Role of ferroptosis in food-borne mycotoxin-induced toxicities.

Contamination by toxic substances is a major global food safety issue, which poses a serious threat to human health. Mycotoxins are major class of food contaminants, mainly including aflatoxins (AFs), zearalenone (ZON), deoxynivalenol (DON), ochratoxin A (OTA), fumonisins (FBs) and patulin (PAT). Ferroptosis is a newly identified iron-dependent form of programmed or regulated cell death, which has been found to be involved in diverse pathological conditions. Recently, a growing body of evidence has shown that ferroptosis is implicated in the toxicities induced by certain types of food-borne mycotoxins, which provides novel mechanistic insights into mycotoxin-induced toxicities and paves the way for developing ferroptosis-based strategy to combat against toxicities of mycotoxins. In this review article, we summarize the key findings on the involvement of ferroptosis in mycotoxin-induced toxicities and propose issues that need to be addressed in future studies for better utilization of ferroptosis-based approach to manage the toxic effects of mycotoxin contamination.

Pore Size Adjustment Strategy for the Fabrication of Molecularly Imprinted Covalent Organic Framework Nanospheres at Room Temperature for Selective Extraction of Zearalenone in Cereal Samples.

Covalent organic frameworks (COFs) are attractive adsorbents for sample pretreatment due to their unique structure and properties. However, the selectivity of COFs for the extraction of hazardous compounds is still limited due to the lack of specific interactions between COFs and targets. Herein, we report a pore size adjustment strategy for room-temperature synthesis of molecularly imprinted COF (MICOF) for selective extraction of zearalenone (ZEN) in complex food samples. The three-dimensional building block tetra(4-aminophenyl) methane was used as a functional monomer, while dialdehyde monomers with different numbers of benzene ring were used to adjust the pore size of MICOF to match with the size of ZEN molecules. The prepared MICOF gave the largest adsorption capacity of 177.2 mg g-1 and the highest imprinting factor of 10.1 for ZEN so far. MICOF was used as the adsorbent for dispersed solid-phase extraction in combination with high-performance liquid chromatography for the determination of trace ZEN in cereals. The high selectivity of the developed method allows simple aqueous standard calibration for the matrix effect-free determination of ZEN in food samples. The limit of detection and the recoveries of the developed method were 0.21 µg kg-1 and 93.7-101.4%, respectively. The precision for the determination of ZEN was less than 3.8% (RSD, n = 6). The developed method is promising for the selective determination of ZEN in complex matrices.

Solvent Regulation Induced Cathode Aggregation-Induced Electrochemiluminescence of Tetraphenylethylene Nanoaggregates for Ultrasensitive Zearalenone Analysis.

Zearalenone (ZEN) is an extremely hazardous chemical widely existing in cereals, and its high-sensitivity detection possesses significant significance to human health. Here, the cathodic aggregation-induced electrochemiluminescence (AIECL) performance of tetraphenylethylene nanoaggregates (TPE NAs) was modulated by solvent regulation, based on which an electrochemiluminescence (ECL) aptasensor was constructed for sensitive detection of ZEN. The aggregation state and AIECL of TPE NAs were directly and simply controlled by adjusting the type of organic solvent and the fraction of water, which solved the current shortcomings of low strength and weak stability of the cathode ECL signal for TPE. Impressively, in a tetrahydrofuran-water mixed solution (volume ratio, 6:4), the relative ECL efficiency of TPE NAs reached 16.03%, which was 9.2 times that in pure water conditions, and the maximum ECL spectral wavelength was obviously red-shifted to 617 nm. In addition, "H"-shape DNA structure-mediated dual-catalyzed hairpin self-assembly (H-D-CHA) with higher efficiency by the synergistic effect between the two CHA reactions was utilized to construct a sensitive ECL aptasensor for ZEN analysis with a low detection limit of 0.362 fg/mL. In conclusion, solvent regulation was a simple and efficient method for improving the performance of AIECL materials, and the proposed ECL aptasensor had great potential for ZEN monitoring in food safety.

Sensitive fluorescence ELISA for the detection of zearalenone based on self-assembly DNA nanocomposites and copper nanoclusters.

