Conversion of mannose to fructose by immobilized mannose isomerase from Pseudomonas cepacia.

The enzyme mannose isomerase (EC 5.3.1.

Regulation of beta-1, 4-Glucosidase Expression by Candida wickerhamii.

Candida wickerhamii NRRL Y-2563 expressed beta-glucosidase activity (3 to 8 U/ml) constitutively when grown aerobically in complex medium containing either glycerol, succinate, xylose, galactose, or cellobiose as the carbon source. The addition of a high concentration of glucose (>75 g/liter) repressed beta-glucosidase expression (<0.3 U/ml); however, this yeast did produce beta-glucosidase when the initial glucose concentration was View Article and Find Full Text PDF

Induction of NADPH-linked D-xylose reductase and NAD-linked xylitol dehydrogenase activities in Pachysolen tannophilus by D-xylose, L-arabinose, or D-galactose.

Considerable interest in the D-xylose catabolic pathway of Pachysolen tannophilus has arisen from the discovery that this yeast is capable of fermenting D-xylose to ethanol. In this organism D-xylose appears to be catabolized through xylitol to D-xylulose. NADPH-linked D-xylose reductase is primarily responsible for the conversion of D-xylose to xylitol, while NAD-linked xylitol dehydrogenase is primarily responsible for the subsequent conversion of xylitol to D-xylulose.

Characterization of cellobiose fermentations to ethanol by yeasts.

Twenty-two different yeasts were screened for their ability to ferment both glucose and cellobiose. The fermentation characteristics of Candida lusitaniae (NRRL Y-5394) and C. wickerhamii (NRRL Y-2563) were selected for further study because their initial rate of ethanol production from cellobiose was faster than the other test cultures.

Biomass conversion: fermentation chemicals and fuels.

Recent events clearly establish that petroleum can no longer be relied upon as a stable, economical raw material for energy and industrial chemicals. Plant biomass is currently being evaluated as a desirable alternative raw material to petroleum because of renewability and abundance. The most abundant form of biomass on the planet earth is lignocellulose which is composed of cellulose, hemicellulose, and lignin.

Continuous and static fermentation of glucose to ethanol by immobilized Saccharomyces cerevisiae cells of different ages.

Glucose was converted to ethanol by calcium-alginate-entrapped Saccharomyces cerevisiae NRRL Y-2034 cells that were 24, 48, 72, and 96 h old in continuous-flow and static repeated-batch fermentors. In general, older yeast cells were more efficient than younger ones. In most cases, the continuous fermentations were better than the static ones in producing maximum ethanol yields (5.

Ethanol production by immobilized Saccharomyces cerevisiae, Saccharomyces uvarum, and Zymomonas mobilis.

Saccharomyces cerevisiae NRRL Y-2034, S, uvarum NRRL Y-1347, and Zymomonas mobilis NRRL B-806 each were separately immobilized in a Ca-alginate matrix and incubated in the presence of a free-flowing and continuous 1, 3, 5, 10, or 20% (w/w) glucose solution. In general, the yeast cells, converted 100percnt; of the 1, 3, and 5% glucose to alcohol within 48 h and maintained such a conversion rate for at least two weeks. The bacterium converted ca.

Bioconversion of wheat straw cellulose/hemicellulose to ethanol by Saccharomyces uvarum and Pachysolen tannophilus.

The information presented in this publication represents current research findings on the production of glucose and xylose from straw and subsequent direct fermentation of both sugars to ethanol. Agricultural straw was subjected to thermal or alkali pulping prior to enzymatic saccharification. When wheat straw (WS) was treated at 170 degrees C for 30-60 min at a water-to-solids ratio of 7:1, the yield of cellulosic pulp was 70-82%.

Decomposition of Lignocellulose by Cyathus stercoreus (Schw.) de Toni NRRL 6473, a "White Rot" Fungus from Cattle Dung.

Cyathus stercoreus (Schw.) de Toni NRRL 6473, isolated from aged and fragmented cattle dung collected from a Michigan pasture, effected substantial losses in lignin (45%) from wheat straw during a 62-day fermentation (25 degrees C). The basidiomycete also improved wheat straw digestibility by freeing alpha-cellulose for enzymatic hydrolysis to glucose (230 mg of glucose per 1,000 mg of fermented residue).

Mycoviruses of Penicillium stoloniferum: influence of carbon-nitrogen nutrition upon replication.

Carbon-nitrogen ratio experiments indicate that limiting nutrition not only hinders Penicillium stoloniferum host proliferation but reduces total PsV-F and PsV-S virus replication. Results of C-N experiments show a pH-induced autolysis and virus release at minimal C levels. Maximal PsV-F levels and biomass were obtained with glucose and sucrose as C sources.

Patulin inhibition of mycovirus replication in Penicillium stoloniferum.

Penicillium stoloniferum NRRL5267 contains two electrophoretically distinct viruses (PsV-F and PsV-S). An in vivo system was developed to test whether a number of fungal metabolites had antiviral properties on PsV-F replication in O.erties on PsV-F replication in P.

Penicillium stoloniferum virus: altered replication in ultraviolet-derived mutants.

Phenotypic mutants of the wild type of Penicillium stoloniferum NRRL5267 were obtained from conidia exposed to ultraviolet light for 60 min (10% survival). Virus content of the wild type and of nine phenotypic mutants was determined by polyacrylamide gel electrophoresis. Four mutants had no detectable Penicillium stoloniferum virus F (PsV-F), whereas the other five had levels of PsV-F in the mycelium similar to the wild-type strain.

Penicillium stoloniferum virus: large-scale concentration and purification by polyethylene glycol.

An experimental procedure developed to concentrate fungal viruses from large volumes of homogenized mycelia with water-soluble polymers, such as polyethylene glycol, possesses advantages over more conventional methods. Concentration of the Penicillium stoloniferum fast-moving virus from mycelial homogenates after addition of polyethylene glycol was rapid and produced large quantities of pure virus.

Virus particles from conidia of Penicillium species.

Virus particles and their component double-stranded ribonucleic acid (dsRNA) have been isolated from conidia and mycelia of certain Penicillium species. The conidia and mycelia of P. stoloniferum NRRL 5267 contained 75 and 85 mug of dsRNA/g (dry weight), respectively.

Mycotoxin-producing strains of Penicillium viridicatum: classification into subgroups.

Fifty-two isolates of Penicillium viridicatum Westling were divided into three groups based on ability to produce ochratoxin and/or citrinin, color, growth rate, type of growth, odor, and isolation source. Members of group I resemble one of the representative strains of P. viridicatum described in the literature; those belonging to group II differ from group I strains in several characteristics; group III is a heterogeneous series of highly variable isolates.