Biodegradation of mycotoxin fumonisin B1 by a novel bacterial consortium SAAS79

The occurrence and management of fumonisin contamination across the food production and supply chains

BACKGROUND

Fumonisins (FUMs) are among the most common mycotoxins in plant-derived food products. FUMs contamination has considerably impacted human and animal health, while causing significant economic losses. Hence, management of FUMs contamination in food production and supply chains is needed. The toxicities of FUMs have been widely investigated. FUMs management has been reported and several available strategies have been developed successfully to mitigate FUMs contamination present in foods. However, currently available management of FUMs contamination from different phases of food chains and the mechanisms of some major strategies are not comprehensively summarized.

AIM OF REVIEW

This review comprehensively characterize the occurrence, impacts, and management of FUMs contamination across food production and supply chains. Pre- and post-harvest strategies to prevent FUMs contamination also are reviewed, with an emphasis on the potential applications and the mechanisms of major mitigation strategies. The presence of modified FUMs products and their potential toxic effects are also considered. Importantly, the potential application of biotechnological approaches and emerging technologies are enunciated.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Currently available pre- and post-harvest management of FUMs contamination primarily involves prevention and decontamination. Prevention strategies are mainly based on limiting fungal growth and FUMs biosynthesis. Decontamination strategies are implemented through alkalization, hydrolysis, thermal or chemical transformation, and enzymatic or chemical degradation of FUMs. Concerns have been raised about toxicities of modified FUMs derivatives, which presents challenges for reducing FUMs contamination in foods with conventional methodologies. Integrated prevention and decontamination protocols are recommended to control FUMs contamination across entire value chains in developed countries. In developing countries, several other approaches, including cultivating, introducing Bt maize, simple sorting/cleaning, and dehulling, are suggested. Future studies should focus on biotechnological approaches, emerging technologies, and metagenomic/genomic identification of new degradation enzymes that could allow better opportunities to manage FUMs contamination in the entire food system.

Capacity and kinetics of zearalenone adsorption by Geotrichum candidum LG-8 and its dried fragments in solution

The application of LG-8 and its dry fragments as zearalenone (ZEN) adsorbents was investigated. The study showed that Geotrichum candidum LG-8 and its fragments dried at 55°C or through lyophilization are able to adsorb around 80% of ZEN. However, besides in water and 55°C-drying conditions, SEM indicated that higher 90% of ZEN binding tended to occur when cell walls of fragments were intact with less adhesion among themselves. Notably, ZEN/LG-8 fragments complexes were quite stable, as only 1.262% and 1.969% of ZEN were released after successive pH treatments for 4 h and 5 min. The kinetic data signified that adsorption of ZEN onto LG-8 fragments followed well the pseudo-first-order kinetic model. Isotherm calculations showed Langmuir model was favourable and monolayer adsorption of ZEN occurred at functional binding sites on fragments surface. Therefore, we conclude that it can be an alternative biosorbent to treat water contained with ZEN, since LG-8 is low-cost biomass and its fragments have a considerable high biosorption capacity avoiding impacting final product quality and immunodeficient patients.

Gut-Faecal Microbial and Health-Marker Response to Dietary Fumonisins in Weaned Pigs

This study investigated effects of dietary fumonisins (FBs) on gut and faecal microbiota of weaned pigs. In total, 18 7-week-old male pigs were fed either 0, 15 or 30 mg FBs (FB1 + FB2 + FB3)/kg diet for 21 days. The microbiota was analysed with amplicon sequencing of the 16S rRNA gene V3-V4 regions (Illumina MiSeq). Results showed no treatment effect (p > 0.05) on growth performance, serum reduced glutathione, glutathione peroxidase and malondialdehyde. FBs increased serum aspartate transaminase, gamma glutamyl-transferase and alkaline phosphatase activities. A 30 mg/kg FBs treatment shifted microbial population in the duodenum and ileum to lower levels (compared to control (p < 0.05)) of the families Campylobacteraceae and Clostridiaceae, respectively, as well as the genera Alloprevotella, Campylobacter and Lachnospiraceae Incertae Sedis (duodenum), Turicibacter (jejunum), and Clostridium sensu stricto 1 (ileum). Faecal microbiota had higher levels of the Erysipelotrichaceae and Ruminococcaceae families and Solobacterium, Faecalibacterium, Anaerofilum, Ruminococcus, Subdoligranulum, Pseudobutyrivibrio, Coprococcus and Roseburia genera in the 30 mg/kg FBs compared to control and/or to the 15 mg/kg FBs diets. Lactobacillus was more abundant in the duodenum compared to faeces in all treatment groups (p < 0.01). Overall, the 30 mg/kg FBs diet altered the pig gut microbiota without suppressing animal growth performance.

