| 1. |
- Ahrén, Dag, et al.
(author)
-
Phylogeny of nematode-trapping fungi based on 18S rDNA sequences
- 1998
-
In: FEMS Microbiology Letters. - : Oxford University Press (OUP). - 0378-1097 .- 1574-6968. ; 158:2, s. 179-184
-
Journal article (peer-reviewed)abstract
- The small subunit (SSU) ribosomal DNA (18S rDNA) from 15 species of nematode-trapping fungi and closely related non-parasitic species were sequenced. Phylogenetic analysis indicated that species within the genera of Arthrobotrys, Dactylaria, Dactylella, Monacrosporium and Duddingtonia formed a monophyletic and isolated clade among an unresolved cluster of apothecial ascomycetes. The phylogenetic patterns within this clade were not concordant with the morphology of the conidia nor the conidiophores, but rather with that of the infection structures. The results from the different methods of tree reconstruction supported three lineages; the species having constricting rings, the non-parasitic species and the species having various adhesive structures (nets, hyphae, knobs and non-constricting rings) to infect nematodes.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Hallberg, K. B., et al.
(author)
-
Arsenic toxicity is not due to a direct effect on the oxidation of reduced inorganic sulfur compounds byThiobacillus caldus
- 1996
-
In: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 145:3, s. 409-414
-
Journal article (peer-reviewed)abstract
- Thiobacillus caldus is a moderately thermophilic acidophile which has been implicated in the biooxidation of arsenic containing mineral sulfides. The toxic effects of arsenic on this bacterium are presented here. Addition of arsenite to a growing culture of T. caldus caused a transient increase in the optical density of the culture while causing a simultaneous decrease in cell viability. The increase in optical density was shown to be due to the formation of extracellular sulfur. The oxidation rates of tetrathionate and thiosulfate were decreased by increasing concentrations of arsenite, while in a culture induced to arsenic resistance the rates were not as adversely effected. Sulfur oxidation was also inhibited to the same extent as tetrathionate oxidation, with the oxidation of solid sulfur being slightly more effected than the oxidation of sulfur dissolved in acetone. Thus, bactericidal arsenite causes a transient formation of extracellular sulfur in the culture supernatant of T. caldus yet the toxicity of arsenite is not due to direct inhibitory effects on reduced inorganic sulfur compound oxidation by these bacteria.
|
|
| 8. |
- Martinez, Javier, et al.
(author)
-
Genes for cysteine proteinases from Trypanosoma rangeli
- 1995
-
In: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 129:2-3, s. 135-141
-
Journal article (peer-reviewed)abstract
- PCR amplification of genomic DNA from the American trypanosome, Trypanosoma rangeli, using as primers oligonucleotides derived from the gene of cruzipain, the major cysteine proteinase (CP) from Trypanosoma cruzi, allowed the production of a probe which was used to obtain three clones encoding a CP with 70% overall identity with cruzipain. The genes are organized in tandem, with a monomere size of approximately 2 kbp, located on two chromosomes which, in some parasite isolates, have a high molecular mass (higher than 5.7 Mbp), and in others are much smaller (about 500 kbp). The low expression of this CP at the protein level correlates well with the low level of specific mRNA found in Northern blots.
|
|
| 9. |
- Sellstedt, Anita, 1955-
(author)
-
SPECIFICITY AND EFFECTIVITY IN NODULATION BY FRANKIA ON SOUTHERN-HEMISPHERE ACTINORHIZA
- 1995
-
In: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 125:2-3, s. 231-236
-
Journal article (peer-reviewed)abstract
- Nodulation ability was tested for Frankia strains HFPCcI3 and EL1, and Frankia sources A.t. and G.a. from Allocasuarina torulosa and Gymnostoma australianum, respectively, on A. torulosa Mig., Casuarina cunninghamiana Mig., G. australianum L. Johnson and Elaeagnus triflora Roxb. It was shown that A. torulosa and C. cunninghamiana formed nodules only with the Frankia sources obtained from their own host plant, while E. triflora formed nodules with three of the four Frankia sources tested. All nodules formed were effectively fixing nitrogen. Specific nitrogenase activity was highest in E. triflora inoculated with the Frankia strain isolated from nodules of the same species. Identification of Frankia sources in the nodules was performed by use of PCR amplification of DNA with a random primer. PCR amplification of DNA isolated from nodules of G. australianum and E. triflora inoculated with Frankia strain EL1 revealed, when compared with DNA amplified from free living Frankia strain EL1, that there was only one Frankia strain causing the observed nodules.
|
|
