# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 8672 | 0 | 0.9949 | Pangenomic and functional investigations for dormancy and biodegradation features of an organic pollutant-degrading bacterium Rhodococcus biphenylivorans TG9. Environmental bacteria contain a wealth of untapped potential in the form of biodegradative genes. Leveraging this potential can often be confounded by a lack of understanding of fundamental survival strategies, like dormancy, for environmental stress. Investigating bacterial dormancy-to-degradation relationships enables improvement of bioremediation. Here, we couple genomic and functional assessment to provide context for key attributes of the organic pollutant-degrading strain Rhodococcus biphenylivorans TG9. Whole genome sequencing, pangenome analysis and functional characterization were performed to elucidate important genes and gene products, including antimicrobial resistance, dormancy, and degradation. Rhodococcus as a genus has strong potential for degradation and dormancy, which we demonstrate using R. biphenylivorans TG9 as a model. We identified four Resuscitation-promoting factor (Rpf) encoding genes in TG9 involved in dormancy and resuscitation. We demonstrate that R. biphenylivorans TG9 grows on fourteen typical organic pollutants, and exhibits a robust ability to degrade biphenyl and several congeners of polychlorinated biphenyls. We further induced TG9 into a dormant state and demonstrated pronounced differences in morphology and activity. Together, these results expand our understanding of the genus Rhodococcus and the relationship between dormancy and biodegradation in the presence of environmental stressors. | 2022 | 34688761 |
| 8861 | 1 | 0.9948 | The biofilm-specific antibiotic resistance gene ndvB is important for expression of ethanol oxidation genes in Pseudomonas aeruginosa biofilms. Bacteria growing in biofilms are responsible for a large number of persistent infections and are often more resistant to antibiotics than are free-floating bacteria. In a previous study, we identified a Pseudomonas aeruginosa gene, ndvB, which is important for the formation of periplasmic glucans. We established that these glucans function in biofilm-specific antibiotic resistance by sequestering antibiotic molecules away from their cellular targets. In this study, we investigate another function of ndvB in biofilm-specific antibiotic resistance. DNA microarray analysis identified 24 genes that were responsive to the presence of ndvB. A subset of 20 genes, including 8 ethanol oxidation genes (ercS', erbR, exaA, exaB, eraR, pqqB, pqqC, and pqqE), was highly expressed in wild-type biofilm cells but not in ΔndvB biofilms, while 4 genes displayed the reciprocal expression pattern. Using quantitative real-time PCR, we confirmed the ndvB-dependent expression of the ethanol oxidation genes and additionally demonstrated that these genes were more highly expressed in biofilms than in planktonic cultures. Expression of erbR in ΔndvB biofilms was restored after the treatment of the biofilm with periplasmic extracts derived from wild-type biofilm cells. Inactivation of ethanol oxidation genes increased the sensitivity of biofilms to tobramycin. Together, these results reveal that ndvB affects the expression of multiple genes in biofilms and that ethanol oxidation genes are linked to biofilm-specific antibiotic resistance. | 2012 | 22505683 |
| 8292 | 2 | 0.9945 | Exopolysaccharide anchoring creates an extreme resistance to sedimentation. By evolving strains of E. coli that hyper-resist sedimentation, we discovered an uncharacterized mechanism that bacteria can use to remain in suspension indefinitely without expending energy. This unusual phenotype was traced to the anchoring of long colanic acid polymers (CAP) that project from the cell surface. Although each characterized mutant activated this same mechanism, the genes responsible and the strengths of the phenotypes varied. Mutations in rcsC, lpp, igaA, or the yjbEFGH operon were sufficient to stimulate sedimentation resistance, while mutations altering the cps promoter, cdgI, or yjbF provided phenotypic enhancements. The sedimentation resistances changed in response to temperature, growth phase, and carbon source and each mutant exhibited significantly reduced biofilm formation. We discovered that the degree of colony mucoidy exhibited by these mutants was not related to the degree of Rcs pathways activation or to the amount of CAP that was produced; rather, it was related to the fraction of CAP that was shed as a true exopolysaccharide. Therefore, these and other mutations