Degradation Of Zearalenone Research Articles

Biodegradation methods and product analysis of zearalenone and its future development trend: A review

Mycotoxins are a class of important pollutants that seriously endanger food security, causing massive food waste and substantial economic losses. Zearalenone (ZEN) has become one of the representative type of mycotoxins owing to its wide range of contamination and high detection rate. With increasing ZEN contamination of food and increased biodegradation and targeting of ZEN, the food production industry has sought biodegradation techniques with enhanced safety and adaptability. We reviewed the identification of ZEN-degrading bacteria (Aspergillus niger, Myxoplasma rosea, etc.), the isolation and modification of ZEN-degrading enzymes (ZHD101, RmZHD, etc.), and the degradation of ZEN by cell factories combined with genetic engineering. The structure and toxicity of the degradation products produced therein, together with the degradation pathways and fate experienced, are analyzed. In future research, we intend to focus on screening and modifying ZEN-degrading enzymes with enhanced degradability and safety. Multi-selectivity and multi-targeting of biodegradation will also be developed for the degradation and removal of various ZEN derivatives. Notably, future biodegradation methods need to be closer to actual production, increase production adaptability, and be further studied with respect to stability and safety.

CotA laccase from Bacillus licheniformis ZOM-1 effectively degrades zearalenone, aflatoxin B1 and alternariol

In the present study, CotA laccase was cloned from Bacillus licheniformis ZOM-1 and expressed in Escherichia coli. In addition to the oxidative degradation of zearalenone (ZEN) and aflatoxin B1 (AFB1), CotA laccase also has the ability to degrade the Alternaria toxin alternariol (AOH). This is the first report of an Alternaria toxin-degrading enzyme. The optimal reaction temperature for CotA laccase is 80 °C, and the optimal reaction pH is approximately 9.0. By high-resolution mass spectrometry, we identified the oxidative degradation products. Additionally, toxicological analysis indicated that the degradation products had a significantly reduced effect on cell viability relative to the original toxins. In addition, we found that B. licheniformis ZOM-1 has the ability to degrade three mycotoxins, ZEN, AOH and alternariol monomethyl ether (AME). These findings provide possible application prospects for CotA laccase and B. licheniformis ZOM-1 as mycotoxin degradation products in food or feed.

Enzymatic Degradation of Zearalenone in the Gastrointestinal Tract of Pigs, Chickens, and Rainbow Trout.

The estrogenic mycotoxin zearalenone (ZEN) is a common contaminant of animal feed. Effective strategies for the inactivation of ZEN in feed are required. The ZEN-degrading enzyme zearalenone hydrolase ZenA (EC 3.1.1.-, commercial name ZENzyme®, BIOMIN Holding GmbH, Getzersdorf, Austria) converts ZEN to hydrolyzed ZEN (HZEN), thereby enabling a strong reduction in estrogenicity. In this study, we investigated the efficacy of ZenA added to feed to degrade ZEN in the gastrointestinal tract of three monogastric animal species, i.e., pigs, chickens, and rainbow trout. For each species, groups of animals received (i) feed contaminated with ZEN (chickens: 400 µg/kg, pigs: 200 µg/kg, rainbow trout: 2000 µg/kg), (ii) feed contaminated with ZEN and supplemented with ZenA, or (iii) uncontaminated feed. To investigate the fate of dietary ZEN in the gastrointestinal tract in the presence and absence of ZenA, concentrations of ZEN and ZEN metabolites were analyzed in digesta of chickens and rainbow trout and in feces of pigs. Upon ZenA administration, concentrations of ZEN were significantly decreased and concentrations of the degradation product HZEN were significantly increased in digesta/feces of each investigated animal species, indicating degradation of ZEN by ZenA in the gastrointestinal tract. Moreover, upon addition of ZenA to the diet, the concentration of the highly estrogenic ZEN metabolite α-ZEL was significantly reduced in feces of pigs. In conclusion, ZenA was effective in degrading ZEN to HZEN in the gastrointestinal tract of chickens, pigs, and rainbow trout, and counteracted formation of α-ZEL in pigs. Therefore, ZenA could find application as a ZEN-degrading feed additive for these animal species.

Kinetics, Thermodynamics and Mechanism of Enzymatic Degradation of Zearalenone in Degummed Corn Oil.

