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PloS One 2023The genus Paracoccus capable of inhabiting a variety of different ecological niches both, marine and terrestrial, is globally distributed. In addition, Paracoccus is...
The genus Paracoccus capable of inhabiting a variety of different ecological niches both, marine and terrestrial, is globally distributed. In addition, Paracoccus is taxonomically, metabolically and regarding lifestyle highly diverse. Until now, little is known on how Paracoccus can adapt to such a range of different ecological niches and lifestyles. In the present study, the genus Paracoccus was phylogenomically analyzed (n = 160) and revisited, allowing species level classification of 16 so far unclassified Paracoccus sp. strains and detection of five misclassifications. Moreover, we performed pan-genome analysis of Paracoccus-type strains, isolated from a variety of ecological niches, including different soils, tidal flat sediment, host association such as the bluespotted cornetfish, Bugula plumosa, and the reef-building coral Stylophora pistillata to elucidate either i) the importance of lifestyle and adaptation potential, and ii) the role of the genomic equipment and niche adaptation potential. Six complete genomes were de novo hybrid assembled using a combination of short and long-read technologies. These Paracoccus genomes increase the number of completely closed high-quality genomes of type strains from 15 to 21. Pan-genome analysis revealed an open pan-genome composed of 13,819 genes with a minimal chromosomal core (8.84%) highlighting the genomic adaptation potential and the huge impact of extra-chromosomal elements. All genomes are shaped by the acquisition of various mobile genetic elements including genomic islands, prophages, transposases, and insertion sequences emphasizing their genomic plasticity. In terms of lifestyle, each mobile genetic elements should be evaluated separately with respect to the ecological context. Free-living genomes, in contrast to host-associated, tend to comprise (1) larger genomes, or the highest number of extra-chromosomal elements, (2) higher number of genomic islands and insertion sequence elements, and (3) a lower number of intact prophage regions. Regarding lifestyle adaptations, free-living genomes share genes linked to genetic exchange via T4SS, especially relevant for Paracoccus, known for their numerous extrachromosomal elements, enabling adaptation to dynamic environments. Conversely, host-associated genomes feature diverse genes involved in molecule transport, cell wall modification, attachment, stress protection, DNA repair, carbon, and nitrogen metabolism. Due to the vast number of adaptive genes, Paracoccus can quickly adapt to changing environmental conditions.
Topics: Paracoccus; DNA Transposable Elements; Genomics; Genomic Islands; Phylogeny; Genome, Bacterial
PubMed: 38117845
DOI: 10.1371/journal.pone.0287947 -
Frontiers in Public Health 2021Disinfection is a key element in controlling infections. Fogging, also known as fumigation, is one of the most effective chemical disinfection methods. Peracetic acid...
Disinfection is a key element in controlling infections. Fogging, also known as fumigation, is one of the most effective chemical disinfection methods. Peracetic acid (PAA) is a powerful oxidant with bactericidal and fungicidal properties. The aim of this study is to determine the type of bacteria and fungi present in educational institutions and whether disinfection by PAA fumigation in these institutions is also effective and useful, as demonstrated previously in healthcare centers. This study was carried out in five kindergartens and five primary schools in Bialystok, Poland. Three rooms have been selected in each of these educational institutions, and the disinfection was carried out in 30 rooms in total. Fogging with PAA was performed in selected rooms. Before and after disinfection, samples were collected from four surfaces: walls, tables, doors, and chair backs. Most frequently detected microorganisms in schools and kindergartens were ssp. . In addition, ssp. were the most prevalent in kindergartens, whereas was the most prevalent in schools. Comparison of the bacterial flora of schools and kindergartens showed statistically significant differences in the prevalence of bacteria on different surfaces. A significant decrease in the number of colonies after disinfection was observed on all surfaces ( < 0.05). In addition, the calculated effectiveness of disinfection was 99.7% in kindergartens and 99.3% in schools. The results indicate that fogging of PAA is a highly effective method of surface disinfection in kindergartens and schools.
