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July 7, 2019

Systems biology analysis of the key genes of surfactin production in Bacillus subtilis MJ01 (isolated from soil contaminated oil in south of Iran), spizizenii, and 168 isolates

Applying microorganism in oil recovery has attracted attentions recently. Surfactin produced by Bacillus subtilis is widely used industrially in a range of industrial applications in pharmecutical and environmental sectors. Little information about molecular mechanism of suffactin compound is available. In this study, we performed promoter and network analysis of surfactin production genes in Bacillus subtilis subsp. MJ01 (isolated from oil contaminated soil in South of Iran), spizizenii and 168. Our analysis revealed that comQ and comX are the genes with sequence alterations among these three strains of Bacillus subtilis and are involved in surfactin production. Promoter analysis indicated that lrp, argR, rpoD, purr and ihf are overrepresented and have the highest number of transcription factor binding sites (TFBs) on the key surfactin production genes in all 3 strains. Also the pattern of TFBs among these three strains was completely different. Interestingly, there is distinct difference between 168, spizizenii and MJ01 in their frequency of TFs that activate genes involve in surfactin production. Attribute weighting algorithms and decision tree analysis revealed ihf, rpoD and flHCD as the most important TF among surfactin production. Network analysis identified two significant network modules. The first one consists of key genes involved in surfactin production and the second module includes key TFs, involved in regulation of surfactin production. Our findings enhance understanding the molecular mechanism of surfactin production through systems biology analysis.

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July 7, 2019

Pectobacterium polaris sp. nov., isolated from potato (Solanum tuberosum).

The genus Pectobacterium, which belongs to the bacterial family Enterobacteriaceae, contains numerous species that cause soft rot diseases in a wide range of plants. The species Pectobacterium carotovorum is highly heterogeneous, indicating a need for re-evaluation and a better classification of the species. PacBio was used for sequencing of two soft-rot-causing bacterial strains (NIBIO1006T and NIBIO1392), initially identified as P. carotovorumstrains by fatty acid analysis and sequencing of three housekeeping genes (dnaX, icdA and mdh). Their taxonomic relationship to other Pectobacterium species was determined and the distance from any described species within the genus Pectobacterium was less than 94?% average nucleotide identity (ANI). Based on ANI, phylogenetic data and genome-to-genome distance, strains NIBIO1006T, NIBIO1392 and NCPPB3395 are suggested to represent a novel species of the genus Pectobacterium, for which the name Pectobacterium polaris sp. nov. is proposed. The type strain is NIBIO1006T (=DSM 105255T=NCPPB 4611T).

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July 7, 2019

Complete genome sequence of Lactobacillus plantarum JBE245 isolated from Meju

Lactobacillus plantarum is widely found in fermented foods and has various phenotypic and genetic characteristics to adapt to the environment. Here we report the complete annotated genome sequence of the L. plantarum strain JBE245 (= KCCM43243) isolated for malolactic fermentation of apple juice. The genome comprises a single circular 3,262,611 bp chromosome with 2907 coding regions, 45 pseudogenes, and 91 RNA genes. The genome contains 4 malate dehydrogenase genes, 3 malate permease genes and various types of plantaricin-synthesizing genes. These genetic traits meet the selection criteria of the strains that should prevent the spoilage of apple juice during fermentation and efficiently convert malate to lactic acid.

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July 7, 2019

Linear peptides are the major products of a biosynthetic pathway that encodes for cyclic depsipeptides.

Three new dentigerumycin analogues are produced by Streptomyces sp. M41, a bacterium isolated from a South African termite, Macrotermes natalensis. The structures of the complex nonribosomal peptide synthetase-polyketide synthase (NRPS/PKS) hybrid compounds were determined by 1D- and 2D-NMR spectroscopy, high-resolution mass spectrometry, and circular dichroism (CD) spectroscopy. Both cyclic and linear peptides are reported, and the genetic organization of the NRPS modules within the biosynthetic gene cluster accounts for the observed structural diversity.

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July 7, 2019

Integrating transcriptomic and proteomic data for accurate assembly and annotation of genomes.

