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We report the draft genome sequence of Thermomonas sp. strain XSG, isolated from a marine sediment. The genome is 3,047,478 bp long with a GC content of 68.5%., We report the draft genome sequence of Thermomonas sp. strain XSG, isolated from a marine sediment. The genome is 3,047,478 bp long with a GC content of 68.5%. Strain XSG was found to be closely related to strain NBRC 101115 of Thermomonas koreensis.

The antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) in Wastewater treatment plants (WWTPs) have attracted increasing attention. In this study, the abundance of ARB and resistance genes tet32 and defA1 were investigated using high-throughput sequencing and high-throughput qPCR in water samples collected from the inlet of the biological treatment pool and outlet of Beilun Yandong WWTP in Ningbo, China. The result shows there was a high level of ARGs in the water of both the inlets and outlets in 2017 and 2018, whereas no ARGs were detected after adding a new baffled bioreactor (BBR) water treatment process in 2019. The BBR process uses Bacillus subtilis, B. thuringiensis, B. megaterium, B. licheniformis and B. amyloliquefaciens to effectively eliminate the ARGs in wastewater. Notably, this process did not significantly change the bacterial community structure of outlet water samples. The findings demonstrate an effective new method for removing ARGs from sewage.

Sulfate-reducing bacteria (SRB) play an important role in sulfur, iron and carbon cycling. The majority of studies have illustrated the role of SRB in biogeochemical cycling in pure cultures. In this study, we established three SRB enrichment cultures (designated HL, NB and WC) from different paddy soils and conducted a transcriptomic analysis of their metabolic characteristics under sulfate and sulfate-free conditions. In the HL cultures, there was no sulfate consumption but ferrihydrite was reduced. This indicated that bacteria in the HL samples can reduce ferrihydrite and preferentially utilize ferrihydrite as the electron acceptor in the absence of both ferrihydrite and sulfate. Sulfate consumption was equal in the NB and the WC cultures, although more ferrihydrite was reduced in the NB cultures. Transcriptomics analysis showed that (i) upregulation of O-acetylserine sulfhydrylase gene expression indicating sulfate assimilation in the WC samples; (ii) the energy conservation trithionate pathway is commonly employed by SRB and (iii) sulfate not only enhanced iron reduction by its conversion to sulfide but also promoted enzymatic electron transfer via c-type cytochromes.

Selenium (Se) is an essential micronutrient in living organisms, having a narrow margin between essential and potentially toxic intake/exposure. Thus, the biochemistry of Se in living organisms must be studied in-depth to determine the underlying mechanism of Se cytotoxicity. In this study, we report the emergence of selenium nanovirus (SeNVs) in selenite-exposed fish (freshwater and saltwater) and plants (dryland) and its toxicity in them. SeNVs were found in both the abdomen and tail of Oryzias melastigma and saltwater Rhodeus ocellatus, which led to their death. The occurrence of the intracellular assembly of SeNVs was observed in the roots and leaves of corn Zea mays, but not in those of Limnobium laevigatum. SeNVs led to the death of Z. mays but caused chronic toxicity in L. laevigatum. SeNVs should be a system or structure that dissipates the intracellular redox gradients of the host cells, with simple information consisting Se–O, Se–N, or Se–S bond, that would ensure elemental Se ligand binding with nearly specific biomolecules in host cells, thereby maintaining their composition and stabilizing their structure. The multiple toxic effects of Se, therefore, could be the consequence of increase of entropy in the host cells caused by the intracellular assembly of SeNVs. This study may provide an insight into the underlying mechanism of Se in environmental toxicology and its applications in human health., Highlights • Intracellularly assembly of SeNPs has been considered as a new interpretation of selenium cytotoxicity. • We provide the concept of SeNVs, which should be a system/structure that dissipates the redox gradients of host cells. • The toxic effect of selenium could be the consequence of structural and functional disorder in the host cell caused by SeNVs. • The concept of SeNVs will be beneficial for understanding the toxicology of selenium.

