Pantoea ananatis, a plant growth stimulating bacterium, and its metabolites isolated from Hydrocotyle umbellata (dollarweed).

A bacterium growing on infected leaves of Hydrocotyle umbellata, commonly known as dollarweed, was isolated and identified as Pantoea ananatis. An ethyl acetate extract of tryptic soy broth (TSB) liquid culture filtrate of the bacterium was subjected to silica gel chromatography to isolate bioactive molecules. Indole was isolated as the major compound that gave a distinct, foul odor to the extract, together with phenethyl alcohol, phenol, tryptophol, N-acyl-homoserine lactone, 3-(methylthio)-1-propanol, cyclo(L-pro-L-tyr), and cyclo(dehydroAla-L-Leu). This is the first report of the isolation of cyclo(dehydroAla-L-Leu) from a Pantoea species. Even though tryptophol is an intermediate in the indoleacetic acid (IAA) pathway, we were unable to detect or isolate IAA. We investigated the effect of P. ananatis inoculum on the growth of plants. Treatment of Lemna paucicostata Hegelm plants with 4 × 109 colony forming units of P. ananatis stimulated their growth by ca. five-fold after 13 days. After 13 days of treatment, some control plants were browning, but treated plants were greener and no plants were browning. The growth of both Cucumis sativus (cucumber) and Sorghum bicolor (sorghum) plants was increased by ca. 20 to 40%, depending on the growth parameter and species, when the rhizosphere was treated with the bacterium after germination at the same concentration. Plant growth promotion by Pantoea ananatis could be due to the provision of the IAA precursor indole.

Nosocomial bloodstream infection pathogen Pantoea dispersa: a case report and literature review.

Pantoea dispersa is a Gram-negative bacterium frequently found in plants, soil, and water. The genus Pantoea is a rare pathogen in human infectious diseases. The known susceptible populations include infants and postoperative and immunocompromised patients. To date, there have been no reports of nosocomial bloodstream infection due to P. dispersa following chest puncture. A 72-year-old Chinese woman suffering from chest distress was found to be blood culture positive for a Gram-negative bacterium. The organism was identified as P. dispersa through Vitek 2, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and 16S rRNA gene sequencing. Although cefoperazone-sulbactam and imipenem were used for treatment, the patient died four days later. To the best of our knowledge, this is the first case of nosocomial bloodstream infection caused by P. dispersa in China. We hope that this article might help clinicians understand better the potential pathogenicity of this pathogen.

Engineering living and regenerative fungal-bacterial biocomposite structures.

Engineered living materials could have the capacity to self-repair and self-replicate, sense local and distant disturbances in their environment, and respond with functionalities for reporting, actuation or remediation. However, few engineered living materials are capable of both responsivity and use in macroscopic structures. Here we describe the development, characterization and engineering of a fungal-bacterial biocomposite grown on lignocellulosic feedstocks that can form mouldable, foldable and regenerative living structures. We have developed strategies to make human-scale biocomposite structures using mould-based and origami-inspired growth and assembly paradigms. Microbiome profiling of the biocomposite over multiple generations enabled the identification of a dominant bacterial component, Pantoea agglomerans, which was further isolated and developed into a new chassis. We introduced engineered P. agglomerans into native feedstocks to yield living blocks with new biosynthetic and sensing-reporting capabilities. Bioprospecting the native microbiota to develop engineerable chassis constitutes an important strategy to facilitate the development of living biomaterials with new properties and functionalities.

Prevention of Diabetes-Associated Cognitive Dysfunction Through Oral Administration of Lipopolysaccharide Derived From Pantoea agglomerans.

Diabetes-related cognitive dysfunction (DRCD) is a serious complication induced by diabetes. However, there are currently no specific remedies for DRCD. Here, we show that streptozotocin-induced DRCD can be prevented without causing side effects through oral administration of lipopolysaccharide (LPS) derived from Pantoea agglomerans. Oral administration of LPS (OAL) prevented the cerebral cortex atrophy and tau phosphorylation induced by DRCD. Moreover, we observed that neuroprotective transformation of microglia (brain tissue-resident macrophages) is important for preventing DRCD through OAL. These findings are contrary to the general recognition of LPS as an inflammatory agent when injected systemically. Furthermore, our results strongly suggest that OAL promotes membrane-bound colony stimulating factor 1 (CSF1) expression on peripheral leukocytes, which activates the CSF1 receptor on microglia, leading to their transformation to the neuroprotective phenotype. Taken together, the present study indicates that controlling innate immune modulation through the simple and safe strategy of OAL can be an innovative prophylaxis for intractable neurological diseases such as DRCD. In a sense, for modern people living in an LPS-depleted environment, OAL is like a time machine that returns microglia to the good old LPS-abundant era.

