scholarly journals Comparative Genomic Analysis and Benzene, Toluene, Ethylbenzene, ando-,m-, andp-Xylene (BTEX) Degradation Pathways of Pseudoxanthomonas spadix BD-a59

2012 ◽  
Vol 79 (2) ◽  
pp. 663-671 ◽  
Author(s):  
Eun Jin Choi ◽  
Hyun Mi Jin ◽  
Seung Hyeon Lee ◽  
Renukaradhya K. Math ◽  
Eugene L. Madsen ◽  
...  

ABSTRACTPseudoxanthomonas spadixBD-a59, isolated from gasoline-contaminated soil, has the ability to degrade all six BTEX (benzene, toluene, ethylbenzene, ando-,m-, andp-xylene) compounds. The genomic features of strain BD-a59 were analyzed bioinformatically and compared with those of another fully sequencedPseudoxanthomonasstrain,P. suwonensis11-1, which was isolated from cotton waste compost. The genome of strain BD-a59 differed from that of strain 11-1 in many characteristics, including the number of rRNA operons, dioxygenases, monooxygenases, genomic islands (GIs), and heavy metal resistance genes. A high abundance of phage integrases and GIs and the patterns in several other genetic measures (e.g., GC content, GC skew, Karlin signature, and clustered regularly interspaced short palindromic repeat [CRISPR] gene homology) indicated that strain BD-a59's genomic architecture may have been altered through horizontal gene transfers (HGT), phage attack, and genetic reshuffling during its evolutionary history. The genes for benzene/toluene, ethylbenzene, and xylene degradations were encoded on GI-9, -13, and -21, respectively, which suggests that they may have been acquired by HGT. We used bioinformatics to predict the biodegradation pathways of the six BTEX compounds, and these pathways were proved experimentally through the analysis of the intermediates of each BTEX compound using a gas chromatograph and mass spectrometry (GC-MS). The elevated abundances of dioxygenases, monooxygenases, and rRNA operons in strain BD-a59 (relative to strain 11-1), as well as other genomic characteristics, likely confer traits that enhance ecological fitness by enabling strain BD-a59 to degrade hydrocarbons in the soil environment.

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1025
Author(s):  
Shaohua Zhao ◽  
Cong Li ◽  
Chih-Hao Hsu ◽  
Gregory H. Tyson ◽  
Errol Strain ◽  
...  

Salmonella is a leading cause of bacterial infections in animals and humans. We sequenced a collection of 450 Salmonella strains from diseased animals to better understand the genetic makeup of their virulence and resistance features. The presence of Salmonella pathogenicity islands (SPIs) varied by serotype. S. Enteritidis carried the most SPIs (n = 15), while S. Mbandaka, S. Cerro, S. Meleagridis, and S. Havana carried the least (n = 10). S. Typhimurium, S. Choleraesuis, S. I 4,5,12:i:-, and S. Enteritidis each contained the spv operon on IncFII or IncFII-IncFIB hybrid plasmids. Two S. IIIa carried a spv operon with spvD deletion on the chromosome. Twelve plasmid types including 24 hybrid plasmids were identified. IncA/C was frequently associated with S. Newport (83%) and S. Agona (100%) from bovine, whereas IncFII (100%), IncFIB (100%), and IncQ1 (94%) were seen in S. Choleraesuis from swine. IncX (100%) was detected in all S. Kentucky from chicken. A total of 60 antimicrobial resistance genes (ARGs), four disinfectant resistances genes (DRGs) and 33 heavy metal resistance genes (HMRGs) were identified. The Salmonella strains from sick animals contained various SPIs, resistance genes and plasmid types based on the serotype and source of the isolates. Such complicated genomic structures shed light on the strain characteristics contributing to the severity of disease and treatment failures in Salmonella infections, including those causing illnesses in animals.


2012 ◽  
Vol 78 (7) ◽  
pp. 2264-2271 ◽  
Author(s):  
Allan L. Delisle ◽  
Ming Guo ◽  
Natalia I. Chalmers ◽  
Gerard J. Barcak ◽  
Geneviève M. Rousseau ◽  
...  