The use of microorganisms in geochemical gold recycling was considered recently. To explore the feasibility of gold biomineralization in this study, bacteria GX-3 were isolated from a heavy metal c...

Biogeochemical interactions of iron and sulfur drive their cycles in many environments, which makes understanding the mechanism of sulfur redox cycling dependent abiotic iron(III) reduction by sulfate-reducing bacteria (SRB) particularly important. Here, we present a newly isolated Desulfitobacterium hafniense strain DH with the potential of reducing sulfate, sulfite, thiosulfate, and elemental sulfur from a paddy soil. Strain DH cannot enzymatically reduce ferrihydrite, but it can abiotically reduce ferrihydrite through extracellular electron transfer with biogenic sulfide or other sulfur compounds acting as electron shuttles. Sulfite, elemental sulfur, and thiosulfate, the oxidation products of sulfide, complete the sulfur cycle between ferrihydrite and strain DH. The presence of strain DH at the ferrihydrite surface results in mineral dissolution and secondary mineralization. Proteomic analysis revealed that the expression level of sulfur reduction functional protein DsrC and a thiosulfate reductase in...

Sulfate-reducing prokaryotes (SRP) represent a diverse group of heterotrophic and autotrophic microorganisms that are ubiquitous in anoxic habitats. In addition to their important role in both sulfur and carbon cycles, SRP are important biotic and abiotic regulators of a variety of sulfur-driven coupled biogeochemical cycling of elements, including: oxygen, nitrogen, chlorine, bromine, iodine and metal(loid)s. SRP gain energy form most of the coupling of element transformation. Once sulfate-reducing conditions are established, sulfide precipitation becomes the predominant abiotic mechanism of metal(loid)s transformation, followed by co-precipitation between metal(loid)s. Anthropogenic contamination, since the industrial revolution, has dramatically disturbed sulfur-driven biogeochemical cycling; making sulfur coupled elements transformation complicated and unpredictable. We hypothesise that sulfur might be detoxication agent for the organic and inorganic toxic compounds, through the metabolic activity of SRP. This review synthesizes the recent advances in the role of SRP in coupled biogeochemical cycling of diverse elements.

A new biogeochemical pathway has been suggested to be present in terrestrial ecosystems, linking the nitrogen and iron cycles via ferric iron reduction coupled to anaerobic ammonium oxidation. However, the underlying microbiological process has not been demonstrated to date. Here we report a stable consortium, HJ-4, composed of Anaerospora hongkongensis (85%) and facultative anaerobe, Comamonadaceae (15%), which can process ferrihydrite reduction coupled to anaerobic ammonium oxidation driven by sulfur redox cycling. In this process, A. hongkongensis reduces elemental sulfur, sulfite, and polysulfides to sulfide, which fuels ferrihydrite reduction. Sulfide, elemental sulfur, sulfite, and polysulfides serve as electron shuttles, completing the sulfur cycle between A. hongkongensis and ferrihydrite. In addition, Comamonadaceae shows ammonium oxidation potential under aerobic conditions, with nitrite as the main product. We inferred that Comamonadaceae mediates simultaneous nitrification-denitrification coupled to iron redox cycling through nitrate/nitrite-dependent ferrous oxidation under anaerobic conditions. Hence, we discovered a novel pathway for ferric iron reduction coupled to ammonium oxidation, highlighting the key role of electron shuttles and nitrate/nitrite-dependent ferrous oxidation in this process. The biogeochemical cycling of sulfur, iron, and nitrogen could be coupled in aquatic and terrestrial ecosystems.