Post-Harvest Prevention of Fusariotoxin Contamination of Agricultural Products by Irreversible Microbial Biotransformation: Current Status and Prospects

Biological degradation of mycotoxins is a promising environmentally-friendly alternative to chemical and physical detoxification methods. To date, a lot of microorganisms able to degrade them have been described; however, the number of studies determining degradation mechanisms and irreversibility of transformation, identifying resulting metabolites, and evaluating in vivo efficiency and safety of such biodegradation is significantly lower. At the same time, these data are crucial for the evaluation of the potential of the practical application of such microorganisms as mycotoxin-decontaminating agents or sources of mycotoxin-degrading enzymes. To date, there are no published reviews, which would be focused only on mycotoxin-degrading microorganisms with the proved irreversible transformation of these compounds into less toxic compounds. In this review, the existing information about microorganisms able to efficiently transform the three most common fusariotoxins (zearalenone, deoxinyvalenol, and fumonisin B1) is presented with allowance for the data on the corresponding irreversible transformation pathways, produced metabolites, and/or toxicity reduction. The recent data on the enzymes responsible for the irreversible transformation of these fusariotoxins are also presented, and the promising future trends in the studies in this area are discussed.

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.

Destruction of Mycotoxins in Poultry Waste under Anaerobic Conditions within Methanogenesis Catalyzed by Artificial Microbial Consortia

To reduce the toxicity of modern feeds polluted by mycotoxins, various sorbents are added to them when feeding animals. A part of the mycotoxins is excreted from the body of animals with these sorbents and remains in the manure. As a result, bulk animal wastes containing mixtures of mycotoxins are formed. It is known that it is partially possible to decrease the initial concentration of mycotoxins in the process of anaerobic digestion (AD) of contaminated methanogenic substrates. The aim of this review was to analyze the recent results in destruction of mycotoxins under the action of enzymes present in cells of anaerobic consortia catalyzing methanogenesis of wastes. The possible improvement of the functioning of the anaerobic artificial consortia during detoxification of mycotoxins in the bird droppings is discussed. Particular attention was paid to the possibility of effective functioning of microbial enzymes that catalyze the detoxification of mycotoxins, both at the stage of preparation of poultry manure for methanogenesis and directly in the anaerobic process itself. The sorbents with mycotoxins which appeared in the poultry wastes composed one of the topics of interest in this review. The preliminary alkaline treatment of poultry excreta before processing in AD was considered from the standpoint of effectively reducing the concentrations of mycotoxins in the waste.

A Novel Cost-Effective Nanobody against Fumonisin B1 Contaminations: Efficacy Test in Dairy Milk and Chickens

BACKGROUND

Fumonisin B1 (FB1) is a secondary metabolite produced mainly by Fusarium verticillioides or Fusarium proliferatum. It poses a huge threat to the sustainable animal industry and human health as well via food chains (egg, meat and milk). Although E. coli-expressed nanobodies are documented for diagnostic applications, nanobodies remain elusive as FB1 detoxifiers in feed and food.

RESULTS

In the present study, the E. coli-expressed nanobody was assessed to remove FB1 in fresh milk, embryonated eggs and broilers. Firstly, 2 alpacas received intramuscularly FB1-adjuvanted BSA 6 times, and then the variable domain of the heavy-chain antibody (VHH) of fb1 genes were amplified to clone into the pCANTAB 5 E vector in order to generate a VHH-FB1 phage antibody display library, yielding 3.4 × 10¹⁰ capacity with 96.7% positivity. Afterwards, 5 anti-FB1 nanobodies were expressed and identified. Furthermore, maximal 43.2% FB1 was removed from milk by 1:2000 concentration of nanobody 5 (Nb5). Furthermore, SPF-embryonated eggs were inoculated into albumens with nanobody-treated FB1. The Nb5 group yielded an 83.3% hatching rate, higher body weight, lower gizzard ulceration and fewer FB1 residuals. In order to warrant the above results, 50 broilers aged 10 days were received orally with 20 ppm of FB1 for 20 days. At the same time, birds were fed orally with 50 μg of Nb5 or bivalent nanobody 11 (BiNb11). Finally, the Nb5 group showed a higher relative body weight gain and lower gastric ulcerations and fewer inflammations in the thymus and bursa.

