Comparison of Ameliorative Effects between Probiotic and Biodegradable Bacillus subtilis on Zearalenone Toxicosis in Gilts

Dietary administration of Bacillus subtilis improves the health parameters and regulates the gene expression in mice receiving zearalenone-contaminated diet

The biodegradation of mycotoxins has become a specific, efficient, and environmentally protective way to reduce the adverse effects of mycotoxins in both foods and feeds. In the current study, the effectiveness of dietary administration of Bacillus subtilis on health parameters and regulated gene expression in mice receiving zearalenone zearalenone-contaminated diet was explored. In this trial, a total of twenty-four white balb/c mice were randomly assigned to three treatments. Dietary treatments were as follows: T1: The control (fed non-zearalenone-contaminated diet), T2: fed zearalenone-contaminated diet, T3: fed zearalenone-contaminated diet + Bacillus subtilis ARKA-S-3 (1 × 109 cfu/kg) for 28 days. The results showed, B. subtilis notably degraded zearalenone in cultured media during 18 h incubation (p < 0.05). It significantly improved average daily weight gain and feed intake. Dietary B. subtilis notably reduced the adverse effects of zearalenone on serum antioxidant indices (GSH-Px, SOD, ) and saved mice from oxidative stress. Also, treatments with B. subtilis improved morphometric characteristics of the ileum ((Villus Height (µm), Villus Width (µm), and Crypt Depth (µm)) in the mice received zearalenone-contaminated diet (p < 0.05). The molecular analysis illustrated that B. subtilis has also improved the mRNA expression levels and antioxidant-related gene expression of SOD and CAT in the jejunum tissue. Moreover, it alleviated the IL-2 and IFN-γ gene profiling in the jejunum tissue. These findings illustrate that dietary administration of B. subtilis by having a degraded effect on zearalenone, possesses a protective effect on the health parameters and gene expression regulation in mice receiving a zearalenone-contaminated diet.

Enhanced glutathione production protects against zearalenone-induced oxidative stress and ferroptosis in female reproductive system

Zearalenone (ZEN, a widespread fusarium mycotoxin) causes evoked oxidative stress in reproductive system, but little is known about whether this is involved in ferroptosis. Melatonin, a well-known antioxidant, has demonstrated unique anti-antioxidant properties in several studies. Here, this study was aimed to investigate whether ZEN-induced oxidative stress in female pig's reproductive system was involved in ferroptosis, and melatonin was then supplemented to protect against ZEN-induced abnormalities in vitro cell models [human granulosa cell (KGN) and mouse endometrial stromal cell (mEC)] and in vivo mouse model. According to the results from female pig's reproductive organs, ZEN-induced abnormalities in vulvar swelling, inflammatory invasion and pathological mitochondria, were closely linked with evoked oxidative stress. Using RNA-seq analysis, we further revealed that ZEN-induced reproductive toxicity was due to activated ferroptosis. Mechanistically, by using in vitro cell models (KGN and mEC) and in vivo mouse model, we observed that ZEN exposure resulted in oxidative stress and ferroptosis in a glutathione-dependent manner. Notably, these ZEN-induced abnormalities above were alleviated by melatonin supplementation through enhanced productions of glutathione peroxidase 4 and glutathione. Herein, the present results suggest that potential strategies to improve glutathione production protect against ZEN-induced reproductive toxicity, including oxidative stress and ferroptosis.

Characterization, Structural Analysis, and Thermal Stability Mutation of a New Zearalenone-Degrading Enzyme Mined from Bacillus subtilis

Zearalenone (ZEN) is a widespread mycotoxin that causes serious damage to animal husbandry and poses a threat to human health. A screen of ZEN-degrading soil bacteria yielded Bacillus subtilis YT-4, which yielded 80% ZEN degradation after 6 h and 95% after 36 h. The gene sequence encoding the degradative enzyme ZENY was mined from the genome of YT-4 and expressed in yeast. ZENY is an α/β-hydrolase with an optimal enzyme activity at 37 °C and pH 8. By breaking the lactone ring of ZEN, it produces ZENY-C18H24O5 with a molecular weight of 320.16 g/mol. Sequence comparison and molecular docking analyses identified the catalytic ZENY triad 99S-245H-123E and the primary ZEN-binding mode within the hydrophobic pocket of the enzyme. To improve the thermal stability of the enzyme for industrial applications, we introduced a mutation at the N-terminus, specifically replacing the fifth residue N with V, and achieved a 25% improvement in stability at 45 °C. These findings aim to achieve ZEN biodegradation and provide insight into the structure and function of ZEN hydrolases.

