css1 mutants display a novel defect in Schizosaccharomyces pombe cell wall formation. The mutant cells are temperature-sensitive and accumulate large deposits of material that stain with calcofluor and aniline blue in their periplasmic space. Biochemical analyses of this material indicate that it consists of alpha- and beta-glucans in the same ratio as found in cell walls of wild-type S. pombe....

Metal contamination of the environment is frequently associated to the presence of two or more metals. This work aimed to study the impact of a mixture of metals (Cd, Pb and Zn) on the physiology of the non-conventional yeast Pichia kudriavzevii. The incubation of yeast cells with 5 mg/l Cd, 10 mg/l Pb and 5 mg/l Zn, for 6 h, induced a loss of metabolic activity (assessed by FUN-1 staining) and...

The few studies that have been carried out on deep-sea fungi in recent years either by culturing or molecular signatures, have provided evidence about their presence. A majority of culture-dependent and culture-independent fungi recovered showed homology to species reported in the terrestrial environment indicating their possible arrival in deep sea either with wind or terrestrial runoffs. Howe...

Using the set of Saccharomyces cerevisiae mutants individually deleted for 5718 yeast genes, we screened for altered sensitivity to the antifungal protein, K1 killer toxin, that binds to a cell wall beta-glucan receptor and subsequently forms lethal pores in the plasma membrane. Mutations in 268 genes, including 42 in genes of unknown function, had a phenotype, often mild, with 186 showing resi...

Fission yeast, Schizoaccharomyces pombe, is a model for studying cellular quiescence. Shifting to a medium that lacks a nitrogen-source induces proliferative cells to enter long-term G0 quiescence. Klf1 is a Krüppel-like transcription factor with a 7-amino acid Cys2His2-type zinc finger motif. The deletion mutant, ∆klf1, normally divides in vegetative medium, but proliferation is not restored a...

Rhizobium meliloti strain SU47 produces the calcofluor-binding exopolysaccharide, succinoglycan, that is required for alfalfa root nodule invasion. Strains derived from R. meliloti SU47 secreted an acidic exopolysaccharide, EPSb, that replaced succinoglycan in nodule invasion. EPSb, which has not formerly been identified among the Rhizobiaceae, consisted of the repeating unit 4,6-O-(1-carboxyet...

Aspergillus luchuensis is a kuro (black) koji fungus that has been used as a starch degrader for the awamori- and shochu-making industries in Japan. In this study, we investigated the effect of ion beam irradiation on A. luchuensis RIB2601 and obtained a high starch-degrading mutant strain U1. Strain U1 showed reduced growth rate, whereas it showed higher α-amylase, glucoamylase, and α-glucosid...

In mosquito larvae, the peritrophic matrix (PM) separates the gut contents from the intestinal epithelium. This report describes a new in vivo assay for estimating PM permeability. The assay also allows for assessment of the permeability of the caecal membrane, a structure that separates each caecum from the gut lumen. Permeability was estimated by the appearance of fluorescently-labeled dextra...

The Rho family of proteins and their effectors are key regulators involved in many eukaryotic cell functions. In Saccharomyces cerevisiae the family consists of six members, Rho1p to Rho5p and Cdc42p. With the exception of Rho5p, these enzymes have been assigned different biological functions, including the regulation of polar growth, morphogenesis, actin cytoskeleton, budding and secretion. He...

The halotolerant strain Rhizobium meliloti EFB1 modifies the production of extracellular polysaccharides in response to salt. EFB1 colonies grown in the presence of 0.3 M NaCl show a decrease in mucoidy, and in salt-supplemented liquid medium this organism produces 40% less exopolysaccharides. We isolated transposon-induced mutant that, when grown in the absence of salt, had a colony morphology...