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. Results obtained through sequence analysis revealed low genetic diversity across the isolates, even when analyzing different species and plant structures. This is the first report concerning the isolation and identification of endophytic bacteria in these plant species

The dermatophyte Trichophyton rubrum secretes an EDTA-sensitive alkaline phosphatase on high-phosphate medium

In this communication, we show that the growth of isolate H6 of the dermatophyte Trichophyton rubrum on non-buffered medium and under saturating phosphate conditions is dependent on the initial growth pH, with an apparent optimum at pH 4.0. In addition, irrespective of the initial growth pH, the pH of the medium altered during cultivation reaching values that ranged from 8.3 to 8.9. Furthermore, this isolate synthesized and secreted almost the same levels of an alkaline phosphatase with an apparent optimum pH ranging from 9.0 to 10.0 when grown on both low- and high-phosphate medium. Also, this alkaline phosphatase is activated by Mg2+ and is EDTA-sensitive. On the other hand, the very low levels of the enzyme retained by the mycelium grown on buffered medium at pH 5.0-5.2 suggest that this enzyme is encoded by an alkaline gene, i.e., a gene responsive to ambient pH signaling