The kinetics and thermodynamics of the enzymatic degradation of zearalenone (ZEN) in degummed corn oil were investigated by analyzing the impacts of temperature, pH, ZEN hydrolase dosage and ZEN concentration on the initial reaction rate. The kinetic study found that the maximum reaction rate was 0.97 μmol × kg−1 min−1, the Michaelis constant (Km) was 11,476 μmol × kg−1 and the Michaelis equation was V = 0.97[S]/(11,476 + [S]). The thermodynamic study showed that the activation energy (Ea) was 70.37 kJ·mol−1, the activation enthalpy change of the reaction (ΔH) > 0, the free energy of activation (ΔG) > 0 and the activation entropy change (ΔS) < 0, indicating the reaction could not be spontaneous. The reaction mechanism of ZEN was studied by a hybrid quadrupole orbitrap mass spectrometer. It was found that ZEN first generated the intermediate G/L/D/W-ZEN+H2O, followed by generating the intermediate W-ZEN-H2O under the action of a degrading enzyme. Then, the lactone bond was opened to produce C18H24O6, and finally the decarboxylation product C17H24O4 formed automatically.

Combined in silico investigation and in vitro characterization of the zearalenone detoxification potential of dye-decolorizing peroxidase from Bacillus subtilis 168

Zearalenone (ZEN), one of the most hazardous mycotoxins commonly present in food, causes severe safety risks to human health. In this work, the ZEN detoxification potential of dye-decolorizing peroxidase BsDyP from Bacillus subtilis 168 was investigated by a combined computational and experimental study. Molecular docking and dynamics simulation suggested that BsDyP could allow the binding of ZEN at the γ-edge of heme and surface exposed redox-active Tyr335 residue. Consistently, the recombinant BsDyP expressed in Escherichia coli was found to be capable of directly oxidizing 83% of ZEN with H2O2 as an electron acceptor. Moreover, the presence of 2, 2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as a redox mediator of BsDyP could enhance ZEN degradation to more than 98% in the pH range of 5.0–10.0. BsDyP-catalyzed ZEN degradation could be regarded as detoxification as the transformation product displayed much less estrogenicity. Moreover, bi-enzymes system including glucose oxidase (GOD) and BsDyP was applied to degrade ZEN in contaminated corn steep liquor and achieved a 33% degradation percentage. The findings suggested that BsDyP could be developed as a biocatalyst for detoxification of ZEN in contaminated food and feed.

Genome Resource for Acinetobacter schindleri H4-3-C1: An Endophyte of Pseudostellaria heterophylla with Degradation Activity to Toxins Produced by Fungal Pathogens

Acinetobacter schindleri is an endophyte of Pseudostellaria heterophylla, a traditional Chinese herbal plant. It has high degradation activity to toxins produced by fungal pathogen Fusarium graminearum. Here, we deployed PacBio single-molecule real-time long-read sequencing technology to generate a complete genome assembly for the Acinetobacter schindleri H4-3-C1 strain and obtained 1.59 Gb of clean reads. These reads were assembled to a single circular DNA chromosome with a length of 3,265,024 bp, and no plasmid was found in the genome. Totals of 3,193 coding sequences, 91 transfer RNA, 21 ribosomal RNA, and 75 small RNAs were identified in the genome. This high-quality genome assembly and gene annotation resource will facilitate the excavation of the zearalenone degradation gene and provide valuable resources for preventing and controlling toxigenic fungal diseases of P. heterophylla. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Removal of Zearalenone from Degummed Corn Oil by Hydrolase on a Batch-Refining Unit.

The removal of zearalenone (ZEN) from degummed corn oil (DCO) using hydrolase on a batch-refining unit was studied. According to single-factor and response surface experiments, the optimum technological conditions for reaching the maximum degradation rate were a temperature of 39.01 °C, a pH of 8.08, a time of 3.9 h, and an enzyme dosage of 44.7 mg/kg, whereby the rate of ZEN degradation can reach 94.66%. Different effects on the removal of ZEN were observed at different initial ZEN contents under the optimal technological conditions, of which the decrease was rapid for high ZEN content and slow for low ZEN content.

Quality Attributes of Sesame Butter (Tahini) Fortified with Lyophilized Powder of Edible Mushroom (Agaricus blazei).