ABSTRACTM102AD is the new designation for aStreptococcus mutansphage described in 1993 as phage M102. This change was necessitated by the genome analysis of anotherS. mutansphage named M102, which revealed differences from the genome sequence reported here. Additional host range analyses confirmed thatS. mutansphage M102AD infects only a few serotype c strains. Phage M102AD adsorbed very slowly to its host, and it cannot adsorb to serotype e and f strains ofS. mutans. M102AD adsorption was blocked by c-specific antiserum. Phage M102AD also adsorbed equally well to heat-treated and trypsin-treated cells, suggesting carbohydrate receptors. Saliva and polysaccharide production did not inhibit plaque formation. The genome of this siphophage consisted of a linear, double-stranded, 30,664-bp DNA molecule, with a GC content of 39.6%. Analysis of the genome extremities indicated the presence of a 3′-overhangcossite that was 11 nucleotides long. Bioinformatic analyses identified 40 open reading frames, all in the same orientation. No lysogeny-related genes were found, indicating that phage M102AD is strictly virulent. No obvious virulence factor gene candidates were found. Twelve proteins were identified in the virion structure by mass spectrometry. Comparative genomic analysis revealed a close relationship betweenS. mutansphages M102AD and M102 as well as withStreptococcus thermophilusphages. This study also highlights the importance of conducting research with biological materials obtained from recognized microbial collections.


2018 ◽  
Vol 85 (2) ◽  
Author(s):  
Liangzhi Li ◽  
Zhenghua Liu ◽  
Delong Meng ◽  
Xueduan Liu ◽  
Xing Li ◽  
...  

ABSTRACTMembers of the genusAcidithiobacillus, which can adapt to extremely high concentrations of heavy metals, are universally found at acid mine drainage (AMD) sites. Here, we performed a comparative genomic analysis of 37 strains within the genusAcidithiobacillusto answer the untouched questions as to the mechanisms and the evolutionary history of metal resistance genes inAcidithiobacillusspp. The results showed that the evolutionary history of metal resistance genes inAcidithiobacillusspp. involved a combination of gene gains and losses, horizontal gene transfer (HGT), and gene duplication. Phylogenetic analyses revealed that metal resistance genes inAcidithiobacillusspp. were acquired by early HGT events from species that shared habitats withAcidithiobacillusspp., such asAcidihalobacter,Thiobacillus,Acidiferrobacter, andThiomonasspecies. Multicopper oxidase genes involved in copper detoxification were lost in iron-oxidizingAcidithiobacillus ferridurans,Acidithiobacillus ferrivorans, andAcidithiobacillus ferrooxidansand were replaced by rusticyanin genes during evolution. In addition, widespread purifying selection and the predicted high expression levels emphasized the indispensable roles of metal resistance genes in the ability ofAcidithiobacillusspp. to adapt to harsh environments. Altogether, the results suggested thatAcidithiobacillusspp. recruited and consolidated additional novel functionalities during the adaption to challenging environments via HGT, gene duplication, and purifying selection. This study sheds light on the distribution, organization, functionality, and complex evolutionary history of metal resistance genes inAcidithiobacillusspp.IMPORTANCEHorizontal gene transfer (HGT), natural selection, and gene duplication are three main engines that drive the adaptive evolution of microbial genomes. Previous studies indicated that HGT was a main adaptive mechanism in acidophiles to cope with heavy-metal-rich environments. However, evidences of HGT inAcidithiobacillusspecies in response to challenging metal-rich environments and the mechanisms addressing how metal resistance genes originated and evolved inAcidithiobacillusare still lacking. The findings of this study revealed a fascinating phenomenon of putative cross-phylum HGT, suggesting thatAcidithiobacillusspp. recruited and consolidated additional novel functionalities during the adaption to challenging environments via HGT, gene duplication, and purifying selection. Altogether, the insights gained in this study have improved our understanding of the metal resistance strategies ofAcidithiobacillusspp.


2018 ◽  
Author(s):  
Wenbang Yu ◽  
Xiaoxiao Chen ◽  
Yilin Sheng ◽  
Qinghong Hong

AbstractStenotrophomonas maltophilia is highly resistant to heavy metals, but the genetic knowledge of metal resistance in S. maltophilia is poorly understood. In this study, the genome of S.maltophilia Pho isolated from the contaminated soil near a metalwork factory was sequenced using PacBio RS II. Its genome is composed of a single chromosome with a GC content of 66.4% and 4434 protein-encoding genes. Comparative analysis revealed high syntney between S.maltophilia Pho and the model strain, S.maltophilia K279a. Then, the type and number of mechanisms for heavy metal uptake were analyzed firstly. Results revealed 7 unspecific ion transporter genes and 13 specific ion transporter genes, most of which were involved in iron transport. But the sulfate permeases belonging to the family of SulT/CysP that can uptake chromate and the high affinity ZnuABC/SitABCD were absent. Secondly, the putative genes controlling metal efflux were identified. Results showed that this bacterium encoded 5 CDFs, 1 copper exporting ATPase and 4 RND systems, including 2 CzcABC efflux pumps. Moreover, the putative metal transformation genes including arsenate and mercury detoxification genes were also identified. This study may provide useful information on the metal resistance mechanisms of S.maltophilia.


2019 ◽  
Vol 8 (40) ◽  
Author(s):  
Zhisong Cui ◽  
Veronika Kivenson ◽  
Na Liu ◽  
Angela Xu ◽  
Xiao Luan ◽  
...  

