Complete genome sequencing and comparative genomic analyses of Bacillus sp. S3, a novel hyper Sb(III)-oxidizing bacterium

2020 ◽  
Author(s):  
Jiaokun Li ◽  
Tianyuan Gu ◽  
Weimin Zeng ◽  
Runlan Yu ◽  
Yuandong Liu ◽  
...  

Abstract Background: Antimonite [Sb(III)]-oxidizing bacterium has great potential in the environmental bioremediation of Sb-polluted sites. Bacillus sp. S3 that was previously isolated from antimony-contaminated soil displayed high Sb(III) resistance and Sb(III) oxidation efficiency. However, the genomic information and evolutionary feature of Bacillus sp. S3 are very scarce. Results: Here, we identified a 5,579,638 bp chromosome with 40.30% GC content and a 241,339 bp plasmid with 36.74% GC content in the complete genome of Bacillus sp. S3. Genomic annotation showed that Bacillus sp. S3 contained a key aioB gene potentially encoding As(III)/Sb(III) oxidase, which was not shared with other Bacillus strains. Further, a series of genes associated with Sb(III) and other heavy metal(loid)s were also ascertained in Bacillus sp. S3, reflecting its adaptive advantage for growth in the harsh eco-environment. Based on the analysis of phylogenetic relationship and the average nucleotide identities (ANI), we found that Bacillus sp. S3 was a novel species within the Bacillus genus. The majority of mobile genetic elements (MGEs) mainly distributed on chromosomes within the Bacillus genus. Pan-genome analysis showed that the 45 genomes contained 554 core genes and many unique genes were dissected in analyzed genomes. Whole genomic alignment showed that Bacillus genus underwent frequently large-scale evolutionary events. In addition, the origin and evolution analysis of Sb(III)-resistance genes revealed that evolutionary relationships and horizontal gene transfer (HGT) events among the Bacillus genus. The assessment of functionality of heavy metal(loid)s resistance genes emphasized its indispensable roles in the harsh eco-environment of Bacillus genus. The real-time Quantitative PCR (RT-qPCR) results of Sb(III)-related genes indicated that the Sb(III) resistance was constantly increased under the Sb(III) stress. Conclusions: The results in this study shed light on the molecular mechanisms of Bacillus sp. S3 coping with Sb(III), extended our understanding on the evolutionary relationship between Bacillus sp. S3 and other closely related species, and further enriched the Sb(III) resistance genetic data sources.

2019 ◽  
Author(s):  
Jiaokun Li ◽  
Tianyuan Gu ◽  
Weimin Zeng ◽  
Runlan Yu ◽  
Yuandong Liu ◽  
...  

Abstract Background: Antimonite [Sb(III)]-oxidizing bacterium have great potential in the environmental bioremediation of Sb-polluted sites. Bacillus sp. S3 isolated from antimony-contaminated soil showed high Sb(III) resistance and Sb(III) oxidation efficiency. However, very little genomic information and evolutionary relationships that bacterial oxidation of Sb(III) is available. Results: Here, we identified a 5579638 bp chromosome with 40.30% GC content and a 241339 bp plasmid with 36.74% GC content in the complete genome of Bacillus sp. S3. Genomic annotation showed that Bacillus sp. S3 contains key aioB gene potentially encoding As(III)/Sb(III) oxidase, is not shared with other Bacillus strains. Further, a series of genes associated with Sb(III) and other heavy metal(loid) were also ascertained, reflecting adaptive advantage for growth in the harsh eco-environment. It is noteworthy that Bacillus sp. S3 is a novel species within the Bacillus genus as indicated by phylogenetic relationship and the average nucleotide identities (ANI) analysis. The presence of genomic plasticity demonstrated a high number of mobile genetic elements (MGEs) that were mainly distributed on chromosomes within the Bacillus genus. The core genome contained 554 core genes and many unique genes were dissected in analyzed genomes, indicating a conserved core but adaptive pan repertoire. Whole genomic alignment indicates that frequently genomic reshuffling and rearrangements, genetic gain and loss, and other recombination events occurred during the evolutionary history of Bacillus genus. In addition, the origin and evolution analysis of Sb(III)-resistance genes revealed that evolutionary relationships and events of horizontal gene transfer (HGT) among the Bacillus genus. The assessment of functionality of heavy metal(loid) resistance genes emphasized its indispensable roles in the harsh eco-environment of Bacillus genus. The real-time Quantitative PCR(RT-qPCR) results of Sb(III)-related genes indicated that the Sb(III) resistance was constantly increased under the Sb(III) stress. Conclusions: The insights provided in this study shed light on the molecular details of Bacillus sp. S3 coping with Sb(III), which extended our understanding on the evolutionary relationship between Bacillus sp. S3 and other closely related species and will enrich the Sb(III) resistance genetic data sources.


