Ochratoxin A biodegradation by Agaricus campestris and statistical optimization of cultural variables

The goal of this study is to identify the optimum conditions for ochratoxin A (OTA) biodegradation by the supernatant of Agaricus campestris strain. The Plackett-Burman and Box-Behnken methods were used to determine optimum OTA degradation conditions of Agaricus campestris under various incubation conditions. The Plackett-Burman method was planned through 16 varied experiments with 15 variants. The three most potent variants, sucrose, yeast extract and wheat bran, were selected using the Box-Behnken methodology. Ochratoxin A biodegradation ratio of 46.67% has been specified in only 1 h under ideal growing conditions. This is the first report on the optimization of OTA biodegradation by Agaricus campestris. When compared to previously published articles, it can be asserted that Agaricus campestris has promise based on its OTA biodegradation ratio in only 1 h of reaction time.

Ochratoxin A: Overview of Prevention, Removal, and Detoxification Methods

Ochratoxins are the secondary metabolites of Penicillium and Aspergillus, among which ochratoxin A (OTA) is the most toxic molecule. OTA is widely found in food and agricultural products. Due to its severe nephrotoxicity, immunotoxicity, neurotoxicity, and teratogenic mutagenesis, it is essential to develop effective, economical, and environmentally friendly methods for OTA decontamination and detoxification. This review mainly summarizes the application of technology in OTA prevention, removal, and detoxification from physical, chemical, and biological aspects, depending on the properties of OTA, and describes the advantages and disadvantages of each method from an objective perspective. Overall, biological methods have the greatest potential to degrade OTA. This review provides some ideas for searching for new strains and degrading enzymes.

Degradation of ochratoxins A and B by lipases: A kinetic study unraveled by molecular modeling

Mycotoxins are toxic substances produced by fungi and, frequently, different mycotoxins cooccur in food commodities. Ochratoxin A (OTA) and Ochratoxin B (OTB) may co-occur in a variety of foods, like red wines and wheat, presenting a significant risk of population exposure. In this study, we investigated the potential of five lipases (Candida rugosa Lipase, Candida antarctica B Lipase, Thermomyces lanuginosus Lipase, Amano Lipase A from Aspergillus niger (ANL) and Porcine Pancreas Lipase (PPL)) to hydrolyze OTA and OTB into non-hazardous products. Only ANL and PPL degraded both substrates, however, with varying degrees of efficiency. PPL completely degraded OTB (9 h), but only 43% of OTA (25 h). Molecular simulations indicated a high binding energy of OTA to PPL, that can be explained by the impact of the chlorine group, impairing hydrolysis. ANL was able to completely degrade both mycotoxins, OTA in 3 h and OTB in 10 h. The ANL enzyme showed also high specificity to OTA, however, the activity of this enzyme is not affected by chlorine and hydrolyzes OTA faster than OTB. These two enzymes were found to be able to detoxify co-occurring ochratoxins A and B, making isolated enzymes an alternative to the direct use of microorganisms for mycotoxin mitigation in food.

Mycotoxin Contamination Status of Cereals in China and Potential Microbial Decontamination Methods

The presence of mycotoxins in cereals can pose a significant health risk to animals and humans. China is one of the countries that is facing cereal contamination by mycotoxins. Treating mycotoxin-contaminated cereals with established physical and chemical methods can lead to negative effects, such as the loss of nutrients, chemical residues, and high energy consumption. Therefore, microbial detoxification techniques are being considered for reducing and treating mycotoxins in cereals. This paper reviews the contamination of aflatoxins, zearalenone, deoxynivalenol, fumonisins, and ochratoxin A in major cereals (rice, wheat, and maize). Our discussion is based on 8700 samples from 30 provincial areas in China between 2005 and 2021. Previous research suggests that the temperature and humidity in the highly contaminated Chinese cereal-growing regions match the growth conditions of potential antagonists. Therefore, this review takes biological detoxification as the starting point and summarizes the methods of microbial detoxification, microbial active substance detoxification, and other microbial inhibition methods for treating contaminated cereals. Furthermore, their respective mechanisms are systematically analyzed, and a series of strategies for combining the above methods with the treatment of contaminated cereals in China are proposed. It is hoped that this review will provide a reference for subsequent solutions to cereal contamination problems and for the development of safer and more efficient methods of biological detoxification.

