-
Ecotoxicology and Environmental Safety Oct 2022Flue gas lead emission during sludge incineration damages to human health and ecological environment seriously. Therefore, a denitrifying bio-trickling filter (DNBTF)...
Flue gas lead emission during sludge incineration damages to human health and ecological environment seriously. Therefore, a denitrifying bio-trickling filter (DNBTF) for lead removal in flue gas from sludge incineration was investigated. Lead removal efficiency was up to 90.7% in 60 days' operation. Lead speciation in biofilms of DNBTF consists of 84.27% residue lead, 15.18% organic bound lead, and less than 1% exchangeable and reducible lead. Lead resistant bacteria and lead resistant-denitrifying bacteria accounted for 85.04% and 58.25%, respectively. Lead resistant microorganisms(Pseudomonas, Azoarcus, Stappia, Pararhodobacter, Paracoccus, Azospirillum, Hyphomonas, Rhodobacter, Polymorphum, Brevunimonas, Stenotrophomonas) could resist the toxicity of Pb in flue gas by transport protein and binding protein, and detoxify Pb in flue gas by extracellular polymeric substances (EPS) adsorption, protein binding and precipitation under the action of resistance genes, such as pbrAB, golT, troABCD, znuABC, czcABCD, pcoB, copA, as shown by integrated metagenomic and metaproteomic analyses. The biofilm was characterized by FTIR, XRD, 3D-EEM, and SEM-EDS. XRD and SEM-EDS spectra indicated the formation of pyromorphite from bioconversion of lead in flue gas. Lead-containing flue gas was bio-stabilized in the form of pyromorphite and HA-Pb via complexation of humic acids in extracellular polymeric substances (EPS), biosorption and biodeposition. This provides a new way of sludge incineration flue gas lead removal using a denitrifying biotricking filter.
Topics: Carrier Proteins; Denitrification; Humans; Humic Substances; Incineration; Lead; Metagenomics; Minerals; Phosphates; Sewage
PubMed: 36087469
DOI: 10.1016/j.ecoenv.2022.114059 -
Biochemistry. Biokhimiia Nov 2019F×F-ATPases of mitochondria, chloroplasts, and microorganisms catalyze transformation of proton motive force (the difference between the electrochemical potentials of... (Review)
Review
F×F-ATPases of mitochondria, chloroplasts, and microorganisms catalyze transformation of proton motive force (the difference between the electrochemical potentials of hydrogen ion across a coupling membrane) to the free energy of ATP phosphoryl potential. It is often stated that F×F-ATPases operate as reversible chemo-mechano-electrical molecular machines that provide either ATP synthesis or hydrolysis depending on particular physiological demands of an organism; the microreversibility principle of the enzyme catalysis is usually taken as a dogma. Since 1980, the author has upheld the view that the mechanisms of ATP synthesis and hydrolysis by the F×F complex are different (Vinogradov, A. D. (2000) J. Exp. Biol., 203, 41-49). In this paper, the author proposes a new model considering the existence in coupling membranes of two non-equilibrium isoforms of F×F unidirectionally catalyzing synthesis and/or hydrolysis of ATP.
Topics: Adenosine Triphosphate; Biocatalysis; Chloroplasts; Hydrolysis; Kinetics; Mitochondria; Paracoccus denitrificans; Proton-Motive Force; Proton-Translocating ATPases
PubMed: 31760915
DOI: 10.1134/S0006297919110038 -
Integrated pathway engineering and transcriptome analysis for improved astaxanthin biosynthesis in .Synthetic and Systems Biotechnology Dec 2022Astaxanthin is a high value carotenoid with a broad range of commercial applications due to its superior antioxidant properties. In this study, β-carotene-producing...
Astaxanthin is a high value carotenoid with a broad range of commercial applications due to its superior antioxidant properties. In this study, β-carotene-producing XK17 constructed in the lab was employed for astaxanthin biosynthesis. The catalytic effects of β-carotene ketolase CrtW and β-carotene hydroxylase CrtZ from various species were investigated. The PspCrtW from sp. and HpCrtZ from were confirmed to be the best combination in converting β-carotene. Several key bottlenecks in biomass and astaxanthin biosynthesis were effectively eliminated by optimizing the expression of the above enzymes and restoring uracil/leucine biosynthesis. In addition, the effects of astaxanthin biosynthesis on cell metabolism were investigated by integrated analysis of pathway modification and transcriptome information. After further optimization, strain DN30 was able to synthesize up to 730.3 mg/L astaxanthin in laboratory 5-L fermenter. This study provides a good metabolic strategy and a sustainable development platform for high-value carotenoid production.