We present the complete genome sequence of fluoranthene-consuming Cycloclasticus sp. strain PY97N. This strain has one circular chromosome with a G+C content of 42.06%. Moreover, two genomic islands were identified as putative conjugative elements. These genomic details are expected to inform our understanding of the remarkable catabolic capacities of organisms of the Cycloclasticus lineage.


2011 ◽  
Vol 77 (20) ◽  
pp. 7418-7424 ◽  
Author(s):  
Jaejoon Jung ◽  
Eugene L. Madsen ◽  
Che Ok Jeon ◽  
Woojun Park

ABSTRACTThe comparative genomics ofAcinetobacter oleivoransDR1 assayed withA. baylyiADP1,A. calcoaceticusPHEA-2, andA. baumanniiATCC 17978 revealed that the incorporation of phage-related genomic regions and the absence of transposable elements have contributed to the large size (4.15 Mb) of the DR1 genome. A horizontally transferred genomic region and a higher proportion of transcriptional regulator- and signal peptide-coding genes were identified as characteristics of the DR1 genome. Incomplete glucose metabolism, metabolic pathways of aromatic compounds, biofilm formation, antibiotics and metal resistance, and natural competence genes were conserved in four compared genomes. Interestingly, only strain DR1 possesses gentisate 1,2-dioxygenase (nagI) and grows on gentisate, whereas other species cannot. Expression of thenagIgene was upregulated during gentisate utilization, and four downstream open reading frames (ORFs) were cotranscribed, supporting the notion that gentisate metabolism is a unique characteristic of strain DR1. The genomic analysis of strain DR1 provides additional insights into the function, ecology, and evolution ofAcinetobacterspecies.


2011 ◽  
Vol 77 (13) ◽  
pp. 4344-4351 ◽  
Author(s):  
Per Johansson ◽  
Lars Paulin ◽  
Elina Säde ◽  
Noora Salovuori ◽  
Edward R. Alatalo ◽  
...  

ABSTRACTLeuconostoc gasicomitatumis a psychrotrophic lactic acid bacterium causing spoilage of cold-stored, modified-atmosphere-packaged (MAP), nutrient-rich foods. Its role has been verified by challenge tests in gas and slime formation, development of pungent acidic and buttery off odors, and greening of beef. MAP meats have especially been prone toL. gasicomitatumspoilage. In addition, spoilage of vacuum-packaged vegetable sausages and marinated herring has been reported. The genomic sequencing project ofL. gasicomitatumLMG 18811Twas prompted by a need to understand the growth and spoilage potentials ofL. gasicomitatum, to study its phylogeny, and to be able to knock out and overexpress the genes. Comparative genomic analysis was done withinL. gasicomitatumLMG 18811Tand the three fully assembledLeuconostocgenomes (those ofLeuconostoc mesenteroides,Leuconostoc citreum, andLeuconostoc kimchii) available. The genome ofL. gasicomitatumLMG 18811Tis plasmid-free and contains a 1,954,080-bp circular chromosome with an average GC content of 36.7%. It includes genes for the phosphoketolase pathway and alternative pathways for pyruvate utilization. As interesting features associated with the growth and spoilage potential, LMG 18811Tpossesses utilization strategies for ribose, external nucleotides, nucleosides, and nucleobases and it has a functional electron transport chain requiring only externally supplied heme for respiration. In respect of the documented specific spoilage reactions, the pathways/genes associated with a buttery off odor, meat greening, and slime formation were recognized. Unexpectedly, genes associated with platelet binding and collagen adhesion were detected, but their functionality and role in food spoilage and processing environment contamination need further study.


2008 ◽  
Vol 74 (9) ◽  
pp. 2852-2863 ◽  
Author(s):  
Shawn R. Starkenburg ◽  
Frank W. Larimer ◽  
Lisa Y. Stein ◽  
Martin G. Klotz ◽  
Patrick S. G. Chain ◽  
...  