Complementing genome sequence with deep transcriptome and proteome data could enable more accurate assembly and annotation of newly sequenced genomes. Here, we provide a proof-of-concept of an integrated approach for analysis of the genome and proteome of Anopheles stephensi, which is one of the most important vectors of the malaria parasite. To achieve broad coverage of genes, we carried out transcriptome sequencing and deep proteome profiling of multiple anatomically distinct sites. Based on transcriptomic data alone, we identified and corrected 535 events of incomplete genome assembly involving 1196 scaffolds and 868 protein-coding gene models. This proteogenomic approach enabled us to add 365 genes that were missed during genome annotation and identify 917 gene correction events through discovery of 151 novel exons, 297 protein extensions, 231 exon extensions, 192 novel protein start sites, 19 novel translational frames, 28 events of joining of exons, and 76 events of joining of adjacent genes as a single gene. Incorporation of proteomic evidence allowed us to change the designation of more than 87 predicted “noncoding RNAs” to conventional mRNAs coded by protein-coding genes. Importantly, extension of the newly corrected genome assemblies and gene models to 15 other newly assembled Anopheline genomes led to the discovery of a large number of apparent discrepancies in assembly and annotation of these genomes. Our data provide a framework for how future genome sequencing efforts should incorporate transcriptomic and proteomic analysis in combination with simultaneous manual curation to achieve near complete assembly and accurate annotation of genomes.© 2017 Prasad et al.; Published by Cold Spring Harbor Laboratory Press.

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July 7, 2019

Letting go: bacterial genome reduction solves the dilemma of adapting to predation mortality in a substrate-restricted environment.

Resource limitation and predation mortality are major determinants of microbial population dynamics, and optimization for either aspect is considered to imply a trade-off with respect to the other. Adaptation to these selective factors may, moreover, lead to disadvantages at rich growth conditions. We present an example of a concomitant evolutionary optimization to both, substrate limitation and predation in an aggregate-forming freshwater bacterial isolate, and we elucidate an underlying genomic mechanism. Bacteria were propagated in serial batch culture in a nutrient-restricted environment either with or without a bacterivorous flagellate. Strains isolated after 26 growth cycles of the predator-prey co-cultures formed as much total biomass as the ancestor at ancestral growth conditions, albeit largely reallocated to cell aggregates. A ~273?kbp genome fragment was lost in three strains that had independently evolved with predators. These strains had significantly higher growth yield on substrate-restricted media than others that were isolated from the same treatment before the excision event. Under predation pressure, the isolates with the deletion outcompeted both, the ancestor and the strains evolved without predators even at rich growth conditions. At the same time, genome reduction led to a growth disadvantage in the presence of benzoate due to the loss of the respective degradation pathway, suggesting that niche constriction might be the price for the bidirectional optimization.

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July 7, 2019

Institutional profile: translational pharmacogenomics at the Icahn School of Medicine at Mount Sinai.

For almost 50 years, the Icahn School of Medicine at Mount Sinai has continually invested in genetics and genomics, facilitating a healthy ecosystem that provides widespread support for the ongoing programs in translational pharmacogenomics. These programs can be broadly cataloged into discovery, education, clinical implementation and testing, which are collaboratively accomplished by multiple departments, institutes, laboratories, companies and colleagues. Focus areas have included drug response association studies and allele discovery, multiethnic pharmacogenomics, personalized genotyping and survey-based education programs, pre-emptive clinical testing implementation and novel assay development. This overview summarizes the current state of translational pharmacogenomics at Mount Sinai, including a future outlook on the forthcoming expansions in overall support, research and clinical programs, genomic technology infrastructure and the participating faculty.

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July 7, 2019

Complete genome sequence of Spirosoma montaniterrae DY10 T isolated from gamma-ray irradiated soil

A Gram-negative, yellow-pigmented, long-rod shaped bacterium Spirosoma montaniterrae DY10T was isolated from a soil sample collected at Mt. Deogyusan, Jeonbuk Province, Republic of Korea. Cells showed extreme gamma radiation resistance with the D10 value of 12 KGy. The complete genome sequence of strain DY10T is consist of a circular chromosome (5,797,678 bp) encoding 5,116 genes, 9 rRNA genes and 39 tRNA genes. The genomic features contain the key enzymes for gamma and UVC radiation.

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July 7, 2019

Tracing origins of the Salmonella Bareilly strain causing a food-borne outbreak in the United States.

