Extremophiles (EXTREMOPHILES)

Publisher: Springer Verlag

Journal description

Extremophiles features original research articles reviews and method papers on the biology molecular biology structure function and applications of life at high or low temperature pressure acidity alkalinity salinity or oxygen concentration; or in the presence of organic solvents heavy metals normally toxic substances radiation or host defense mechanisms. Fields covered: molecular biology biodiversity genetics macromolecular structure development growth biotechnology / fermentation technology ultrastructure biotransformation metabolism enzymology biomembranes bioenergetics physiology cell biology symbiosis ecology bioremediation methodologies evolution isolation phylogeny taxonomy

Current impact factor: 2.31

Impact Factor Rankings

2015 Impact Factor Available summer 2016
2014 Impact Factor 2.306
2013 Impact Factor 2.174
2012 Impact Factor 2.203
2011 Impact Factor 2.941
2010 Impact Factor 2.16
2009 Impact Factor 2
2008 Impact Factor 1.782
2007 Impact Factor 2.317
2006 Impact Factor 1.921
2005 Impact Factor 2.125
2004 Impact Factor 1.897
2003 Impact Factor 1.955
2002 Impact Factor 2.165
2001 Impact Factor 2.291
2000 Impact Factor 2.688
1999 Impact Factor 3.133
1998 Impact Factor 2.593
1997 Impact Factor

Impact factor over time

Impact factor

Additional details

5-year impact 2.58
Cited half-life 6.90
Immediacy index 0.48
Eigenfactor 0.00
Article influence 0.71
Website Extremophiles website
Other titles Extremophiles (Online)
ISSN 1431-0651
OCLC 42900820
Material type Document, Periodical, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details

Springer Verlag

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author can archive a post-print version
  • Conditions
    • Author's pre-print on pre-print servers such as arXiv.org
    • Author's post-print on author's personal website immediately
    • Author's post-print on any open access repository after 12 months after publication
    • Publisher's version/PDF cannot be used
    • Published source must be acknowledged
    • Must link to publisher version
    • Set phrase to accompany link to published version (see policy)
    • Articles in some journals can be made Open Access on payment of additional charge
  • Classification