that activate this phenotype are likely to be absent from genetic screens that relied on centrifugation to harvest bacteria. We also found that this anchored CAP form is not linked to LPS cores and may not be attached to the outer membrane.IMPORTANCEBacteria can partition in aqueous environments between surface-dwelling, planktonic, sedimentary, and biofilm forms. Residence in each location provides an advantage depending on nutritional and environmental stresses and a community of a single species is often observed to be distributed throughout two or more of these niches. Another adaptive strategy is to produce an extracellular capsule, which provides an environmental shield for the microbe and can allow escape from predators and immune systems. We discovered that bacteria can either shed or stably anchor capsules to dramatically alter their propensity to sediment. The degree to which the bacteria anchor their capsule is controlled by a stress sensing system, suggesting that anchoring may be used as an adaptive response to severe environmental challenges. | 2021 | 33753470 |
| 8595 | 3 | 0.9945 | Antimicrobial poly(ionic liquid)-induced bacterial nanotube formation and drug-resistance spread. Bacterial nanotubes are tubular membranous structures bulging from the cell surface that can connect neighboring bacteria for the exchange of intercellular substances. However, little is known about the formation and function of bacterial nanotubes under the stress of antimicrobial materials. Herein, an imidazolium-type cationic poly(ionic liquid) (PIL) and corresponding PIL membranes with antimicrobial properties were synthesized. The effects of these cationic polymers on the formation of bacterial nanotubes between Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) or Vibrio fischeri (V. fischeri), followed by intraspecies and interspecies exchange of antibiotic resistance genes (ARGs) were investigated. The results showed that bacteria tend to produce more nanotubes accompanied by drug-resistance trade, which can even make the ARGs of pathogens spread to the environmental microbes of V. fischeri. Given the unique antimicrobial sustainability toward bacteria after they acquire ARGs via bacterial nanotubes, antimicrobial PILs demonstrate bright prospects in the battle against resistant bacteria. | 2022 | 36155673 |
| 8620 | 4 | 0.9943 | Changes in Microbiome Confer Multigenerational Host Resistance after Sub-toxic Pesticide Exposure. The gut is a first point of contact with ingested xenobiotics, where chemicals are metabolized directly by the host or microbiota. Atrazine is a widely used pesticide, but the role of the microbiome metabolism of this xenobiotic and the impact on host responses is unclear. We exposed successive generations of the wasp Nasonia vitripennis to subtoxic levels of atrazine and observed changes in the structure and function of the gut microbiome that conveyed atrazine resistance. This microbiome-mediated resistance was maternally inherited and increased over successive generations, while also heightening the rate of host genome selection. The rare gut bacteria Serratia marcescens and Pseudomonas protegens contributed to atrazine metabolism. Both of these bacteria contain genes that are linked to atrazine degradation and were sufficient to confer resistance in experimental wasp populations. Thus, pesticide exposure causes functional, inherited changes in the microbiome that should be considered when assessing xenobiotic exposure and as potential countermeasures to toxicity. | 2020 | 32023487 |
| 693 | 5 | 0.9943 | Effect of acid adaptation on the fate of Listeria monocytogenes in THP-1 human macrophages activated by gamma interferon. In Listeria monocytogenes the acid tolerance response (ATR) takes place through a programmed molecular response which ensures cell survival under unfavorable conditions. Much evidence links ATR with virulence, but the molecular determinants involved in the reactivity to low pHs and the behavior of acid-exposed bacteria within host cells are still poorly understood. We have investigated the effect of acid adaptation on the fate of L. monocytogenes in human macrophages. Expression of genes encoding determinants for cell invasion and intracellular survival was tested for acid-exposed bacteria, and invasive behavior in the human myelomonocytic cell line THP-1 activated with gamma interferon was assessed. Functional approaches demonstrated that preexposure to an acidic pH enhances the survival of L. monocytogenes in activated human macrophages and that this effect is associated with an altered pattern of