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.


2020 ◽  
Author(s):  
Xueping LI ◽  
Jianhong Li ◽  
Yonghong Qi ◽  
Yonggang Liu ◽  
Minquan Li

Abstract BackgroundFusarium equiseti is a plant pathogen with a wide range of hosts and diverse effects, including probiotic activity. However, the underlying molecular mechanisms remain unclear, hindering its effective control and utilization. In this study, the Illumina HiSeq 4000 and PacBio platforms were used to sequence and assemble the whole genome of Fusarium equiseti D25-1.ResultsThe assembly included 16 fragments with a GC content of 48.01%, gap number of zero, and size of 40,776,005 bp. There were 40,110 exons and 26,281 introns having a total size of 19,787,286 bp and 2,290,434 bp, respectively. The genome had an average copy number of 333, 71, 69, 31, and 108 for tRNAs, rRNAs, sRNAs, snRNAs, and miRNAs, respectively. The total repetitive sequence length was 1,713,918 bp, accounting for 4.2033% of the genome. In total, 13,134 functional genes were annotated, accounting for 94.97% of the total gene number. Toxin-related genes, including two related to zearalenone and 23 related to trichothecene, were identified. A comparative genomic analysis supported the high quality of the F. equiseti assembly, exhibiting good collinearity with the reference strains, 3,483 species-specific genes, and 1,805 core genes. A gene family analysis revealed more than 2,500 single-copy orthologs. F. equiseti was most closely related to Fusarium pseudograminearum based on a phylogenetic analysis at the whole-genome level.ConclusionsOur comprehensive analysis of the whole genome of F. equiseti provides basic data for studies of gene expression, regulatory and functional mechanisms, evolutionary processes, as well as disease prevention and control.


2021 ◽  
Author(s):  
Debasis Nayak ◽  
Basanta Sahu ◽  
Prativa Majee ◽  
Ravi Singh ◽  
Niranjan Sahoo

Abstract Contagious pustular dermatitis is a disease that primarily infects small ruminants and has the zoonotic potential evoked by a Parapoxvirus, Orf virus (ORFV). This study evaluated an ORFV outbreak in goats that arose in Madhya Pradesh, a state of central India, during 2017 by constructing phylogenetic trees and unveiling its transboundary potential. Thereafter, the complete genome of an ORFV strain named Ind/MP has revealed the presence of 139,807bp nucleotide sequences, GC content 63.7%, 132 open reading frames (ORFs) circumscribed by inverted terminal repeats (ITRs) of 3,910bp. Evolutionary parameters such as selection pressure (θ=dN/dS), nucleotide diversity (π), etc., demonstrate the ORFV exhibit purifying selection. A total of forty recombination events were observed, out of which Ind/MP strains were engaged in twenty-one recombination events indicating this strain can recombine for the generation of new variants.


2021 ◽  
Vol 12 ◽  
Author(s):  
Bin-Bin Chi ◽  
Ya-Nan Lu ◽  
Ping-Chuan Yin ◽  
Hong-Yan Liu ◽  
Hui-Ying Chen ◽  
...  

Heavy metal pollution is a global knotty problem and fungi hold promising potential for the remediation of wastewater containing heavy metals. Here, a new highly chromium-tolerance species, Penicillium janthinellum P1, is investigated. The genome of P1 was sequenced and assembled into 30 Mb genome size containing 10,955 predicted protein-coding genes with a GC content of 46.16% through an integrated method of Illumina short-read sequencing and single-molecule real-time Pacific Biosciences sequencing platforms. Through a phylogenetic analysis with model species of fungi, the evolutionary divergence time of Penicillium janthinellum P1 and Penicillium oxalicum 114-2 was estimated to be 74 MYA. 33 secondary metabolism gene clusters were identified via antiSMASH software, mainly including non-ribosomal peptide synthase genes and T1 polyketide synthase genes. 525 genes were annotated to encode enzymes that act on carbohydrates, involving 101 glucose-degrading enzymes and 24 polysaccharide synthase. By whole-genome sequence analysis, large numbers of metal resistance genes were found in strain P1. Especially ABC transporter and Superoxide dismutase ensure that the P1 fungus can survive in a chromium-polluted environment. ChrA and ChrR were also identified as key genes for chromium resistance. Analysis of their genetic loci revealed that the specific coding-gene arrangement may account for the fungus’s chromium resistance. Genetic information and comparative analysis of Penicillium janthinellum are valuable for further understanding the mechanism of high resistance to heavy metal chromium, and gene loci analysis provides a new perspective for identifying chromium-resistant strains.