Potent antiplasmodial alkaloids from the rhizobacterium Pantoea agglomerans as hemozoin modulators.

Global health concern regarding malaria has increased since the first report of artemisinin-resistant Plasmodium falciparum (Pf) two decades ago. The current therapies suffer various drawbacks such as low efficacy and significant side effects, alarming for an urgent need of more effective and less toxic drugs with higher patient compliance. Chemical entities with natural origins become progressively attractive as new drug leads due to their structural diversity and bio-compatibility. This study initially aimed at the targeted isolation of hydroxyquinoline derivatives following our published genomics and metabolomics study of Pantoea agglomerans (Pa). Fermentation of Pa on a pre-selected medium followed by chromatographic isolation, NMR and HRMS analyses led to the characterisation of one new hydroxyquinoline alkaloid together with another six known congeners and two known hydroxyquinolone derivatives. When screened for their antimalarial activity by high throughput screening against asexual blood-stage parasites, almost all compounds showed potent and selective sub-micromolar activities. Computational investigation was performed to identify the antiplasmodial potential targets. Ligand-based similarity search predicted the tested compounds to act as hemozoin inhibitors. Computational target identification results were further validated by competitive hemozoin inhibitory properties of hydroxyquinoline and hydroxyquinolone derivatives in vitro. The overall results suggest this natural scaffold is of potential to be developed as antimalarial drug lead.

Endophytic bacteria from strawberry plants control gray mold in fruits via production of antifungal compounds against Botrytis cinerea L.

Botrytis cinerea causes the gray mold disease in a wide range of plant hosts, especially in post-harvest periods. The control of this phytopathogen has been accomplished through the application of fungicides. However, this practice can cause environmental problems and increase fruit production costs. In addition, this fungus species has developed resistance to conventional synthetic fungicides. In this context, plant growth-promoting bacteria have shown potential for application in agricultural production because they are able to stimulate plant growth through different mechanisms, including the biological control of phytopathogens (indirect growth promotion mechanism). The aim of this work was to evaluate in vitro and in fruits the potential for indirect plant growth-promotion of bacteria isolated from strawberry leaves and roots. Dual plate method and inverted plate method were used to verify the ability of controlling in vitro the growth of Botrytis cinerea via the production of diffusible and volatile antifungal compounds, respectively. The effect of six bacterial isolates that showed greater potential for biological control in vitro was evaluated by scanning electron microscopy. Antifungal compounds produced by these bacterial isolates were identified by liquid chromatography coupled with mass spectrometry. Six bacterial strains were tested on strawberry pseudofruits. Five selected strains belong to the genus Bacillus and one to the genus Pantoea sp. Selected strains were able to inhibit more than 80 % of the mycelial growth of B. cinerea by the production of diffusible compounds and 90 % by volatile antifungal compounds production. Scanning electron microscopy showed the intense degradation of fungal hyphae caused by the presence of all bacterial strains. Bioactive compounds (salycilamide, maculosin, herniarin, lauroyl diethanolamide, baptifoline, undecanedioic acid, botrydial, 8 3-butylidene-7-hydroxyphthalide and N-(3-oxo-henoyl)-homoserine lactone) were obtained from liquid culture of these strains and extraction with ethyl acetate. All six isolates tested in vivo reduced the incidence of gray mold in strawberry pseudofruits in postharvest. It is concluded that isolates 26, 29, 65, 69, 132 (Bacillus sp.) and MQT16M1 (Pantoea sp.) have potential application for the biological control of Botrytis cinerea in strawberry via the production of diffusible and volatile antifungal compounds.

Structure characterization, antioxidant and emulsifying capacities of exopolysaccharide derived from Pantoea alhagi NX-11.