Zearalenone (ZEN), produced by Fusarium species, is a potential risk to human health. Traditional enzyme-linked immunosorbent assay (ELISA) is restricted due to low sensitivity for the detection of ZEN. Herein, enzyme nanocomposites (ALP-SA-Bio-ssDNA, ASBD) were prepared with the self-assembly strategy based on streptavidin-labeled alkaline phosphatase (SA-ALP) and dual-biotinylated ssDNA (B2-ssDNA). The enzyme nanocomposites improved the loading amount of ALP and catalyzed more ascorbic acid 2-phosphate to generate ascorbic acid (AA). Subsequently, Cu2+ could be reduced to copper nanoclusters (CuNCs) having strong fluorescence signal by AA with poly T. Benefiting from the high enzyme load of nanocomposites and the strong signal of CuNCs, the fluorescence ELISA was successfully established for the detection of ZEN. The proposed method exhibited lower limit of detection (0.26 ng mL-1) than traditional ELISA (1.55 ng mL-1). The recovery rates ranged from 92.00% to 108.38% (coefficient of variation < 9.50%) for the detection of zearalenone in corn and wheat samples. In addition, the proposed method exhibited no cross reaction with four other mycotoxins. This proposed method could be used in trace detection for food safety.

Development of a corn flour certified reference material for the accurate determination of zearalenone.

A certified reference material (CRM, KRISS 108-01-002) for zearalenone in corn flour was developed to assure reliable and accurate measurements in testing laboratories. Commercially available corn flour underwent freeze-drying, pulverization, sieving, and homogenization. The final product was packed in amber bottles, approximately 14 g per unit, and preserved at -70 °C. 13C18-Zearalenone was used as an internal standard (IS) for the certification of zearalenone by isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC‒MS/MS) and for the analysis of α-zearalenol, ß-zearalenol, and zearalanone by LC‒MS/MS. The prepared CRM was sufficiently homogeneous, as the among-unit relative standard deviation for each mycotoxin ranged from 2.2 to 5.7 %. Additionally, the stability of the mycotoxins in the CRM was evaluated under different temperature conditions and scheduled test periods, including storage at -70°C, -20°C, and 4°C and room temperature for up to 12 months, 6 months, and 1 month, respectively. The content of each target mycotoxin in the CRM remained stable throughout the monitoring period at each temperature. Zearalenone content (153.6 ± 8.0 µg/kg) was assigned as the certified value. Meanwhile, the contents of α-zearalenol (1.30 ± 0.17 µg/kg), ß-zearalenol (4.75 ± 0.33 µg/kg), and zearalanone (2.09 ± 0.16 µg/kg) were provided as informative values.

An electrochemical aptasensor for zearalenone detection based on the Co3O4/MoS2/Au nanocomposites and hybrid chain reaction.

An electrochemical aptasensor was used for the fast and sensitive detection of zearalenone (ZEN) based on the combination of Co3O4/MoS2/Au nanocomposites and the hybrid chain reaction (HCR). The glassy carbon electrode was coated with Co3O4/MoS2/Au nanomaterials to immobilize the ZEN-cDNA that had been bound with ZEN-Apt by the principle of base complementary pairing. In the absence of ZEN, the HCR could not be triggered because the ZEN-cDNA could not be exposed. After ZEN was added to the surface of the electrode, a complex structure was produced on the modified electrode by the combination of ZEN and ZEN-Apt. Therefore, the ZEN-cDNA can raise the HCR to produce the long-strand dsDNA structure. Due to the formation of dsDNA, the methylene blue (MB) could be inserted into the superstructure of branched DNA and the peak currents of the MB redox signal dramatically increased. So the concentration of ZEN could be detected by the change of signal intensity. Under optimized conditions, the developed electrochemical biosensing strategy showed an outstanding linear detection range of 1.0×10-10 mol/L to 1.0×10-6 mol/L, a low detection limit (LOD) of 8.5×10-11 mol/L with desirable selectivity and stability. Therefore, the fabricated platform possessed a great application potential in fields of food safety, medical detection, and drug analysis.

Equine Mycotoxins.

The main mycotoxins involved in adverse equine health issues are aflatoxins, fumonisins, trichothecenes, and probably ergovaline (fescue grass endophyte toxicosis). Most exposures are through contaminated grains and grain byproducts, although grasses and hays can contain mycotoxins. Clinical signs are often nonspecific and include feed refusal, colic, diarrhea, and liver damage but can be dramatic with neurologic signs associated with equine leukoencephalomalacia and tremorgens. Specific antidotes for mycotoxicosis are rare, and treatment involves stopping the use of contaminated feed, switching to a "clean" feed source, and providing supportive care.

