Tingwen Wang,Gang Yang,Kewei Chen,Muying Du,Zsolt Zalán,Ferenc Hegyi,Sameh Awad,Nassra Dabou,Amel Ahmed Ibrahim,Jianquan Kan
Patulin (PAT) is a neurotoxic fungal metabolite that commonly contaminates fruits and their derivatives, causing substantial economic loss and serious harm to human health. In this study, we screened a PAT-degrading yeast strain, Geotrichum candidum XG1, among 12 probiotic strains. It efficiently degraded 96.80 % of PAT (5 μg/mL) within 48 h in potato dextrose broth and completely degraded PAT in fresh apple juice. G. candidum XG1 degraded PAT mainly by secreting intracellular enzymes, which were induced by PAT, and the degradation rate increased with increasing induction time. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry identified ascladiol as a PAT degradation product that disappeared within 96 h. Notably, both G. candidum XG1 and its intracellular enzymes affected the quality of apple juice, and G. candidum XG1 enhanced the flavor of apple juice. Overall, these results highlight the potential of G. candidum XG1 to remove PAT from apple juice.
Gang Yang,Bin Li,Kewei Chen,Muying Du,Zsolt Zalán,Ferenc Hegyi,Jianquan Kan
Identifying aflatoxin-detoxifying probiotics remains a significant challenge in mitigating the risks associated with aflatoxin contamination in crops. Biological detoxification is a popular technique that reduces mycotoxin hazards and garners consumer acceptance. Through multiple rounds of screening and validation tests, Geotrichum candidum XG1 demonstrated the ability to degrade aflatoxin B 1 (AFB 1 ) by 99–100%, exceeding the capabilities of mere adsorption mechanisms. Notably, the degradation efficiency was demonstrably influenced by the presence of copper and iron ions in the liquid medium, suggesting a potential role for proteases in the degradation process. Subsequent validation experiments with red pepper revealed an 83% reduction in AFB 1 levels following fermentation with G. candidum XG1. Furthermore, mass spectrometry analysis confirmed the disruption of the AFB 1 furan ring structure, leading to a subsequent reduction in its toxicity. Collectively, these findings establish G. candidum XG1 as a promising candidate for effective aflatoxin degradation, with potential applications within the food industry.
Gang Yang,Xinrui Zhang,Muying Du,Kewei Chen,András Nagy,Krisztina Takács,Ferenc Hegyi,Amel Ahmed Ibrahim,Nassra Dabour,Sameh Awad,Zsolt Zalán,Jianquan Kan
Corn is highly susceptible to pathogen invasion, such as Aspergillus flavus , leading to aflatoxin contamination and posing a significant threat to food safety. Yeasts are widely applied in the food industry, and the use of yeasts for pathogen control as an alternative to physical and chemical methods has gained increasing attention. Previous studies have investigated the aflatoxin-degrading capability of Geotrichum candidum XG1 (an unconventional yeast), but its antifungal activity and application potential have not been explored. In this study, the antifungal activity of G. candidum XG1 was evaluated both in vitro and in vivo , and its impact on corn quality was investigated. The mechanisms and safety of the yeast were also further examined. The results indicated that G. candidum XG1 significantly inhibited A. flavus , reducing the fungus and aflatoxin contamination by over 90% on corn. A 75-day storage experiment assessing changes in corn color, starch, protein, fat, and fatty acid values revealed that G. candidum XG1 had minimal impact on corn quality. Compared to the control group (infected with A. flavus ), it significantly reduced the quality deterioration caused by A. flavus invasion. Gas chromatography-mass spectrometry (GC-MS) analysis identified phenylethyl alcohol as a key compound involved in the antifungal activity of the yeast. Phenylethyl alcohol inhibited A. flavus by affecting its cell morphology, energy metabolism, and defense systems. Safety evaluations, including whole-genome sequencing and animal trials, confirmed the safety of the strain. This study provides valuable insights into the application of antagonists like G. candidum XG1 for controlling pathogen in corn.
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