Pantoea alhagi exopolysaccharides (PAPS) have been shown to enhance crop resistance to abiotic stress. However, physicochemical properties and structure of PAPS have not yet been analyzed. In this study, two PAPSs, named PAPS1 and PAPS2, were isolated and purified from the P. alhagi NX-11. The results showed PAPS1 and PAPS2 were composed of glucose, galactose, glucuronic acid, glucosamine and mannose with average molecular weight of 1.326 × 106 Da and 1.959 × 106 Da, respectively. Moreover, the structure of PAPS1 and PAPS2 was investigated by FT-IR and NMR analysis. PAPS1 was identified to have the backbone structure of →4)-ß-D-GlcpA-(1→2)-α-D-Galp-(1→3)-ß-D-Galp-(1→3)-ß-D-GlcpN- (1→3)-α-D-Galp-(1→3)-ß-D-Galp-(1→. PAPS2 had the backbone structure of →4)-ß-D-GlcpA-(1→2)-α-D-Galp-(1→3)-ß-D-Glcp-(1→3)-ß-D-GlcpN-(1→3)-α-D-Galp-(1→3)-α-D-GlcpN-(1→. In addition, PAPS1 and PAPS2 had moderate antioxidant and emulsifying capacities. Overall, the structure analysis of PAPS may point out the direction for the subsequent study of PAPS-mediated microbial and plant interactions, and further exploration of the application of PAPS.

Lipopolysaccharide of Pantoea agglomerans 7460: O-specific polysaccharide and lipid A structures and biological activity.

Lipopolysaccharide (LPS) was isolated from Pantoea agglomerans 7460 cells by phenol-water extraction. Mild acid degradation allowed to separate OPS and lipid A. Lipid A was analyzed by negative-ion mode ESI MS and found to consist mainly of hexaacylated derivative containing biphosphorylated GlcN disaccharide, four 14:0 (3-OH), 18:0 and 12:0 fatty acids. The structure of the O-specific polysaccharide was established by chemical, NMR and computational methods: The LPS of Р. agglomerans 7460 showed low level of toxicity and pyrogenicity to compare with LPS of E. coli O55:B5 and pyrogenal, respectively. The ability of the modified (succinylated) LPS, which have lost its toxicity, to block the toxic effects of native LPS has been shown.

Useful Cases of Patients With Developmental Disorders Improved by Oral Administration of LPS Derived from Pantoea agglomerans.

BACKGROUND: Developmental disorders are associated with microglial dysfunction. Oral administration of lipopolysaccharide derived from Pantoea agglomerans bacteria (LPSp) leads to normalization of phagocytic activity of microglia and suppression of inflammation in mice. In this article, we report on a successful trial in which we achieved a significant improvement of symptoms in patients with developmental disorders. PATIENTS AND METHODS: Five pediatric patients diagnosed with autism spectrum disorders (ASD)/attention deficit hyperactivity disorder (ADHD) who visited our clinic received either 0.75 or 1 mg/day LPSp for 6 months or more, in addition to our usual therapy regimens (detoxification therapy, nutritional therapy, and vibration therapy). A survey questionnaire was completed by the patients' parents and evaluated using the Numerical Rating Scale. RESULTS: Behavior, verbal ability, and communication disabilities associated with ASD/ADHD improved in all patients. CONCLUSION: Oral administration of LPSp may represent a new treatment option in the area of developmental disorders where there is currently no treatment available.

Effects of exopolysaccharide derived from Pantoea alhagi NX-11 on drought resistance of rice and its efficient fermentation preparation.

Exopolysaccharide (EPS) plays an important role in plant growth-promoting bacteria (PGPB)-mediated enhancement of plant abiotic stress resistance. In this study, it is found that EPS from Pantoea alhagi NX-11 foliar sprayed at 20, 50, and 100 ppm could significantly enhance drought resistance of rice seedlings. The fresh weight and relative water content of EPS sprayed were increased. In addition, malondialdehyde content reduced while total chlorophyll, proline and soluble sugar content, prominent enhanced. Meanwhile, the antioxidant enzymes, CAT, POD and SOD, were also significantly increased. The drought resistance of rice was most pronounced at the 50 ppm EPS dose. For the sake of commercializing the gram-negative EPS-producing PGPB which were difficult to preserve, it is vital to improve the EPS yield. First, the carbon source, nitrogen source and inorganic salt were optimized. Subsequently, the effect of three oxygen vectors, which could increase the efficiency of oxygen mass transfer, on EPS yield was studied by response surface methodology. The maximum EPS yield (19.27 g/L) was obtained, which is 51.7% higher than the initial yield of 12.7 g/L. Overall, it may provide a new way for the industrialization of PGPB to increase the yield of EPS.

Structure of O-Polysaccharide and Lipid A of Pantoea Agglomerans 8488.

