Adsorption of Saccharomyces cerevisiae onto cellulose and ECTEOLA-cellulose films for ethanol production

Epichlorohydrin-triethanolamine (ECTEOLA)-cellulose films (paper and cloth) have been found to bind Saccharomyces cerevisiae cells which were able to develop metabolically active colonies on the surface of the films. Unmodified cellulose films also bound the yeast but to a lesser extent. Film fermenters were constructed by coiling a double layer of the cloth and copper screen and vertically placing the resulting cartridge into a column. These film fermenters were able to convert the sugars (14%) in the hydrolysate of a Jerusalem artichoke tuber into ethanol, with 90% of the theoretical yield after 6 h of fermentation. The bound yeast produced ethanol at a specific rate of 1.0 g ethanol per g cell per hour.     

Identification of COS markers in the Pinaceae

Conserved ortholog set (COS) markers are evolutionary conserved, single-copy genes, identified from large databases of express sequence tags (ESTs). They are of particular use for constructing syntenic genetic maps among species. In this study, we identified a set of 1,813 putative single-copy COS markers between spruce and loblolly pine, then designed primers for 931 of these markers and tested these primers with DNA from spruce, pine, and Douglas fir. Of these 931 primers, 56% (524) amplified a product in both spruce and pine, and 71% (373) of these were single-banded; 224 amplicons were single-banded in all three species. Even though these COS markers were selected from large EST databases, a substantial proportion (20–30%) of amplicons displayed multiple bands or smears, suggesting significant paralogy. Sequencing of three single-banded amplicons showed high nucleotide similarities among 29 conifer species, suggesting orthology of single-banded amplicons. Screening for COS marker polymorphism in two pedigrees of white spruce and two pedigrees of loblolly pine revealed an average informativeness of 36% for spruce and 24% for pine (e.g., at least one parent was heterozygous for a single-nucleotide polymorphism within the entire amplified product). This corresponds to an average nucleotide heterozygosity of 0.05% and 0.03%, respectively, which is considerably lower than that found in other studies of spruce and pine. Thus, the advantages of COS markers for constructing syntenic maps are offset by their lower polymorphism. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Yeast Pescadillo is required for multiple activities during 60S ribosomal subunit synthesis

The Pescadillo protein was identified via a developmental defect and implicated in cell cycle progression. Here we report that human Pescadillo and its yeast homolog (Yph1p or Nop7p) are localized to the nucleolus. Depletion of Nop7p leads to nuclear accumulation of pre-60S particles, indicating a defect in subunit export, and it interacts genetically with a tagged form of the ribosomal protein Rpl25p, consistent with a role in subunit assembly. Two pre-rRNA processing pathways generate alternative forms of the 5.8S rRNA, designated 5.8S(L) and 5.8Ss. In cells depleted for Nop7p, the 27SA3 pre-rRNA accumulated, whereas later processing intermediates and the mature 5.8Ss rRNA were depleted. Less depletion was seen for the 5.8S(L) pathway. TAP-tagged Nop7p coprecipitated precursors to both 5.8S(L) and 5.8Ss but not the mature rRNAs. We conclude that Nop7p is required for efficient exonucleolytic processing of the 27SA3 pre-rRNA and has additional functions in 60S subunit assembly and transport. Nop7p is a component of at least three different pre-60S particles, and we propose that it carries out distinct functions in each of these complexes.