Phagensensibilität, Zellwand‐Zusammensetzung und Taxonomie von Actinomyceten

Prauser, H.; Falta, Rosmarie

doi:10.1002/jobm.19680080106

Cited by 62 publications

(33 citation statements)

References 17 publications

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“…Culture conditions, media, antibiotic concentrations, transformation and conjugation methods followed the general procedures for E. coli (34) and Streptomyces (18). S. coelicolor was cultivated in 79 liquid medium (32). For expression studies, the strains were cultivated on plates containing R2 or MM agar supplemented with 1% mannitol (18).…”

Section: Methodsmentioning

confidence: 99%

The Level of AdpA Directly Affects Expression of Developmental Genes in Streptomyces coelicolor

et al. 2011

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AdpA is a key regulator of morphological differentiation in Streptomyces. In contrast to Streptomyces griseus, relatively little is known about AdpA protein functions in Streptomyces coelicolor. Here, we report for the first time the translation accumulation profile of the S. coelicolor adpA (adpA Sc ) gene; the level of S. coelicolor AdpA (AdpA Sc ) increased, reaching a maximum in the early stage of aerial mycelium formation (after 36 h), and remained relatively stable for the next several hours (48 to 60 h), and then the signal intensity decreased considerably. AdpA Sc specifically binds the adpA Sc promoter region in vitro and in vivo, suggesting that its expression is autoregulated; surprisingly, in contrast to S. griseus, the protein presumably acts as a transcriptional activator. We also demonstrate a direct influence of AdpA Sc on the expression of several genes whose products play key roles in the differentiation of S. coelicolor: STI, a protease inhibitor; RamR, an atypical response regulator that itself activates expression of the genes for a small modified peptide that is required for aerial growth; and ClpP1, an ATP-dependent protease. The diverse influence of AdpA Sc protein on the expression of the analyzed genes presumably results mainly from different affinities of AdpA Sc protein to individual promoters.Streptomycetes, GC-rich Gram-positive soil bacteria known for their ability to produce many valuable antibiotics and other secondary metabolites, undergo complex morphological differentiation (4, 10). The genome of the model species Streptomyces coelicolor A3(2) was the first among the Streptomycetes to be completely sequenced (2).Streptomyces bacteria grow by tip extension and hyphal branching to form a dense mycelial network of vegetative hyphae. In response to nutrient depletion and other signals, the vegetative mycelium is partially self-cannibalized by a nuclease(s) and protease(s) to supply nutrients for the growth of aerial hyphae, which subsequently transform into long chains of spores (3,27). This morphological differentiation, which is usually accompanied by the production of secondary metabolite(s), is controlled by multilevel regulatory mechanisms. A key coordinating role in the regulation of morphological differentiation is played by the protein AdpA, which was originally discovered in Streptomyces griseus (37,38). In all Streptomyces genomes sequenced so far, translation of adpA mRNA depends on a leucyl-tRNA for a rarely used TTA codon; the tRNA UAA Leu is encoded by the bldA gene required for aerial mycelium formation. AdpA belongs to the AraC/XylS family of transcription regulators, whose members contain a dual helix-turn-helix (HTH) motif in the C-terminal DNA binding domain. In S. griseus, AdpA activates a number of genes whose products are required for morphological development and for secondary metabolites synthesis (e.g., streptomycin) (12, 28). During vegetative growth, the transcription of S. griseus adpA (adpA Sg ) is repressed by ArpA, the receptor protein for the signal...

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Section: Methodsmentioning

confidence: 99%

The Level of AdpA Directly Affects Expression of Developmental Genes in Streptomyces coelicolor

et al. 2011

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“…For subcultivation, four different media, ISP-2 agar, ISP-3 agar [49]. M79 agar [40] and brain heart infusion agar (Difco, USA), were used. All plates were incubated for 10-21 days at 28 oc.…”

Section: Isolationmentioning

confidence: 99%

Analysis of Actinobacteria from mould-colonized water damaged building material

Schafer

Jäckel

Kämpfer

2010

Systematic and Applied Microbiology

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Mould-colonized water damaged building materials are frequently eo-colonized by actinomycetes. Here, we report the results of the analyses of Actinobacteria on different wall materials from water damaged buildings obtained by both cultivation-dependent and cultivation-independent methods. Actinobacteria were detected in all but one of the investigated materials by both methods. The detected concentrations of Actinobacteria ranged between 1.8 x 10 4 and 7.6 x 10 7 CFU g-1 of investigated material. A total of265 isolates from 17 materials could be assigned to 31 different genera of the classActinobacteria on the basis of 165 rRNA gene sequence analyses. On the basis of the cultivation-independent approach, 165 rRNA gene inserts of 800 clones (50%) were assigned to 47 different genera. Representatives of the genera Streptomyces, Amycolatopsis, Nocardiopsis, Saccharopolyspora, Promicromonospora, and Pseudonocardia were found most frequently. The results derived from both methods indicated a high abundance and variety of Actinobacteria in water damaged buildings. Four bioaerosol samples were investigated by the cultivation-based approach in order to compare the communities of Actinobacteria in building material and associated air samples. A comparison of the detected genera of bioaerosol samples with those directly obtained from material samples resulted in a congruent finding of 9 of the overall 35 detected genera (25%), whereas four genera were only detected in bioaerosolsamples.

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“…The agar plates were incubated at 28 u C for about 4 weeks. Subcultivation of the isolate was done on solidified organic medium 79 (Prauser & Falta, 1968; http://www.dsmz.de/ microorganisms/html/media/medium000426.html) and ISP 2 medium (Difco; Shirling & Gottlieb, 1966). Pure cultures of strain HKI 0501…”

Section: Strain Hki 0501mentioning

confidence: 99%