PubMed: 36092272
DOI: 10.1016/j.synbio.2022.08.001 -
Frontiers in Microbiology 2021As the unique component of , dendrobine-type sesquiterpenoid alkaloids (DSAs) possess a variety of medicinal properties. It has been well documented that plant...
As the unique component of , dendrobine-type sesquiterpenoid alkaloids (DSAs) possess a variety of medicinal properties. It has been well documented that plant endophytes can synthesize secondary metabolites identical or similar to metabolites produced by their host plants. This study aimed to investigate the composition and distribution of endophytic bacteria of stems by Illumina MiSeq platform sequencing and cultivation-dependent methods and then to assess the potential for endophytic bacteria to produce DSAs. Results indicated that it was necessary to combine both cultivation-dependent and cultivation-independent methods to analyze the community structure of endophytic bacterial in plants comprehensively. The length of the stems influenced the endophytic bacterial community. The diversity and richness of endophytic bacteria in group J10_15cm of stems were the highest, which showed a significant difference from the other stem groups. However, there was no certain connection between the diversity and richness of endophytic bacteria and the content of dendrobine. It was most likely due to the influence of several specific endophytic bacteria genera, such as and . , , as pathogenic fungi, and subsp. , as pathogenic bacteria of , were used to determine the antimicrobial activities. In these assays, six strains belonging to five genera showed antimicrobial activity against at least two phytopathogens. The strain BL-YJ10_15-29 ( THG-N2.35, 98.98%) showed the best antimicrobial activity against the three phytopathogens. In addition, 2 DSAs (6-hydroxydendrobine and nobilonine) were identified in the fermentation supernatant of the strain CM-YJ10_15-44 ( CHA0, 99.24%), whereas the whole-genome analysis results further demonstrated that the precursors of the two DSAs [geranyl-PP and (E, E)-famesyl-PP] were synthesized mainly through the methyl-D-erythritol 4-phosphate pathway in this strain. This study provides new insight into the studies on the biosynthesis of DSAs and provides potential biocontrol bacteria.
PubMed: 35069479
DOI: 10.3389/fmicb.2021.775665 -
RSC Advances Aug 2020A pilot-scale anaerobic/anoxic/aerobic-membrane aerated biofilm reactor (A/O-MABR) system was constructed to enhance carbon and nitrogen removal. The effects of major...
A pilot-scale anaerobic/anoxic/aerobic-membrane aerated biofilm reactor (A/O-MABR) system was constructed to enhance carbon and nitrogen removal. The effects of major operating parameters including the nitrate recycling ratio (), sludge recycling ratio (), and aerobic tank dissolved oxygen (DO) concentration on the system performance were investigated. The average removal efficiencies of the chemical oxygen demand (COD), ammonium nitrogen (NH -N), and total nitrogen (TN) were 89.0 ± 3.2%, 98.8 ± 1.3%, and 68.5 ± 4.2%, respectively, and their effluent concentrations were averagely 22.6 ± 7.3, 0.32 ± 0.2, and 13.3 ± 1.2 mg L. The suspended sludge and biofilm in aerobic tank facilitated the simultaneous nitrification and denitrification (SND) processes. Indeed, unique biofilm layered structure and abundant microbial community in the biofilm on MABR would enhance nitrogen removal. Compared with the A/O system, the A/O-MABR system exhibited higher nitrifying bacteria oxygen uptake rate (OUR) of 58.1 and 54.5 mgO per gMLSS per h in suspended sludge and biofilm, respectively, and the lower mixed liquor suspended solid (MLSS) concentration of 1800 mg L. Moreover, high-throughput sequencing indicated that putative nitrogen removal bacteria such as and could be effectively enriched in the biofilm. Since the volume proportions of the anaerobic, anoxic, aerobic and settling tank in the existing A/O system of the WWTP was not changed, the A/O-MABR system was simple and practical for the upgrading of A/O system.
PubMed: 35520069
DOI: 10.1039/d0ra04120c -
Environmental Microbiology Dec 2021Toxic organoarsenicals enter the environment from biogenic and anthropogenic activities such as microbial methylation of inorganic arsenic and pentavalent herbicides...