The Pantoea agglomerans 8488 lipopolysaccharide (LPS) was isolated, purified and characterized by monosaccharide and fatty acid analysis. The O-polysaccharide and lipid A components of the LPS were separated by mild acid degradation. Lipid A was studied by electrospray ionization mass spectrometry (ESI-MS) and found to consist of hexa-, penta-, tetra- and tri-acylated species. Two-dimensional nuclear magnetic resonance (NMR) spectroscopy revealed the following structure of the O-polysaccharide repeating unit →3)-α-L-Rhap-(1→6)-α-D-Manp-(1→3)-α-L-Fucp-(1→3)-ß-D-GlcNAcp-(1→. The LPS showed a low level of toxicity, was not pyrogenic, and reduced the adhesiveness index of microorganisms to 2.12, which was twofold less than the control. LPS modified by complex compounds of germanium (IV) and tin (IV) were obtained. It was found that six LPS samples modified by Sn compounds and two LPS samples modified by Ge compounds lost their toxic activity when administered to mice in a dose of LD50 (105 µg/mice or 5 mg/kg). However, none of the modified LPS samples changed their serological activity in an Ouchterlony double immunodiffusion test in agar.

Subchronic (90-day) toxicity assessment of Somacy-FP100, a lipopolysaccharide-containing fermented wheat flour extract from Pantoea agglomerans.

Pantoea agglomerans is a Gram-negative bacterium that is ubiquitous in the environment, colonizing animals, humans, and numerous plants, including cotton and wheat. A lipopolysaccharide-containing fermented wheat flour extract from P. agglomerans (Somacy-FP100) is proposed for use as a food ingredient for individuals seeking foods for healthy aging. Previously published genotoxicity studies with Somacy-FP100 reported its lack of genotoxicity in vitro, but a subchronic toxicity study has not yet been performed. Therefore, to demonstrate the safety of Somacy-FP100 for use as a food ingredient, a 90-day oral (gavage) toxicity study in rats was conducted. Male and female Han Wistar rats were administered vehicle (control) or Somacy-FP100 at 500, 1500, or 4500 mg/kg body weight/day at a dose volume of 10 mL/kg body weight, for at least 90 days. No test article-related adverse clinical signs or effects on body weight, food consumption, or clinical pathology were observed, and there were no macroscopic or microscopic findings related to the test article. Therefore, 4500 mg/kg body weight/day (the highest dose tested and highest feasible dose) was established as the no-observed-adverse-effect level. This absence of subchronic toxicity, in addition to the previously reported lack of genotoxicity, demonstrates the safety of Somacy-FP100 for use as a food ingredient.

A novel exopolysaccharide from marine bacterium Pantoea sp. YU16-S3 accelerates cutaneous wound healing through Wnt/ß-catenin pathway.

Natural polysaccharides with versatile properties are the potential candidates for wound healing applications. In this study, an exopolysaccharide, EPS-S3, isolated from a marine bacteria Pantoea sp. YU16-S3 was evaluated for its wound-healing abilities by studying the key molecular mechanisms in vitro and in vivo. Basic characterisation showed EPS-S3 as a heteropolysaccharide with glucose, galactose, N-acetyl galactosamine and glucosamine. The molecular weight of EPS-S3 was estimated to be 1.75 × 105 Da. It showed thermal stability up to 200 °C and shear-thickening non-Newtonian behaviour. It was biocompatible with dermal fibroblasts and keratinocytes and showed cell adhesion and cell proliferation properties. EPS-S3 facilitated cell migration in fibroblasts, induced rapid transition of cell cycle phases and also activated macrophages. In vivo experiments in rats showed the re-epithelialization of injured tissue with increased expression of HB-EGF, FGF, E-cadherin and ß-catenin in EPS-S3 treatment. The results indicate that EPS-S3 modulates healing process through Wnt/ß-catenin pathway due to its unique characteristics. In conclusion, EPS-S3 biosynthesized by the marine bacterium is a potential biomolecule for cutaneous wound healing applications.

Pantoea agglomerans chronic exposure induces epithelial-mesenchymal transition in human lung epithelial cells and mice lungs.

