Characterization of the Deoxyribonucleic Acid of Various Strains of Halophilic Bacteria

Moore, Richard; McCarthy, Brian J.

doi:10.1128/jb.99.1.248-254.1969

Cited by 101 publications

(27 citation statements)

References 41 publications

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“…Little is known about the genetics of halobacteria and other archaebacteria. The separation of large amounts of satellite DNA from the main DNA on the basis of different guanine plus cytosine contents of these two DNAs has been reported for different species of Halobacterium (1,3,4). At least for H. halobium we could demonstrate that the ATricher satellite DNA is indistinguishable, by its restriction pattem, from a large plasmid, pHH1, isolated from this species.…”

supporting

confidence: 61%

“…These sequences are not shared by other only moderately halophilic species, regardless of whether or not they carry plasmids. As shown for H. halobium (9), these sequences are indistinguishable from the minor satellite DNA component which possesses a lower guanine plus cytosine content (57 to 60 mol%) than the chromosome (66 to 68 mol%) and has been identified in this and other species of extremely halophilic halobacteria and halococci (3). In addition to their different halophilic properties, halobacteria of the first group often form gas vacuoles, bacteriorhodopsin, and bacterioruberin(s), which the others (with the possible exception of bacterioruberin) fail to synthesize.…”

Section: Resultsmentioning

confidence: 64%

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Genetic variability in Halobacterium halobium

Pfeifer¹,

Weidinger²,

Goebel³

1981

J Bacteriol

122

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Halobacterium halobium exhibits an extraordinary degree of spontaneous variability. Mutants which are defective in the formation of gas vacuoles (vac) arise at a frequency of 102. Other easily detectable phenotypes, like the synthesis of bacterioruberin (Rub) or the synthesis of retinal (Ret) and bacterio-opsin (Ops), the two components which form the purple membrane (Pum) of H. halobium, are lost at a frequency of about 10'. With the same frequency a mutant type appears which exhibits an extremely high variability in these phenotypes. With the exception of the ret mutants, all spontaneously arising mutants show alterations, i.e., insertions, rearrangements, or deletions, in the plasmid pHHl. It appears that the introduction of one insertion into pHH1 triggers further insertions, which makes the identification ofrelationships between phenotypic and genotypic alterations rather difficult. From the analysis of a large number of spontaneous vac mutants and their vac+ revertants it can be concluded that the fornation of the gas vacuoles is determined or controlled by plasmid genes. No such conclusion is yet possible for the rub mutants, although all mutants of this type so far analyzed exhibit a defined insertion. pum mutants which have lost the capability of forming bacterio-opsin carry insertions in the plasmid which are distributed over a rather large region of the plasmid. No strains of H. halobium could be obtained which had lost plasmid pHHl completely.Halobacteria live under conditions of extremely high salinity, but are obligate aerobic heterotrophs. Since the solubility of oxygen in these ecosystems is very low, the gas vesicles found in many halobacteria might serve to keep the cells near the surface. The purple membrane (bacteriorhodopsin) also encountered in several species of Halobacterium provides these organisms with a mechanism for utilizing light as a source of energy (8). These bacteria seem to have retained several properties which distinguish them from most procaryotes but are similar to those observed in a few other procaryotes living in extreme environments. These properties include the absence of peptidoglycan cell walls, the occurrence of ether-linked lipids, and characteristic modifications in the base sequence of rRNA's and tRNA's (13). It is an intriguing question whether these so-called archaebacteria may have conserved genetic structures and mechanisms different from those found in the present procaryotes. Little is known about the genetics of halobacteria and other archaebacteria. The separation of large amounts of satellite DNA from the main DNA on the basis of different guanine plus cytosine contents of these two DNAs has been reported for different species of Halobacterium (1,3,4). At least for H. halobium we could demonstrate that the ATricher satellite DNA is indistinguishable, by its restriction pattem, from a large plasmid, pHH1, isolated from this species. This finding is com-plemented by the isolation of other plasmids from halobacteria which share closely related sequence homo...