The genus Bradyrhizobium is considered to be widespread and abundant group of symbiotic bacteria in many plant-soil ecosystems. However, the ecological versatility of this phylogenetic group remains highly understudied in man-made ecosystems, mainly due to the lack of pure cultures and genomic data. To further expand our understanding of this genus for human health, we analyzed the high quality draft genome of Bradyrhizobium strain BL, isolated from a municipal wastewater treatment plant in Ningbo, China. The Bradyrhizobium sp. BL draft genome has a total size of 7,718,431 bp with an overall G + C content of 46.43%. From a total of 7236 predicted sequences, 7176 and 60 are protein and RNA coding sequences, respectively. Moreover, 63.51% of the predicted genes were assigned into to Clusters of Orthologous Groups (COG) functional categories. The Bradyrhizobium sp. BL genome contains various defense mechanisms against antibiotics that up to predicted 60 antibiotic resistance coding genes. The Bradyrhizobium sp. BL genome contains 237 termed virulence factors coding genes which show its potential pathogenicity. This study provides important insights into the genomic diversity of the genus Bradyrhizobium and provides a foundation for future comparative genomic studies that will generate a better understanding of the antibiotic resistance process.

Sewage in WWTPs is one of main way to spread antibiotic resistant microbes (ARMs), and beach bay water is in direct contact with human skin. It is necessary to pay attention to remove the ARMs in WWTP sewage and bay water. Our results showed that ARMs and total microbes (TMs) can be effectively removed by S2O82-/Fe2+ in the effluent stage of WWTPs and bay water. Quenching experiments using tert-butyl alcohol, dimethyl sulfoxide and Al2O3 as scavengers confirmed that the primary reactive oxidants responsible for microbes removal during the Fe(II)-activated persulfate oxidation process might be SO4•- and Fe(IV), rather than •OH. The bacterial community shifted and the alpha diversity significantly reduced after treatment. In WWTP group, relative abundance of Firmicutes increased to 8.56%, and potential pathogens such as genus Vibrio decreased to 0.03% in bay water after treatment. The ecological toxicity to the environment of S2O82-/Fe2+ further illustrated that the mortality of indicator species Oryzias latipes did not increase after treatment, and the dosage of 60/30 μM can be potentially ideal dosage of S2O82-/Fe2+. This study revealed Fe(II)-activated persulfate oxidation as an eco-friendly and economical method could reduce TMs and ARMs in WWTP sewage and bay water.

Studies on the bacterial predation rate by rumen protozoa were carried out under laboratory conditions using a technique of fluorescence-labeled bacteria (FLB). Four Xuhuai goats were used in this experiment to obtain rumen protozoa and bacteria. Two groups were designed as follows: One group was the whole bacteria which were labeled using fluorescence through removing free bacteria from rumen fluid (WFLB); the other group was the bacteria which were labeled using fluorescence without removing free bacteria from rumen fluid (FLB). The result indicated that the bacterial predation rates of rumen protozoa was 398.4 cells/(cell h) for the group WFLB, 230.4 cells/(cell h) for the group FLB, when the corresponding values expressed as bacteria-N, they were 2.15 pg N/(cell h) for the group WFLB, and 1.24 pg N/(cell h) for the group FLB, respectively. Extrapolating the assimilation quantity of nitrogen by ciliates on bacteria of Xuhuai goat, there were 103.2 mg N/(d capita) for the group WFLB, and 59.5 mg N/(d capita) for the group FLB, respectively. It was estimated that protein losses due to microbial recycling were 0.645 g pro/(d capita) for the group WFLB and 0.372 g pro/(d capita) for the group FLB, respectively. In addition, the fluorescence-labeled technique would be a potential assay for the determination of bacterial predation rate by rumen protozoa.

Desulfitobacterium hafniense strain DH is a sulfate-reducing species. Here, we report the draft genome sequence of strain DH, with a size of 5,368,588 bp, average G+C content of 47.48%, and 5,296 predicted protein-coding sequences.

In a recent issue of Liver International, Agiasotelli D et al.(1) assessed serum and ascitic-fluid (AF) lipopolysaccharide binding proteins(LBP) and examined their association with mortality in patients with decompensated cirrhosis (DC). After undergoing a multivariate Cox regression analysis to 70 patients without infection at baseline, the authors found that high lnLBP(LBP values were converted to natural logarithms) (≥13.49) levels were associated with higher 90-day mortality compared to those with lower values. However, no difference in 90-day mortality among 18 patients with infection at baseline was shown between high and low (