Marucchini, 2006). Free and adsorbed tebuconazole was directly analysed in LC-TQMS following the instrumental conditions described before.…”