Topics: Acinetobacter; Actinobacteria; Micrococcaceae; Paracoccus; Peracetic Acid; Schools; Staphylococcus
PubMed: 34604154
DOI: 10.3389/fpubh.2021.697917 -
Frontiers in Immunology 2021Microbiota acquired during labor and through the first days of life contributes to the newborn's immune maturation and development. Mother provides probiotics and... (Observational Study)
Observational Study
Microbiota acquired during labor and through the first days of life contributes to the newborn's immune maturation and development. Mother provides probiotics and prebiotics factors through colostrum and maternal milk to shape the first neonatal microbiota. Previous works have reported that immunoglobulin A (IgA) secreted in colostrum is coating a fraction of maternal microbiota. Thus, to better characterize this IgA-microbiota association, we used flow cytometry coupled with 16S rRNA gene sequencing (IgA-Seq) in human colostrum and neonatal feces. We identified IgA bound bacteria (IgA+) and characterized their diversity and composition shared in colostrum fractions and neonatal fecal bacteria. We found that IgA2 is mainly associated with , , and , among other genera shared in colostrum and neonatal fecal samples. We found that metabolic pathways related to epithelial adhesion and carbohydrate consumption are enriched within the IgA2+ fecal microbiota. The association of IgA2 with specific bacteria could be explained because these antibodies recognize common antigens expressed on the surface of these bacterial genera. Our data suggest a preferential targeting of commensal bacteria by IgA2, revealing a possible function of maternal IgA2 in the shaping of the fecal microbial composition in the neonate during the first days of life.
Topics: Antigens; Bacteria; Colostrum; Feces; Female; Gastrointestinal Microbiome; Humans; Immunoglobulin A; Infant, Newborn; Linear Models; Longitudinal Studies; Pregnancy; Prospective Studies; RNA, Ribosomal, 16S
PubMed: 34804008
DOI: 10.3389/fimmu.2021.712130 -
Journal of Bacteriology Apr 2023The periplasmic (NAP) and membrane-associated (Nar) nitrate reductases of Paracoccus denitrificans are responsible for nitrate reduction under aerobic and anaerobic...
The periplasmic (NAP) and membrane-associated (Nar) nitrate reductases of Paracoccus denitrificans are responsible for nitrate reduction under aerobic and anaerobic conditions, respectively. Expression of NAP is elevated in cells grown on a relatively reduced carbon and energy source (such as butyrate); it is believed that NAP contributes to redox homeostasis by coupling nitrate reduction to the disposal of excess reducing equivalents. Here, we show that deletion of either (one of two homologs in the P. denitrificans genome) or / (encoding a bifunctional ppGpp synthetase and hydrolase) eliminates the butyrate-dependent increase in promoter and NAP enzyme activity. We conclude that ppGpp likely signals growth on a reduced substrate and, together with DksA1, mediates increased expression of the genes encoding NAP. Support for this model comes from the observation that promoter activity is increased in cultures exposed to a protein synthesis inhibitor that is known to trigger ppGpp synthesis in other organisms. We also show that, under anaerobic growth conditions, the redox-sensing RegAB two-component pair acts as a negative regulator of NAP expression and as a positive regulator of expression of the membrane-associated nitrate reductase Nar. The and / genes are conditionally synthetically lethal; the double mutant has a null phenotype for growth on butyrate and other reduced substrates while growing normally on succinate and citrate. We also show that the second homolog () and / have roles in regulation of expression of the flavohemoglobin Hmp and in biofilm formation. Paracoccus denitrificans is a metabolically versatile Gram-negative bacterium that is used as a model for studies of respiratory metabolism. The organism can utilize nitrate as an electron acceptor for anaerobic respiration, reducing it to dinitrogen via nitrite, nitric oxide, and nitrous oxide. This pathway (known as denitrification) is important as a route for loss of fixed nitrogen from soil and as a source of the greenhouse gas nitrous oxide. Thus, it is important to understand those environmental and genetic factors that govern flux through the denitrification pathway. Here, we identify four proteins and a small molecule (ppGpp) which function as previously unknown regulators of expression of enzymes that reduce nitrate and oxidize nitric oxide.
Topics: Nitrates; Paracoccus denitrificans; Guanosine Tetraphosphate; Nitrous Oxide; Nitric Oxide; Nitrate Reductase; Nitrate Reductases; Respiration; Butyrates
PubMed: 36920204
DOI: 10.1128/jb.00027-23 -
Frontiers in Microbiology 2022Electrified biotrickling filters represent sustainable microbial electrochemical technology for treating organic carbon-deficient ammonium-contaminated waters. However,...