CONCLUSIONS

Based on the above evidence, the Nb5 nanobody may be considered as an additional FB1 detoxifier, contributing to FB1 decontamination.

FumDSB can alleviate the inflammatory response induced by fumonisin B1 in growing pigs

Fumonisin B₁ (FB₁) has the highest natural contamination rate among all fumonisin analogs and can inhibit food intake and weight gain of pigs. Under laboratory conditions, carboxylesterase FumDSB has a high FB₁ degradation rate and excellent pH and thermal stability. The present study sought to estimate the effects of FumDSB on growing pigs from the perspective of a brain-intestinal axis. Twenty-four growing pigs of similar weight were divided into Control, FB₁ (5 mg FB₁/kg feed), and FumDSB (5 mg FB₁/kg and 0.1% FumDSB in the feed) groups. After 42 days of feeding, hypothalamus and jejunum samples were collected for quantitative real-time fluorescence, western blotting, and immunohistochemistry. The results showed that FB₁ consumption can destruct the tissue structure of hypothalamus and jejunum, affect the expression and distribution of several appetite-related neuropeptides and inflammatory cytokines, thereby inducing neuroinflammatory responses and affecting food intake and weight gain. However, these anorexia effects and inflammatory responses are alleviated when FumDSB is added to the feed. In short, FumDSB can alleviate the inflammatory response induced by FB₁ in growing pigs.

Toxic Mechanism and Biological Detoxification of Fumonisins

Food safety is related to the national economy and people's livelihood. Fumonisins are widely found in animal feed, feed raw materials, and human food. This can not only cause economic losses in animal husbandry but can also have carcinogenicity or teratogenicity and can be left in animal meat, eggs, and milk which may enter the human body and pose a serious threat to human health. Although there are many strategies to prevent fumonisins from entering the food chain, the traditional physical and chemical methods of mycotoxin removal have some disadvantages, such as an unstable effect, large nutrient loss, impact on the palatability of feed, and difficulty in mass production. As a safe, efficient, and environmentally friendly detoxification technology, biological detoxification attracts more and more attention from researchers and is gradually becoming an accepted technique. This work summarizes the toxic mechanism of fumonisins and highlights the advances of fumonisins in the detoxification of biological antioxidants, antagonistic microorganisms, and degradation mechanisms. Finally, the future challenges and focus of the biological control and degradation of fumonisins are discussed.

Invited review: Remediation strategies for mycotoxin control in feed

Mycotoxins are secondary metabolites of different species of fungi. Aflatoxin B1 (AFB1), deoxynivalenol (DON), zearalenone (ZEN) and fumonisin B1 (FB1) are the main mycotoxins contaminating animal feedstuffs. These mycotoxins can primarily induce hepatotoxicity, immunotoxicity, neurotoxicity and nephrotoxicity, consequently cause adverse effects on the health and performance of animals. Therefore, physical, chemical, biological and nutritional regulation approaches have been developed as primary strategies for the decontamination and detoxification of these mycotoxins in the feed industry. Meanwhile, each of these techniques has its drawbacks, including inefficient, costly, or impractically applied on large scale. This review summarized the advantages and disadvantages of the different remediation strategies, as well as updates of the research progress of these strategies for AFB1, DON, ZEN and FB1 control in the feed industry.

Biological Detoxification of Mycotoxins: Current Status and Future Advances

Mycotoxins are highly toxic metabolites produced by fungi that pose a huge threat to human and animal health. Contamination of food and feed with mycotoxins is a worldwide issue, which leads to huge financial losses, annually. Decades of research have developed various approaches to degrade mycotoxins, among which the biological methods have been proved to have great potential and advantages. This review provides an overview on the important advances in the biological removal of mycotoxins over the last decade. Here, we provided further insight into the chemical structures and the toxicity of the main mycotoxins. The innovative strategies including mycotoxin degradation by novel probiotics are summarized in an in-depth discussion on potentialities and limitations. We prospected the promising future for the development of multifunctional approaches using recombinant enzymes and microbial consortia for the simultaneous removal of multiple mycotoxins.