A sensitive electrochemical aptasensor for zearalenone detection based on target-triggered branched hybridization chain reaction and exonuclease I-assisted recycling.

Traditional methods for detecting antibiotic and mycotoxin residues rely on large-scale instruments, which are expensive and require complex sample pretreatment processes and professional operators. Although aptamer-based electrochemical sensors have the advantages of simplicity, speed, low cost, and high sensitivity, most aptamer-based sensors lack a signal amplification strategy due to their direct use of aptamers as probes, resulting in insufficient sensitivity. To solve the sensitivity problem in the electrochemical detection process, a novel electrochemical sensing strategy was established for ultrasensitive zearalenone (ZEN) detection on the basis of exonuclease I (Exo I) and branched hybridization chain reaction (bHCR) to amplify the signal. The amplification strategy showed excellent analytical performance towards ZEN with a low detection limit at 3.1×10-12 mol/L and a wide linear range from 10-11 to 10-6 mol/L. Importantly, the assay was utilized in the corn powder samples with satisfactory results, holding promising applications in food safety detection and environmental monitoring.

A novel dual-channel immunochromatographic strip using up-conversion nanoparticles for simultaneous detection of AFB1 and ZEN in maize.

Due to universal contamination and synergistic toxicity of multiple mycotoxins in foodstuff, reliable and high-throughput detection methods for multiple mycotoxins are urgently needed in corn products. In this study, a novel dual-channel immunochromatographic assay (ICA) based on improved up-conversion nanoparticles (IUCNPs) was developed for rapidly detecting aflatoxin B1 (AFB1) and zearalenone (ZEN). The synthesized IUCNPs doped by 30% Lu3+ showed a larger size, more regular structure, and brighter fluorescence intensity than conventional UCNPs. The limits of detection (LODs) of single-channel ICA test strips for AFB1 and ZEN detection were 0.01 and 0.1 ng/mL, respectively. After the optimization, the dual-channel ICA of AFB1 and ZEN in 10 min was conducted, resulting in low detection limits of 0.025 and 0.1 ng/mL, respectively. Moreover, the built assay was revealed to be highly specific for six other food-contaminated mycotoxins, and exhibited excellent accuracy, with corresponding R2 of 0.9931 and 0.9982 in calibration curves, respectively. Long-term storage experiments indicated that the dual-channel test strips had superior stability and precision. The LODs of AFB1 and ZEN in spiked maize were 0.025 and 0.25 µg/kg, demonstrating great sensitivity and matrix tolerance. Furthermore, the IUNCP-ICA was validated by high-performance liquid chromatography (HPLC) analyses, and a satisfactory consistency was obtained in 15 natural maize samples. Thus, the IUCNPs-ICA proposed in this work realized rapid and sensitive detection of AFB1 and ZEN, providing broad application potential in on-site screening for multiple mycotoxins in agricultural products.

Amphiphilic polymers facilitated solid-phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry for direct extraction and analysis of zearalenone and zearalanone in corn juice samples.

In this work, amphiphilic polymers synthesized from carboxylated carbon nanotubes stabilized high internal phase emulsions are demonstrated to be capable of direct extracting zearalenone and zearalanone in samples consisting of an oil-water emulsion system. Under optimal conditions, the maximum adsorption capacities for zearalenone and zearalanone are 17.27 and 13.26 mg/g. The adsorption is mainly attributed to π-π interaction, hydrophobic interaction, and hydrogen-bonding interaction for zearalenone and zearalanone. The adsorption isotherms reveal that the adsorption of zearalenone and zearalanone on amphiphilic polymers synthesized from carboxylated carbon nanotubes stabilized high internal phase emulsions follows Freundlich model with multilayer and heterogeneous adsorption due to the presence of multiple kinds of adsorption sites. The relative recoveries of the spiked zearalenone and zearalanone in corn juice samples range from 85% to 93% with relative standard deviations lower than 3.52%. The results manifest the high efficiency of amphiphilic polymers synthesized from carboxylated carbon nanotubes stabilized high internal phase emulsions for the adsorption and separation of analytes in the oil-water emulsion system. This study provides a new perspective on adsorbent engineering for the adsorption application in heterogeneous media.