Sesame butter (tahini) is a common appetizer and food additive in the Mediterranean basin. Pathogenic strains and mycotoxin content are the most hazardous issues in the final product. This investigation aimed to enhance the quality and safety properties of tahini products against microbial hazards and mycotoxins. Local samples of tahini were evaluated for natural contamination, including mycotoxin level determinations. Agaricus blazei was utilized as a bioactive source and evaluated for the bioactive content of laccase, B-glucan, antioxidant activity, and phenolic content, as well as antimicrobial and antioxidant potency. Two fortification ratios (0.5% and 1.0%) were chosen to apply Agaricus in tahini sesame as a model. Chemical composition, color attributes, sensory properties, emulsion, and oxidative stability were evaluated for the fortified samples versus the control. The results reflected increments of protein (22.91 ± 0.64% to 29.34 ± 0.96%), fiber content (3.09 ± 0.05% to 6.27 ± 0.06%), emulsion stability (84.9 ± 1.24% to 95.41 ± 0.56%), oxidative stability, and bioactive group content. The fortification process is reflected by the absence of Salmonella, Listeria, and E. coli bacteria from contaminated samples after 30 days of storage. The water activity for 1.0% fortification (0.154 ± 0.001) was recorded as lower than the control sample (0.192 ± 0.002). Moreover, the degradation of aflatoxins and zearalenone content was recorded during storage. The degradation ratio reached 68% and 97.2% for 0.5% and 1.0% fortifications, respectively, while zearalenone degradation recorded a decline of 26.7% and 33.7%, respectively, for the same fortification ratios. These results recommended 1.0% lyophilized mushroom fortification as a quality and ameliorative safety treatment for tahini products.

Insight into the boosted ZEN degradation over defective Bi2WO6 ultrathin layers: ROS-mediated mechanism and application in corn oil

Establishing an effective and sustainable strategy for zearalenone (ZEN) degradation is of great significance to agricultural development and food safety. Herein, more than 98 % of ZEN (2 ppm) was photocatalytic degraded within 90 min over the oxygen-deficient Bi2WO6 ultrathin layers (BWO-U), along with the sharp elimination of biotoxicity to GES-1 cells. Theoretical calculations and characterizations revealed the ultrathin structure and oxygen vacancies endowed BWO-U with strengthened photoelectrochemical activity and O2-adsorption capacity, facilitating the generation of •O2– and 1O2 which play decisive roles in ZEN degradation. Furthermore, a possible mechanism was proposed based on nine intermediates identified via LC-MS, including the steps of cis–trans isomerization, oxidation and cleavage. Eventually, the method also exhibited immense potential in reducing ZEN-contamination in corn oil, and made no significant impact on the quality of corn oil. This work might provide a feasible strategy to mitigate ZEN-contamination and cast a new light on the ROS-mediated mechanism.

Zearalenone lactonase: characteristics, modification, and application.

Zearalenone (ZEN) and its derivatives are one of the most contaminated fungal toxins worldwide, posing a severe threat to food security and human life. Traditional physical and chemical detoxifying methods are unsatisfactory due to incomplete detoxification, nutrient loss, and secondary pollutants. In recent years, bioremediation for eliminating fungal toxins has been gradually investigated. ZEN lactone hydrolase (lactonase) has been widely studied because of its high activity, mild conditions, and non-toxic product property. This review comprehensively represents the gene mining, characterization, molecular modification, and application of microbial-derived ZEN lactonases. It is aimed to elucidate the advantages and challenges of ZEN lactonases in industrial application, which also provides perspectives on obtaining innovative and promising biocatalysts for ZEN degradation. KEY POINTS: • A timely and concise review related to enzymatic elimination towards ZEN is shown. • The catalytic conditions and mechanism of ZEN lactonase is presented. • The modification and application of ZEN lactonase are exhibited also.

Isolation and Mechanistic Characterization of a Novel Zearalenone-Degrading Enzyme.