FumDSB Can Reduce the Toxic Effects of Fumonisin B1 by Regulating Several Brain-Gut Peptides in Both the Hypothalamus and Jejunum of Growing Pigs

Fumonisin B₁ (FB₁) is the most common food-borne mycotoxin produced by the Fusarium species, posing a potential threat to human and animal health. Pigs are more sensitive to FB₁ ingested from feed compared to other farmed livestock. Enzymatic degradation is an ideal detoxification method that has attracted much attention. This study aimed to explore the functional characteristics of the carboxylesterase FumDSB in growing pigs from the perspective of brain–gut regulation. A total of 24 growing pigs were divided into three groups. The control group was fed a basal diet, the FB₁ group was supplemented with FB₁ at 5 mg/kg feed, and the FumDSB group received added FumDSB based on the diet of the FB₁ group. After 35 days of animal trials, samples from the hypothalamus and jejunum were analyzed through HE staining, qRT-PCR and immunohistochemistry. The results demonstrated that the ingestion of FB₁ can reduce the feed intake and weight gain of growing pigs, indicating that several appetite-related brain-gut peptides (including NPY, PYY, ghrelin and obestatin, etc.) play important roles in the anorexia response induced by FB₁. After adding FumDSB as detoxifying enzymes, however, the anorexia effects of FB₁ were alleviated, and the expression and distribution of the corresponding brain-gut peptides exhibited a certain degree of regulation. In conclusion, the addition of FumDSB can reduce the anorexia effects of FB₁ by regulating several brain-gut peptides in both the hypothalamus and the jejunum of growing pigs.

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.

Microbial Reduction of Fumonisin B1 by the New Isolate Serratia marcescens 329-2

The mycotoxin fumonisin (FB) has become a major problem in maize products in southeastern Asia. Fumonisin can affect the health of humans and many animals. Fumonisin contamination can be reduced by detoxifying microbial enzyme. Screening of 95 potent natural sources resulted in 5.3% of samples yielding a total of five bacterial isolates that were a promising solution, reducing approximately 10.0-30.0% of fumonisin B1 (FB1). Serratia marcescens, one of the dominant degrading bacteria, was identified with Gram staining, 16S rRNA gene, and MALDI-TOF/TOF MS. Cell-free extract showed the highest fumonisin reduction rates, 30.3% in solution and 37.0% in maize. Crude proteins from bacterial cells were analyzed with a label-free quantification technique. The results showed that hydrolase enzymes and transferase enzymes that can cooperate in the fumonisin degradation process were highly expressed in comparison to their levels in a control. These studies have shown that S. marcescens 329-2 is a new potential bacterium for FB1 reduction, and the production of FB1-reducing enzymes should be further explored.

Effects of Selenium-enriched probiotics on ochratoxin A-induced kidney injury and DNMTs expressions in piglets

Effects of Selenium-enriched probiotics (SP) on ochratoxin A-induced kidney injury, growth performance, antioxidant injury, selenoprotein and DNA methylation transferases (DNMTs) expression of piglets were investigated in the article. A total of 48 piglets were randomly divided into 4 groups and fed with basal diet (Con, 0.15 mg Se/kg and OTA at 0.00 mg/kg), basal diets added with OTA (OTA, 0.40 mg OTA/kg), SP and OTA (SP1, 0.15 mg Se/kg and 0.40 mg OTA/kg), SP and OTA (SP2, 0.30 mg Se/kg and 0.40 mg OTA/kg) respectively for 42 days. From each group, six piglets were randomly selected for blood collection on Days 0 and 42 and three piglets were selected for tissue collection on Day 42.The results showed that OTA at 0.40 mg /kg significantly decreased growth performance of pigs, induced the histopathological lesions of kidney and increased urea and creatine levels of serum, decreased GPx and SOD activities, and increased MDA levels. OTA decreased GPx1, GPx4 and SelS expressions, and increased TR1, DNMT 1, DNMT3a and SOCS3 expressions. Both SP1 and SP2 improved OTA-induced poor growth performance, kidney injury, poor antioxidant statues, GPx1, SelS, TR1, SOCS3, DNMT1 and DNMT3a expressions in kidney of pigs. The effects of SP2 on the above parameters changes were better than that of SP1. SP increased GPx and SOD activities and decreased MDA levels changes induced by OTA treatment. These results suggest that SP may serve as a better feed additive for piglets under mycotoxin contamination environments.

