Evaluation of coverall field dry aerosol decontamination methods using a manikin.

A full-size manikin dressed in fire-resistant coveralls coated in 120 g of sodium bicarbonate was randomly given one of three treatments for dry aerosol decontamination. The three treatments were high-efficiency particulate air (HEPA) vacuum, a commercially available air shower, and the no treatment control. Immediately after the treatment, the coveralls were doffed and an air sample was taken in the breathing zone of the manikin to estimate airborne total and respirable dust concentrations to an unprotected worker post decontamination. Each treatment was applied four times for a total of 12 trials. Using analysis of variance (ANOVA) with alpha =.05 and Tukey's Honestly Significant Difference multiple comparison post-test, it was determined that HEPA vacuuming was not significantly different from the air shower for respirable dust, but only the air shower was significantly better than no decontamination (p =.037). For total dust, HEPA was not significantly different from the air shower, but both were significantly better than no treatment (p =.007, p =.004, respectively).

Candida bituminiphila, a novel anamorphic species of yeast.

A novel anamorphic species of yeast belonging to the genus Candida was isolated from tar in Canada. Morphological and physiological observations, as well as phylogenetic analyses, were performed. Conidiophores were produced, were usually short and had sympodial growth, numerous bud scars and a rachis-like structure. They bore one or more conidia. Pseudomycelium was scarcely produced and true mycelium was sparse. No sexual reproduction was observed on corn meal, malt, Gorodkowa, Dextrose Yeast Peptone or V8 agars. Zygoascus hellenicus was physiologically the most closely related species, but it differed from the novel species by its ability to assimilate D-galacturonate and L-rhamnose, ferment sucrose and grow at 37 degrees C. From sequence analysis of the 26S rDNA D1/D2 region, Z. hellenicus and Candida bertae var. bertae were the closest species with 54 and 56 bp substitutions, respectively. Similar results have been obtained from analysis of the 18S rDNA. All these data support the hypothesis that the yeast, named Candida bituminiphila, is a novel species closely related to Z. hellenicus. The holotype and only isolate of C. bituminiphila is strain CBS 8813T (= MUCL 41424T).

Large-scale production of a soluble human beta-1,4-galactosyltransferase using a Saccharomyces cerevisiae expression system.

We report in this communication the first large-scale heterologous expression of a glycosyltransferase in yeast. A soluble form of a human beta-1,4-galactosyltransferase (EC 2.4.1.38) was expressed using a Saccharomyces cerevisiae expression system. Fermentation technology afforded the means to increase the expression level of the beta-1,4-galactosyltransferase up to a concentration of 700 mU/liter. The enzyme was produced at a scale of 200 units. The recombinant soluble enzyme was purified 766-fold to a specific activity of approx. 2 U/mg using a purification protocol based on sequential affinity chromatography on N-acetylglucosaminyl- and alpha-lactalbumin-Sepharose, respectively. This study demonstrates that heterologous expression of a glycosyltransferase is possible on a large scale and offers an alternative to natural sources like human breast milk or bovine colostrum.