Novel Strategies for the Biodegradation and Detoxification of Mycotoxins in Post-Harvest Grain

Mycotoxins are toxic secondary metabolites produced by filamentous fungi belonging, in particular, to the Aspergillus, Fusarium, and Penicillium genera [...].

Crosstalk between Mycotoxins and Intestinal Microbiota and the Alleviation Approach via Microorganisms

Mycotoxins are secondary metabolites produced by fungus. Due to their widespread distribution, difficulty in removal, and complicated subsequent harmful by-products, mycotoxins pose a threat to the health of humans and animals worldwide. Increasing studies in recent years have highlighted the impact of mycotoxins on the gut microbiota. Numerous researchers have sought to illustrate novel toxicological mechanisms of mycotoxins by examining alterations in the gut microbiota caused by mycotoxins. However, few efficient techniques have been found to ameliorate the toxicity of mycotoxins via microbial pathways in terms of animal husbandry, human health management, and the prognosis of mycotoxin poisoning. This review seeks to examine the crosstalk between five typical mycotoxins and gut microbes, summarize the functions of mycotoxins-induced alterations in gut microbes in toxicological processes and investigate the application prospects of microbes in mycotoxins prevention and therapy from a variety of perspectives. The work is intended to provide support for future research on the interaction between mycotoxins and gut microbes, and to advance the technology for preventing and controlling mycotoxins.

Selenium-chitosan alleviates the toxic effects of Zearalenone on antioxidant and immune function in mice

This study assessed the protective effects of selenium-chitosan (SC) against antioxidant and immune function-related damage induced by zearalenone (ZEN) in mice. In total, 150 female mice were allotted to five groups for a 30-day study. Control mice were fed a basal diet. Mice in the ZEN, ZEN-Se1, ZEN-Se2 and ZEN-Se3 groups were fed the basal diet supplemented with same dose of ZEN (2 mg/kg) and different doses of SC, 0.0, 0.2, 0.4 and 0.6 mg/kg, respectively (calculated by selenium). After 30 days, the total antioxidant capacity (T-AOC) level, glutathione peroxidase (GSH-Px) activity, total superoxide dismutase (T-SOD) activity and malondialdehyde (MDA) content in plasma and liver, as well as Con A-induced splenocyte proliferation, plasma interleukins concentrations and liver interleukin mRNA expression levels were determined. The plasma and liver GSH-Px activities, liver T-AOC levels, Con A-induced splenocyte proliferation, interleukin (IL) contents and mRNA expression levels in the ZEN group were significantly lower than in the control group (P < 0.01 or P < 0.05), whereas plasma and liver MDA contents in the ZEN group were significantly higher than in the control group (P < 0.01 or P < 0.05). Additionally, plasma and liver GSH-Px activities, liver T-AOC levels, Con A-induced splenocyte proliferation, IL-1β, IL-17A, IL-2 and IL-6 contents and mRNA expression levels in ZEN+Se2 and ZEN+Se3 groups were significantly higher than in the ZEN group (P < 0.01 or P < 0.05), whereas plasma and liver MDA contents in the ZEN+Se2 and ZEN+Se3 groups were significantly lower than in the ZEN group (P < 0.01 or P < 0.05). The plasma and liver GSH-Px activities, Con A-induced splenocyte proliferation, IL-1β and IL-6 contents, IL-2 and IL-17A mRNA expression levels in the ZEN+Se1 group were also significantly higher than in the ZEN group (P < 0.01 or P < 0.05), whereas the plasma MDA content in the ZEN+Se1 group was also significantly lower than in the ZEN group (P < 0.01). Thus, SC may alleviate antioxidant function-related damage and immunosuppression induced by ZEN in mice.

Screening of Pig-Derived Zearalenone-Degrading Bacteria through the Zearalenone Challenge Model, and Their Degradation Characteristics

Zearalenone (ZEN) is widely found in food and feed. Its cytotoxicity, reproductive toxicity, genetic toxicity, immunotoxicity and hepatorenal toxicity have serious impacts on human and animal health. In order to help animals avoid ZEN poisoning in feed, ZEN-degrading bacterial strains were screened from fecal samples through a zearalenone challenge pig model, and their degradation characteristics were researched. Through the optimization of parameters such as the culture time, pH value, temperature, and strain concentration, the optimal conditions for the ZEN-degrading ability of these strains were preliminarily determined, and the active site of the ZEN degradation was explored. In this study, three strains (SY-3, SY-14, SY-20) with high ZEN degradation capacities were obtained. SY-3 was identified as Proteus mirabilis, and its main degrading component was the supernatant. SY-14 and SY-20 were identified as Bacillus subtilis. Their main degrading components were the intracellular fluid of SY-14, and the intracellular fluid and cell wall of SY-20. The above results showed that the ZEN challenge model was an effective way to screen ZEN-degrading bacteria.