Life on Earth

Schleper, Simone

doi:10.26481/dis.20170426mss

Cited by 4 publications

(6 citation statements)

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“…Evidence for the accurate representation of the phylogenetic diversity in the metagenomic libraries came from the sequencing of three hundred randomly picked clones containing amplicons of 16s rRNA genes amplified from metagenomic DNA, which proved the broad taxonomic distribution of the bacteria identified [19]. Thus, the identification of only cobalt-dependent NHases might reflect a more real picture of the abundance of iron-and cobalt-dependent NHases among bacteria than the one that has emerged from the NHase-sequences of cultivated organisms.…”

Section: Resultsmentioning

confidence: 99%

Identification and Expression in E. coli of Novel Nitrile Hydratases from the Metagenome

Liebeton

Eck

2004

Engineering in Life Sciences

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A PCR‐based screening procedure using degenerate consensus primers was employed to identify nitrile hydratase (NHase) encoding genes in libraries of cloned environmental DNA. Screening of about 3 Gbp of metagenomic DNA led to the identification of twelve novel and highly diverse NHase α‐subunits, ten β‐subunits, and three NHase activator proteins. The disruption of the natural arrangement of the genes encoding the NHase subunits and a reduced temperature proved to be beneficial for the soluble expression in E. coli. Of nine NHases investigated, six were produced in an active conformation. The co‐expression of corresponding activator proteins resulted in the activation of a previously inactive enzyme and a marked increase in activity of another enzyme. Thus, the sequence‐homology based screening approach led to the identification and finally the production of novel and diverse NHase enzymes.

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Section: Resultsmentioning

confidence: 99%

Identification and Expression in E. coli of Novel Nitrile Hydratases from the Metagenome

Liebeton

Eck

2004

Engineering in Life Sciences

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“…The /3-galactosidase gene from S. ,~olfataricus has been cloned [34] and constitutes a promising marker, especially because S. so!fataricus mutants exist that give white colonies on plates with X-Gal (5-bromo-4-chloro-3-indolyl-/3-D-galactopyranoside) [35] and can be complemented by transfection with an SSVI virus where the /3-galactosidase gene has been inserted (W. Zillig, personal commun. ).…”

Section: Phenotypic Markersmentioning

confidence: 99%

General vectors for archaeal hyperthermophiles: Strategies based on a mobile intron and a plasmid

Aagaard

1996

FEMS Microbiology Reviews

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Although there are currently no cloning and expression vectors available for archaeal hyperthermophiles, small cryptic plasmids have been characterized for these organisms as well as viruses and introns capable of spreading between cells. Below, we review the recent progress in adapting these genetic elements as vectors for Pyrococcus furiosus and Sulfolobus acidocaldarius. An efficient and reliable transformation procedure is described for both organisms. The potential of the mobile intron from Desulfurococcus mobilis, inserted into the bacterial vector pUC 18 to generate a new type of vector, was investigated in S. acidocaldarius. A polylinker was inserted upstream from the open reading frame encoding the homing enzyme I-DmoI. Both the polylinker and a 276 bp fragment of the tetracycline gene from pBR322 could be inserted into the intron-plasmid construct and spreading still occurred in the culture of S. acidocaldarius. Experiments are in progress to test the co-mobility of the alcohol dehydrogenase and /3-galactosidase genes from Sulfolobus species with the intron. A shuttle vector pCSV1 was also produced by fusing the pGT5 plasmid from Pyrococcus abyssi and the bacterial vector pUC19 which, on transformation, is stable in both organisms without selection. Growth inhibition studies indicate that both P. furiosus and S. acidocaldarius are sensitive to the antibiotics carbomycin, celesticetin, chloramphenicol and thiostrepton as well as butanol and butylic alcohol. Spontaneous mutants resistant to these drugs have been isolated carrying single site mutations in their 23S rRNA gene; they include mutants of S. acidocaldarius resistant to chloramphenicol, carbomycin and celesticetin with the mutation C2452U and thiostrepton-resistant mutants of P. furiosus carrying the mutation A1067G (both numbers corresponding to Escherichia coli 23S rRNA). These mutated genes are being developed as selective markers. Moreover, two 13-galactosidase genes from P. furiosus have been cloned as possible phenotypic markers; one of these exhibits maximum activity at 95°C with O-nitrophenyl /3-D-galactopyranoside as substrate.

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“…Most remarkable is also the progress in calculating multi-leg amplitudes. Using conventional as well as string theory techniques it has become possible to compute scattering amplitudes involving up to 22 gluons The measured inclusive W+3jet production cross section for pp collisions at the Tevatron as function of the Third Jet E T ; from [1]. Right: Scale dependence of LO and NLO cross sections for the process pp → ttbb + X at the LHC.…”

Section: Qcd At Collidersmentioning

confidence: 99%

“…Consistency with the ρ-parameter then requires an adjustement of different parameters at the level of 1%, which is sometimes considered to be 'unnatural' 1 . This fine-tuning can be avoided in models with more fields such as the next-to-minimal supersymmetric Standard Model (NMSSM) or 'little Higgs' models, where the Higgs fields appear as pseudo-Goldstone bosons of a global symmetry containing SU(2) L × SU(2) R → SU (2) …”

Section: Pos(eps-hep 2009)029mentioning

confidence: 99%

“…To improve our quantitative understanding of this theory has remained a theoretical challenge for more than three decades. In recent years important topics have been the determination of the scale-dependent strong coupling α s (Q 2 ), higher-order calculations of matrix elements, the analysis of multi-leg final states and soft processes including underlying events and diffraction [1].…”

Section: Qcd At Collidersmentioning

confidence: 99%

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