Pantoea agglomerans is gram-negative bacteria widely distributed in nature. It predominates in inhalable dust from grain, herbs, and flax, and was identified as the most important cause of hypersensitivity pneumonitis (HP) in eastern Poland. To better understand the molecular mechanism of HP development studies focused on the interactions between P. agglomerans and alveolar epithelial cells as well as lung tissue with particular emphasis on the epithelial-mesenchymal transition (EMT). The studies were conducted on human normal lung epithelial NL20 cells and mice strain C57BL/6J. Cells and mice underwent chronic exposure to saline extract of P. agglomerans (SE-PA). Morphological changes were evaluated under light microscopy, the concentration of fibrosis markers was examined by the ELISA method, while the expression of genes involved in EMT was evaluated by RealTime PCR. During incubation with SE-PA epithelial cells underwent conversion and assumed fibroblast phenotype characterized by a decrease in epithelial cells markers (CDH1, CLDN1, JUP) and increase in mesenchymal cells markers (FN1, VIM, CDH2). Mice lungs collected after 14 days of SE-PA treatment revealed inflammation with marked lymphocytes infiltration. The intensified inflammatory process accompanied by increased proliferation of fibrous connective tissue was noted in mice lungs after 28 days of SE-PA exposure. Histological changes correlated with an increase of fibrosis markers (hydroxyproline, collagens), downregulation of epithelial markers (Cdh1, Cldn1, Jup, Ocln) and upregulation of myofibroblasts markers (Acta2, Cdh2, Fn1, Vim). Obtained results revealed SE-PA ability to induce EMT in human lung epithelial cells and mice lung tissue, with the scale of changes proportional to the time of treatment.

Induction of Cryptic Antifungal Pulicatin Derivatives from Pantoea agglomerans by Microbial Co-Culture.

Microbial co-culture or mixed fermentation proved to be an efficient strategy to expand chemical diversity by the induction of cryptic biosynthetic pathways, and in many cases led to the production of new antimicrobial agents. In the current study, we report a rare example of the induction of silent/cryptic bacterial biosynthetic pathway by the co-culture of Durum wheat plant roots-associated bacterium Pantoea aggolomerans and date palm leaves-derived fungus Penicillium citrinum. The initial co-culture indicated a clear fungal growth inhibition which was confirmed by the promising antifungal activity of the co-culture total extract against Pc. LC-HRMS chemical profiling demonstrated a huge suppression in the production of secondary metabolites (SMs) of axenic cultures of both species with the emergence of new metabolites which were dereplicated as a series of siderophores. Large-scale co-culture fermentation led to the isolation of two new pulicatin derivatives together with six known metabolites which were characterised using HRESIMS and NMR analyses. During the in vitro antimicrobial evaluation of the isolated compounds, pulicatin H (2) exhibited the strongest antifungal activity against Pc, followed by aeruginaldehyde (1) and pulicatin F (4), hence explaining the initial growth suppression of Pc in the co-culture environment.

Identification and Characterization of pantocin wh-1, a Novel Cyclic Polypeptide Produced by Pantoea dispersa W18.

Pantoea dispersa W18, isolated from contaminated soil, was found to exert antimicrobial activity against Mycobacterium species, including Mycobacterium tuberculosis, an important human pathogen. Here, the anti-mycobacterial compound produced by Pantoea dispersa W18 was purified by a combination of hydrophobic interaction chromatography, cation exchange chromatography, and reverse phase HPLC. Active compounds from Pantoea dispersa W18 were identified as a natural peptide named pantocin wh-1 with a 1927 Da molecular weight. The primary structure of this compound was detected by N-terminal amino acid sequencing. The amino acid sequence of pantocin wh-1 consisted of 16 amino acid residues with a cyclic structure. The pantocin wh-1 could be inactivated by protease K, but was heat stable and unaffected by pH (2-12). However, the activity was not completely inactivated by trypsin and pepsin. This is the first report of a cyclic polypeptide purified from a strain of Pantoea dispersa.

Biocontrol activity and putative mechanism of Bacillus amyloliquefaciens (SF14 and SP10), Alcaligenes faecalis ACBC1, and Pantoea agglomerans ACBP1 against brown rot disease of fruit.