2019 ◽  
Author(s):  
Liu Bin ◽  
Zhiqiu Yin ◽  
Chao Yuan ◽  
Yuhui Du ◽  
Pan Yang ◽  
...  

Abstract Background The Hafnia genus is an opportunistic pathogen that has been implicated in both nosocomial and community-acquired infections. Although Hafnia is fairly often isolated from clinical material, its taxonomy has remained an unsolved riddle, and the involvement and importance of Hafnia in human disease is also uncertain. Here, we used comparative genomic analysis to define the taxonomy of Hafnia, identify species-specific genes that may be the result of ecological and pathogenic specialization, and reveal virulence-related genetic profiles that may contribute to pathogenesis. Results One complete genome sequence and 19 draft genome sequences for Hafnia strains were generated and combined with 27 publicly available genomes. We provided high-resolution typing methods by constructing phylogeny and population structure based on single-copy core genes in combination with whole genome average nucleotide identity to identify two distant Hafnia species (alvei and paralvei) and one mislabeled strain. The open pan-genome and the presence of numerous mobile genetic elements reveal that Hafnia has undergone massive gene rearrangements. Presence of species-specific core genomes associated with metabolism and transport suggests the putative niche differentiation between alvei and paralvei. We also identified possession of diverse virulence-related profiles in both Hafnia species., including the macromolecular secretion system, virulence, and antimicrobial resistance. In the macromolecular system, T1SS, Flagellum 1, Tad pilus and T6SS-1 were conserved in Hafnia, whereas T4SS, T5SS, and other T6SSs exhibited the evolution of diversity. The virulence factors in Hafnia are related to adherence, toxin, iron uptake, stress adaptation, and efflux pump. The identified resistance genes are associated with beta-lactamases and tetracycline. These virulence-related profiles identified at the genomic level provide insights into Hafnia pathogenesis and the differentiation between alvei and paralvei. Conclusions Our research using core genome phylogeny and comparative genomics analysis of a larger collection of strains provides a comprehensive view of the taxonomy and species-specific traits between Hafnia species. Deciphering the genome of Hafnia strains possessing a reservoir of macromolecular secretion systems, virulence factors, and resistance genes related to pathogenicity may provide insights into addressing its numerous infections and devising strategies to combat the pathogen.


2017 ◽  
Author(s):  
Ian Goodhead ◽  
Frances Blow ◽  
Philip Brownridge ◽  
Margaret Hughes ◽  
John Kenny ◽  
...  

AbstractThe majority of bacterial genomes have high coding efficiencies, but there are some genomes of intracellular bacteria that have low gene density. The genome of the endosymbiont Sodalis glossinidius contains almost 50% pseudogenes containing mutations that putatively silence them at the genomic level. We have applied multiple ‘omic strategies, combining: Illumina and Pacific Biosciences Single-Molecule Real Time DNA-sequencing and annotation; stranded RNA-sequencing; and proteome analysis to better understand the transcriptional and translational landscape of Sodalis pseudogenes, and potential mechanisms for their control. Between 53% and 74% of the Sodalis transcriptome remains active in cell-free culture. Mean sense transcription from Coding Domain Sequences (CDS) is four-times greater than that from pseudogenes. Comparative genomic analysis of six Illumina-sequenced Sodalis isolates from different host Glossina species shows pseudogenes make up ~40% of the 2,729 genes in the core genome, suggesting that they are stable and/or Sodalis is a recent introduction across the Glossina genus as a facultative symbiont. These data further shed light on the importance of transcriptional and translational control in deciphering host-microbe interactions. The combination of genomics, transcriptomics and proteomics give a multidimensional perspective for studying prokaryotic genomes with a view to elucidating evolutionary adaptation to novel environmental niches.ImportanceBacterial genes are generally 1Kb in length, organized efficiently (i.e. with few gaps between genes or operons), and few open reading frames (ORFs) lack any predicted function. Intracellular bacteria have been removed from extracellular selection pressures acting on pathways of declining importance to fitness and thus, these bacteria tend to delete redundant genes in favour of smaller functional repertoires. In the genomes of endosymbionts with a recent evolutionary relationship with their host, however, this process of genome reduction is not complete; Genes and pathways may be at an intermediate stage, undergoing mutation linked to reduced selection and small population numbers being vertically transmitted from mother to offspring in their hosts, resulting in an increase in abundance of pseudogenes and reduced coding capacities. A greater knowledge of the genomic architecture of persistent pseudogenes, with respect to their DNA structure, mRNA transcription and even putative translation to protein products, will lead to a better understanding of the evolutionary trajectory of endosymbiont genomes, many of which have important roles in arthropod ecology.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6495 ◽  
Author(s):  
Chao Niu ◽  
Min Jiang ◽  
Na Li ◽  
Jianguo Cao ◽  
Meifang Hou ◽  
...  