Sequestration of zearalenone using microorganisms blend in vitro.

Zearalenone (ZEN) is an estrogenic mycotoxin produced by the Fusarium species and induces severe reproductive disorders in animals thus a major concern in the livestock industry. Probiotic bacteria treatments have been shown to inactivate mycotoxins, therefore, in this study, we investigated the effect of two commercial probiotic feed additives on the sequestration of ZEN. Commercial probiotic blends containing clay-based binder with Aspergillus niger, Bacillus licheniformis, Bacillus pumilus, and Bacillus subtilis at various proportions from BioMatrix International were incubated with ZEN in a time-dependent manner and then analyzed by Enzyme-Linked Immunosorbent Assay (ELISA) to quantify unbound ZEN. Sequestration of ZEN was further verified by using MCF-7 cell-based cytotoxicity and/or cell proliferation assays. ZEN, or probiotic mix, was nontoxic to MCF-7 cells. Probiotic blends decreased ZEN concentration by 45% (∼100 µg L-1) and prevented ZEN from inducing MCF-7 cell proliferation (20%-28% reduction). The probiotic feed supplements tested show a potential utility in ZEN neutralization.

Quantitative determination of four mycotoxins in cereal by fluorescent microsphere based immunochromatographic assay.

BACKGROUND: Mycotoxins are secondary metabolites produced by fungi, which have serious effects on humans and animals. In this study, we selected the monodispersed polystyrene fluorescent microspheres with good luminescence performance and strong stability as markers to conjugate with four mycotoxins antibodies for preparing fluorescent probes. We have developed a fluorescent microsphere based immunochromatographic assay (FMICA) to detect sensitively and quickly zearalenone (ZEN), aflatoxin B1 (AFB1 ), fumonisin B1 (FB1 ), and ochratoxin A (OTA) in cereal. RESULTS: Under optimal experimental conditions, the procedure of this method can be completed within 10 min. The limit of detection (LOD) of FMICA for ZEN, AFB1 , FB1 , and OTA is 0.072, 0.093, 0.32, and 0.19 µg L-1 , respectively. And FMICA has good specificity and no cross-reactivity with other mycotoxins. Four mycotoxins in naturally contaminated cereal samples (corn, rice, and oat) are detected by this method, and the results are highly consistent with that of ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). CONCLUSION: The developed FMICA has good accuracy, high sensitivity, simplicity, convenience, rapidity, and low cost, and it could be employed for sensitive and quantitative detecting of mycotoxins in cereal on-site. © 2022 Society of Chemical Industry.

[Mycotoxins in spices consumed in Russia].