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: The bacterium Deinococcus radiodurans-like all other organisms-introduces nucleotide modifications into its ribosomal RNA. We have previously found that the bacterium contains a Carbon-5 methylation on cytidine 2499 of its 23S ribosomal RNA, which is so far the only modified version of cytidine 2499 reported. Using homology search, we identified the open reading frame DR_0049 as the primary candidate gene for the methyltransferase that modifies cytidine 2499. Mass spectrometric analysis demonstrated that recombinantly expressed DR0049 protein methylates E. coli cytidine 2499 both in vitro and in vivo. We also inactivated the DR_0049 gene in D. radiodurans through insertion of a chloramphenicol resistance cassette. This resulted in complete absence of the cytidine 2499 methylation, which all together demonstrates that DR_0049 encodes the methyltransferase producing m(5)C2499 in D. radiodurans 23S rRNA. Growth experiments disclosed that inactivation of DR_0049 is associated with a severe growth defect, but available ribosome structures show that cytidine 2499 is positioned very similar in D. radiodurans harbouring the modification and E. coli without the modification. Hence there is no obvious structure-based explanation for the requirement for the C2499 posttranscriptional modification in D. radiodurans.
    Extremophiles 11/2015; DOI:10.1007/s00792-015-0800-z
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    ABSTRACT: The biodiversity and biotechnological potential of microbes from central Argentinean halophilic environments have been poorly explored. Salitral Negro and Colorada Grande salterns are neutral hypersaline basins exploded for NaCl extraction. As part of an ecological analysis of these environments, two bacterial and seven archaeal representatives were isolated, identified and examined for their biotechnological potential. The presence of hydrolases (proteases, amylases, lipases, cellulases and nucleases) and bioactive molecules (surfactants and antimicrobial compounds) was screened. While all the isolates exhibited at least one of the tested activities or biocompounds, the species belonging to Haloarcula genus were the most active, also producing antimicrobial compounds against their counterparts. In general, the biosurfactants were more effective against olive oil and aromatic compounds than detergents (SDS or Triton X-100). Our results demonstrate the broad spectrum of activities with biotechnological potential exhibited by the microorganisms inhabiting the Argentinean salterns and reinforce the importance of screening pristine extreme environments to discover interesting/novel bioactive molecules.
    Extremophiles 09/2015; DOI:10.1007/s00792-015-0785-7
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    ABSTRACT: The deleterious effects of ionizing radiation are a major concern of the modern world. In the last decades, outstanding interest has been given to developing new therapeutic tools designed for protection against the toxic effects of ionizing radiation. Deinococcus spp. are among the most radioresistant organisms on Earth, being able to survive extreme doses of radiation, 1000-fold higher than most vertebrates. The molecular mechanisms underlying DNA repair and biomolecular protection, which are responsible for the remarkable radioresistance of Deinococcus bacteria, have been a debatable subject for the last 60 years. This paper is focused on the most recent findings regarding the molecular background of radioresistance and on Deinococcus bacteria response to oxidative stress. Novel proteins and genes involved in the highly regulated DNA repair processes, and enzymatic and non- enzymatic antioxidant systems are presented. In addition, a recently proposed mechanism that may contribute to oxidative damage protection in Deinococcus bacteria is discussed. A better understanding of these molecular mechanisms may draw future perspectives for counteracting radiation-related toxicity.
    Extremophiles 06/2015; 19(4). DOI:10.1007/s00792-015-0759-9
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    ABSTRACT: A total of 33 halophilic protease producers were isolated from different salt samples collected from Emisal salt company at Lake Qarun, Fayoum, Egypt. Of these strains, an extremely halophilic strain that grew optimally at 30 % (w/v) NaCl was characterized and identified as Halobacterium sp. strain HP25 based on 16S rRNA gene sequencing and phenotypic characterization. A halo-alkali-thermophilic protease was purified in three successive steps from the culture supernatant. The purified halophilic protease consisted of a single polypeptide chain with a molecular mass of 21 kDa and was enriched 167-fold to a specific activity of 6350 U mg(-1). The purified enzyme was active over a broad pH range from 6.0 to 11.0, with maximum activity at pH 8.0, exhibited a broad temperature range from 30 to 80 °C with optimum activity at 60 °C, and was active at salt concentrations ranging from 5 to 25 % (w/v), with optimum activity at 17 % NaCl (w/v). The K M and V max values of the purified halophilic protease with casein as a substrate were 523 µg mL(-1) and 2500 µg min(-1) mL(-1), respectively. In addition, this enzyme was stable in the tested organic solvents and laundry detergents such methanol, propanol, butanol, hexane, Persil and Ariel. The unusual properties of this enzyme allow it to be used for various applications, such as the ripening of salted fish. Furthermore, its stability and activity in the presence of organic solvents and detergents also allow the use of this enzyme for further novel applications and as an additive in detergent formulations.
    Extremophiles 05/2015; 19(4). DOI:10.1007/s00792-015-0752-3