Toxic organoarsenicals enter the environment from biogenic and anthropogenic activities such as microbial methylation of inorganic arsenic and pentavalent herbicides such as monosodium methylarsenate (MSMA or MAs(V)). Trivalent MAs(III) is considerably more toxic than arsenite or arsenate. Microbes have evolved mechanisms to detoxify organoarsenicals. We previously identified ArsV, a flavin-linked monooxygenase and demonstrated that it confers resistance to methylarsenite by oxidation to methylarsenate. The arsV gene is usually in an arsenic resistance (ars) operon controlled by an ArsR repressor and adjacent to a methylarsenite efflux gene, either arsK or a gene for a putative transporter. Here we show that Paracoccus sp. SY oxidizes methylarsenite. It has an ars operon with three genes, arsR, arsV and a transport gene termed arsW. Heterologous expression of arsV in Escherichia coli conferred resistance to MAs(III), while arsW did not. Co-expression of arsV and arsW increased resistance compared with either alone. The cells oxidized methylarsenite and accumulated less methylarsenate. Everted membrane vesicles from E. coli cells expressing arsW-accumulated methylarsenate. We propose that ArsV is a monooxygenase that oxidizes methylarsenite to methylarsenate, which is extruded by ArsW, one of only a few known pentavalent organoarsenical efflux permeases, a novel pathway of organoarsenical resistance.
Topics: Anti-Bacterial Agents; Arsenic; Arsenicals; Escherichia coli; Operon
PubMed: 34676971
DOI: 10.1111/1462-2920.15817 -
Microorganisms Sep 2023Pachymaran (PCP), the major medicinal constituent of Poria cocos, has a regulatory effect on immunosuppressive lung injury, but its mechanism of action with respect to...
Pachymaran (PCP), the major medicinal constituent of Poria cocos, has a regulatory effect on immunosuppressive lung injury, but its mechanism of action with respect to gut microorganisms and their metabolites is not clear. The aim of this study was to investigate the protective effect of PCP against immunosuppressive lung injury caused by cyclosporine A (CsA), and to reveal its possible mechanism of action via the comprehensive analysis of 16S rRNA and LC-MS. We demonstrated that PCP was effective at alleviating CsA-induced immunosuppressive lung injury by restoring the organ indices and lung tissue morphology and structure. PCP significantly altered the composition of the gut and lung microbiota in mice with CsA-induced immunosuppressive lung injury by increasing the number of beneficial bacteria from the , , , and , and reducing the pathogenic to fulfill its immunomodulatory role. In lung tissue microecology, PCP intervention significantly reduced the abundance of , , , and and increased the abundance of . The LC-MS results showed that PCP alleviated the CsA-induced immunosuppression of lung tissue injury. The model serum metabolite Americine decreased the expression of PC(O-18:1(4Z)/0:0). Our results suggest that PCP may be involved in regulating the composition, function, and metabolism of the gut and lung microbiota to reverse CsA-induced immunosuppressive lung injury.
PubMed: 37764093
DOI: 10.3390/microorganisms11092249 -
Environment International Aug 2023The polyethylene (PE) film mulching as a water conservation technology has been widely used in dryland agriculture, yet the long-term mulching has led to increasing...
The polyethylene (PE) film mulching as a water conservation technology has been widely used in dryland agriculture, yet the long-term mulching has led to increasing accumulation of secondary pollutants in soils. The decomposition of PE film-sourced pollutants is directly associated with the enrichment of specific bacterial communities. We therefore hypothesized that plant biomass may act as an organic media to mediate the pollutant decomposition via reshaping bacterial communities. To validate this hypothesis, plant biomass (dried maize straw and living clover) was embedded at the underlying surface of PE film, to track the changes in the composition and function of bacterial communities in maize field across two years. The results indicated that both dry crop straw and alive clover massively promoted the α-diversity and abundance of dominant bacteria at plastisphere, relative to bulk soil. Bacterial communities tended to be clustered at plastisphere, forming the bacteria islands to enrich pollutant-degrading bacteria, such as Sphingobacterium, Arthrobacter and Paracoccus. As such, plastisphere bacteria islands substantially enhanced the degradation potential of chloroalkene and benzoate (p < 0.05). Simultaneously, bacterial network became stabilized and congregated at plastisphere, and markedly improved the abundance of plastisphere module hubs and connectors bacteria via stochastic process. Particularly, bacterial community composition and plastic film-sourced pollutants metabolism were evidently affected by soil pH, carbon and nitrogen sources that were mainly derived from the embedded biomass. To sum up, plant biomass embedding as a nature-based strategy (NbS) can positively mediate the decomposition of plastic-sourced pollutants through plastisphere bacteria island effects.