Spices and herbs have been used since ancient times as flavor and aroma enhancers, colorants, preservatives and traditional medicines. As many other plant products, they can be exposed to contaminants, ones of which are mycotoxins, secondary metabolites of fungi. Such contamination can occur during harvesting, processing and storage, distribution, retailing and consumer use. Although they are used and consumed in small quantities, but added to a wide variety of products, especially ready-to-eat products. So the assessment of their contamination with mycotoxins is very important. The aim of the study was to investigate the contamination of spices and herbs with mycotoxins of fungi of the genera Aspergillus, Penicillium, Fusarium and Alternaria, as well as to assess the mycotoxins intake per person when consuming these food groups. Material and methods. Concentration of mycotoxins in 155 samples of spices and herbs was determined by ultra high-performance liquid chromatography coupled to tandem mass-spectrometric detection (UHPLC-MS/MS). The list of mycotoxins included deoxynivalenol, aflatoxins, ochratoxin A, zearalenone, T-2 toxin, fumonisins, sterigmatocistin, HT-2 toxin, diacetoxyscirpenol, enniatins, beauvericin, neosolaniol, citreoviridin, mycophenolic acid, citrinin, tentoxin, altenuene, alternariol and its monomethyl ether. Results. Among the regulated in plant products mycotoxins in the studied samples there were found aflatoxins (B1 - in 19% of samples, from 0.4 to 48.2 µg/kg, B2 - 8%, from < limit of quantitation (LOQ) to 3.2 µg/kg, G1 - 2%, 0.75-21 µg/kg, G2 - 5%, 0.5- 12.5 µg/kg), ochratoxin A (15% samples, 0.8-14 µg/kg), fumonisin B1 (8%, 16.1-722.6 µg/kg), and fumonisin B2 (14%, < LOQ - 79.6 µg/kg). T-2 toxin and deoxynivalenol were found in 10% of samples (< LOQ - 6.5 µg/kg and < LOQ - 65.5 µg/kg respectively), zearalenone - in 4 samples (1.7-106.2 µg/kg), HT-2 toxin - in 8 samples (5.4-19.8 µg/kg). Among little-studied (emergent) mycotoxins in the spices and herbs samples there were found tentoxin (in 36% of samples, in an amount from 0.7 to 10.9 µg/kg), altenuene (in 8%, 14.5-161.5 µg/kg). 10% of the samples were contaminated with alternariol and its methyl ether (from less than LOQ to 12.8 and < LOQ to 55.7 µg/kg, respectively), 4% - with sterigmatocystin (0.4-7.8 µg/kg), 5% - mycophenolic acid (13.1-297 µg/kg), 2% of the samples were contaminated with citrinin and enniatin B (< LOQ - 27.7 and 0.1-1 µg/kg), in 9 samples (6%) beauvericin was detected (< LOQ - 1.7 µg/kg). Over 60% of samples were contaminated with more than one mycotoxin. The content of aflatoxin B1 exceeded the maximum permissible level set in the EU (5 µg/kg) in nine samples. Conclusion. To the best of our knowledge, the present study is the first in the Russian Federation to report results indicating to the contamination of spices and herbs with mycotoxins. High occurrence of aflatoxins, tentoxin, ochratoxin A and fumonisin B2 has been observed. In calculating the potential exposure of mycotoxins, the possibility of high levels of aflatoxin B1 intake have been shown to be possible, which could lead to a public health risk when consuming contaminated spices, herbs and foods containing them.

Dual-Modal Immunochromatographic Test for Sensitive Detection of Zearalenone in Food Samples Based On Biosynthetic Staphylococcus aureus-Mediated Polymer Dot Nanocomposites.

The rapid detection of toxins is of great significance to food security and human health. In this work, a dual-modality immunochromatographic test (DICT) mediated by Staphylococcus aureus (SA)-biosynthesized polymer dots (SABPDs) was constructed for sensitive monitoring of zearalenone (ZEN) in agro products. The SABPDs as potent microorganism nanoscaffolds with excellent solubility, brightness, and stability were ingeniously fabricated employing hydroquinone and SA as precursors in the Schiff base reaction and a self-assembly technique. Thanks to the fact that they not only preserved an intact microsphere for loading Fc regions of monoclonal antibodies (mAbs) and the affinity of their labeled mAbs to antigen but also generated superb colorimetric-fluorescent dual signals, the versatile SABPDs manifested unique possibilities as the new carriers for dual-readout ICT with remarkable enhancement in sensitivity in ZEN screening (limit of detection = 0.036 ng/mL, which was 31-fold lower than that of traditional gold nanoparticle-based ICT). Ultimately, the proposed immunosensor performed well in millet and corn samples with satisfactory recoveries, demonstrating its potential for point-of-care testing. This work offers a bio-friendly strategy for biosynthesizing cell-based PD vehicles with bimodal signals for food safety analysis.

Stability of a calibrant as certified reference material for determination of trans-zearalenone by high performance liquid chromatography-diode array detection-triple quadrupole tandem mass spectrometry.

In this study, a trans-zearalenone (trans-ZEN) calibrant in acetonitrile as certified reference material (CRM) was prepared and intensively investigated the stability by high performance liquid chromatography coupled diode array detection and triple quadrupole tandem mass spectrometry (HPLC-DAD-MS/MS). The photoisomerization and degradation of main component and related impurities in trans-ZEN calibrant CRM was studied in detail under different light conditions such as UV light (254 nm), sunlight, and visible light. Trans-ZEN in acetonitrile was confirmed a significant shift toward cis-ZEN up to a 52% cis-isomerization rate after exposing to UV light (254 nm) in transparent ampule for 1 day. The unsaturated double bond photosensitive groups of trans-ZEN and cis-ZEN will further undergo photoreaction to generate more isomers and related products with the increase of UV irradiation time. The calibrant in amber ampules was relatively stable after exposing to sunlight for 28 days, with only 0.35% cis-isomer observed. The results indicated that trans-ZEN solution calibrant should be packed in amber ampules to avoid UV rays. Thermal stability test exhibited this calibrant was stable over 6 weeks even at 60 °C. Trans-ZEN was found to be more stable in acetonitrile than in methanol since an unknown impurity was observed in methanol after 6 weeks placed at 25 °C. The stability study of trans-ZEN calibrant provided a basis for the usage, storage, and transportation of the CRM. A concentration and expanded uncertainty of the trans-ZEN calibrant CRM of 11.01 ± 0.18 µg/mL was developed.

