Microbial diversity of soils on the banks of the Solimões and Negro rivers, state of Amazonas, Brazil.

Analysis of bacterial diversity in soils along the banks of the Solimões and Negro rivers, state of Amazonas, Brazil, was by partial sequencing of the genes codifying the rDNA16S region. Diversity of operational taxonomic units (OTU) and of the divergent sequences obtained were applied in comparative analysis of microbiological diversity in the two environments, based on richness estimators and OTU diversity indices. The higher OTU diversity in the Solimões was based on the higher number of parameters that evoke this.

Isolation of endophytic bacteria from arboreal species of the Amazon and identification by sequencing of the 16S rRNA encoding gene.

Endophytic bacteria from three arboreal species native to the Amazon (Carapa guianenses, Ceiba pentandra, and Swietenia macrophylla), were isolated and identified, through partial sequencing of the 16S rRNA encoding gene. From these, 16 isolates were obtained, although, when compared to sequences deposited in GenBank, only seven had produced identifiable fragments. Bacillus, Pantoea and two non-culturable samples were identified.

Anoxia- and hypoxia-induced expression of LDH-A* in the Amazon Oscar, Astronotus crassipinis.

Adaptation or acclimation to hypoxia occurs via the modulation of physiologically relevant genes, such as erythropoietin, transferrin, vascular endothelial growth factor, phosphofructokinase and lactate dehydrogenase A. In the present study, we have cloned, sequenced and examined the modulation of the LDH-A gene after an Amazonian fish species, Astronotus crassipinis (the Oscar), was exposed to hypoxia and anoxia. In earlier studies, we have discovered that adults of this species are extremely tolerant to hypoxia and anoxia, while the juveniles are less tolerant.

The pH signaling transcription factor PacC mediates the growth of Trichophyton rubrum on human nail in vitro.

We report here the isolation, molecular cloning and initial characterization of the Trichophytonrubrum pacC gene, which encodes a putative protein that is homologous to the PacC/Rim101p family of pH signaling transcription regulators. The promoter region of the T. rubrumpacC gene contains four recognition sites 5'-GCCAAG-3' for the PacC protein, suggesting that the transcription of this gene itself could be induced under alkaline growth conditions.

Role of the ABC transporter TruMDR2 in terbinafine, 4-nitroquinoline N-oxide and ethidium bromide susceptibility in Trichophyton rubrum.

A single-copy gene, designated TruMDR2, encoding an ATP-binding cassette (ABC) transporter was cloned and sequenced from the dermatophyte Trichophyton rubrum. The ORF of TruMDR2 was 4048 nt and the deduced amino acid sequence showed high homology with ABC transporters involved in drug efflux in other fungi. The encoded ABC protein predicted 12 transmembrane segments (TMSs) and two almost identical nucleotide-binding domains (NBDs) arranged in two halves in a (TMS(6)-NBD)(2) configuration and could be classified as a member of the multidrug-resistance (MDR) class of ABC transporters.