expression of genes involved in acid resistance and cell invasion. Significantly decreased transcription of the plcA gene, encoding a phospholipase C involved in vacuolar escape and cell-to-cell spread, was observed in acid-adapted bacteria. This effect was due to a reduction in the quantity of the bicistronic plcA-prfA transcript, concomitant with an increase in the level(s) of the monocistronic prfA mRNA(s). The transcriptional shift from distal to proximal prfA promoters resulted in equal levels of the prfA transcript (and, as a consequence, of the inlA, hly, and actA transcripts) under neutral and acidic conditions. In contrast, the sodC and gad genes, encoding a cytoplasmic superoxide dismutase and the glutamate-based acid resistance system, respectively, were positively regulated at a low pH. Morphological approaches confirmed the increased intracellular survival and growth of acid-adapted L. monocytogenes cells both in vacuoles and in the cytoplasm of interferon gamma-activated THP-1 macrophages. Our data indicate that preexposure to a low pH has a positive impact on subsequent challenge of L. monocytogenes with macrophagic cells. | 2002 | 12117947 |
| 7908 | 6 | 0.9943 | DNA-based stable isotope probing deciphered the active denitrifying bacteria and triclosan-degrading bacteria participating in granule-based partial denitrification process under triclosan pressure. Granule-based partial denitrification (PD) is a technology that can supply stable nitrite for applying anaerobic ammonia oxidation in wastewater treatment, and triclosan (TCS) is a frequently detected antibacterial agent in wastewater treatment plants, therefore it is possible that TCS could enter into wastewater that is treated using PD technology. However, the active microorganisms responsible for PD and TCS removing in granule-based PD system have not been clearly identified and it is currently not clear how TCS affects the PD process. In this study, the impacts of TCS on PD performance, PD microbial community, antibiotic resistance genes (ARGs), active PD bacteria and TCS-degrading bacteria in a granule-based PD system were investigated. 3 mg/L TCS had adverse influence on PD process, but PD system could recover gradually after inhibiting of 10 days. After a period of domestication, PD granular sludge could achieve 10.66% of TCS degradation efficiency and 43.62% of TCS adsorption efficiency. Microbes might increase their resistance to TCS by increasing the secretion of extracellular polymeric substances, and the secretion of protein might play a more pivotal role than the secretion of polysaccharides in resisting TCS. The short-term shock of TCS might cause the propagation of acrA-03, while the long-term operation of TCS could propagate fabK and intI1. DNA stable isotope probing assay indicated that Thauera was active PD bacteria and TCS-degrading bacteria in the granule-based PD system, and it could contribute to nitrite accumulation and TCS degradation, simultaneously. | 2022 | 34979468 |
| 8544 | 7 | 0.9942 | Closed fixed-bed bacteria-algae biofilm reactor: A promising solution for phenol containing wastewater treatment and resource transformation. This study focuses on treating phenolic wastewater with a novel closed fixed-bed bacteria-algae biofilm reactor (CF-BABR) to enhance resource transformation for phenolic substances. The CF-BABR showed strong impact - load resistance and stable degradation efficiency, fully degrading phenolic compounds at concentrations from 0 to 150 mg/L. From the inflow to the outflow, the effective sequences, abundance, and diversity of bacteria decreased. Chlorobaculum was the dominant bacterium for phenolic pollutant degradation. The abundance of fungi decreased gradually, while their diversity increased. Kalenjinia and Cutaneotrichosporon played a synergistic role in reducing pollutant toxicity. The high - concentration pollutants at the influent led to a higher abundance of microalgal communities, and Scenedesmaceae became the most dominant algal family, which was positively correlated with the degradation of phenolic compounds. Functional gene prediction indicated that the abundance of functional genes in bacteria decreased overall along the wastewater flow. Carbohydrate metabolism and amino acid metabolism were the most active secondary pathways. In fungi, the predicted gene functions had the highest abundance in the upstream region. Metabolic intermediates such as organic acids and derivatives, lipids and lipid - like molecules, and carboxylic acids and derivatives demonstrated the degradation effect of CF-BABR on phenolic compounds. | 2025 | 40194331 |
