Isolation of Gas Vesicles from Methanosarcina barken

Archer, David B.; King, N. R.

doi:10.1099/00221287-130-1-167

Cited by 18 publications

(14 citation statements)

References 14 publications

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“…The sequence adjacent to the 5Ј end includes the same order of gene orthologs found in Among genes encoding biosynthetic functions, a group of 14 sequential ORFs encode predicted gas vesicles with highest identity to gvpANOFGJKLM (MbarA 326 to 339) in the haloarchaea, which includes the minimal gene set for expression of vesicle in Haloferax volcanii (34). Although there are no prior reports of gas vesicles in M. barkeri Fusaro, gas vesicles have been reported in another strain of M. barkeri, FR-1, and in Methanosarcina vacuolata, which has a DNA-DNA reassociation value of 61% with the type strain of M. barkeri (1,51,52). Interestingly, M. barkeri has three sequential copies of gvpA that encode the ribs of the vesicle wall and influence the strength and width of the vesicles (4).…”

Section: Resultsmentioning

confidence: 96%

The Methanosarcina barkeri Genome: Comparative Analysis with Methanosarcina acetivorans and Methanosarcina mazei Reveals Extensive Rearrangement within Methanosarcinal Genomes

et al. 2006

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We report here a comparative analysis of the genome sequence of Methanosarcina barkeri with those of Methanosarcina acetivorans and Methanosarcina mazei. The genome of M. barkeri is distinguished by having an organization that is well conserved with respect to the other Methanosarcina spp. in the region proximal to the origin of replication, with interspecies gene similarities as high as 95%. However, it is disordered and marked by increased transposase frequency and decreased gene synteny and gene density in the distal semigenome. Of the 3,680 open reading frames (ORFs) in M. barkeri, 746 had homologs with better than 80% identity to both M. acetivorans and M. mazei, while 128 nonhypothetical ORFs were unique (nonorthologous) among these species, including a complete formate dehydrogenase operon, genes required for N-acetylmuramic acid synthesis, a 14-gene gas vesicle cluster, and a bacterial-like P450-specific ferredoxin reductase cluster not previously observed or characterized for this genus. A cryptic 36-kbp plasmid sequence that contains an orc1 gene flanked by a presumptive origin of replication consisting of 38 tandem repeats of a 143-nucleotide motif was detected in M. barkeri. Three-way comparison of these genomes reveals differing mechanisms for the accrual of changes. Elongation of the relatively large M. acetivorans genome is the result of uniformly distributed multiple gene scale insertions and duplications, while the M. barkeri genome is characterized by localized inversions associated with the loss of gene content. In contrast, the short M. mazei genome most closely approximates the putative ancestral organizational state of these species.Biological methanogenesis by the methane-producing archaea has a significant role in the global carbon cycle. This process is one of several anaerobic degradative processes that complement aerobic degradation by utilizing alternative electron acceptors in habitats where O 2 is not available (39). The efficiency of this microbial process is directly dependent upon the interaction of three metabolically distinct groups of microorganisms: the fermentative and acetogenic bacteria and the methanogenic archaea. The methanogenic archaea have two pivotal roles in methanogenic consortia (28). By consuming hydrogen for methanogenesis and effectively lowering its partial pressure by the process of interspecies hydrogen exchange, the methanogens provide a thermodynamically favorable environment for the fermentative and acetogenic species to utilize protons as electron acceptors. This interaction enables fermenters to conserve more energy by producing a more oxidized product, acetate, which is also a substrate for methanogenesis. The second role of the methanogens is the fermentation of acetate, which accounts for 70% of the global methane produced by biological methane production (28). The net effect of these microbial interactions is the diversion of protons to hydrogen and carbon to acetate, which ultimately yields methane and carbon dioxide via methanogenesis.The genus M...

