| 1. |
- Wouters, Johanna, et al.
(författare)
-
Cloning and expression of a putative cyclodextrine glycosyltransferase from the symbiotically competet cyanobacteruium Nostoc sp. PCC 9229
- 2003
-
Ingår i: FEMS Microbioloy Letters. - 0378-1097. ; 219:2, s. 181-185
-
Tidskriftsartikel (refereegranskat)abstract
- A polymerase chain reaction-based method was used to isolate a Nostoc sp. PCC 9229 cDNA from infected glands of Gunnera chilensis. The complete gene sequence was isolated from a genomic Nostoc sp. PCC 9229 library. Sequence analysis showed 84% amino acid similarity to a putative cyclodextrin glycosyltransferase from Nostoc sp. PCC 7120 and the gene was therefore termed cgt. Southern blot revealed that the cgt gene was present in symbiotically competent cyanobacteria. The cgt gene was expressed in free-living nitrogen-fixing cultures in light or in darkness when supplemented with fructose. This is the first expression analysis of a cgt gene from a cyanobacterium.
|
|
| 2. |
- Asiegbu, F.O., et al.
(författare)
-
Isolation of a novel antimicrobal peptide gene (Sp-AMP) homologue from Pinus sylvestris (Scots pine) following infection with the root rot fungus Heterobasidion annosum
- 2003
-
Ingår i: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 228:1, s. 27-31
-
Tidskriftsartikel (refereegranskat)abstract
- A new family of antimicrobial peptide homologues termed Sp-Amp has been discovered in Pinus sylvestris (Scots pine). This is the first report of such proteins to be characterized in a conifer species. Sp-AMP1 was identified in a substructured cDNA library of root tissue infected with the root rot fungus Heterobasidion annosum and encodes a mature peptide of 79 amino acid residues. Three additional members of the Sp-AMP family (Sp-AMPs 2–4) encode cysteine-rich proteins of 105 amino acids, each containing an N-terminal region with a probable cleavage signal sequence. Northern analysis confirmed that Sp-AMP expression is elevated in Scots pine roots upon infection with H. annosum. These peptides share 64% amino acid identity with a mature protein from Macadamia integrifolia (MiAMP1), which allowed us to build a homology model for preliminary analysis. Southern analyses further confirmed that several copies of the gene are present in the Scots pine genome. The potential significance of Sp-AMP in the H. annosum–conifer pathosystem is discussed.
|
|
| 3. |
- Grahn, Niclas, et al.
(författare)
-
Identification of mixed bacterial DNA contamination in broad-range PCR amplification of 16S rDNA V1 and V3 variable regions by pyrosequencing of cloned amplicons
- 2003
-
Ingår i: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 219:1, s. 87-91
-
Tidskriftsartikel (refereegranskat)abstract
- Using a sensitive and rapid method combining broad-range PCR amplification of bacterial 16S rDNA fragments and pyrosequencing for detection, identification and typing, we have found contaminating bacterial DNA in our reagents used for PCR. Identified bacteria are the water-borne bacterial genera Pseudomonas, Stenotrophomonas, Xanthomonas, Ralstonia and Bacillus. Our results are in concordance with recent reports of contaminated industrial water systems. In light of this conclusion, we believe that there is a need for increased awareness of possible contamination in uncertified widely used molecular biology reagents, including ultra-pure water. Since sequence-based 16S rDNA techniques are used in a variety of settings for bacterial typing and the characterization of microbial communities, we feel that future certification of molecular biology reagents, as free of nucleic acids, would be advantageous. ⌐ 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
|
|
| 4. |
- Lai, Xin-He, et al.
(författare)
-
Francisella strains express hemolysins of distinct characteristics
- 2003
-
Ingår i: FEMS Microbiology Letters. - : Elsevier. - 0378-1097 .- 1574-6968. ; 224:1, s. 91-95
-
Tidskriftsartikel (refereegranskat)abstract
- Historically, Francisella strains have been described as nonhemolytic. In this study, we show by use of solid and liquid hemolysis assays that some Francisella strains have hemolytic properties. The Francisella novicida type strain U112 is hemolytic to horse erythrocytes and Francisella philomiragia type strain FSC144 is hemolytic towards both human and horse erythrocytes. The F. novicida strain U112 released a protein (novilysin A) into the culture supernatant which cross-reacted with antiserum against Escherichia coli HlyA whereas there was no similar protein detectable with this cross-reactive property from the supernatant of the F. philomiragia strain.
|
|
| 5. |
- Lehtio, J., et al.
(författare)
-
Directed immobilization of recombinant staphylococci on cotton fibers by functional display of a fungal cellulose-binding domain
- 2001
-
Ingår i: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 195:2, s. 197-204
-
Tidskriftsartikel (refereegranskat)abstract
- The immobilization of recombinant staphylococci onto cellulose fibers through surface display of a fungal cellulose-binding domain (CBD) was investigated. Chimeric proteins containing the CBD from Trichoderma reesei cellulase Cel6A were found to be correctly targeted to the cell wall of Staphylococcus carnosus cells. since full-length proteins could be extracted and affinity-purified. Furthermore. surface accessibility of the CBD was verified using a monoclonal antibody and functionality in terms of cellulose-binding was demonstrated in two different assays in which recombinant staphylococci were found to efficiently bind to cotton fibers. The implications of this strategy of directed immobilization Tor the generation of whole-cell microbial tools Fur different applications will be discussed.
|
|
| 6. |
- Leitz, G, et al.