Topics: Soil; Biomass; Polyethylene; Environmental Pollutants; Water; Agriculture; Plastics; Bacteria; Soil Microbiology
PubMed: 37499460
DOI: 10.1016/j.envint.2023.108114 -
Journal of Immunology Research 2021To conduct a preliminary investigation that shows the possible correlation between the change of gut microbiota and missed abortions (MAs), which further provides a new...
OBJECTIVE
To conduct a preliminary investigation that shows the possible correlation between the change of gut microbiota and missed abortions (MAs), which further provides a new potential insight for the prevention and therapy of MAs.
METHOD
One hundred women, including 50 patients with MAs (case group) and 50 normal pregnant women (control group), were enrolled in the study. Fecal specimens were collected in the first trimester. Bacterial DNA was extracted, hybridized with primers of specific genes, and then detected by bacterial chip. The composition and the relative abundance of the gut microbiota were compared and analyzed. Furthermore, Kyoto Encyclopedia of Genes and Genomes enrichment analysis was used to explore the relative pathways.
RESULTS
(1) The -diversity and -diversity of the gut microbiota in patients with MAs were significantly lower than that those in normal pregnant women ( < 0.05). At the phylum level, , , , and accounted for the main proportion of intestinal flora in the 2 groups. Only was high in the case group. Significant differences were found between the two groups at the phylum level ( < 0.05). , , and were significantly more abundant in the control group than in the case group at the genus level ( < 0.05). (2) KEGG pathway enrichment analysis found significant differences in 27 signaling pathways and metabolic pathways between the two groups of differentially expressed genes (all adjusted < 0.05). (3) The positive rate of (MH) detection in the control group was significantly higher in the MA group ( = 7.853, = 0.004).
CONCLUSION
The high abundance of in the MA group was the first time found and reported in the study. The dysbiosis of the gut microbiota correlates with MAs. This study provided insights into the potential change of gut microbiota of MAs and the potential underlying mechanisms through certain impaired lipid metabolism and aroused inflammation pathways. Comprehensive insights regarding gut microbiota may facilitate improved understanding and the development of novel therapeutic and preventive strategies for MAs.
Topics: Abortion, Missed; Adult; Biodiversity; China; Computational Biology; Disease Susceptibility; Dysbiosis; Female; Gastrointestinal Microbiome; Humans; Metagenomics; Mycoplasma; Pregnancy; Risk Factors
PubMed: 34966824
DOI: 10.1155/2021/5571894 -
Frontiers in Microbiology 2022Complex dynamic bacterial-fungal interactions play key roles during mushroom growth, ranging from mutualism to antagonism. These interactions convey a large influence on...
Complex dynamic bacterial-fungal interactions play key roles during mushroom growth, ranging from mutualism to antagonism. These interactions convey a large influence on mushroom's mycelial and fruiting body formation during mushroom cultivation. In this study, high-throughput amplicon sequencing was conducted to investigate the structure of bacterial communities in spent mushroom substrates obtained from cultivation of two different groups of with (A) high yield and (B) low yield of fruiting body production. It was found that species richness and diversity of microbiota in group (A) samples were significantly higher than in group (B) samples. Among the identified 765 bacterial OTUs, 5 bacterial species found to exhibit high differential abundance between group (A) and group (B) were , , , , and . The co-cultivation with selected bacterial strains showed that TBRC 12900 co-cultivated with TBRC-BCC 42794 promoted a high level of mycelial growth. Proteomics analysis was performed to elucidate the biological activities involved in the mutualistic association between TBRC 12900 and TBRC-BCC 42794. After co-cultivation of TBRC 12900 and TBRC-BCC 42794, 1,616 proteins were detected including 578 proteins of origin and 1,038 proteins of origin. Functional analysis and PPI network construction revealed that the high level of mycelial growth in the co-culture condition most likely resulted from concerted actions of (a) carbohydrate-active enzymes including hydrolases, glycosyltransferases, and carbohydrate esterases important for carbohydrate metabolism and cell wall generation/remodeling, (b) peptidases including cysteine-, metallo-, and serine-peptidases, (c) transporters including the ABC-type transporter superfamily, the FAT transporter family, and the VGP family, and (d) proteins with proposed roles in formation of metabolites that can act as growth-promoting molecules or those normally contain antimicrobial activity (e.g., indoles, terpenes, -lactones, lanthipeptides, iturins, and ectoines). The findings will provide novel insights into bacterial-fungal interactions during mycelial growth and fruiting body formation. Our results can be utilized for the selection of growth-promoting bacteria to improve the cultivation process of with a high production yield, thus conveying potentially high socio-economic impact to mushroom agriculture.
PubMed: 36299733
DOI: 10.3389/fmicb.2022.1006446