Electrified biotrickling filters represent sustainable microbial electrochemical technology for treating organic carbon-deficient ammonium-contaminated waters. However, information on the microbiome of the conductive granule bed cathode remains inexistent. For uncovering this black box and for identifying key process parameters, minimally invasive sampling units were introduced, allowing for the extraction of granules from different reactor layers during reactor operation. Sampled granules were analyzed using cyclic voltammetry and molecular biological tools. Two main redox sites [-288 ± 18 mV and -206 ± 21 mV vs. standard hydrogen electrode (SHE)] related to bioelectrochemical denitrification were identified, exhibiting high activity in a broad pH range (pH 6-10). A genome-centric analysis revealed a complex nitrogen food web and the presence of typical denitrifiers like and with none of these species being identified as electroactive microorganism so far. These are the first results to provide insights into microbial structure-function relationships within electrified biotrickling filters and underline the robustness and application potential of bioelectrochemical denitrification for environmental remediation.
PubMed: 35711746
DOI: 10.3389/fmicb.2022.869474 -
Frontiers in Microbiology 2022Antimicrobial chemicals are used as preservatives in cosmetics, pharmaceuticals, and food to prevent the growth of bacteria and fungi in the products. Unintentional...
Antimicrobial chemicals are used as preservatives in cosmetics, pharmaceuticals, and food to prevent the growth of bacteria and fungi in the products. Unintentional exposure in humans to such chemicals is well documented, but whether they also interfere with human oral microbiome composition is largely unexplored. In this study, we explored whether the oral bacterial composition is affected by exposure to antibacterial and environmental chemicals. Gingival fluid, urine, and interview data were collected from 477 adults (18-47 years) from the RHINESSA study in Bergen, Norway. Urine biomarkers of triclosan, triclocarban, parabens, benzophenone-3, bisphenols, and 2,4- and 2,5-dichlorophenols (DCPs) were quantified (by mass spectrometry). Microbiome analysis was based on 16S amplicon sequencing. Diversity and differential abundance analyses were performed to identify how microbial communities may change when comparing groups of different chemical exposure. We identified that high urine levels (>75th percentile) of propyl parabens were associated with a lower abundance of bacteria genera , and , as compared with low propylparaben levels (<25 percentile). High exposure to ethylparaben was associated with a higher abundance of . High urine levels of bisphenol A were associated with a lower abundance of and exposure to another environmental chemical, 2,4-DCP, was associated with a lower abundance of , and . High exposure to antibacterial and environmental chemicals was associated with an altered composition of gingiva bacteria; mostly commensal bacteria in the oral cavity. Our results highlight a need for a better understanding of how antimicrobial chemical exposure influences the human microbiome.
PubMed: 35572708
DOI: 10.3389/fmicb.2022.790496 -
Frontiers in Microbiology 2021Interactions between autotrophic and heterotrophic bacteria are fundamental for marine biogeochemical cycling. How global warming will affect the dynamics of these...
Interactions between autotrophic and heterotrophic bacteria are fundamental for marine biogeochemical cycling. How global warming will affect the dynamics of these essential microbial players is not fully understood. The aims of this study were to identify the major groups of heterotrophic bacteria present in a culture originally isolated from the Red Sea and assess their joint responses to experimental warming within the metabolic ecology framework. A co-culture of sp. RS9907 and their associated heterotrophic bacteria, after determining their taxonomic affiliation by 16S rRNA gene sequencing, was acclimated and maintained in the lab at different temperatures (24-34°C). The abundance and cellular properties of and the three dominant heterotrophic bacterial groups (pertaining to the genera , , and ) were monitored by flow cytometry. The activation energy of , which grew at 0.94-1.38 d, was very similar (0.34 ± 0.02 eV) to the value hypothesized by the metabolic theory of ecology (MTE) for autotrophs (0.32 eV), while the values of the three heterotrophic bacteria ranged from 0.16 to 1.15 eV and were negatively correlated with their corresponding specific growth rates (2.38-24.4 d). The corresponding carrying capacities did not always follow the inverse relationship with temperature predicted by MTE, nor did we observe a consistent response of bacterial cell size and temperature. Our results show that the responses to future ocean warming of autotrophic and heterotrophic bacteria in microbial consortia might not be well described by theoretical universal rules.
PubMed: 34040590
DOI: 10.3389/fmicb.2021.612732 -
Microorganisms Jun 2023Heterotrophic nitrification-aerobic denitrification (HN-AD) is an efficient nitrogen removal process and the genus is one important group of the HN-AD bacteria. During...
Three Novel Marine Species of , sp. nov., sp. nov. and sp. nov., and the Characterization of Their Capability to Perform Heterotrophic Nitrification and Aerobic Denitrification.
