In silico characterization of microsatellites in Eucalyptus spp: abundance, length variation and transposon associations

This study assessed the abundance of microsatellites, or simple sequence repeats (SSR), in 19 Eucalyptus EST libraries from FORESTs, containing cDNA sequences from five species: E. grandis, E. globulus, E. saligna, E. urophylla and E. camaldulensis. Overall, a total of 11,534 SSRs and 8,447 SSR-containing sequences (25.5% of total ESTs) were identified, with an average of 1 SSR/2.5 kb when considering all motifs and 1 SSR/3.1 kb when mononucleotides were not included. Dimeric repeats were the most abundant (41.03%), followed by trimerics (36.11%) and monomerics (19.59%). The most frequent motifs were A/T (87.24%) for monomerics, AG/CT (94.44%) for dimerics, CCG/CGG (37.87%) for trimerics, AAGG/CCTT (18.75%) for tetramerics, AGAGG/CCTCT (14.04%) for pentamerics and ACGGCG/CGCCGT (6.30%) for hexamerics. According to sequence length, Class II or potentially variable markers were the most commonly found, followed by Class III. Two sequences presented high similarity to previously published Eucalyptus sequences from the NCBI database, EMBRA_72 and EMBRA_122. Local blastn search for transposons did not reveal the presence of any transposable elements with a cut-off value of 10-50. The large number of microsatellites identified will contribute to the refinement of marker-assisted mapping and to the discovery of novel markers for virtually all genes of economic interest

Isolation, properties and kinetics of growth of thermophilic Bacillus

A strictly aerobic, thermophilic, spore-forming bacteria was isolated from a soil sample collected in Campos dos Goytacazes City, Rio de Janeiro, Brazil. The cells of this organism were Gram-positive, catalase positive, actively motile, 1.2µm wide and 5.3µm long. Growth occurred at pH values ranging from 6.5 to 9.0, and optimum growth occurred at about pH 7.0. The optimum temperature for growth was around 55ºC, and the upper temperature limit for growth was a around 70ºC. Yeast extract stimulated growth on glucose and was obligately required at supraoptimal temperatures (65ºC). The results of 16S rRNA sequence comparisons indicated that the isolate was closely related to Bacillus caldoxylolyticus and Bacillus sp strain AK1, and these three organisms exhibited levels of ribossomal DNA sequence homology of 94 (per cent).