Gut pathobiome mediates behavioral and developmental disorders in biotoxin-exposed amphibians

Emerging evidence suggests a link between alterations in the gut microbiome and adverse health outcomes in the hosts exposed to environmental pollutants.Yet,the causal relationships and underlying mechanisms remain largely undefined.Here we show that exposure to biotoxins can affect gut pathobiome assembly in amphibians,which in turn triggers the toxicity of exogenous pollutants.We used Xenopus laevis as a model in this study.Tadpoles exposed to tropolone demonstrated notable developmental impairments and increased locomotor activity,with a reduction in total length by 4.37%e22.48%and an increase in swimming speed by 49.96%e84.83%.Fusobacterium and Cetobacterium are predominant taxa in the gut pathobiome of tropolone-exposed tadpoles.The tropolone-induced developmental and behavioral disorders in the host were mediated by assembly of the gut pathobiome,leading to transcriptome reprogramming.This study not only advances our understanding of the intricate interactions between environmental pollutants,the gut pathobiome,and host health but also emphasizes the potential of the gut pathobiome in mediating the toxicological effects of environmental contaminants.

Characterization of the chemical fungicides-responsive and bacterial pathogen-preventing Bacillus licheniformis in rice spikelet

Seed-borne bacterial pathogens cause severe yield loss and biotoxin contamination in rice,leading to increasing concern on the global food supply and environmental safety.Plant native microbes play an important role in defending against diseases,but their actions are often influ-enced by the chemical fungicides applied in the field.Here,Bacillus licheniformis mmj was isolated from rice spikelet,which uniquely showed not only fungicide-responsiveness but also broad-spectrum antimicrobial activity against major rice bacterial pathogens including Xanthomonas oryzae pv.oryzae,Burkholderia plantari and Burkholderia glumae.To understand the hallmark underlying the environmental adaptation and anti-microbial activity of B.licheniformis mmj,the genome sequence was determined by SMRT and subjected to bioinformatics analysis.Genome sequence analysis enabled the identification of a set of antimicrobial-resistance and antibacterial activity genes together with an array of harsh environment-adaptive genes.Moreover,B.licheniformis mmj metabolites were analyzed with gas chromatography coupled to triple quadrupole mass spectrometry,and the volatile components that were linked with the antimicrobial activity were preliminarily profiled.Collectively,the present findings reveal the genomic and metabolic landscapes underlying fungicide-responsive B.licheniformis,which offers a new opportunity to design harsh environment-adaptive biopesticides to cope with prevalent bacterial phytopathogens.

Synthesis of a novel ternary HA/Fe-Mn oxides-loaded biochar composite and its application in cadmium(Ⅱ) and arsenic(Ⅴ) adsorption

Cadmium (Cd) and arsenic (As) are two of the most toxic elements.However,the chemical behaviors of these two elements are different,making it challenging to utilize a single adsorbent with high adsorption capacity for both Cd(Ⅱ) and As(Ⅴ) removal.To solve this problem,we synthesized HA/Fe-Mn oxides-loaded biochar (HFMB),a novel ternary material,to perform this task,wherein scanning electron microscopy (SEM) combined with EDS (SEM-EDS) was used to characterize its morphological and physicochemical properties.The maximum adsorption capacity of HFMB was 67.11 mg/g for Cd(Ⅱ) and 35.59 mg/g for As(Ⅴ),which is much higher compared to pristine biochar (11.06 mg/g,0 mg/g for Cd(Ⅱ) and As(Ⅴ),respectively).The adsorption characteristics were investigated by adsorption kinetics and the effects of the ionic strength and pH of solutions.X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR) revealed that chelation and deposition were the adsorption mechanisms that bound Cd(Ⅱ) to HFMB,while ligand exchange was the adsorption mechanism that bound As(Ⅴ).

Specific biotests to assess eco-toxicity of biodegradable polymer materials in soil

Eco-toxicity investigation of polymer materials was considered extremely necessary for their potential menace,which was widely use as mulching materials in agricultural.In this study,polyethylene(PE),polystyrene(PS)and synthetic biomaterials-Ecoflex and cellulose were applying into soil cultivated with two potential indicator plants species:oat(A v ena sati v a)and red radish(Raphanus sativum).Variety of chemical,biochemical parameters and enzyme activity in soil were proved as effective approach to evaluate polymers phytotoxicity in plant-soil mesocosm.The F-value of biomass,pH,heavy metal and electoral conductivity of Raphanus behaved significant different from T0.Significant analysis results indicated biodegradation was fast in PE than PS,besides,heavy metals were dramatically decrease in the end implied the plant absorption may help decrease heavy metal toxicity.The increase value at T2 of Dehydrogenase activity(0.84 higher than average value for Avena&0.91 higher for Raphanus),Metabolic Index(3.12 higher than average value for Avena&3.81 higher for Raphanus)means during soil enzyme activity was promoted by biodegradation for its heterotrophic organisms’energy transportation was stimulated.Statistics analysis was carried on Biplot PC1(24.2%of the total variance),PC2(23.2%of the total variance),versus PC3(22.8%of the total variance),which indicated phosphatase activity and metabolic index was significant correlated,and high correlation of ammonium and protease activity.Furthermore,the effects were more evident in Raphanus treatments than in Avena,suggesting the higher sensitivity of Raphanus to polymers treatment,which indicate biodegradation of polymers in Raphanus treatment has produced intermediate phytotoxic compounds.