Frontiers in Microbiology
Công bố khoa học tiêu biểu
* Dữ liệu chỉ mang tính chất tham khảo
Sắp xếp:
Life Within a Contaminated Niche: Comparative Genomic Analyses of an Integrative Conjugative Element ICEnahCSV86 and Two Genomic Islands From Pseudomonas bharatica CSV86T Suggest Probable Role in Colonization and Adaptation Comparative genomic and functional analyses revealed the presence of three genomic islands (GIs, >50 Kb size): ICEnah CSV86, Pseudomonas bharatica genomic island-1 (PBGI-1), and PBGI-2 in the preferentially aromatic-degrading soil bacterium, Pseudomonas bharatica CSV86T . Site-specific genomic integration at or near specific transfer RNAs (tRNAs), near-syntenic structural modules, and phylogenetic relatedness indicated their evolutionary lineage to the type-4 secretion system (T4SS) ICEclc family, thus predicting these elements to be integrative conjugative elements (ICEs). These GIs were found to be present as a single copy in the genome and the encoded phenotypic traits were found to be stable, even in the absence of selection pressure. ICEnah CSV86 harbors naphthalene catabolic (nah -sal ) cluster, while PBGI-1 harbors Co-Zn-Cd (czc ) efflux genes as cargo modules, whereas PBGI-2 was attributed to as a mixed-function element. The ICEnah CSV86 has been reported to be conjugatively transferred (frequency of 7 × 10–8 /donor cell) to Stenotrophomonas maltophilia CSV89. Genome-wide comparative analyses of aromatic-degrading bacteria revealed nah -sal clusters from several Pseudomonas spp. as part of probable ICEs, syntenic to conjugatively transferable ICEnah CSV86 of strain CSV86T , suggesting it to be a prototypical element for naphthalene degradation. It was observed that the plasmids harboring nah -sal clusters were phylogenetically incongruent with predicted ICEs, suggesting genetic divergence of naphthalene metabolic clusters in the Pseudomonas population. Gene synteny, divergence estimates, and codon-based Z -test indicated that ICEnah CSV86 is probably derived from PBGI-2, while multiple recombination events masked the ancestral lineage of PBGI-1. Diversifying selection pressure (dN-dS = 2.27–4.31) imposed by aromatics and heavy metals implied the modular exchange-fusion of various cargo clusters through events like recombination, rearrangement, domain reshuffling, and active site optimization, thus allowing the strain to evolve, adapt, and maximize the metabolic efficiency in a contaminated niche. The promoters (Pnah and Psal ) of naphthalene cargo modules (nah , sal ) on ICEnah CSV86 were proved to be efficient for heterologous protein expression in Escherichia coli . GI-based genomic plasticity expands the metabolic spectrum and versatility of CSV86T , rendering efficient adaptation to the contaminated niche. Such isolate(s) are of utmost importance for their application in bioremediation and are the probable ideal host(s) for metabolic engineering.
Frontiers in Microbiology - Tập 13
Conserved Metabolic and Evolutionary Themes in Microbial Degradation of Carbamate Pesticides Carbamate pesticides are widely used as insecticides, nematicides, acaricides, herbicides and fungicides in the agriculture, food and public health sector. However, only a minor fraction of the applied quantity reaches the target organisms. The majority of it persists in the environment, impacting the non-target biota, leading to ecological disturbance. The toxicity of these compounds to biota is mediated through cholinergic and non-cholinergic routes, thereby making their clean-up cardinal. Microbes, specifically bacteria, have adapted to the presence of these compounds by evolving degradation pathways and thus play a major role in their removal from the biosphere. Over the past few decades, various genetic, metabolic and biochemical analyses exploring carbamate degradation in bacteria have revealed certain conserved themes in metabolic pathways like the enzymatic hydrolysis of the carbamate ester or amide linkage, funnelling of aryl carbamates into respective dihydroxy aromatic intermediates, C1 metabolism and nitrogen assimilation. Further, genomic and functional analyses have provided insights on mechanisms like horizontal gene transfer and enzyme promiscuity, which drive the evolution of degradation phenotype. Compartmentalisation of metabolic pathway enzymes serves as an additional strategy that further aids in optimising the degradation efficiency. This review highlights and discusses the conclusions drawn from various analyses over the past few decades; and provides a comprehensive view of the environmental fate, toxicity, metabolic routes, related genes and enzymes as well as evolutionary mechanisms associated with the degradation of widely employed carbamate pesticides. Additionally, various strategies like application of consortia for efficient degradation, metabolic engineering and adaptive laboratory evolution, which aid in improvising remediation efficiency and overcoming the challenges associated with in situ bioremediation are discussed.
Frontiers in Microbiology - Tập 12
The Synergistic Effect of High Pressure CO2 and Nisin on Inactivation of Bacillus subtilis Spores in Aqueous Solutions
Frontiers in Microbiology - Tập 07
Estimating and mapping ecological processes influencing microbial community assembly
Frontiers in Microbiology - Tập 6
Traits of Exogenous Species and Indigenous Community Contribute to the Species Colonization and Community Succession
Frontiers in Microbiology - Tập 9
Changes in community assembly may shift the relationship between biodiversity and ecosystem function
Frontiers in Microbiology - Tập 5
Biodegradation and Biotransformation of Indole: Advances and Perspectives
Frontiers in Microbiology - Tập 9
Reconstruction and Analysis of a Genome-Scale Metabolic Model of Ganoderma lucidum for Improved Extracellular Polysaccharide Production
Frontiers in Microbiology - Tập 9
Phyto-Mediated Synthesis of Porous Titanium Dioxide Nanoparticles From Withania somnifera Root Extract: Broad-Spectrum Attenuation of Biofilm and Cytotoxic Properties Against HepG2 Cell Lines
Frontiers in Microbiology - Tập 11
Tổng số: 336
- 1
- 2
- 3
- 4
- 5
- 6
- 10