Background Current environmental pollution factors, particularly the distribution and diffusion of heavy metals in soil and water, are a high risk to local environments and humans. Despite striking advances in methods to detect contaminants by a variety of chemical and physical solutions, these methods have inherent limitations such as small dimensions and very low coverage. Therefore, identifying novel contaminant biomarkers are urgently needed. Methods To better track heavy metal contaminations in soil and water, integrated bioinformatics analysis to identify biomarkers of relevant heavy metal, such as As, Cd, Pb and Cu, is a suitable method for long-term and large-scale surveys of such heavy metal pollutants. Subsequently, the accuracy and stability of the results screened were experimentally validated by quantitative PCR experiment. Results We obtained 168 differentially expressed genes (DEGs) which contained 59 up-regulated genes and 109 down-regulated genes through comparative bioinformatics analyses. Subsequently, the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments of these DEGs were performed, respectively. GO analyses found that these DEGs were mainly related to responses to chemicals, responses to stimulus, responses to stress, responses to abiotic stimulus, and so on. KEGG pathway analyses of DEGs were mainly involved in the protein degradation process and other biologic process, such as the phenylpropanoid biosynthesis pathways and nitrogen metabolism. Moreover, we also speculated that nine candidate core biomarker genes (namely, NILR1, PGPS1, WRKY33, BCS1, AR781, CYP81D8, NR1, EAP1 and MYB15) might be tightly correlated with the response or transport of heavy metals. Finally, experimental results displayed that these genes had the same expression trend response to different stresses as mentioned above (Cd, Pb and Cu) and no mentioned above (Zn and Cr). Conclusion In general, the identified biomarker genes could help us understand the potential molecular mechanisms or signaling pathways responsive to heavy metal stress in plants, and could be applied as marker genes to track heavy metal pollution in soil and water through detecting their expression in plants growing in those environments.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Muhammad Zubair Shabbir ◽  
Aziz-ul Rahman ◽  
Muhammad Munir

AbstractA string of complete genome sequences of Small ruminant morbillivirus (SRMV) have been reported from different parts of the globe including Asia, Africa and the Middle East. Despite individual genome sequence-based analysis, there is a paucity of comparative genomic and evolutionary analysis to provide overarching and comprehensive evolutionary insights. Therefore, we first enriched the existing database of complete genome sequences of SRMVs with Pakistan-originated strains and then explored overall nucleotide diversity, genomic and residue characteristics, and deduced an evolutionary relationship among strains representing a diverse geographical region worldwide. The average number of pairwise nucleotide differences among the whole genomes was found to be 788.690 with a diversity in nucleotide sequences (0.04889 ± S.D. 0.00468) and haplotype variance (0.00001). The RNA-dependent-RNA polymerase (L) gene revealed phylogenetic relationship among SRMVs in a pattern similar to those of complete genome and the nucleoprotein (N) gene. Therefore, we propose another useful molecular marker that may be employed for future epidemiological investigations. Based on evolutionary analysis, the mean evolution rate for the complete genome, N, P, M, F, H and L genes of SRMV was estimated to be 9.953 × 10–4, 1.1 × 10–3, 1.23 × 10–3, 2.56 × 10–3, 2.01 × 10–3, 1.47 × 10–3 and 9.75 × 10–4 substitutions per site per year, respectively. A recombinant event was observed in a Pakistan-originated strain (KY967608) revealing Indian strains as major (98.1%, KR140086) and minor parents (99.8%, KT860064). Taken together, outcomes of the study augment our knowledge and current understanding towards ongoing phylogenomic and evolutionary dynamics for better comprehensions of SRMVs and effective disease control interventions.


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