Limits...
Genome sequence of Desulfitobacterium hafniense DCB-2, a Gram-positive anaerobe capable of dehalogenation and metal reduction.

Kim SH, Harzman C, Davis JK, Hutcheson R, Broderick JB, Marsh TL, Tiedje JM - BMC Microbiol. (2012)

Bottom Line: In addition, it contained genes for 53 molybdopterin-binding oxidoreductases, 19 flavoprotein paralogs of the fumarate reductase, and many other FAD/FMN-binding oxidoreductases, proving the cell's versatility in both adaptive and reductive capacities.Together with the ability to form spores, the presence of the CO2-fixing Wood-Ljungdahl pathway and the genes associated with oxygen tolerance add flexibility to the cell's options for survival under stress.D. hafniense DCB-2's genome contains genes consistent with its abilities for dehalogenation, metal reduction, N2 and CO2 fixation, anaerobic respiration, oxygen tolerance, spore formation, and biofilm formation which make this organism a potential candidate for bioremediation at contaminated sites.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Microbial Ecology, Michigan State University, East Lansing, MI, USA. kimsang8@msu.edu

ABSTRACT

Background: The genome of the Gram-positive, metal-reducing, dehalorespiring Desulfitobacterium hafniense DCB-2 was sequenced in order to gain insights into its metabolic capacities, adaptive physiology, and regulatory machineries, and to compare with that of Desulfitobacterium hafniense Y51, the phylogenetically closest strain among the species with a sequenced genome.

Results: The genome of Desulfitobacterium hafniense DCB-2 is composed of a 5,279,134-bp circular chromosome with 5,042 predicted genes. Genome content and parallel physiological studies support the cell's ability to fix N2 and CO2, form spores and biofilms, reduce metals, and use a variety of electron acceptors in respiration, including halogenated organic compounds. The genome contained seven reductive dehalogenase genes and four nitrogenase gene homologs but lacked the Nar respiratory nitrate reductase system. The D. hafniense DCB-2 genome contained genes for 43 RNA polymerase sigma factors including 27 sigma-24 subunits, 59 two-component signal transduction systems, and about 730 transporter proteins. In addition, it contained genes for 53 molybdopterin-binding oxidoreductases, 19 flavoprotein paralogs of the fumarate reductase, and many other FAD/FMN-binding oxidoreductases, proving the cell's versatility in both adaptive and reductive capacities. Together with the ability to form spores, the presence of the CO2-fixing Wood-Ljungdahl pathway and the genes associated with oxygen tolerance add flexibility to the cell's options for survival under stress.

Conclusions: D. hafniense DCB-2's genome contains genes consistent with its abilities for dehalogenation, metal reduction, N2 and CO2 fixation, anaerobic respiration, oxygen tolerance, spore formation, and biofilm formation which make this organism a potential candidate for bioremediation at contaminated sites.

Show MeSH

Related in: MedlinePlus

Alignment and GC-profiles of the genomes of D. hafniense DCB-2 and D. hafniense Y51. Alignment of the two genomes, shown with colored blocks of DNA and connecting lines, was performed by using Mauve v 2.3.1 with a view of 24 LCBs (locally collinear blocks). The lines between the genomes indicate the homologous regions in each genome. Translocation of a 1.22 mb DNA segment is seen as two contiguous blocks colored purple and green. Two transposase genes found next to the 1.22 mb DNA segment are indicated as red triangles. Positions of reductive dehalogenase (Rdh) operons in each genome are indicated. The two outer panels show the corresponding GC profiles of the two genomes, depicted as compositionally distinct domains. The profiles were obtained by using GC-Profile program which was developed based on a segmentation algorithm and cumulative GC profile technique.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3306737&req=5

Figure 1: Alignment and GC-profiles of the genomes of D. hafniense DCB-2 and D. hafniense Y51. Alignment of the two genomes, shown with colored blocks of DNA and connecting lines, was performed by using Mauve v 2.3.1 with a view of 24 LCBs (locally collinear blocks). The lines between the genomes indicate the homologous regions in each genome. Translocation of a 1.22 mb DNA segment is seen as two contiguous blocks colored purple and green. Two transposase genes found next to the 1.22 mb DNA segment are indicated as red triangles. Positions of reductive dehalogenase (Rdh) operons in each genome are indicated. The two outer panels show the corresponding GC profiles of the two genomes, depicted as compositionally distinct domains. The profiles were obtained by using GC-Profile program which was developed based on a segmentation algorithm and cumulative GC profile technique.