Microbial detoxification of mycotoxins in food and feed

Mycotoxins are metabolites produced by fungi growing in food or feed, which can produce toxic effects and seriously threaten the health of humans and animals. Mycotoxins are commonly found in food and feed, and are of significant concern due to their hepatotoxicity, nephrotoxicity, carcinogenicity, mutagenicity, and ability to damage the immune and reproductive systems. Traditional physical and chemical detoxification methods to treat mycotoxins in food and feed products have limitations, such as loss of nutrients, reagent residues, and secondary pollution to the environment. Thus, there is an urgent need for new detoxification methods to effectively control mycotoxins and treat mycotoxin pollution. In recent years, microbial detoxification technology has been widely used for the degradation of mycotoxins in food and feed because this approach offers the potential for treatment with high efficiency, low toxicity, and strong specificity, without damage to nutrients. This article reviews the application of microbial detoxification technology for removal of common mycotoxins such as Aflatoxin, Ochratoxin, Zearalenone, Deoxynivalenol, and Fumonisins, and discusses the development trend of this important technology.

Isolation and characterization of a Pseudomonas poae JSU-Y1 with patulin degradation ability and biocontrol potential against Penicillium expansum

Patulin, one of the most common mycotoxins produced primarily by the Penicillium, Aspergillus and Byssochlamys species, is often associated with fruits and fruit-based products. Biodegradation by microbes is an effective method to remove or detoxify mycotoxins. In this study, a bacterial strain with patulin degradation capability was selectively isolated using oxindole, an analogue to patulin, as the sole carbon source, and identified as Pseudomonas poae JSU-Y1 by phylogenetic analysis on the basis of 16S rRNA sequence. This isolated bacterium could inhibit the growth of Penicillium expansum both on plate medium and apple fruit with inhibition ratio of 30.3% and 44.9%, respectively. Up to 87.7% of the initial patulin (2.5 μg/mL) was removed after incubation with Pseudomonas poae JSU-Y1 in liquid medium at 30 °C for 72 h. When challenged with apple juice, 79% of patulin could be degraded by this isolated strain. Additionally, ascladiol was tentatively identified as the patulin degradation intermediate by LC-MS analysis. Taken together, the experiment results indicated that the isolated Pseudomonas poae JSU-Y1 would be a promising bacterial resource to control patulin contamination and toxigenic fungal growth in agricultural products.

Fumonisin B1: Mechanisms of toxicity and biological detoxification progress in animals

Fumonisin B1 (FB₁) is a toxic secondary metabolite produced by the Fusarium molds that can contaminate food and feed. It has been found that FB₁ can cause systemic toxicity, including neurotoxicity, hepatotoxicity, nephrotoxicity and mammalian cytotoxicity. This review addresses the toxicity studies carried out on FB₁ and outlines the probable mechanisms underlying its immunotoxicity, reproductive toxicity, joint toxicity, apoptosis, and autophagy. In the present work, the research progress of FB₁ detoxification in recent years is reviewed, which provides reference for controlling and reducing the toxicity of FB₁.

Biological detoxification of fumonisin by a novel carboxylesterase from Sphingomonadales bacterium and its biochemical characterization

Fumonisins have posed hazardous threat to human and animal health worldwide. Enzymatic degradation is a desirable detoxification approach but is severely hindered by serious shortage of detoxification enzymes. After mining enzymes by bioinformatics analysis, a novel carboxylesterase FumDSB from Sphingomonadales bacterium was expressed in Escherichia coli, and confirmed to catalyze fumonisin B1 to produce hydrolyzed fumonisin B1 by liquid chromatography mass spectrometry for the first time. FumDSB showed high sequence novelty, sharing only ~34% sequence identity with three reported fumonisin detoxification carboxylesterases. Besides, FumDSB displayed its high degrading activity at 30-40 °C within a broad pH range from 6.0 to 9.0, which is perfectly suitable to be used in animal physiological condition. It also exhibited excellent pH stability and moderate thermostability. This study provides a FB1 detoxification carboxylesterase which could be further used as a potential food and feed additive.