| 8807 | 8 | 0.9942 | Dietary watermelon residue influencing the nonspecific immunity of juvenile Pseudorasbora parva. The study explored the improvement of disease resistance, non-specific immunity and anti-oxidation reactions for Pseudorasbora parva (PP) using dietary watermelon residue. The cumulative PP mortality and the pathogenic bacteria number in 15-45% groups reduced relative to those in control group (CK). Under 15-45% groups, AKP, ACP activities and akp, acp genes expression levels were increased markedly in nonspecific immunity system. Similarly, antioxidant response (SOD, CAT activities) and their genes was promoted also at 15-45% groups. Organic matter (vitamin and polyphenols) in watermelon residue improved AKP, ACP, SOD, CAT activities by increasing corresponding gene expressions. Theoretically, they could also function as stimulus signal, active center or composition to modulate enzyme activities and gene expressions. Besides, watermelon residue ameliorated NF-kB, mTOR responses pathway, and consequently suppressed Aeromonas hydrophila which augmented disease resistance. | 2021 | 34534653 |
| 6170 | 9 | 0.9942 | Resistance and susceptibility of mice to bacterial infection. IV. Functional specificity in natural resistance to facultative intracellular bacteria. The effect of opsonic antibody on resistance of susceptibility of three strains of mice, C57Bl/10, BALB/c, and CBA to the intracellular bacteria Listeria monocytogenes, Salmonella typhimurium, and Brucella abortus was tested. Bacteria were opsonized by serum treatment before their injection into mice, or the mice were preimmunized by injection with alcohol killed bacteria which induces antibody without macrophage activation. Antibody did not increase the rate of clearance of Listeria from the bloodstream, nor did it affect the subsequent growth of that organism in the spleen and liver. Blood clearance of S. typhimurium and of B. abortus was increased by preopsonization with specific antibody, indicating that opsonins were a limiting factor in resistance to these two bacteria. However, neither opsonization before infection nor immunization with alcohol killed vaccines had any effect on the strain distribution of resistance/susceptibility, which differs for each of the three intracellular pathogens. Thus, even in the presence of adequate opsonization the three strains of mice showed different patterns of resistance/susceptibility to Listeria, S. typhimurium, and B. abortus. This implies that each has a unique cellular mechanism of early nonspecific resistance. | 1983 | 6413682 |
| 8424 | 10 | 0.9942 | Postseptational chromosome partitioning in bacteria. Mutations in the spoIIIE gene prevent proper partitioning of one chromosome into the developing prespore during sporulation but have no overt effect on partitioning in vegetatively dividing cells. However, the expression of spoIIIE in vegetative cells and the occurrence of genes closely related to spoIIIE in a range of nonsporulating eubacteria suggested a more general function for the protein. Here we show that SpoIIIE protein is needed for optimal chromosome partitioning in vegetative cells of Bacillus subtilis when the normal tight coordination between septation and nucleoid partitioning is perturbed or when septum positioning is altered. A functional SpoIIIE protein allows cells to recover from a state in which their chromosome has been trapped by a closing septum. By analogy to its function during sporulation, we suggest that SpoIIIE facilitates partitioning by actively translocating the chromosome out of the septum. In addition to enhancing the fidelity of nucleoid partitioning, SpoIIIE also seems to be required for maximal resistance to antibiotics that interfere with DNA metabolism. The results have important implications for our understanding of the functions of genes involved in the primary partitioning machinery in bacteria and of how septum placement is controlled. | 1995 | 7567988 |