This study aimed at evaluating the antagonistic activity of 16 bacterial strains for the control of brown rot disease caused by Monilinia fructigena, and M. laxa under in vitro and a semi-commercial large-scale trial. These bacterial antagonists' belonging to the genera Alcaligenes, Bacillus, Brevibacterium, Pantoea, Pseudomonas, and Serratia were previously proven effective for control of fire blight of apple. The in vitro dual culture bioassay showed the highest inhibition rates of mycelial growth ranging from 55 to 95% and from 43 to 94% for M. fructigena and M. laxa, respectively. The in vivo bioassay showed moderate and strong inhibition for M. fructigena and M. laxa, respectively. The inhibition rates were dependent on incubation time as well as pathogen virulence. The free-cell bacterial filtrate revealed substantial mycelial growth inhibition ranging from 66 to 86%. The inhibition of conidial germination was from 32 to 78%, suggesting the involvement of metabolites in their biocontrol activity. The antifungal effect of the volatile compounds (VCOs) was observed for all bacteria with mycelial inhibition varying from 12 to 70%. Overall, their efficacy was substantially affected by the nature of the bacterial strains and the modes of action. Taken together, these results underscore that ACBC1 and SF14 for M. fructigena and SP10 and ACBP1 for M. laxa were the most effective bacterial strains. These strains were confirmed effective in a semi-commercial large-scale trial. Interestingly, their efficacies were found to be comparable to those of both commercial BCAs (B. subtilis Y1336 and P. agglomerans P10c), but slightly lower than thiophanate-methyl fungicide. The ability of most bacterial strains to produce lytic enzymes (Amylase, Protease or Cellulase) and lipopeptides (bacillomycin, fengycin, iturin and surfactin) was demonstrated by biochemical and molecular analyzes. Therefore, our findings suggest that the bacterial antagonists ACBC1, SF14, SP10 and ACBP1, have the potential to prevent brown rot disease.

Pantoea agglomerans P1a lipopolysaccharide: Structure of the O-specific polysaccharide and lipid A and biological activity.

O-specific polysaccharide and lipid A were obtained from the lipopolysaccharide from new strain of Рantoea agglomerans P1a by mild acid hydrolysis. It was found that the major form of lipid A presented by tetraacylated derivative containing biphosphorylated GlcN disaccharide, three 14:0 (3-OH) and 12:0 residues. The structure of the O-specific polysaccharide was established by chemical, NMR and computational methods: →3)-α-D-Manp-(1 → 4)-ß-D-Fucp-(1 → 4)-ɑ-D-Fucp-(1→The LPS of Р. agglomerans P1a showed low level of toxicity and pyrogenicity to compare with LPS of E. coli O55:B5 and pyrogenal (respectively).

Preventive Effect of Oral Administration of Pantoea agglomerans-derived LPS in a Hypertensive Rat Model Upon Salt Loading.

BACKGROUND/AIM: Oral administration of Pantoea agglomerans-derived lipopolysaccharide (LPSp) has been reported to have a preventive effect against various lifestyle-related diseases. Therefore, we examined the preventive effect on high blood pressure, which is a kind of reserve arm for lifestyle-related diseases. MATERIALS AND METHODS: Spontaneous hypertensive rat (SHR) and WKY rat were bred from 6 to 16 weeks of age. SHR were orally administered 100 µg/kg LPSp and 0.1% NaCl, and blood pressure was measured at 6, 10, 13 and 16 weeks. Furthermore, at 16 weeks of age, blood biochemical markers were measured and microbial community composition was analyzed. RESULTS: SHRs developed hypertension with age, which was exacerbated by salt loading. Although there was almost no reduction in blood pressure in SHRs that received LPSp. It was suppressed at 13-16 weeks of age in those with salt loading. CONCLUSION: Oral administration of LPSp showed a preventive effect on salt-loaded hypertension.

Aflatoxin B1 removal by three bacterial strains and optimization of fermentation process parameters.

Aflatoxin B1 (AFB1 ) removing bacterial strains were isolated from different habitats that were easily contaminated by AFB1 . Furthermore, the composition of the fermentation medium and conditions of fermentation process were optimized, including carbon source, nitrogen source, metal ions, temperature, initial pH value, inoculation volume, and culture broth volume. Using coumarin as the sole carbon and energy source, we primarily screened 31 strains, and 10 strains were found to be capable to remove AFB1 . Among them, the highest removal rate of 71.91% appeared in those isolated from rotten wood (poplar). Strains XY1, XY3, and T6 were carried out to identify, and the results were Klebsiella sp., Klebsiella pneumonia, and Pantoea sp., respectively. Corn cob powder and tryptone can significantly increase the AFB1 removal activity of these strains. The AFB1 removal activity of Klebsiella sp.XY1 and K. pneumonia XY3 can be enhanced by Ca2+ , and those of Pantoea sp. T6 can be enhanced by Cu2+ . Temperature and initial pH were positively correlated with the AFB1 removal activity of these strains in a certain range. This study not only provides reference for the screening and application of AFB1 removing bacteria, but also provides a basis for possible application in the food and feed industry.