Research progress of ochratoxin a bio-detoxification

Ochratoxins (OTs) is an extremely toxic mycotoxin in which Ochratoxin A (OTA) is the most toxic and prevalent in the ochratoxin family. OTA is among the five most critical mycotoxins that are subject to legal regulations. Animals and humans may be exposed to OTA through dietary intake, inhalation, and dermal contact. OTA is considered nephrotoxic, genotoxic, cytotoxic, teratogenic, carcinogenic, mutagenic, immunotoxic, and myelotoxic. So, intake of OTA contaminated foods and feeds can impact the productivity of animals and health of people. According to this review, several studies have reported on the approaches that have been established for OTA removal. This review focused on the control approaches to mitigate OTA contamination, OTA bio-detoxification materials and their applicable techniques, recombinant strains for OTA bio-detoxification, and their detoxification effects, recombinant OTA-degrading enzymes and their sources, recombinant fusion enzymes for OTA, ZEN and AFB1 mycotoxins detoxification, as well as the current application and commercialized OTA bio-detoxification products. However, there is no single technique that has been approved to detoxify OTA by 100% to date. Some preferred current strategies for OTA bio-detoxification have been recombinant degrading enzymes and genetic engineering technology due to their efficiency and safety. Therefore, prospective studies should focus on standardizing pure enzymes from genetically engineered microbial strains that have great potential for OTA detoxification.

Biodegradation of ochratoxin A by endophytic Trichoderma koningii strains

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus spp. and Penicillium spp. that causes a threat to food safety and human health. Fungal biodegradation might be a promising strategy for reducing the OTA contamination in the future. In this study, the ability of Trichoderma koningii strains to degrade OTA produced by Aspergillus niger T2 (MW513392.1) isolated from tomato seeds was investigated. Among T. koningii strains tested, three strains; AUMC11519, AUMC11520 and AUMC11521 completely eliminated OTA from the culture medium, while AUMC11522 strain eliminated only 41.82% of OTA. OTα-amide, 3-phenylpropionic acid, OTα and phenylalanine were assayed as degradation products by FTIR analysis and LC-MS/MS spectra. Carboxypeptidase A (CPA) was found responsible for OTA degradation when a metal ion chelator, EDTA, was added to cell free supernatants of the three effective strains. OTA detoxification by T. koningii could present new prospective strategies for a possible application in food commodities intoxicated with ochratoxin.

Unveiling ochratoxin a controlling and biodetoxification molecular mechanisms: Opportunities to secure foodstuffs from OTA contamination

Anarchic growth of ochratoxin A (OTA) producing fungi during crop production, prolonged storage, and processing results in OTA contamination in foodstuffs. OTA in food exacerbates the risk of health and economic problems for consumers and farmers worldwide. Although the toxic effects of OTA on human health have not been well established, comprehensive preventive and remedial measures will be essential to eliminate OTA from foodstuffs. Strict regulations, controlling OTA at pre- or post-harvest stage, and decontamination of OTA have been adopted to prevent human and animal OTA exposure. Biological control of OTA and bio-decontamination are the most promising strategies due to their safety, specificity and nutritional value. This review addresses the current understanding of OTA biodegradation mechanisms and recent developments in OTA control and bio-decontamination strategies. Additionally, this review analyses the strength and weaknesses of different OTA control methods and the contemporary approaches to enhance the efficiency of biocontrol agents. Overall, this review will support the implementation of new strategies to effectively control OTA in food sectors. Further studies on efficacy-related issues, production issues and cost-effectiveness of OTA biocontrol are to be carried out to improve the knowledge, develop improved delivery technologies and safeguard the durability of OTA biocontrol approaches.

Degradation of Ochratoxin A by a UV-Mutated Aspergillus niger Strain

Ochratoxin A (OTA) is a mycotoxin that can contaminate a wide range of crops such as grains and grapes. In this study, a novel fungal mutant strain (FS-UV-21) with a high OTA degradation rate (74.5%) was obtained from Aspergillus niger irradiated with ultraviolet light (15 W for 20 min). The effect of pH, temperature, and inoculation concentration on the degradation of OTA by FS-UV-21 was investigated, and the results revealed that the detoxification effect was optimal (89.4%) at a pH of 8 and a temperature of 30 °C. Ultra-performance liquid chromatography-tandem mass spectrometry was used to characterize the degraded products of OTA, and the main degraded product was ochratoxin α. Triple quadrupole-linear ion trap-mass spectrometry combined with LightSight software was used to analyze the biotransformation pathway of OTA in FS-UV-21, to trace the degraded products, and to identify the main metabolite, P1 (C19H18ClNO6, m/z 404). After the FS-UV-21 strain was treated with OTA, the HepG2 cellular toxicity of the degradation products was significantly reduced. For the real sample, FS-UV-21 was used to remove OTA from wheat bran contaminated by mycotoxins through fermentation, resulting in the degradation of 59.8% of OTA in wheat bran. Therefore, FS-UV-21 can be applied to the degradation of OTA in agricultural products and food.

