Yeast
not annotated - annotated - LINNAEUS only
20173012
Sporosalibacterium faouarense gen. nov., sp. nov., a moderately halophilic bacterium isolated from oil-contaminated soil.
A novel strictly anaerobic, moderately halophilic and mesophilic bacterium, designated strain SOL3f37(T), was isolated from a hydrocarbon-polluted soil surrounding a deep petroleum environment located in south Tunisia. Cells of strain SOL3f37(T) stained Gram-positive and were motile, straight and spore-forming. Strain SOL3f37(T) had a typical Gram-positive-type cell-wall structure, unlike the thick, multilayered cell wall of its closest relative Clostridiisalibacter paucivorans. The major fatty acids were iso-C(15 : 0) (41 %), iso-C(14 : 0) 3-OH and/or iso-C(15 : 0) dimethyl acetal (21.6 %), iso-C(13 : 0) (4.4 %), anteiso-C(15 : 0) (3.9 %) and iso-C(15 : 1) (2.8 %). Strain SOL3f37(T) grew between 20 and 48 ^0C (optimum 40 ^0C) and at pH 6.2-8.1 (optimum pH 6.9). Strain SOL3f37(T) required at least 0.5 NaCl l(-1) and grew in the presence of NaCl concentrations up to 150 g l(-1) (optimum 40 g l(-1)). Yeast extract (2 g l(-1)) was required for degradation of pyruvate, fumarate, fructose, glucose and mannitol. Also, strain SOL3f37(T) grew heterotrophically on yeast extract, peptone and bio-Trypticase, but was unable to grow on Casamino acids. Sulfate, thiosulfate, sulfite, elemental sulfur, fumarate, nitrate and nitrite were not reduced. The DNA G+C content was 30.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SOL3f37(T) was a member of the family Clostridiaceae in the order Clostridiales; strain SOL3f37(T) was related to members of various genera of the family Clostridiaceae. It exhibited highest 16S rRNA gene sequence similarity (93.4 %) with Clostridiisalibacter paucivorans 37HS60(T), 91.8 % with Thermohalobacter berrensis CTT3(T) and 91.7 % with Caloranaerobacter azorensis MV1087(T). On the basis of genotypic, phenotypic and phylogenetic data, it is suggested that strain SOL3f37(T) represents a novel species in a new genus. The name Sporosalibacterium faouarense gen. nov., sp. nov. is proposed, with SOL3f37(T) (=DSM 21485(T) =JCM 15487(T)) as the type strain of Sporosalibacterium faouarense.
22008745
Identification and characterization of a putative basic helix-loop-helix transcription factor involved in the early stage of conidiophore development in Aspergillus oryzae.
The helix-loop-helix (HLH) family of transcriptional factors is a key player in a wide range of developmental processes. HLH proteins form homo- and/or heterodimers with other HLH proteins and bind to E-box motifs. The regulation and functions of these proteins can be complex due to their bifunctional roles as activators and repressors of gene transcription. In this study, we isolated and characterized a novel predicted bHLH protein-encoding gene, AO090023000902, designated ecdR (early conidiophore development regulator), in Aspergillus oryzae. The ecdR gene disruptant produced very few conidia. Conversely, the overexpression of ecdR resulted in the formation of a large number of conidia at an early stage, suggesting that the EcdR protein is required for early asexual development. Additionally, when serially diluted conidia were spread-cultivated onto malt agar medium, we found that conidial number of the control strain depended on the cultivated conidium density, while the ecdR-overexpressing strain showed no significant change in conidiation. These phenotypes of ecdR-disruptant and ecdR-overexpressing strains are partially similar to those of the sclR-overexpressing strain and sclR-disruptant, respectively. Yeast two-hybrid assays and sclR, ecdR-double deletion experiment indicated that EcdR plays a major role in conidiation, and SclR represses this function by competitively interacting with EcdR in A. oryzae.
21511048
The contribution of the S-phase checkpoint genes MEC1 and SGS1 to genome stability maintenance in Candida albicans.
Genome rearrangements, a common feature of Candida albicans isolates, are often associated with the acquisition of antifungal drug resistance. In Saccharomyces cerevisiae, perturbations in the S-phase checkpoints result in the same sort of Gross Chromosomal Rearrangements (GCRs) observed in C. albicans. Several proteins are involved in the S. cerevisiae cell cycle checkpoints, including Mec1p, a protein kinase of the PIKK (phosphatidyl inositol 3-kinase-like kinase) family and the central player in the DNA damage checkpoint. Sgs1p, the ortholog of BLM, the Bloom's syndrome gene, is a RecQ-related DNA helicase; cells from BLM patients are characterized by an increase in genome instability. Yeast strains bearing deletions in MEC1 or SGS1 are viable (in contrast to the inviability seen with loss of MEC1 in S. cerevisiae) but the different deletion mutants have significantly different phenotypes. The mec1Delta/Delta colonies have a wild-type colony morphology, while the sgs1Delta/Delta mutants are slow-growing, producing wrinkled colonies with pseudohyphal-like cells. The mec1Delta/Delta mutants are only sensitive to ethylmethane sulfonate (EMS), methylmethane sulfonate (MMS), and hydroxyurea (HU) but the sgs1Delta/Delta mutants exhibit a high sensitivity to all DNA-damaging agents tested. In an assay for chromosome 1 integrity, the mec1Delta/Delta mutants exhibit an increase in genome instability; no change was observed in the sgs1Delta/Delta mutants. Finally, loss of MEC1 does not affect sensitivity to the antifungal drug fluconazole, while loss of SGS1 leads to an increased susceptibility to fluconazole. Neither deletion elevated the level of antifungal drug resistance acquisition.
21907817
GintAMT2, a new member of the ammonium transporter family in the arbuscular mycorrhizal fungus Glomus intraradices.
In the symbiotic association of plants and arbuscular mycorrhizal (AM) fungi, the fungus delivers mineral nutrients, such as phosphate and nitrogen, to the plant while receiving carbon. Previously, we identified an NH(4)(+) transporter in the AM fungus Glomus intraradices (GintAMT1) involved in NH(4)(+) uptake from the soil when preset at low concentrations. Here, we report the isolation and characterization of a new G. intraradicesNH(4)(+) transporter gene (GintAMT2). Yeast mutant complementation assays showed that GintAMT2 encodes a functional NH(4)(+) transporter. The use of an anti-GintAMT2 polyclonal antibody revealed a plasma membrane location of GintAMT2. GintAMT1 and GintAMT2 were differentially expressed during the fungal life cycle and in response to N. In contrast to GintAMT1, GintAMT2 transcript levels were higher in the intraradical than in the extraradical fungal structures. However, transcripts of both genes were detected in arbuscule-colonized cortical cells. GintAMT1 expression was induced under low N conditions. Constitutive expression of GintAMT2 in N-limiting conditions and transitory induction after N re-supply suggests a role for GintAMT2 to retrieve NH(4)(+) leaked out during fungal metabolism.