Whole-genome sequencing of the efficient industrial fuel-ethanol fermentative Saccharomyces cerevisiae strain CAT-1

The Saccharomyces cerevisiae strains widely used for industrial fuel-ethanol production have been developed by selection, but their underlying beneficial genetic polymorphisms remain unknown. Here, we report the draft whole-genome sequence of the S. cerevisiae strain CAT-1, which is a dominant fuel-ethanol fermentative strain from the sugarcane industry in Brazil. Our results indicate that strain CAT-1 is a highly heterozygous diploid yeast strain, and the ~12-Mb genome of CAT-1, when compared with the reference S228c genome, contains ~36,000 homozygous and ~30,000 heterozygous single nucleotide polymorphisms, exhibiting an uneven distribution among chromosomes due to large genomic regions of loss of heterozygosity (LOH). In total, 58 % of the 6,652 predicted protein-coding genes of the CAT-1 genome constitute different alleles when compared with the genes present in the reference S288c genome. The CAT-1 genome contains a reduced number of transposable elements, as well as several gene deletions and duplications, especially at telomeric regions, some correlated with several of the physiological characteristics of this industrial fuel-ethanol strain. Phylogenetic analyses revealed that some genes were likely associated with traits important for bioethanol production. Identifying and characterizing the allelic variations controlling traits relevant to industrial fermentation should provide the basis for a forward genetics approach for developing better fermenting yeast strains.     

Phylogenetic Analysis of Clinically Relevant Fusarium Species in Iran

Mycopathologia - Fungi of the genus Fusarium are well known as major plant pathogens but also cause a broad spectrum of human infections. Sixty-three clinical isolates, collected during...     

LKB1 is required for hepatic bile acid transport and canalicular membrane integrity in mice

LKB1 is a 'master' protein kinase implicated in the regulation of metabolism, cell proliferation, cell polarity and tumorigenesis. However, the long-term role of LKB1 in hepatic function is unknown. In the present study, it is shown that hepatic LKB1 plays a key role in liver cellular architecture and metabolism. We report that liver-specific deletion of LKB1 in mice leads to defective canaliculi and bile duct formation, causing impaired bile acid clearance and subsequent accumulation of bile acids in serum and liver. Concomitant with this, it was found that the majority of BSEP (bile salt export pump) was retained in intracellular pools rather than localized to the canalicular membrane in hepatocytes from LLKB1KO (liver-specific Lkb1-knockout) mice. Together, these changes resulted in toxic accumulation of bile salts, reduced liver function and failure to thrive. Additionally, circulating LDL (low-density lipoprotein)-cholesterol and non-esterified cholesterol levels were increased in LLKB1KO mice with an associated alteration in red blood cell morphology and development of hyperbilirubinaemia. These results indicate that LKB1 plays a critical role in bile acid homoeostasis and that lack of LKB1 in the liver results in cholestasis. These findings indicate a novel key role for LKB1 in the development of hepatic morphology and membrane targeting of canalicular proteins.     

The structural topology of wild-type phospholamban in oriented lipid bilayers using 15N solid-state NMR spectroscopy

For the first time, 15N solid-state NMR experiments were conducted on wild-type phospholamban (WT-PLB) embedded inside mechanically oriented phospholipid bilayers to investigate the topology of its cytoplasmic and transmembrane domains. 15N solid-state NMR spectra of site-specific 15N-labeled WT-PLB indicate that the transmembrane domain has a tilt angle of 13 degrees+/-6 degrees with respect to the POPC (1-palmitoyl-2-oleoyl-sn-glycero-phosphocholine) bilayer normal and that the cytoplasmic domain of WT-PLB lies on the surface of the phospholipid bilayers. Comparable results were obtained from site-specific 15N-labeled WT-PLB embedded inside DOPC/DOPE (1,2-dioleoyl-sn-glycero-3-phosphocholine/1,2-dioleoyl-sn-glycero-3-phosphoethanolamine) mechanically oriented phospholipids' bilayers. The new NMR data support a pinwheel geometry of WT-PLB, but disagree with a bellflower structure in micelles, and indicate that the orientation of the cytoplasmic domain of the WT-PLB is similar to that reported for the monomeric AFA-PLB mutant.     

Identification of the New Pathogen (Stemphylium lycopersici) Causing Leaf Spot on Pepino (Solanum muricatum)

Pepino (Solanum muricatum var. pepino) plants were found affected by an extensive leaf spot caused by plant pathogenic fungi during a survey in the Cameron highlands, Pahang state, Malaysia. Symptomatic leaf samples were collected from infected pepino plants and cultivated on PDA medium, and the pathogen was isolated and purified; then, consequently, all isolates were identified as Stemphylium lycopersici on the basis of their cultural and morphological characteristics and combined sequences of the internal transcribed spacer (ITS) and glyceraldehyde‐3‐phosphate dehydrogenase (gpd) regions. A pathogenicity assay on detached leaves further confirmed that S. lycopersici causes leaf spot disease. To the best of our knowledge, this is the first report of S. lycopersici causing leaf spot on pepino in Malaysia and worldwide.     

Selected Physical and Chemical Properties of Feverfew (<Emphasis Type="BoldItalic">Tanacetum parthenium</Emphasis>) Extracts Important for Formulated Product Quality and Performance

The objectives of this research are: (1) to assess selected formulation-relevant physical properties of several commercial Feverfew extracts, including flowability, hygroscopicity, compressibility and compactibility (2) to develop and validate a suitable extraction method and HPLC assay, and (3) to determine the parthenolide content of several commercial Feverfew extracts. Carr’s index, minimum orifice diameter and particle-particle interaction were used to evaluate powder flowability. Hygroscopicity was evaluated by determining the equilibrium moisture content (EMC) after storage at various % relative humidities. Heckle analysis and compression pressure-radial tensile strength relationship were used to represent compression and compaction properties of feverfew extracts. An adapted analytical method was developed based on literature methods and then validated for the determination of parthenolide in feverfew. The commercial extracts tested exhibited poor to very poor flowability. The comparatively low mean yield pressure suggested that feverfew extracts deformed mainly plastically. Hygroscopicity and compactibility varied greatly with source. No commercial feverfew extracts tested contained the label claimed parthenolide. Even different batches from the same manufacturer showed significantly different parthenolide content. Therefore, extract manufactures should commit to proper quality control procedures that ensure accurate label claims, and supplement manufacturers should take into account possible differences in physico-chemical properties when using extracts from multiple suppliers.