Using a novel combination of whole-genome sequencing (WGS) analysis and geographic metadata, we traced the origins of Salmonella Bareilly isolates collected in 2012 during a widespread food-borne outbreak in the United States associated with scraped tuna imported from India.Using next-generation sequencing, we sequenced the complete genome of 100 Salmonella Bareilly isolates obtained from patients who consumed contaminated product, from natural sources, and from unrelated historically and geographically disparate foods. Pathogen genomes were linked to geography by projecting the phylogeny on a virtual globe and produced a transmission network.Phylogenetic analysis of WGS data revealed a common origin for outbreak strains, indicating that patients in Maryland and New York were infected from sources originating at a facility in India.These data represent the first report fully integrating WGS analysis with geographic mapping and a novel use of transmission networks. Results showed that WGS vastly improves our ability to delimit the scope and source of bacterial food-borne contamination events. Furthermore, these findings reinforce the extraordinary utility that WGS brings to global outbreak investigation as a greatly enhanced approach to protecting the human food supply chain as well as public health in general. Published by Oxford University Press for the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

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July 7, 2019

Microbial bioinformatics for food safety and production.

In the production of fermented foods, microbes play an important role. Optimization of fermentation processes or starter culture production traditionally was a trial-and-error approach inspired by expert knowledge of the fermentation process. Current developments in high-throughput ‘omics’ technologies allow developing more rational approaches to improve fermentation processes both from the food functionality as well as from the food safety perspective. Here, the authors thematically review typical bioinformatics techniques and approaches to improve various aspects of the microbial production of fermented food products and food safety. © The Author 2015. Published by Oxford University Press.

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July 7, 2019

Effects of genome structure variation, homeologous genes and repetitive DNA on polyploid crop research in the age of genomics.

Compared to diploid species, allopolyploid crop species possess more complex genomes, higher productivity, and greater adaptability to changing environments. Next generation sequencing techniques have produced high-density genetic maps, whole genome sequences, transcriptomes and epigenomes for important polyploid crops. However, several problems interfere with the full application of next generation sequencing techniques to these crops. Firstly, different types of genomic variation affect sequence assembly and QTL mapping. Secondly, duplicated or homoeologous genes can diverge in function and then lead to emergence of many minor QTL, which increases difficulties in fine mapping, cloning and marker assisted selection. Thirdly, repetitive DNA sequences arising in polyploid crop genomes also impact sequence assembly, and are increasingly being shown to produce small RNAs to regulate gene expression and hence phenotypic traits. We propose that these three key features should be considered together when analyzing polyploid crop genomes. It is apparent that dissection of genomic structural variation, elucidation of the function and mechanism of interaction of homoeologous genes, and investigation of the de novo roles of repeat sequences in agronomic traits are necessary for genomics-based crop breeding in polyploids. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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July 7, 2019

Wide geographical dissemination of the multiresistant Staphylococcus capitis NRCS-A clone in neonatal intensive-care units.

Nosocomial late-onset sepsis represents a frequent cause of morbidity and mortality in preterm neonates. The Staphylococcus capitis clone NRCS-A has been previously described as an emerging cause of nosocomial bacteraemia in French neonatal intensive-care units (NICUs). In this study, we aimed to explore the possible unrecognized dissemination of this clone on a larger geographical scale. One hundred methicillin-resistant S. capitis strains isolated from neonates (n = 86) and adult patients (n = 14) between 2000 and 2013 in four different countries (France, Belgium, the UK, and Australia) were analysed with SmaI pulsed-field gel electrophoresis (PFGE) and dru typing. The vast majority of NICU strains showed the NRCS-A pulsotype and the dt11c type (96%). We then randomly selected 14 isolates (from neonates, n = 12, three per country; from adult patients, n = 2), considered to be a subset of representative isolates, and performed further molecular typing (SacII PFGE, SCCmec typing, and multilocus sequence typing-like analysis), confirming the clonality of the S. capitis strains isolated from neonates, despite their distant geographical origin. Whole genome single-nucleotide polymorphism-based phylogenetic analysis of five NICU isolates (from the different countries) attested to high genetic relatedness within the NRCS-A clone. Finally, all of the NRCS-A strains showed multidrug resistance (e.g. methicillin and aminoglycoside resistance, and decreased vancomycin susceptibility), with potential therapeutic implications for infected neonates. In conclusion, this study represents the first report of clonal dissemination of methicillin-resistant coagulase-negative Staphylococcus clone on a large geographical scale. Questions remain regarding the origin and means of international spread, and the reasons for this clone’s apparent predilection for neonates. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

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July 7, 2019

Complete Sequences and Characterization of Two Novel Plasmids Carrying aac(6′)-Ib-cr and qnrS Gene in Shigella flexneri.