ABSTRACT The alphaproteobacterium Nitrobacter hamburgensis X14 is a gram-negative facultative chemolithoautotroph that conserves energy from the oxidation of nitrite to nitrate. Sequencing and analysis of the Nitrobacter hamburgensis X14 genome revealed four replicons comprised of one chromosome (4.4 Mbp) and three plasmids (294, 188, and 121 kbp). Over 20% of the genome is composed of pseudogenes and paralogs. Whole-genome comparisons were conducted between N. hamburgensis and the finished and draft genome sequences of Nitrobacter winogradskyi and Nitrobacter sp. strain Nb-311A, respectively. Most of the plasmid-borne genes were unique to N. hamburgensis and encode a variety of functions (central metabolism, energy conservation, conjugation, and heavy metal resistance), yet ∼21 kb of a ∼28-kb “autotrophic” island on the largest plasmid was conserved in the chromosomes of Nitrobacter winogradskyi Nb-255 and Nitrobacter sp. strain Nb-311A. The N. hamburgensis chromosome also harbors many unique genes, including those for heme-copper oxidases, cytochrome b 561, and putative pathways for the catabolism of aromatic, organic, and one-carbon compounds, which help verify and extend its mixotrophic potential. A Nitrobacter “subcore” genome was also constructed by removing homologs found in strains of the closest evolutionary relatives, Bradyrhizobium japonicum and Rhodopseudomonas palustris. Among the Nitrobacter subcore inventory (116 genes), copies of genes or gene clusters for nitrite oxidoreductase (NXR), cytochromes associated with a dissimilatory nitrite reductase (NirK), PII-like regulators, and polysaccharide formation were identified. Many of the subcore genes have diverged significantly from, or have origins outside, the alphaproteobacterial lineage and may indicate some of the unique genetic requirements for nitrite oxidation in Nitrobacter.


2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Jean N. Hakizimana ◽  
Jean B. Ntirandekura ◽  
Clara Yona ◽  
Lionel Nyabongo ◽  
Gladson Kamwendo ◽  
...  

AbstractSeveral African swine fever (ASF) outbreaks in domestic pigs have been reported in Burundi and Malawi and whole-genome sequences of circulating outbreak viruses in these countries are limited. In the present study, complete genome sequences of ASF viruses (ASFV) that caused the 2018 outbreak in Burundi (BUR/18/Rutana) and the 2019 outbreak in Malawi (MAL/19/Karonga) were produced using Illumina next-generation sequencing (NGS) platform and compared with other previously described ASFV complete genomes. The complete nucleotide sequences of BUR/18/Rutana and MAL/19/Karonga were 176,564 and 183,325 base pairs long with GC content of 38.62 and 38.48%, respectively. The MAL/19/Karonga virus had a total of 186 open reading frames (ORFs) while the BUR/18/Rutana strain had 151 ORFs. After comparative genomic analysis, the MAL/19/Karonga virus showed greater than 99% nucleotide identity with other complete nucleotides sequences of p72 genotype II viruses previously described in Tanzania, Europe and Asia including the Georgia 2007/1 isolate. The Burundian ASFV BUR/18/Rutana exhibited 98.95 to 99.34% nucleotide identity with genotype X ASFV previously described in Kenya and in Democratic Republic of the Congo (DRC). The serotyping results classified the BUR/18/Rutana and MAL/19/Karonga ASFV strains in serogroups 7 and 8, respectively. The results of this study provide insight into the genetic structure and antigenic diversity of ASFV strains circulating in Burundi and Malawi. This is important in order to understand the transmission dynamics and genetic evolution of ASFV in eastern Africa, with an ultimate goal of designing an efficient risk management strategy against ASF transboundary spread.


2018 ◽  
Vol 63 (2) ◽  
pp. e01718-18 ◽  
Author(s):  
Srijan Ranjitkar ◽  
Adriana K. Jones ◽  
Mina Mostafavi ◽  
Zachary Zwirko ◽  
Oleg Iartchouk ◽  
...  

ABSTRACT Efflux pumps contribute to antibiotic resistance in Gram-negative pathogens. Correspondingly, efflux pump inhibitors (EPIs) may reverse this resistance. D13-9001 specifically inhibits MexAB-OprM in Pseudomonas aeruginosa. Mutants with decreased susceptibility to MexAB-OprM inhibition by D13-9001 were identified, and these fell into two categories: those with alterations in the target MexB (F628L and ΔV177) and those with an alteration in a putative sensor kinase of unknown function, PA1438 (L172P). The alterations in MexB were consistent with reported structural studies of the D13-9001 interaction with MexB. The PA1438L172P alteration mediated a >150-fold upregulation of MexMN pump gene expression and a >50-fold upregulation of PA1438 and the neighboring response regulator gene, PA1437. We propose that these be renamed mmnR and mmnS for MexMN regulator and MexMN sensor, respectively. MexMN was shown to partner with the outer membrane channel protein OprM and to pump several β-lactams, monobactams, and tazobactam. Upregulated MexMN functionally replaced MexAB-OprM to efflux these compounds but was insusceptible to inhibition by D13-9001. MmnSL172P also mediated a decrease in susceptibility to imipenem and biapenem that was independent of MexMN-OprM. Expression of oprD, encoding the uptake channel for these compounds, was downregulated, suggesting that this channel is also part of the MmnSR regulon. Transcriptome sequencing (RNA-seq) of cells encoding MmnSL172P revealed, among other things, an interrelationship between the regulation of mexMN and genes involved in heavy metal resistance.


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