Zearalenone degradation by two Pseudomonas strains from soil

Abstract

This study describes the screening of soil bacteria for their capability to degrade zearalenone (ZEN), employing an enrichment technique in which ZEN is used as the sole carbon source. Two isolates that were able to degrade ZEN belonged to the genus Pseudomonas according to biochemical characterization and 16S rRNA gene sequence and were named as Pseudomonas alcaliphila TH-C1 and Pseudomonas plecoglossicida TH-L1, respectively. The results showed that the degradation rates of P. alcaliphila TH-C1 and P. plecoglossicida TH-L1 for ZEN (2 μg/ml) were 68 ± 0.85 % and 57 ± 0.73%, when incubated for 72 h at 30 °C in a rotary shaker (160 rpm) and detected by high-performance liquid chromatograms (HPLC). These results suggest that the two Pseudomonas strains are new bacterial resource for degrading ZEN and can provide a new approach for the detoxification of ZEN.

Strategies and Methodologies for Developing Microbial Detoxification Systems to Mitigate Mycotoxins

“…A careful selection of environmental sources more likely to harbor MBMs should increase the probability of finding functional microorganisms. Previous studies have isolated microorganisms from a range of environmental [12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29], plant [30,31,32,33,34,35,36,37,38] and animal [39,40,41,42,43,44,45,46,47,48] sources.…”

“…It has been reported that DON, ZEA, PAT and CIT can be utilized as a sole carbon source and ultimately biotransformed by a number of microbial strains [13,15,18,23,24,26,27,29,32,41,54]. Due to the high cost and toxicity of many pure mycotoxins, chemically-related compounds may be substituted as the sole carbon source when screening for potential MBMs [25,46,55,56].…”

“…These may include light [18,54], phase contrast, bright field [59] and electron microscopy [12,16,57] to determine cell size, shape and Gram-stain type. Biochemical tests, such as carbon source utilization, enzyme activity and chemical sensitivities [18,19,27,33,38,45,46,50,58,59,81], as well as commercial identification systems, such as BIOLOG or API ® strips, may also be used for the identification of MBMs [12,21,35,60]. In addition, fatty acid and ribosomal protein profiles may be determined using gas chromatographic analysis of fatty acid methyl esters (GC-FAME) and matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) techniques, respectively [12,59].…”

“…For example, DON was extracted from mouldy corn with 84% acetonitrile (acetonitrile/water 84:16, v / v ) on a rocking platform at 60 RPM for two hours at room temperature [100] before HPLC analysis. ZEA was usually recovered by a mixture of water and methanol (50:50) [18,41] before HPLC analysis. Solvent extraction can be performed under regular shaking conditions or more efficiently with the aid of an ultrasonicator [18].…”

“…ZEA was usually recovered by a mixture of water and methanol (50:50) [18,41] before HPLC analysis. Solvent extraction can be performed under regular shaking conditions or more efficiently with the aid of an ultrasonicator [18]. Table 3 summarizes the solvents used during the extraction of various mycotoxins and can be used as a baseline to choose appropriate extraction solvents for the analysis of mycotoxins.…”