Trace analysis of emerging and regulated mycotoxins in infant stool by LC-MS/MS.

Infants are sensitive to negative effects caused by food contaminants such as mycotoxins. To date, analytical methods assessing mycotoxin mixture exposure in infant stool are absent. Herein, we present a novel multi-mycotoxin LC-MS/MS assay capable of detecting 30+ analytes including the regulated mycotoxin classes (aflatoxins, trichothecenes, ochratoxins, zearalenone, citrinin), emerging Alternaria and Fusarium toxins, and several key metabolites. Sample preparation consisted of a 'dilute, filter, and shoot' approach. The method was in-house validated and demonstrated that 25 analytes fulfilled all required criteria despite the high diversity of chemical structures included. Extraction recoveries for most of the analytes were in the range of 65-114% with standard deviations below 30% and limits of detection between 0.03 and 11.3 ng/g dry weight. To prove the methods' applicability, 22 human stool samples from premature Austrian infants (n = 12) and 12-month-old Nigerian infants (n = 10) were analyzed. The majority of the Nigerian samples were contaminated with alternariol monomethyl ether (8/10) and fumonisin B1 (8/10), while fumonisin B2 and citrinin were quantified in some samples. No mycotoxins were detected in any of the Austrian samples. The method can be used for sensitive human biomonitoring (HBM) purposes and to support exposure and, potentially, risk assessment of mycotoxins. Moreover, it allows for investigating potential associations between toxicant exposure and the infants' developing gut microbiome.

Recent advances in the highly sensitive determination of zearalenone residues in water and environmental resources with electrochemical biosensors.

Zearalenone (ZEN), a significant class of mycotoxin which is considered as a xenoestrogen, permits, similar to natural estrogens, it's binding to the receptors of estrogen resulting in various reproductive diseases especially, hormonal misbalance. ZEN has toxic effects on human and animal health as a result of its teratogenicity, carcinogenicity, mutagenicity, nephrotoxicity, genotoxicity, and immunotoxicity. To ensure water and environmental resources safety, precise, rapid, sensitive, and reliable analytical and conventional methods can be progressed for the determination of toxins such as ZEN. Different selective nanomaterial-based compounds are used in conjunction with different analytical detection approaches to achieve this goal. The current review demonstrates the state-of-the-art advances of nanomaterial-based electrochemical sensing assays including various sensing, apta-sensing and, immunosensing studies to the highly sensitive determination of various ZEN families. At first, a concise study of the occurrence, structure, toxicity, legislations, and distribution of ZEN in monitoring has been performed. Then, different conventional and clinical techniques and procedures to sensitive and selective sensing techniques have been reviewed and the efficient comparison of them has been thoroughly discussed. This study has also summarized the salient features and the requirements for applying various sensing and biosensing platforms and diverse immobilization techniques in ZEN detection. Finally, we have defined the performance of several electrochemical sensors applying diverse recognition elements couples with nanomaterials fabricated using various recognition elements coupled with nanomaterials (metal NPs, metal oxide nanoparticles (NPs), graphene, and CNT) the issues limiting development, and the forthcoming tasks in successful construction with the applied nanomaterials.

Shinella oryzae sp. nov., a novel zearalenone-resistant bacterium isolated from rice paddy soil.