Zearalenone (ZEN) and its derivatives pose a serious threat to global food quality and animal health. The use of enzymes to degrade mycotoxins has become a popular method to counter this threat. In this study, Aspergillus niger ZEN-S-FS10 extracellular enzyme solution with ZEN-degrading effect was separated and purified to prepare the biological enzyme, FSZ, that can degrade ZEN. The degradation rate of FSZ to ZEN was 75–80% (pH = 7.0, 28 °C). FSZ can function in a temperature range of 28–38 °C and pH range of 2.0–7.0 and can also degrade ZEN derivatives (α-ZAL, β-ZOL, and ZAN). According to the enzyme kinetics fitting, ZEN has a high degradation rate. FSZ can degrade ZEN in real samples of corn flour. FSZ can be obtained stably and repeatedly from the original strain. One ZEN degradation product was isolated: FSZ−P(C18H26O4), with a relative molecular weight of 306.18 g/mol. Amino-acid-sequencing analysis revealed that FSZ is a novel enzyme (homology < 10%). According to the results of molecular docking, ZEN and ZAN can utilize their end-terminal carbonyl groups to bind FSZ residues PHE307, THR55, and GLU129 for a high-degradation rate. However, α-ZAL and β-ZOL instead contain hydroxyl groups that would prevent binding to GLU129; thus, the degradation rate is low for these derivatives.

Isolation and characterization of novel soil bacterium, Klebsiella pneumoniae strain GS7-1 for the degradation of zearalenone in major cereals

Zearalenone (ZEN) is one of the major agricultural feed contaminants causing serious health hazards worldwide and its degradation by beneficial microbial agents is now being widely examined. In this study we investigated the degradation ability of Klebsiella pneumoniae strain GS7-1 isolated from corn field in Shandong province in China on ZEN. The effects of temperature, incubation time and pH were studied. Furthermore, it was examined if the washed cell pellet and the supernatant of fermented culture (SFC) of the bacterial cell components could detoxify ZEN. ZEN removal increased with increase in pH from 61.3% at pH 5–100% at pH 8. The minimum and maximum temperatures at which K. pneumoniae strain GS7-1 degraded ZEN were 28 °C and 60 °C, respectively. Increase in incubation time increased the degradation effect as ZEN was completely degraded at 96 h. The SFC of strain GS7-1 reduced the ZEN content by 100%, while the first and second washed of the cell pellets in PBS reduced the ZEN content by 30% and 25%, respectively. The rate of SFC degradation significantly decreased after treatment with proteinase K, SDS and the combination of proteinase K and SDS. There exists a significant correlation between temperature, incubation time and pH regarding ZEN degradation by strain GS7-1. The results also suggest that enzymes present in the supernatant of Klebsiella pneumoniae GS7-1 were involved in ZEN degradation. The biodegradation of ZEN is a very feasible method for food and feed purification as physical and chemical methods may not only eliminate mycotoxins, but also nutrients and sensory-related compounds.

Effects of Intestinal Microorganisms on Metabolism and Toxicity Mitigation of Zearalenone in Broilers

Simple SummaryZearalenone (ZEN) widely contaminates all the feed crops, and ZEN may cause harmful damage to animals and humans. Different animals have different sensitivity to ZEN. Among these animals, chickens show a strong resistance. Intestinal microorganisms are essential in digestion and degradation. Therefore, we hypothesise whether intestinal microorganisms in chickens play an important role in digesting and degrading ZEN. In this study, we found that intestinal microorganisms could degrade ZEN to a certain degree by both vivo and vitro experiments. We concluded that the intestinal microbiota of broilers had metabolic effects on ZEN and alleviated antioxidant and liver damage caused by ZEN to broilers. Moreover, we found some key bacteria that are important in degrading ZEN.Zearalenone (ZEN) is an estrogenic mycotoxin, and chickens are relatively insensitive to it. In this study, the effects of intestinal microorganisms on ZEN metabolism and toxicity mitigation in broilers were studied by two experiments. Firstly, in vitro, ZEN was incubated anaerobically with chyme from each part of the chicken intestine to study its intestinal microbial metabolism. Then, in vivo, we explored the effects of intestinal microbiota on ZEN by inhibiting intestinal microorganisms. Broilers were fed a control diet, 2.5 mg/kg ZEN diet, microbial inhibition diet or ‘microbial inhibition +2.5 mg/kg ZEN’ diet. In vitro, the results showed that the rates of ZEN degradation by microorganisms in the duodenum, ileum, caecum, and colon were 56%, 12%, 15%, and 17%, respectively, and the microorganisms could convert ZEN into Zearalenol (ZOL). After microbial inhibition in vivo, the content of ZEN and its metabolites in excreta of broilers increased significantly, and antioxidant damage and liver damage were aggravated. 16S rRNA sequencing results showed that antioxidant indices and the content of ZEN and its metabolites in excreta were significantly correlated with the relative abundance of Streptococcus, Lactococcus and Enterococcus, etc. In conclusion, the intestinal microorganisms of broilers play an important role in ZEN metabolism and ZEN-induced antioxidant and liver injury mitigation, among which the key bacteria include Streptococcus, Lactococcus and Enterococcus, etc.