| 9011 | 11 | 0.9941 | The role of osmoregulated periplasmic glucans in the biofilm antibiotic resistance of Yersinia enterocolitica. The formation of biofilms by bacteria is of great significance because it involves many physiological changes that serve to protect the cells from various stresses. One of the best-known biofilm-specific properties of bacteria is that bacteria that grow in biofilms are generally more resistant to antibiotics than their planktonic counterparts. In a previous study, osmoregulated periplasmic glucans (OPGs), catalyzed by the opgGH operon, were identified and found to function in Rcs signalling in Yersinia enterocolitica. In this study, the possible contribution of OPGs to antimicrobial resistance of Y. enterocolitica biofilms were investigated, and the results showed that OPGs, especially when overexpressed, conferred a high level of biofilm resistance to two different classes of antibiotics onto Y. enterocolitica. Subsequent analysis revealed that OPGs regulated the biofilm architecture in Y. enterocolitica by promoting the bacteria to form large cell aggregates. Moreover, the opgGH genes in biofilms showed higher expression than in planktonic cultures. OPGs were required to induce the expression of genes related to flagella, extracellular polysaccharide, and c-di-GMP biosynthesis in Y. enterocolitica biofilms and this effect was more significant when OPGs were overproduced. The current investigation showed an extension in the biological role of OPGs in Y. enterocolitica and provided a strong theoretical basis to further study this resistance mechanism at the molecular level to identify new drug targets or disinfectants for the treatment of infections caused by Y. enterocolitica within biofilms. | 2020 | 32492459 |
| 315 | 12 | 0.9941 | Phosphorothioate DNA as an antioxidant in bacteria. Diverse bacteria contain DNA with sulfur incorporated stereo-specifically into their DNA backbone at specific sequences (phosphorothioation). We found that in vitro oxidation of phosphorothioate (PT) DNA by hydrogen peroxide (H(2)O(2)) or peracetic acid has two possible outcomes: DNA backbone cleavage or sulfur removal resulting in restoration of normal DNA backbone. The physiological relevance of this redox reaction was investigated by challenging PT DNA hosting Salmonella enterica cells using H(2)O(2). DNA phosphorothioation was found to correlate with increasing resistance to the growth inhibition by H(2)O(2). Resistance to H(2)O(2) was abolished when each of the three dnd genes, required for phosphorothioation, was inactivated. In vivo, PT DNA is more resistant to the double-strand break damage caused by H(2)O(2) than PT-free DNA. Furthermore, sulfur on the modified DNA was consumed and the DNA was converted to PT-free state when the bacteria were incubated with H(2)O(2). These findings are consistent with a hypothesis that phosphorothioation modification endows DNA with reducing chemical property, which protects the hosting bacteria against peroxide, explaining why this modification is maintained by diverse bacteria. | 2012 | 22772986 |
| 572 | 13 | 0.9940 | The RSP_2889 gene product of Rhodobacter sphaeroides is a CueR homologue controlling copper-responsive genes. Metal homeostasis is important in all living cells in order to provide sufficient amounts of metal ions for biological processes but to prevent toxic effects by excess amounts. Here we show that the gene product of RSP_2889 of the facultatively photosynthetic bacterium Rhodobacter sphaeroides is homologous to CueR, a regulator of copper metabolism in Escherichia coli and other bacteria. CueR binds to the promoter regions of genes for a copper-translocating ATPase and for a copper chaperone and is responsible for their high expression when cells are exposed to elevated levels of copper ions. While deletion of RSP_2889 has no significant effect on copper resistance, expression from a low-copy-number plasmid mediates increased sensitivity to copper. | 2011 | 21903751 |
| 340 | 14 | 0.9940 | Study of MFD-type repair in locus determining resistance of Escherichia coli to streptomycin. The yield of induced mutations to streptomycin resistance (Str) in E. coli, UV-irradiated and temporarily incubated in liquid medium not permitting protein synthesis, depends upon the conditions of preirradiation growth and preirradiation treatment of the bacteria, i.e. on their physiological state at the moment of irradiation. This fact is not readily reconciled with a model postulating mutation production in the structural genes of E. coli during excision repair. A preferred explanation is offered, based on the assumption that the efficiency of mutagenesis at the rpsL (strA) locus is determined by interference of antimutagenic (generalized excision repair and MFD) and promutagenic (mutation fixation of excision repair) events. The participation of macromolecular syntheses in Str mutation fixation is suggested. | 1986 | 3537780 |