A novel bacterium, designated Z-25 T, was isolated from a rice paddy rhizosphere soil sample from Wuchang County, China. The Z-25 T strain is gram-negative, rod-shaped, non-spore-forming, aerobic, motile by unipolar flagella and straw white in color. A phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain Z-25 belongs to the genus Shinella, and the closest members are Shinella zoogloeoides ATCC 19623 T with 98.58% similarity, S. kummerowiae CCBAU 25,048 T (98.03%) and S. granuli Ch06 T (97.37%). The average nucleotide identity and in silico DNA-DNA hybridization values between strain Z-25 T and the closest members were less than 85.29% and 28.70%, respectively. The predominant fatty acids were the sums of features comprising C18:1 ω7c and/or C18:1 ω6c (34.62%), C18:1 ω7c -11-methyl (20.48%), and C19:0 cyclo ω8c (18.19%). The only respiratory quinone was ubiquinone-10, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Additionally, a genome analysis showed that Z-25 T presented potential functional genes related to the degradation of zearalenone (ZEN). An HPLC analysis indicated that Z-25 T could remove 74.13% of 10 mg/L ZEN after 144 h at 30 °C. Therefore, based on phenotypic, chemotaxonomic, phylogenetic and genotypic analyses, strain Z-25 T represents a novel species in the genus Shinella, for which the name Shinella oryzae sp. nov. is proposed. The type strain is Z-25 T (= GDMCC 1.2424 T = KCTC 82660 T).

Assessment of multiple mycotoxin exposure and its association with food consumption: a human biomonitoring study in a pregnant cohort in rural Bangladesh.

Aflatoxins (AFs), ochratoxin A (OTA), citrinin (CIT), fumonisin B1 (FB1), zearalenone (ZEN), and deoxynivalenol (DON) are mycotoxins that may contaminate diets, especially in low-income settings, with potentially severe health consequences. This study investigates the exposure of 439 pregnant women in rural Bangladesh to 35 mycotoxins and their corresponding health risks and links their exposure to certain foods and local stimulants. Overall, 447 first-morning urine samples were collected from pregnant women between July 2018 and November 2019. Mycotoxin biomarkers were quantified by DaS-HPLC-MS/MS. Urinary concentration of frequently occurring mycotoxins was used to estimate dietary mycotoxin exposure. Median regression analyses were performed to investigate the association between the consumption of certain foods and local stimulants, and urinary concentration of frequently occurring mycotoxins. Only in 17 of 447 urine samples (4%) were none of the investigated mycotoxins detected. Biomarkers for six major mycotoxins (AFs, CIT, DON, FB1, OTA, and ZEN) were detected in the urine samples. OTA (95%), CIT (61%), and DON (6%) were most frequently detected, with multiple mycotoxins co-occurring in 281/447 (63%) of urine samples. Under the lowest exposure scenario, dietary exposure to OTA, CIT, and DON was of public health concern in 95%, 16%, and 1% of the pregnant women, respectively. Consumption of specific foods and local stimulants-betel nut, betel leaf, and chewing tobacco-were associated with OTA, CIT, and DON urine levels. In conclusion, exposure to multiple mycotoxins during early pregnancy is widespread in this rural community and represents a potential health risk for mothers and their offspring.

Fungal diversity and mycotoxins detected in maize stored in silo-bags: a review.

Silo-bags are hermetic storage systems that inhibit fungal growth because of their atmosphere with low humidity, as well as low pH and O2 concentrations, and a high CO2 concentration. If a silo-bag with stored maize loses its hermetic nature, it favors the development of fungi and the production of mycotoxins. To the best of our knowledge, this is the first review on the diversity of fungal species and mycotoxins that were reported in maize stored under the environmental conditions provided by silo-bags. The genera Penicillium, Aspergillus and Fusarium were found more frequently, whereas Acremonium spp., Alternaria sp., Candida sp., Cladosporium sp., Debaryomyces spp., Epiconum sp., Eupenicillium spp., Eurotium sp., Eurotium amstelodami, Hyphopichia spp., Hyphopichia burtonii, Moniliella sp., Wallemia sp. and genera within the orden Mucorales were reported less recurrently. Despite finding a great fungal diversity, all of the studies focused their investigations on a small group of toxins: fumonisins (FBs), aflatoxins (AFs), deoxynivalenol (DON), zearalenone (ZEA), patulin (PAT), toxin T2 (T2) and ochratoxin (OT). Of the FBs, fumonisin B1 and fumonisin B2 presented higher incidence percentages, followed by fumonisin B3 . Of the AFs, the only one reported was aflatoxin B1. The mycotoxins DON, ZEA and OT were found with lower incidences, whereas PAT and T2 were not detected. Good management practices of the silo-bags are necessary to achieve a hermetically sealed environment, without exchange of gases and water with the external environment during the storage period. © 2022 Society of Chemical Industry.