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Magnetotactic bacteria as potential sources of bioproducts.

Araujo AC, Abreu F, Silva KT, Bazylinski DA, Lins U - Mar Drugs (2015)

Bottom Line: As a result of this control, magnetosomes have narrow and uniform size ranges, relatively specific magnetic and crystalline properties, and an enveloping biological membrane.Most currently described MTB have been isolated from saline or brackish environments and the availability of their genomes has contributed to a better understanding and culturing of these fastidious microorganisms.More specifically, we discovered that the genome of the cultured MTB Magnetovibrio blakemorei, among other MTB, contains several metabolic pathways for the synthesis of secondary metabolites and other compounds, thereby raising the possibility of the co-production of new bioactive molecules along with magnetosomes by this species.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho, 373, CCS, UFRJ, Rio de Janeiro, RJ 21941-902, Brazil. acvaraujo@gmail.com.

ABSTRACT
Magnetotactic bacteria (MTB) produce intracellular organelles called magnetosomes which are magnetic nanoparticles composed of magnetite (Fe3O4) or greigite (Fe3S4) enveloped by a lipid bilayer. The synthesis of a magnetosome is through a genetically controlled process in which the bacterium has control over the composition, direction of crystal growth, and the size and shape of the mineral crystal. As a result of this control, magnetosomes have narrow and uniform size ranges, relatively specific magnetic and crystalline properties, and an enveloping biological membrane. These features are not observed in magnetic particles produced abiotically and thus magnetosomes are of great interest in biotechnology. Most currently described MTB have been isolated from saline or brackish environments and the availability of their genomes has contributed to a better understanding and culturing of these fastidious microorganisms. Moreover, genome sequences have allowed researchers to study genes related to magnetosome production for the synthesis of magnetic particles for use in future commercial and medical applications. Here, we review the current information on the biology of MTB and apply, for the first time, a genome mining strategy on these microorganisms to search for secondary metabolite synthesis genes. More specifically, we discovered that the genome of the cultured MTB Magnetovibrio blakemorei, among other MTB, contains several metabolic pathways for the synthesis of secondary metabolites and other compounds, thereby raising the possibility of the co-production of new bioactive molecules along with magnetosomes by this species.

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Phylogenetic tree of known MTB based on their 16S rRNA gene sequences. The tree was constructed using the Neighbor Joining method [52] using MEGA software version 5.2 [53]. Taxa in bold type indicate cultured strains, whereas taxa in plain type indicate described but uncultured strains. Accession numbers are given between brackets. Symbols alongside taxa names indicate the environmental type of the strain and the availability of complete or partial genome sequences, as indicated in the accompanying legend.
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marinedrugs-13-00389-f002: Phylogenetic tree of known MTB based on their 16S rRNA gene sequences. The tree was constructed using the Neighbor Joining method [52] using MEGA software version 5.2 [53]. Taxa in bold type indicate cultured strains, whereas taxa in plain type indicate described but uncultured strains. Accession numbers are given between brackets. Symbols alongside taxa names indicate the environmental type of the strain and the availability of complete or partial genome sequences, as indicated in the accompanying legend.

Mentions: MTB are generally ubiquitous in aquatic environments [6] and at least once were detected in wet soils [42]. They are usually found in or below the oxic-anoxic transition zone in stratified water columns or sediments [41]. Their occurrence in deep-sea sediments has also been documented [43]. Most cultured MTB were isolated from freshwater or brackish sediments at ambient temperature (these MTB are mesophilic) although their ecological distribution includes saline, hypersaline, polar, thermal, and extreme alkaline habitats [44] (Figure 2). There is evidence that the richness and diversity of MTB in different environments is strongly influenced by salinity [45,46] although temperature, iron availability and concentrations of nitrogen and sulfur compounds are also clearly important in the distribution of MTB [46,47,48,49]. The numbers of MTB cells is any environment is very variable: Their abundance in some marine sediments has been estimated at 104 cells mL−1 and 106 cells mL−1 in some saline lakes [50].