| 8234 | 15 | 0.9940 | Contradictory roles for antibody and complement in the interaction of Brucella abortus with its host. The ability of serum complement to kill bacteria has been linked to host resistance to Gram-negative bacteria. A mechanism for killing extracellular organisms during early invasion, following release from infected phagocytic cells, or during bacteremia would contribute to a host's ability to resist disease. In fact, the ability of serum complement to kill bacteria has been linked to disease resistance. Brucella abortus are Gram-negative intracellular pathogens. Resistance to these bacteria involves the coordinated activities of the cellular and humoral immune systems. The existence of serum-resistant forms of B. abortus has been established, and it has been shown that these bacteria can resist the killing action of complement even in the presence of specific antibody. Antibody is usually necessary for complement-mediated killing of smooth (virulent) forms of Gram-negative bacteria. An anomolous situation exists with some isolates of smooth B. abortus. Sera containing high titers of specific antibody do not support killing unless they are diluted. In the bovine, this phenomenon is associated with IgG1 and IgG2 antibodies. This finding may account for the lack of positive correlation between antibody levels and resistance to disease, which has led, perhaps wrongly, to the idea that antibody and complement are not important in resistance to brucellosis. Available evidence suggests that antibody may have contradictory roles in the interactions between a host and bacteria. Avirulent (rough) forms of the organism would be rapidly killed by complement shortly after invasion, but serum-resistant smooth forms of the organism would survive and invade resident phagocytic cells. During the process of invasion and phagocytosis, the bacteria would initiate an immune response. With time, some B. abortus organisms would be released from infected phagocytic cells. In the early stages of this process, the bacteria would encounter IgM antibody and low concentrations of IgG antibody. These would cause complement-mediated killing, and infection would be restricted to resident phagocytic cells. However, the immune response to B. abortus antigens would be intensified, and IgG antibody levels would increase. High concentrations of antibody do no support complement-mediated killing of extracellular B. abortus, but the bacteria would be opsonized by antibody and complement component fragments. This would lead to increased phagocytosis of extracellular B. abortus as they appear, and concomitant extension of disease. Because of high levels of antibody would block complement-mediated killing of B. abortus, resistance to disease at this point would be dependent on cell-mediated immunity. | 1995 | 8845060 |
| 8426 | 16 | 0.9940 | Ionizing radiation responses appear incidental to desiccation responses in the bdelloid rotifer Adineta vaga. BACKGROUND: The remarkable resistance to ionizing radiation found in anhydrobiotic organisms, such as some bacteria, tardigrades, and bdelloid rotifers has been hypothesized to be incidental to their desiccation resistance. Both stresses produce reactive oxygen species and cause damage to DNA and other macromolecules. However, this hypothesis has only been investigated in a few species. RESULTS: In this study, we analyzed the transcriptomic response of the bdelloid rotifer Adineta vaga to desiccation and to low- (X-rays) and high- (Fe) LET radiation to highlight the molecular and genetic mechanisms triggered by both stresses. We identified numerous genes encoding antioxidants, but also chaperones, that are constitutively highly expressed, which may contribute to the protection of proteins against oxidative stress during desiccation and ionizing radiation. We also detected a transcriptomic response common to desiccation and ionizing radiation with the over-expression of genes mainly involved in DNA repair and protein modifications but also genes with unknown functions that were bdelloid-specific. A distinct transcriptomic response specific to rehydration was also found, with the over-expression of genes mainly encoding Late Embryogenesis Abundant proteins, specific heat shock proteins, and glucose repressive proteins. CONCLUSIONS: These results suggest that the extreme resistance of bdelloid rotifers to radiation might indeed be a consequence of their capacity to resist complete desiccation. This study paves the way to functional genetic experiments on A. vaga targeting promising candidate proteins playing central roles in radiation and desiccation resistance. | 2024 | 38273318 |