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supporting

confidence: 61%

Section: Resultsmentioning

confidence: 64%

Genetic variability in Halobacterium halobium

Pfeifer¹,

Weidinger²,

Goebel³

1981

J Bacteriol

122

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“…The small peak at 325 nm may be ascribed to photodissociation of a DNA hetero adduct as observed with Streptomyces (Ikenaga et al, 1971), since halobacterial DNA has a high G-C content, i.e. 66-68'/0 for major DNA and 57-60% for satellite DNA (Moore and McCarthy, 1969). The action spectrum obtained suggests that carotenoid pigments do not take part in the photoreactivation as a donor of energy transfer to the photoreactivating system, since photoreactivation decreased above 450 nm and was background level at 500 nm.…”

Section: Action Spectrum Of Photoreactivationmentioning

confidence: 86%

PHOTOREACTIVATION OF Halobacterium halobium: ACTION SPECTRUM AND ROLE OF PIGMENTATION

Iwasa

Tokutomi

Tokunaga

1988

Photochem & Photobiology

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Abstract— An action spectrum for photoreactivation was measured with Halobacterium halobium R1m1 to prove a role of carotenoid pigments in photoreactivation of the bacteria. The action spectrum obtained showed a main peak at 435 nm and a minor peak at about 325 nm. The action spectrum was similar to that of Streptomyces pigment (Eker et al., 1981) suggesting that the chromophore of the photoreactivating enzyme in Halobacterium halobium is 8‐OH‐5‐deazaflavin. The minor peak may be due to photochemical cleavage of a pyrimidine6–4 hetero adduct. The result indicates that carotenoid pigments do not play a positive role in enhancing photoreactivation. This was confirmed also by comparing the efficiency of photoreactivation at 465 nm among three strains of Halobacterium halobium having different carotenoid pigments; R1m1. R1 and W5002–1.

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“…Analyses of halobacterial DNA had been carried out in the 1960s (e.g. Moore & McCarthy, 1969), and halobacterial ribosomes had been studied by Donn J. Kushner and colleagues at the Division of Biosciences of the National Research Council (NRC) in Ottawa (e.g. Bayley & Kushner, 1964;Oren, 2002) [due to their stability, the ribosomes of halophiles such as Halobacterium marismortui (now Haloarcula marismortui, see Oren et al, 1990) have played an important role in determining ribosomal structure (e.g.…”

Section: The Genetics Of Microbial Rhodopsins and Halobacteriamentioning

confidence: 99%

Enlightening the life sciences: the history of halobacterial and microbial rhodopsin research

Grote

O’Malley

2011

FEMS Microbiol Rev

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The history of research on microbial rhodopsins offers a novel perspective on the history of the molecular life sciences. Events in this history play important roles in the development of fields such as general microbiology, membrane research, bioenergetics, metagenomics and, very recently, neurobiology. New concepts, techniques, methods and fields have arisen as a result of microbial rhodopsin investigations. In addition, the history of microbial rhodopsins sheds light on the dynamic connections between basic and applied science, and hypothesis-driven and data-driven approaches. The story begins with the late nineteenth century discovery of microorganisms on salted fish and leads into ecological and taxonomical studies of halobacteria in hypersaline environments. These programmes were built on by the discovery of bacteriorhodopsin in organisms that are part of what is now known as the archaeal genus Halobacterium. The transfer of techniques from bacteriorhodopsin studies to the metagenomic discovery of proteorhodopsin in 2000 further extended the field. Microbial rhodopsins have also been used as model systems to understand membrane protein structure and function, and they have become the target of technological applications such as optogenetics and nanotechnology. Analysing the connections between these historical episodes provides a rich example of how science works over longer time periods, especially with regard to the transfer of materials, methods and concepts between different research fields.

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Characterization of the Deoxyribonucleic Acid of Various Strains of Halophilic Bacteria

Cited by 101 publications

References 41 publications

Genetic variability in Halobacterium halobium

Genetic variability in Halobacterium halobium

PHOTOREACTIVATION OF Halobacterium halobium: ACTION SPECTRUM AND ROLE OF PIGMENTATION

Enlightening the life sciences: the history of halobacterial and microbial rhodopsin research

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