Magnetotactic bacteria as potential sources of bioproducts.

Araujo AC, Abreu F, Silva KT, Bazylinski DA, Lins U - Mar Drugs (2015)

Phylogenetic tree of known MTB based on their 16S rRNA gene sequences. The tree was constructed using the Neighbor Joining method [52] using MEGA software version 5.2 [53]. Taxa in bold type indicate cultured strains, whereas taxa in plain type indicate described but uncultured strains. Accession numbers are given between brackets. Symbols alongside taxa names indicate the environmental type of the strain and the availability of complete or partial genome sequences, as indicated in the accompanying legend.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4306944&req=5

marinedrugs-13-00389-f002: Phylogenetic tree of known MTB based on their 16S rRNA gene sequences. The tree was constructed using the Neighbor Joining method [52] using MEGA software version 5.2 [53]. Taxa in bold type indicate cultured strains, whereas taxa in plain type indicate described but uncultured strains. Accession numbers are given between brackets. Symbols alongside taxa names indicate the environmental type of the strain and the availability of complete or partial genome sequences, as indicated in the accompanying legend.
Mentions: MTB are generally ubiquitous in aquatic environments [6] and at least once were detected in wet soils [42]. They are usually found in or below the oxic-anoxic transition zone in stratified water columns or sediments [41]. Their occurrence in deep-sea sediments has also been documented [43]. Most cultured MTB were isolated from freshwater or brackish sediments at ambient temperature (these MTB are mesophilic) although their ecological distribution includes saline, hypersaline, polar, thermal, and extreme alkaline habitats [44] (Figure 2). There is evidence that the richness and diversity of MTB in different environments is strongly influenced by salinity [45,46] although temperature, iron availability and concentrations of nitrogen and sulfur compounds are also clearly important in the distribution of MTB [46,47,48,49]. The numbers of MTB cells is any environment is very variable: Their abundance in some marine sediments has been estimated at 104 cells mL−1 and 106 cells mL−1 in some saline lakes [50].

Bottom Line: As a result of this control, magnetosomes have narrow and uniform size ranges, relatively specific magnetic and crystalline properties, and an enveloping biological membrane.Most currently described MTB have been isolated from saline or brackish environments and the availability of their genomes has contributed to a better understanding and culturing of these fastidious microorganisms.More specifically, we discovered that the genome of the cultured MTB Magnetovibrio blakemorei, among other MTB, contains several metabolic pathways for the synthesis of secondary metabolites and other compounds, thereby raising the possibility of the co-production of new bioactive molecules along with magnetosomes by this species.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho, 373, CCS, UFRJ, Rio de Janeiro, RJ 21941-902, Brazil. acvaraujo@gmail.com.

ABSTRACT
Magnetotactic bacteria (MTB) produce intracellular organelles called magnetosomes which are magnetic nanoparticles composed of magnetite (Fe3O4) or greigite (Fe3S4) enveloped by a lipid bilayer. The synthesis of a magnetosome is through a genetically controlled process in which the bacterium has control over the composition, direction of crystal growth, and the size and shape of the mineral crystal. As a result of this control, magnetosomes have narrow and uniform size ranges, relatively specific magnetic and crystalline properties, and an enveloping biological membrane. These features are not observed in magnetic particles produced abiotically and thus magnetosomes are of great interest in biotechnology. Most currently described MTB have been isolated from saline or brackish environments and the availability of their genomes has contributed to a better understanding and culturing of these fastidious microorganisms. Moreover, genome sequences have allowed researchers to study genes related to magnetosome production for the synthesis of magnetic particles for use in future commercial and medical applications. Here, we review the current information on the biology of MTB and apply, for the first time, a genome mining strategy on these microorganisms to search for secondary metabolite synthesis genes. More specifically, we discovered that the genome of the cultured MTB Magnetovibrio blakemorei, among other MTB, contains several metabolic pathways for the synthesis of secondary metabolites and other compounds, thereby raising the possibility of the co-production of new bioactive molecules along with magnetosomes by this species.

Show MeSH
Related in: MedlinePlus