Ochratoxin A: Occurrence and recent advances in detoxification

Ochratoxin A (OTA), one of the most important mycotoxins, is mainly produced by fungi in the genera Aspergillus and Penicillium, and commonly found in food and agricultural products. In addition to causing significant economic losses, the occurrence of OTA in foods poses a serious threat to human health. Therefore, it is very important to develop approaches to control or detoxify OTA contamination and thus ensure food safety. In this paper, we review the source and occurrence of OTA in food and agricultural products and the latest achievements in the removal and detoxification of OTA using physical, chemical, and biological methods, with specific attention to influencing factors and mechanisms related to the biodetoxification of OTA. Moreover, the advantages and disadvantages of these methods and their potential application prospect were also discussed.

Food-Grade Expression of Manganese Peroxidases in Recombinant Kluyveromyces lactis and Degradation of Aflatoxin B1 Using Fermentation Supernatants

Aflatoxins are naturally occurring high-toxic secondary metabolites, which cause worldwide environmental contaminations and wastes of food and feed resources and severely threaten human health. Thus, the highly efficient methods and technologies for detoxification of aflatoxins are urgently needed in a long term. In this work, we report the construction of recombinant Kluyveromyces lactis strains GG799(pKLAC1-Phsmnp), GG799(pKLAC1-Plomnp), GG799(pKLAC1-Phcmnp), and then the food-grade expression of the three manganese peroxidases in these strains, followed by the degradation of aflatoxin B₁ (AFB₁) using the fermentation supernatants. The expression of the manganese peroxidases was achieved in a food-grade manner since Kluyveromyces lactis is food-safe and suitable for application in food or feed industries. The inducible expression process of the optimal recombinant strain GG799(pKLAC1-Phcmnp) and the aflatoxin B₁ degradation process were both optimized in detail. After optimization, the degradation ratio reached 75.71%, which was an increase of 49.86% compared to the unoptimized results. The degradation product was analyzed and determined to be AFB₁-8,9-dihydrodiol. The recombinant strain GG799(pKLAC1-Phcmnp) supernatants degraded more than 90% of AFB₁ in the peanut samples after twice treatments. The structural computational analysis for further mutagenesis of the enzyme PhcMnp was also conducted in this work. The food-grade recombinant yeast strain and the enzyme PhcMnp have potential to be applied in food or feed industries.

Bio-control on the contamination of Ochratoxin A in food: Current research and future prospects

Ochratoxin A (OTA) is a secondary metabolite of several fungi and widely exists in various species of foods. The establishment of effective methods for OTA reduction is a key measure to ensure food processing and human health. This article reviews the current research of OTA reduction by biological approaches, summarizes the characteristics and efficiency of them, and evaluates the transformation pathways and metabolites safety of each degradation technology. The shortcomings of various methods are pointed out and future prospects are also proposed. Biological methods are the most promising approaches for OTA control. The defect of them is the long processing time and the growth of microbial cells may affect the product quality. Therefore, the control of OTA contamination should be conducted according to the food processing and their product types. Besides, it is significant for the exploitation of new strains, enzyme and novel adsorbents.

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The application of physical and chemical methods has been restricted.

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Existing biological methods can effectively detoxify OTA.

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OTA reduction systems should be established for different food.

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The exploitation of novel equipment, enzyme and adsorbents is essential.

Microbiological Decontamination of Mycotoxins: Opportunities and Limitations

The contamination of food and feeds with mycotoxins poses a global health risk to humans and animals, with major economic consequences. Good agricultural and manufacturing practices can help control mycotoxin contamination. Since these actions are not always effective, several methods of decontamination have also been developed, including physical, chemical, and biological methods. Biological decontamination using microorganisms has revealed new opportunities. However, these biological methods require legal regulations and more research before they can be used in food production. Currently, only selected biological methods are acceptable for the decontamination of feed. This review discusses the literature on the use of microorganisms to remove mycotoxins and presents their possible mechanisms of action. Special attention is given to Saccharomyces cerevisiae yeast and lactic acid bacteria, and the use of yeast cell wall derivatives.