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Section: Resultsmentioning

confidence: 96%

The Methanosarcina barkeri Genome: Comparative Analysis with Methanosarcina acetivorans and Methanosarcina mazei Reveals Extensive Rearrangement within Methanosarcinal Genomes

et al. 2006

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“…The primary role of buoyancy in phototrophs is to maintain the micro-organisms either near the surface of the water or in the metalimnion of lakes, where they are exposed to favourable light intensities (Walsby, 1994). In other gas-vacuolate micro-organisms, such as the methanogen Methanosarcina barkeri (Archer & King, 1984) and various sea-ice bacteria (Gosink & Staley,199S), the role of buoyancy is less obvious. Petter (1932) suggested that gas vesicles might be important to aerobic halobacteria in buoying them to the water surface, where the concentrations of oxygen are highest.…”

Section: Introductionmentioning

confidence: 99%

Growth competition between Halobacterium salinarium strain PHH1 and mutants affected in gas vesicle synthesis

1997

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To investigate the role of the buoyancy provided by gas vesicles in the facultative anaerobe Halobacterium salinarium PHHl, the growth of a gasvacuolate (Gv' ) strain in competition with two gas-vesicle-def ective ( G e mutants was examined. The Gv+ strain synthesized gas vesicles throughout its growth cycle, and floated up to form a thick surface scum during the exponential growth phase in static culture. Mutant GvM produced significantly fewer gas vesicles than the Gv+ strain in corresponding stages of growth, although in late stationary phase a small proportion of cells floated up to the surface of static cultures. Mutant Gvd& had a much lower gas vesicle content in shaken culture and produced negligible amounts of gas vesicles in static culture. The Gv+ and the two G f l strains grew equally well in shaken cultures, but in static cultures, where steep vertical gradients of oxygen concentration were established, Gvdefl was outgrown by the Gv* strain. Gd* outcompeted the Gv+ strain in shallow static cultures, perhaps because Gvdefz carried a smaller protein burden, which offset the benefits of buoyancy. This selection for Gvdefz was lost in deeper static cultures, although it could be restored by aerating static cultures from below. The results support the hypothesis that the role of buoyancy in halobacteria is to maintain cells at the more aerated surface of brine pools.

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“…To isolate gas vesicles, cells are allowed to grow in substrate depleted medium which results in the formation of protoplast (Archer and King, 1984).Vacuolate protoplasts are separated from unvacuolate ones by flotation and the protoplast membrane removed by Tween 20, liberating the gas vesicles. The gas vesicles are then purified by flotation after initial passage through a 0.45 pm filter to remove contaminating material.…”

Section: Gas Vesiclementioning

confidence: 99%

How to obtain the organelles of prokaryotic and microbial eukaryotic cells

Aderiye¹,

Oluwole²

2014

J. Cell Anim. Biol.

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An organelle is a specialized functional subunit within cells carrying out specific functions. These compartments which may or may not be enclosed in a lipid bilayer are found in microorganisms. While those found in eukaryotic cells are usually enclosed in lipid bilayer, those in prokaryotes don't. All microbes have compartments common to them like the nucleic acids, protein, ribosomes as well as unique intracellular structures found only in microbial subgroups. Such compartments include the mitochondria, endoplasmic reticulum, golgi apparatus amongst others unique to all eukaryotic cells only. Prokaryotes contain some micro-compartments unique to them including the carboxysomes, lipid bodies, polyhydroxybutyrate granules. The right choice of cell disruption methods that limit damage to the compartments is important in achieving successful compartment isolation and purification. Commonly applied methods include sonication, enzymatic lysis, detergent lysis, cavitation amongst others depending on the type of cells involved. Fractionation is the commonly utilized method for isolation and purification of organelles, utilizing ultracentrifugation and techniques that exploits size, density and surface charge variations of protoplasmic content. Such techniques include gradient centrifugation methods, use of beads, affinity purification chromatography methods and electrophoresis. Here, we review the compartments in microbial cells and the techniques employed to isolate and purify these intracellular components.

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Isolation of Gas Vesicles from Methanosarcina barken

Cited by 18 publications

References 14 publications

The Methanosarcina barkeri Genome: Comparative Analysis with Methanosarcina acetivorans and Methanosarcina mazei Reveals Extensive Rearrangement within Methanosarcinal Genomes

The Methanosarcina barkeri Genome: Comparative Analysis with Methanosarcina acetivorans and Methanosarcina mazei Reveals Extensive Rearrangement within Methanosarcinal Genomes

Growth competition between Halobacterium salinarium strain PHH1 and mutants affected in gas vesicle synthesis

How to obtain the organelles of prokaryotic and microbial eukaryotic cells

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