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    ABSTRACT: Psychrophilic microorganisms are cold-adapted with distinct properties from other thermal classes thriving in cold conditions in large areas of the earth's cold environment. Maintenance of functional membranes, evolving cold-adapted enzymes and synthesizing a range of structural features are basic adaptive strategies of psychrophiles. Among the cold-evolved enzymes are the cold-active lipases, a group of microbial lipases with inherent stability-activity-flexibility property that have engaged the interest of researchers over the years. Current knowledge regarding these cold-evolved enzymes in psychrophilic bacteria proves a display of high catalytic efficiency with low thermal stability, which is a differentiating feature with that of their mesophilic and thermophilic counterparts. Improvement strategies of their adaptive structural features have significantly benefited the enzyme industry. Based on their homogeneity and purity, molecular characterizations of these enzymes have been successful and their properties make them unique biocatalysts for various industrial and biotechnological applications. Although, strong association of lipopolysaccharides from Antarctic microorganisms with lipid hydrolases pose a challenge in their purification, heterologous expression of the cold-adapted lipases with affinity tags simplifies purification with higher yield. The review discusses these cold-evolved lipases from bacteria and their peculiar properties, in addition to their potential biotechnological and industrial applications.
    Extremophiles 03/2015; 19(2):235-247. DOI:10.1007/s00792-014-0710-5
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    ABSTRACT: Pristine and oil-contaminated desert soil samples from Kuwait harbored between 10 and 100 cells g(-1) of hydrocarbonoclastic bacteria capable of growth at 50 °C. Enrichment by incubation of moistened soils for 6 months at 50 °C raised those numbers to the magnitude of 10(3) cells g(-1). Most of these organisms were moderately thermophilic and belonged to the genus Bacillus; they grew at 40-50 °C better than at 30 °C. Species belonging to the genera Amycolatopsis, Chelativorans, Isoptericola, Nocardia, Aeribacillus, Aneurinibacillus, Brevibacillus, Geobacillus, Kocuria, Marinobacter and Paenibacillus were also found. This microbial diversity indicates a good potential for hydrocarbon removal in soil at high temperature. Analysis of the same desert soil samples by a culture-independent method (combined, DGGE and 16S rDNA sequencing) revealed dramatically different lists of microorganisms, many of which had been recorded as hydrocarbonoclastic. Many species were more frequent in the oil contaminated than in the pristine soil samples, which may reflect their hydrocarbonoclastic activity in situ. The growth and hydrocarbon consumption potential of all tested isolates were dramatically enhanced by amendment of the cultures with Ca(2+) (up to 2.5 M CaSO4). This enhanced effect was even amplified when in addition 8 % w/v dipicolinic acid was amended. These novel findings are useful in suggesting biotechnologies for waste hydrocarbon remediation at moderately high temperature.
    Extremophiles 02/2015; 19(3). DOI:10.1007/s00792-015-0739-0
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    ABSTRACT: On Saturday 5 July 2014, Wilhelmus Nicolaas Konings (known as Wil Konings), Emeritus Professor of Molecular Microbiology, passed away at the age of 76. He was born and grew up in Maastricht, the Netherlands. He received his Ph.D. from the University of Groningen in 1969. From 1969 until 1971 he worked at the National Institute of Health, Bethesda, as a post-doctoral fellow. In 1971, he was appointed lecturer and in 1980 promoted to professor in Microbiology at the University of Groningen; in 2002 he retired as Professor Emeritus, leaving a legacy of more than 440 scientific papers and 7 patents, and numerous students and post docs who were trained in his laboratory.Wil Konings was an engaging and striking personality, who, from the middle of the seventies, played a prominent role in the field of microbiology and in particular the area of the membrane biology. He was a very talented researcher with an international reputation and stature that fits in the rich tradition of Dutch microbio ...
    Extremophiles 02/2015; 19(2). DOI:10.1007/s00792-015-0736-3
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    ABSTRACT: The in vivo functions of Hje and Hjc, two Holliday junction resolvases in Sulfolobus islandicus were investigated. We found that deletion of either hje or hjc had no effect on normal cell growth, while deletion of both hje and hjc is lethal. Although Hjc is the conserved resolvase in all archaea, the hje deletion rather than hjc deletion rendered cells more sensitive to DNA-damaging agents such as hydroxyurea, cisplatin, and methyl methanesulfonate than the wild type (WT). Intriguingly, the sensitivity of Δhje could not be rescued by ectopic expression of Hje from a plasmid and Hje overexpression slowed growth and large cells appeared with more than two genome equivalents. We showed that Hje was maintained at a low level in WT cells. Furthermore, transcriptomic microarray analysis revealed that the abundance of transcripts of many genes including those involved in DNA replication, repair, transcription regulation, and cell division changed drastically in the Hje-overexpressed strain. However, only limited genes were up- or downregulated in the hje deletion strain. Our findings collectively suggest that Hje is the primary resolvase involved in DNA repair and its expression must be tightly controlled in cells.
    Extremophiles 02/2015; 19(2). DOI:10.1007/s00792-015-0734-5