Heterotrophic nitrification-aerobic denitrification (HN-AD) is an efficient nitrogen removal process and the genus is one important group of the HN-AD bacteria. During an investigation of the microbial diversity in marine ranching of the Pearl River Estuary (PR China), three bacterial strains, designated SCSIO 75817, SCSIO 76264 and SCSIO 80058, were isolated from sediments. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the three strains belonged to the genus and their closest neighbors were DSM 22220 (97.6-98.0%), . CGMCC 1.13898 (97.3-97.6%) and . MCCC 1A16381 (97.1-97.4%), respectively. The analysis results of 16S rRNA gene similarity, ANI, AAI and dDDH showed that the pairwise similarities between these three strains and their closest neighbors were 97.4-98.5%, 76.9-81.0%, 75.5-79.6% and 20.3-23.3%, respectively. Polyphasic taxonomic data of the phylogenetic, phenotypic and chemotaxonomic analyses indicate that these strains represent three novel species in the genus , for which the names sp. nov., sp. nov. and sp. nov. are proposed, respectively. The study also demonstrated the heterotrophic nitrification-aerobic denitrification (HN-AD) ability of the novel species SCSIO 75817. When it was aerobically cultivated at 28 °C using NH-N, NO-N and NO-N as the sole nitrogen sources, the nitrogen removal efficiencies were 73.4, 55.27 and 49.2%, respectively, and the maximum removal rates were 3.05, 1.82 and 1.63 mg/L/h, respectively. The results suggest that it has promising potential for wastewater treatment.
PubMed: 37375034
DOI: 10.3390/microorganisms11061532 -
Insects Nov 2020Wood-feeding insects should have a source of enzymes like cellulases to digest their food. These enzymes can be produced by the insect, or by microbes living in the wood...
Wood-feeding insects should have a source of enzymes like cellulases to digest their food. These enzymes can be produced by the insect, or by microbes living in the wood and/or inside the insect gut. The coconut rhinoceros beetle, , is a pest whose digestive microbes are of considerable interest. This study describes the compartments of the gut and compares their microbiomes using culturing-enriched metabarcoding. Beetle larvae were collected from a coconut grove in southern Taiwan. Gut contents from the midgut and hindgut were plated on nutrient agar and selective carboxymethylcellulose agar plates. DNA was extracted from gut and fat body samples and 16S rDNA metabarcoding performed to identify unculturable bacteria. Cellulase activity tests were performed on gut fluids and microbe isolates. The midgut and hindgut both showed cellulolytic activity. , and the cellulolytic fungus were cultured from both gut sections in most larvae. Metabarcoding did not find , and found that either or sp. were the dominant gut microbes in any given larva. No significant differences were found between midgut and hindgut microbiomes. and are common animal gut microbes frequently found in studies while and the uncultured sp. had not been identified in this insect before. Some or all of these may well have digestive functions for the beetle, and are most likely acquired from the diet, meaning they may be transient commensalists rather than obligate mutualists. Broader collection efforts and tests with antibiotics will resolve ambiguities in the beetle-microbe interactions.
PubMed: 33187223
DOI: 10.3390/insects11110782 -
Molecules (Basel, Switzerland) Feb 2020Methomyl is a broad-spectrum oxime carbamate commonly used to control arthropods, nematodes, flies, and crop pests. However, extensive use of this pesticide in... (Review)
Review
Methomyl is a broad-spectrum oxime carbamate commonly used to control arthropods, nematodes, flies, and crop pests. However, extensive use of this pesticide in agricultural practices has led to environmental toxicity and human health issues. Oxidation, incineration, adsorption, and microbial degradation methods have been developed to remove insecticidal residues from soil/water environments. Compared with physicochemical methods, biodegradation is considered to be a cost-effective and ecofriendly approach to the removal of pesticide residues. Therefore, micro-organisms have become a key component of the degradation and detoxification of methomyl through catabolic pathways and genetic determinants. Several species of methomyl-degrading bacteria have been isolated and characterized, including , , , , , , , , and . The degradation pathways of methomyl and the fate of several metabolites have been investigated. Further in-depth studies based on molecular biology and genetics are needed to elaborate their role in the evolution of novel catabolic pathways and the microbial degradation of methomyl. In this review, we highlight the mechanism of microbial degradation of methomyl along with metabolic pathways and genes/enzymes of different genera.
Topics: Adsorption; Alcaligenes; Bacillus; Biodegradation, Environmental; Cholinesterase Inhibitors; Flavobacterium; Humans; Incineration; Insecticides; Metabolic Networks and Pathways; Methomyl; Oxidation-Reduction; Paracoccus; Pseudomonas; Serratia; Soil Pollutants; Trametes; Water Pollutants, Chemical
PubMed: 32046287
DOI: 10.3390/molecules25030738