IN VITRO STUDY OF THE EFFICACY OF MYCOTOXINS DEGRADATION BY FEED ENZYMES

Providing healthy and safe food in terms of mycotoxicological safety is an imperative for not only good and sustainable livestock production, but also for the population that consumes food of both plant and animal origin. Climate change in the temperate regions of southern Europe has led to frequent occurrence of aflatoxins, deoxynivalenol and zearalenone in cereals. In order to reduce harmful effects of these toxins on animal health as well as to avoid large economic losses, various feed additives are increasingly being used. All of them must first of all be safe, and then have certain efficiency in the fight against mycotoxins. Although in vivo experiments are mandatory to assess the efficacy, in vitro test offers the advantage of rapid screening of the efficacy of a large number of food additives. In this paper, the efficiency of two commercial products belonging to the enzyme group for animal nutrition was investigated for degradation of aflatoxin B1, zearalenone and deoxynivalenol using in vitro experiments. For this purpose, two different methodologies were used according to the recommendation of the enzyme manufacturer. The percentage of mycotoxin degradation was recorded by high pressure liquid chromatography and ELISA methods. One of the tested enzymes showed a very high efficiency in zearalenone degradation being as much as 96%. Both tested enzyme samples showed similar percentage of aflatoxin B1 degradation (about 35%). Deoxynivalenol was not significantly degradable under the applied test conditions.

Zearalenone Degradation by Dielectric Barrier Discharge Cold Plasma: The Kinetics and Mechanism.

In this study, dielectric barrier discharge (DBD) cold plasma was used to degrade zearalenone and the efficiency of degradation were evaluated. In addition, the degradation kinetics and possible pathway of degradation were investigated. The results showed that zearalenone degradation percentage increased with increasing voltage and time. When it was treated at 50 KV for 120 s, the degradation percentage could reach 98.28%. Kinetics analysis showed that the degradation process followed a first-order reaction, which fitted the exponential function model best (R² = 0.987). Meanwhile, liquid chromatographywith quadrupole time-of-flight mass spectrometry (Q-TOF LC/MS) was used to analyze the degradation products, one major compound was identified. In this study, the reactive species generated in cold plasma was analyzed by Optical Emission Spectroscopy (OES) and the free radicals were detected by Electron Spin Resonance (ESR). This study could provide a theoretical basis for the degradation of zearalenone to a certain extent.

Detoxification of the mycoestrogen zearalenone by Bacillus licheniformis spore CotA laccase and application of immobilized laccase in contaminated corn meal

Zearalenone (ZEN) is an estrogen-like mycotoxin posing a great threat to human and animal health. The present study showed that the induction of spore CotA laccase production of Bacillus licheniformis by ions Mn2+ and Cu2+ promoted the ZEN-degrading ability of the strain. The spore CotA laccase heterologously expressed in Escherichia coli was capable of directly oxidizing ZEN with Km, Kcat and Vmax values of 90.43 μg mL−1, 0.11s−1 and 35.48 μg min−1 mg−1, respectively. The use of 2, 2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), acetosyringone, ferulic acid, caffeic acid and methyl syringate as redox mediators could enhance ZEN degradation by CotA laccase. The human breast cancer MCF-7 cell proliferation assay showed that CotA laccase and CotA laccase-mediator systems eliminated the estrogenicity of ZEN. Immobilized CotA laccase onto chitosan microspheres exhibited higher thermal stability over free CotA laccase, maintaining about 87% of its initial activity after heat treatment at 80 °C for 30 min. The removal rate of ZEN in corn meal by free and immobilized CotA laccase was 70% and 90%, respectively. Meanwhile, immobilized enzyme could achieve a 54% ZEN degradation in corn meal after three consecutive cycles. Thus, CotA laccase could be a promising biocatalyst for detoxification of ZEN in corn meal.

Characterization and Whole-Genome Analysis of a Zearalenone-Degrading Stappia sp. WLB 29.