| 8819 | 17 | 0.9940 | Responses of Bacillus sp. under Cu(II) stress in relation to extracellular polymeric substances and functional gene expression level. The production and composition of extracellular polymeric substances (EPS), as well as the EPS-related functional resistance genes and metabolic levels of Bacillus sp. under Cu(II) stress, were investigated. EPS production increased by 2.73 ± 0.29 times compared to the control when the strain was treated with 30 mg L(-1) Cu(II). Specifically, the polysaccharide (PS) content in EPS increased by 2.26 ± 0.28 g CDW(-1) and the PN/PS (protein/polysaccharide) ratio value increased by 3.18 ± 0.33 times under 30 mg L(-1) Cu(II) compared to the control. The increased EPS secretion and higher PN/PS ratio in EPS strengthened the cells' ability to resist the toxic effect of Cu(II). Differential expression of functional genes under Cu(II) stress was revealed by Gene Ontology pathway enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. The enriched genes were most obviously upregulated in the UMP biosynthesis pathway, the pyrimidine metabolism pathway, and the TCS metabolism pathway. This indicates an enhancement of EPS regulation-related metabolic levels and their role as a defense mechanism for cells to adapt to Cu(II) stress. Additionally, seven copper resistance genes were upregulated while three were downregulated. The upregulated genes were related to the heavy metal resistance, while downregulated genes were related to cell differentiation, indicating that the strain had initiated an obvious resistance to Cu(II) despite its severe cell toxicity. These results provided a basis for promoting EPS-regulated associated functional genes and the application of gene-regulated bacteria in heavy metal-containing wastewater treatment. | 2023 | 37195605 |
| 8541 | 18 | 0.9940 | Insights into the response of anammox process to oxytetracycline: Impacts of static magnetic field. The long-term effects of oxytetracycline (OTC) with a high concentration on the anaerobic ammonium oxidation (Anammox) process were evaluated, and the role of static magnetic field (SMF) was further explored. The stress of OTC at 50 mg/L had little effect on the nitrogen removal of anammox process at the first 16 days. With the continuous addition of OTC and the increase of nitrogen loading, the OTC inhibited the nitrogen removal and anammox activity severely. During the 32 days of recovery period without OTC addition, the nitrogen removal was further deteriorated, indicating the inhibition of OTC on anammox activity was irreversible and persistent. The application of SMF alleviated the inhibition of OTC on anammox to some extent, and the specific anammox activity was enhanced by 47.1% compared to the system without SMF during the OTC stress stage. Antibiotic efflux was the major resistance mechanism in the anammox process, and tetA, tetG and rpsJ were the main functional antibiotic resistance genes. The addition of OTC weakened the metabolic interactions between the anammox bacteria and the symbiotic bacteria involved in the metabolism of cofactors and secondary metabolites, leading to the poor anammox activity. The adaptability of microbes to the OTC stress was improved by the application of SMF, which can enhance the metabolic pathways related to bacterial growth and resistance to environmental stress. | 2023 | 37586490 |
| 599 | 19 | 0.9940 | RNase III participates in control of quorum sensing, pigmentation and oxidative stress resistance in Rhodobacter sphaeroides. RNase III is a dsRNA-specific endoribonuclease, highly conserved in bacteria and eukarya. In this study, we analysed the effects of inactivation of RNase III on the transcriptome and the phenotype of the facultative phototrophic α-proteobacterium Rhodobacter sphaeroides. RNA-seq revealed an unexpectedly high amount of genes with increased expression located directly downstream to the rRNA operons. Chromosomal insertion of additional transcription terminators restored wild type-like expression of the downstream genes, indicating that RNase III may modulate the rRNA transcription termination in R. sphaeroides. Furthermore, we identified RNase III as a major regulator of quorum-sensing autoinducer synthesis in R. sphaeroides. It negatively controls the expression of the autoinducer synthase CerI by reducing cerI mRNA stability. In addition, RNase III inactivation caused altered resistance against oxidative stress and impaired formation of photosynthetically active pigment-protein complexes. We also observed an increase in the CcsR small RNAs that were previously shown to promote resistance to oxidative stress. Taken together, our data present interesting insights into RNase III-mediated regulation and expand the knowledge on the function of this important enzyme in bacteria. | 2023 | 37823424 |