Mentions: D. hafniense DCB-2 carries a single circular genome of 5,279,134 bp with a total of 5,042 predicted genes (Table 1) excluding 70 pseudogenes and gene remnants. Five rRNA operons and 74 tRNA genes constitute a total of 89 RNA genes leaving 4,953 protein-encoding genes (CDS). D. hafniense Y51 contains six rRNA operons and 59 tRNA genes, and has a slightly larger genome by 448 kb (8.5% of the DCB-2 genome) with 166 more genes [9]. Similar proportions of genes were observed for transmembrane proteins and for twin-arginine signal peptide proteins (Table 1). However, genes for signal peptide proteins were found more abundantly in the genome of DCB-2 (725 genes) than Y51 (661 genes). The number of horizontally transferred genes that putatively originated from organisms above the level of the Peptococcaceae family was 264 in DCB-2 and 285 in Y51. When the two genomes were compared at the level of CDS, the number of genes found only in the DCB-2 genome was 614. Among them, 341 were with no functional hit. The Y51 genome had 583 unique genes including 319 with no functional hit. The larger number of the unique genes in DCB-2, despite its smaller number of total CDS, suggests that the Y51 genome contains more gene duplications, as indicated by the number of paralogs in Table 1. Among the DCB-2 genes with no homolog in Y51, most notable are the genes for reductive dehalogenases (RDases) and prophage-like sequences. Six out of the seven RDase genes in DCB-2 are located in a cluster, while there are only two in Y51 (Figure 1) [9]. Multiple prophage sequences that are unique to each genome were found in both strains. The DCB-2 genome contains at least three prophage-like sequences though none of them contained a full gene set in comparison with the known prophage equivalents. A fourteen-gene-encoding prophage sequence spanning 11.8-kb (Dhaf_1454-1467) appears to belong to the phage HK97 family, a lambda-like double-stranded DNA bacteriophage. The genome of the functional Escherichia coli phage HK97 contains 74 genes on a 39.7-kb genome [11]. Also found only in D. hafniense DCB-2 were genes for rhamnan biosynthesis (Dhaf_4461-4467) and 4-hydroxy-2-oxovalerate aldolase (Dhaf_1245) which converts 4-hydroxy-2-oxovalerate to acetaldehyde and pyruvate. A nar operon was identified in the Y51 genome that is responsible for respiratory nitrate reduction which was absent in DCB-2.


Genome sequence of Desulfitobacterium hafniense DCB-2, a Gram-positive anaerobe capable of dehalogenation and metal reduction.

Kim SH, Harzman C, Davis JK, Hutcheson R, Broderick JB, Marsh TL, Tiedje JM - BMC Microbiol. (2012)

Alignment and GC-profiles of the genomes of D. hafniense DCB-2 and D. hafniense Y51. Alignment of the two genomes, shown with colored blocks of DNA and connecting lines, was performed by using Mauve v 2.3.1 with a view of 24 LCBs (locally collinear blocks). The lines between the genomes indicate the homologous regions in each genome. Translocation of a 1.22 mb DNA segment is seen as two contiguous blocks colored purple and green. Two transposase genes found next to the 1.22 mb DNA segment are indicated as red triangles. Positions of reductive dehalogenase (Rdh) operons in each genome are indicated. The two outer panels show the corresponding GC profiles of the two genomes, depicted as compositionally distinct domains. The profiles were obtained by using GC-Profile program which was developed based on a segmentation algorithm and cumulative GC profile technique.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3306737&req=5