Zearalenone (ZEN) is a widely distributed mycotoxin that frequently contaminates crops and animal feed. Our previous studies showed that a new strain, Stappia sp. WLB 29 with a 97.47% of similarity to Stappia indica B106T, isolated from the soil samples in the rhizosphere of the crops in Xinjiang, was capable of effectively degrading ZEN in minimal medium. In this study, we determined the complete genomic sequence of the Stappia sp. WLB 29 (Genbank accession number: JALBGD000000000; BioProject ID in GenBank is PRJNA814005). The total length of all sequences was 4,745,415bp with a GC content of 67.08%. Moreover, the genome-wide analysis showed the presence of laccase- and peroxiredoxin-encoding genes in Stappia sp. WLB 29, which may be associated with ZEN degradation. The genome sequence of Stappia sp. WLB 29 reported here will serve as a reference for comparative genomic studies of ZEN degradation in the feed and food industry.

Isolation, Characterization, and Application of Clostridium sporogenes F39 to Degrade Zearalenone under Anaerobic Conditions.

Zearalenone (ZEN) is produced by Fusarium spp. and is widely found in moldy wheat, corn, and other grains. ZEN has a strong toxicity and causes reproductive and immune disorders and estrogenic syndrome in animals and humans. Biodegradation has been demonstrated as an efficient way to control the hazardous effect of ZEN. A promising way to apply biodegradation in feed is to introduce anaerobic ZEN-degrading microorganisms, which can function during the digestion process in animal intestines. The aim of this study was to isolate anaerobic ZEN-degrading bacteria from anaerobic environments. A strain named F39 was isolated from animal intestinal contents and had a ZEN-degradation rate of 87.35% in 48 h to form trace amount of α- and β-zearalenol. Based on the morphological and physiological properties and phylogenetic analysis of 16S rRNA and rpoB gene sequences, F39 was identified as Clostridium sporogenes. The optimum temperature for the growth of F39 was 37 °C, the optimum pH was 7.0, and the most suitable carbon source was beef extract, while the optimal conditions for the degradation of ZEN were as follows: 35 °C, pH 7.0, and GAM medium. ZEN was degraded by F39 with a high efficiency in the concentration range of 1–15 mg/L. The bioactive factors responsible for ZEN degradation were mainly distributed intracellularly. F39 can degrade most of the ZEN present, but a small amount is broken down into two secondary metabolites, α- and β-zearalenol, and the toxicity of the degradation products is reduced. With an efficiency of 49%, F39 can more effectively degrade ZEN in wheat-based feedstuffs than in other feedstuff, and the degradation efficiency was pH related. To the best of our knowledge, this is the first report of Clostridium sporogenes F39’s ability to maintain the biodegradation potentials.

Excavation, expression, and functional analysis of a novel zearalenone-degrading enzyme.

Zearalenone (ZEN) is a toxic secondary metabolite of Fusarium sp. commonly found in wheat, corn, and other crops. In addition to economic losses, ZEN can seriously endanger the health of both humans and livestock, thus presenting an urgent need for ZEN-detoxifying enzymes that function in the extreme heat or pH conditions of industrial fermenters. Here, we identify and characterize the activity of the ZEN-degrading enzyme from Exophiala spinifera, ZHD_LD, which shares 60.15% amino acid identity and a conserved catalytic triad with the well-characterized ZEN-detoxifying protein ZHD101 from Clonostachys rosea. Biochemical activity and stability assays indicated that purified recombinant ZHD_LD exhibited high activity against ZEN with optimal reaction conditions of 50 ℃ and pH 7.0-10.0. Structural modeling of the ZHD_LD active site and comparison with ZHD101 revealed its likely mechanism of ZEN degradation. This research provides an industrially valuable candidate enzyme for ZEN detoxification in food and livestock feed.

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

A novel bacterium, designated Z-25T, was isolated from a rice paddy rhizosphere soil sample from Wuchang County, China. The Z-25T 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 19623T with 98.58% similarity, S. kummerowiae CCBAU 25,048T (98.03%) and S. granuli Ch06 T (97.37%). The average nucleotide identity and in silico DNA-DNA hybridization values between strain Z-25T 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-25T presented potential functional genes related to the degradation of zearalenone (ZEN). An HPLC analysis indicated that Z-25T could remove 74.13% of 10mg/L ZEN after 144h at 30°C. Therefore, based on phenotypic, chemotaxonomic, phylogenetic and genotypic analyses, strain Z-25T represents a novel species in the genus Shinella, for which the name Shinella oryzae sp. nov. is proposed. The type strain is Z-25T (= GDMCC 1.2424T = KCTC 82660T).