The complete sequences of two previously reported plasmids carrying plasmid-mediated quinolone resistance genes from Shigella flexneri in China have not been available. The present study using the p5-C3 assembly method revealed that (1) the plasmid pSF07201 with aac(6′)-Ib-cr had 75,335?bp with antibiotic resistance genes CTX-M-3, TEM-1, and FosA3; (2) seven fragments of pSF07201 had more than 99% homology with the seven corresponding plasmids; (3) the other plasmid pSF07202 with qnrS had 47,669?bp with antibiotic resistance gene TEM-1 and 99.95% homology with a segment of pKF362122, which has the qnrS gene from location 162,490 to 163,146. A conjugation and electrotransformation experiment suggested that these two plasmids might horizontally transfer between and coexist in Escherichia coli J53 and S. flexneri 2a 301. Either the aac(6′)-Ib-cr or qnrS gene contributed to, but only the coexistence of the two genes conferred to the resistance to ciprofloxacin in these two strains. To the best of our knowledge, this is the first report of the complete sequences of the aac(6′)-Ib-cr- and qnrS-positive plasmids in Shigella isolates. Our findings indicate that two genes probably evolve through horizontal plasmid transfer between the different bacterial types.

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July 7, 2019

Genetic and functional characterization of an extracellular modular GH6 endo-ß-1,4-glucanase from an earthworm symbiont, Cellulosimicrobium funkei HY-13.

The gene (1608-bp) encoding a GH6 endo-ß-1,4-glucanase (CelL) from the earthworm-symbiotic bacterium Cellulosimicrobium funkei HY-13 was cloned from its whole genome sequence, expressed recombinantly, and biochemically characterized. CelL (56.0 kDa) is a modular enzyme consisting of an N-terminal catalytic GH6 domain (from Val57 to Pro396), which is 71 % identical to a GH6 protein (accession no.: WP_034662937) from Cellulomonas sp. KRMCY2, together with a C-terminal CBM 2 domain (from Cys429 to Cys532). The highest catalytic activity of CelL toward carboxymethylcellulose (CMC) was observed at 50 °C and pH 5.0, and was relatively stable at a broad pH range of 4.0-10.0. The enzyme was capable of efficiently hydrolyzing the cellulosic polymers in the order of barley ß-1,3-1,4-D-glucan > CMC > lichenan > Avicel > konjac glucomannan. However, cellobiose, cellotriose, p-nitrophenyl derivatives of mono- and disaccharides, or structurally unrelated carbohydrate polymers including ß-1,3-D-glucan, ß-1,4-D-galactomannan, and ß-1,4-D-xylan were not susceptible to CelL. The enzymatic hydrolysis of cellopentaose resulted in the production of a mixture of 68.6 % cellobiose and 31.4 % cellotriose but barley ß-1,3-1,4-D-glucan was 100 % degraded to cellotriose by CelL. The enzyme strongly bound to Avicel, ivory nut mannan, and chitin but showed relatively weak binding affinity to lichenan, lignin, or poly(3-hydroxybutyrate) granules.

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July 7, 2019

First Azospirillum genome from aquatic environments: Whole-genome sequence of Azospirillum thiophilum BV-S(T), a novel diazotroph harboring a capacity of sulfur-chemolithotrophy from a sulfide spring.

Azospirillum thiophilum BV-S(T), isolated from a sulfide spring, is a novel nitrogen-fixing bacterium harboring sulfur-lithotrophy. In order to identify genetic characteristics with habitat- and metabolic features contrasting to those from terrestrial Azospirillum species, we present here the genome sequence of a novel species A. thiophilum BV-S(T), with a significance of first genome report in the aquatic Azospirillum species. The genome of strain BV-S(T) is comprised of 7.6Mb chromosome with a GC content of 68.2%. This information will contribute to expand understandings of sulfur-oxidizer microbes that preserve inherencies as a diazotroph, and further it will provide insights into genome plasticity of the genus Azospirillum for niche specific adaptations. Copyright © 2015 Elsevier B.V. All rights reserved.

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