Figure 1: Alignment and GC-profiles of the genomes of D. hafniense DCB-2 and D. hafniense Y51. Alignment of the two genomes, shown with colored blocks of DNA and connecting lines, was performed by using Mauve v 2.3.1 with a view of 24 LCBs (locally collinear blocks). The lines between the genomes indicate the homologous regions in each genome. Translocation of a 1.22 mb DNA segment is seen as two contiguous blocks colored purple and green. Two transposase genes found next to the 1.22 mb DNA segment are indicated as red triangles. Positions of reductive dehalogenase (Rdh) operons in each genome are indicated. The two outer panels show the corresponding GC profiles of the two genomes, depicted as compositionally distinct domains. The profiles were obtained by using GC-Profile program which was developed based on a segmentation algorithm and cumulative GC profile technique.
Mentions: D. hafniense DCB-2 carries a single circular genome of 5,279,134 bp with a total of 5,042 predicted genes (Table 1) excluding 70 pseudogenes and gene remnants. Five rRNA operons and 74 tRNA genes constitute a total of 89 RNA genes leaving 4,953 protein-encoding genes (CDS). D. hafniense Y51 contains six rRNA operons and 59 tRNA genes, and has a slightly larger genome by 448 kb (8.5% of the DCB-2 genome) with 166 more genes [9]. Similar proportions of genes were observed for transmembrane proteins and for twin-arginine signal peptide proteins (Table 1). However, genes for signal peptide proteins were found more abundantly in the genome of DCB-2 (725 genes) than Y51 (661 genes). The number of horizontally transferred genes that putatively originated from organisms above the level of the Peptococcaceae family was 264 in DCB-2 and 285 in Y51. When the two genomes were compared at the level of CDS, the number of genes found only in the DCB-2 genome was 614. Among them, 341 were with no functional hit. The Y51 genome had 583 unique genes including 319 with no functional hit. The larger number of the unique genes in DCB-2, despite its smaller number of total CDS, suggests that the Y51 genome contains more gene duplications, as indicated by the number of paralogs in Table 1. Among the DCB-2 genes with no homolog in Y51, most notable are the genes for reductive dehalogenases (RDases) and prophage-like sequences. Six out of the seven RDase genes in DCB-2 are located in a cluster, while there are only two in Y51 (Figure 1) [9]. Multiple prophage sequences that are unique to each genome were found in both strains. The DCB-2 genome contains at least three prophage-like sequences though none of them contained a full gene set in comparison with the known prophage equivalents. A fourteen-gene-encoding prophage sequence spanning 11.8-kb (Dhaf_1454-1467) appears to belong to the phage HK97 family, a lambda-like double-stranded DNA bacteriophage. The genome of the functional Escherichia coli phage HK97 contains 74 genes on a 39.7-kb genome [11]. Also found only in D. hafniense DCB-2 were genes for rhamnan biosynthesis (Dhaf_4461-4467) and 4-hydroxy-2-oxovalerate aldolase (Dhaf_1245) which converts 4-hydroxy-2-oxovalerate to acetaldehyde and pyruvate. A nar operon was identified in the Y51 genome that is responsible for respiratory nitrate reduction which was absent in DCB-2.

Bottom Line: In addition, it contained genes for 53 molybdopterin-binding oxidoreductases, 19 flavoprotein paralogs of the fumarate reductase, and many other FAD/FMN-binding oxidoreductases, proving the cell's versatility in both adaptive and reductive capacities.Together with the ability to form spores, the presence of the CO2-fixing Wood-Ljungdahl pathway and the genes associated with oxygen tolerance add flexibility to the cell's options for survival under stress.D. hafniense DCB-2's genome contains genes consistent with its abilities for dehalogenation, metal reduction, N2 and CO2 fixation, anaerobic respiration, oxygen tolerance, spore formation, and biofilm formation which make this organism a potential candidate for bioremediation at contaminated sites.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Microbial Ecology, Michigan State University, East Lansing, MI, USA. kimsang8@msu.edu

ABSTRACT

Background: The genome of the Gram-positive, metal-reducing, dehalorespiring Desulfitobacterium hafniense DCB-2 was sequenced in order to gain insights into its metabolic capacities, adaptive physiology, and regulatory machineries, and to compare with that of Desulfitobacterium hafniense Y51, the phylogenetically closest strain among the species with a sequenced genome.

Results: The genome of Desulfitobacterium hafniense DCB-2 is composed of a 5,279,134-bp circular chromosome with 5,042 predicted genes. Genome content and parallel physiological studies support the cell's ability to fix N2 and CO2, form spores and biofilms, reduce metals, and use a variety of electron acceptors in respiration, including halogenated organic compounds. The genome contained seven reductive dehalogenase genes and four nitrogenase gene homologs but lacked the Nar respiratory nitrate reductase system. The D. hafniense DCB-2 genome contained genes for 43 RNA polymerase sigma factors including 27 sigma-24 subunits, 59 two-component signal transduction systems, and about 730 transporter proteins. In addition, it contained genes for 53 molybdopterin-binding oxidoreductases, 19 flavoprotein paralogs of the fumarate reductase, and many other FAD/FMN-binding oxidoreductases, proving the cell's versatility in both adaptive and reductive capacities. Together with the ability to form spores, the presence of the CO2-fixing Wood-Ljungdahl pathway and the genes associated with oxygen tolerance add flexibility to the cell's options for survival under stress.

Conclusions: D. hafniense DCB-2's genome contains genes consistent with its abilities for dehalogenation, metal reduction, N2 and CO2 fixation, anaerobic respiration, oxygen tolerance, spore formation, and biofilm formation which make this organism a potential candidate for bioremediation at contaminated sites.

Show MeSH
Related in: MedlinePlus