(författare)
-
Laser-based micromanipulation for separation and identification of individual Frankia vesicles
- 2003
-
Ingår i: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 224:1, s. 97-100
-
Tidskriftsartikel (refereegranskat)abstract
- In studies of symbiotic efficiency it is of great importance to identify and separate individual Frankia strains from a nodule. Therefore, a new laser-based micromanipulation technique has been developed in which individual vesicles from root nodules of two Frankia-Alnus symbioses have been successfully cut loose and separated from clusters of vesicles in sterile conditions under light microscopy using a laser scalpel and optical tweezers. Vesicles from the Alnus incana-Frankia AvCIl symbiosis were successfully isolated and grown in culture using this technique. The DNA from both Frankia sources was amplified by polymerase chain reaction (PCR). The work shows that a combination of laser-based manipulation techniques and PCR can be used for the separation and study of individual vesicles. This novel laser-based micromanipulation technique opens up various new possibilities, for instance, to study whether several Frankia strains can grow simultaneously in the same root nodule. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
|
|
| 7. |
- Magnusson, Jesper, et al.
(författare)
-
Broad and complex antifungal activity among environmental isolates of lactic acid bacteria
- 2003
-
Ingår i: FEMS Microbiology Letters. - : Elsevier. - 0378-1097 .- 1574-6968. ; 219:1, s. 129-135
-
Tidskriftsartikel (refereegranskat)abstract
- More than 1200 isolates of lactic acid bacteria isolated from different environments were screened for antifungal activity in a dual-culture agar plate assay. Approximately 10% of the isolates showed inhibitory activity and 4% showed strong activity against the indicator mould Aspergillus fumigatus. The antifungal spectra for 37 isolates with strong activity and five isolates with low or no activity were determined. Several of the strains showed strong inhibitory activity against the moulds A. fumigatus, Aspergillus nidulans, Penicillium commune and Fusarium sporotrichioides, and also against the yeast Rhodotorula mucilaginosa. Penicillium roqueforti and the yeasts Pichia anomala and Kluyveromyces marxianus were not inhibited. Several isolates showed reduced antifungal activity after storage and handling. The majority of the fungal inhibitory isolates were identified by 16S rDNA sequencing as Lactobacillus coryniformis. Lactobacillus plantarum and Pediococcus pentosaceus were also frequently identified among the active isolates. The degree of fungal inhibition was not only related to production of lactic or acetic acid. In addition, antifungal cyclic dipeptides were identified after HPLC separation and several other active fractions were found suggesting a highly complex nature of the antifungal activity.
|
|
| 8. |
- Monstein, Hans-Jurg, 1946-, et al.
(författare)
-
Rapid molecular identification and subtyping of Helicobacter pylori by pyrosequencing of the 16S rDNA variable V1 and V3 regions
- 2001
-
Ingår i: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 199:1, s. 103-107
-
Tidskriftsartikel (refereegranskat)abstract
- We describe here the use of real-time DNA sequence analysis of Helicobacter pylori 16S rRNA gene fragments by pyrosequencingÖ for rapid molecular identification and subtyping of clinical isolates based on DNA sequence heterogeneity within the variable V1 and V3 regions. Six individual 16S rDNA V1 alleles (position 75-100) were identified in 23 clinical isolates obtained from gastric biopsy specimens. Eleven of these revealed sequence identities with H. pylori 26695 and one was identical with the rrn genes in strain J99. The other V1 alleles showing single or double nucleotide mutations or single nucleotide insertions could be divided into four groups with 5, 4, 1, and 1 isolates each. Two out of 25 isolates demonstrated single C to T transitions in the V3 region (position 990-1020). The present findings show that subtle DNA sequence variation occurs sufficiently often in the 16S rDNA variable V1 and V3 regions of H. pylori to provide a consistent system for subtyping.
|
|
| 9. |
- Nahalkova, Jarmila, et al.
(författare)
-
Red fluorescent protein (DsRed2) as a novel reporter in Fusarium oxysporum f. sp. Lycopersici
- 2003
-
Ingår i: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 225:2, s. 305-309
-
Tidskriftsartikel (refereegranskat)abstract
- pAn-DsRed2 vector was constructed for constitutive cytoplasmic expression of the red fluorescent protein (DsRed2) under control of the glyceraldehyde-3-phosphate dehydrogenase gene promoter from Aspergillus nidulans. DsRed2-transformation of two Fusarium oxysporum f. sp. lycopersici strains pathogenic against tomato host resulted in bright red cytoplamic fluorescence of the fungus. The transformants were screened based on the hygromycin B resistance, brightness, stability and rate of appearance of the DsRed2 fluorescence. The transormed fungi were growing normally and their pathogenicity did not change after transformation procedure. The function of novel DsRed2 marker was verified by fluorescence microscopy of the infected tomato seedlings. The results indicate that DsRed2 can be used as a efficient novel reporter gene for monitoring of the F. oxysporum within the host tissues.
|
|
| 10. |
|
|
