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Biomedical subjects

F Nerud

Publications and source records attributed to F Nerud.

29 records · Page 2Linked to original sources
PubMed1996

The effect of white-rot basidiomycetes on chemical composition and in vitro digestibility of wheat straw.

Five white-rot basidiomycetes were evaluated for their potential to improve ruminal degradation of wheat straw. Polyorus brumalis, Lyophyllum ulmarium III, Trametes gibbosa, Pleurotus ostreatus, and a Pleurotus ostreatus mutant were incubated on wheat straw for 30 d at 28 degrees C. Detergent fiber, crude protein and in vitro dry matter digestibility (IVDMD) were determined. The results showed increasing crude protein and ash contents in fungus-treated straw. IVDMD values were increased in straws treated with P. ostreatus, P. ostreatus mutant and T. gibbosa only. Relative to untreated wheat straw the detergent fiber content-neutral detergent fiber (NDF), and acid detergent fiber (ADF) was reduced in fungus-treated straw and out of three fractions-hemicellulose, cellulose, and lignin, hemicellulose showed the largest proportionate loss whereas lignin the smallest one in all 5 samples of fungus treated straw.

Animal Feed↗
PubMed1996

Effect of white-rot basidiomycetes-treated wheat straw on rumen fermentation in artificial rumen.

This study evaluated three white-rot basidiomycetes for their potential to improve the ruminal degradation of wheat straw. Pleurotus ostreatus (PO), Pleurotus ostreatus-mutant (PO-M) and Trametes gibbosa (TG) were incubated on wheat straw for 30 days at 28 degrees C. Neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein and in vitro dry matter digestibility (IVDMD) were determined. The results demonstrated increasing crude protein and ash contents (%) in the fungi-treated straws. The IVDMD values were also increased. Compared to untreated wheat straw (UWS), the NDF and ADF contents were reduced in fungi-treated straw (TWS). Out of the three fractions-hemicellulose, cellulose and lignin-hemicellulose showed the largest proportionate loss and lignin the smallest in all three fungi-treated straws. TWS with Pleurotus ostreatus (TWS-PO), Pleurotus ostreatus-mutant (TWS-PO-M) and Trametes gibbosa (TWS-TG) together with barley (80:20%) were used as the experimental diets in the artificial rumen. UWS with barley (80:20%) served as the control diet. The results revealed significantly higher IVDMD values, NDF, ADF and cellulose digestibilities (%) with the experimental diets. The production of propionic acid decreased, n-butyric, n-valeric and isovaleric acids (mmol/day-1) increased and the volatile fatty acid (VFA) production expressed in mol VFAs.kg-1 digested dry matter decreased in experimental diets. The total microbial production also decreased at fermentation in the experimental diets.

Animals↗
PubMed1994

Degradation of wood by the basidiomycete Coriolopsis occidentalis.

Chemical and microscopic features of wood decay by the basidiomycete Coriolopsis occidentalis are described. The fungus was grown on blocks of poplar, oak, and fir wood and caused significant mass, lignin, and saccharide losses in all kinds of wood. Poplar wood was particularly strongly affected. Twelve weeks after inoculation dry mass, lignin, and saccharide contents were reduced by about 50%. The blocks became covered with mycelia and electron microscopy showed that secondary cell walls were degraded from the lumina and middle lamellae dissolved during later stages of incubation. The results indicate that the fungus belongs to simultaneous white-rotters.

Basidiomycota↗
PubMed1985

Glucose-2-oxidase activity in mycelial cultures of basidiomycetes.

The activity of intracellular glucose-2-oxidase was tested in 40 species of 26 basidiomycete genera. The enzyme catalyzing the oxidation of D-glucose to the dicarbonyl sugar D-arabino-2-hexosulose was demonstrated in mycelial extracts of 9 species of Aphyllophorales and 6 species of Agaricales cultivated in liquid media. In the majority of species exhibiting this activity hexosulose was detected in the cultivation medium. The highest enzyme activity was detected in Oudemansiella mucida, Coriolopsis occidentalis, Fomes fomentarius, Trametes versicolor and a not-yet-classified species of the genus Trametes.

Basidiomycota↗
PubMed1982

Metabolism of aromatic acids in the antibiotic-producing basidiomycete Oudemansiella mucida.

Aromatic acids were determined in the mycelium and fermentation medium of Oudemansiella mucida. Coumaric acids (both m- and p-), p-hydroxybenzoic acid (salicylic acid) and benzoic acid were found to predominate in the mycelium. Phenylacetic acid represents the main component in the medium. Phenylalanine ammonia-lyase catalyzing conversion of phenylalanine to cinnamic acid which is further metabolized to benzoic acid was detected in the mycelium. The results are discussed with respect to the synthesis of the antibiotic mucidin.

Alkenes↗
PubMed1982

Effect of tryptophan on the production of mucidin in cultures of basidiomycete Oudemansiella mucida.

Addition of L-tryptophan to cultures of the basidiomycete Oudemansiella mucida brought about a pronounced increase of production of the antibiotic mucidin. The highest increase was reached in the presence of 0.15-0.20% tryptophan and after its addition to a l-d culture. The methyl ester of tryptophan exhibited the same effect. Mycelium growing during the initial phases in the presence of tryptophan synthesized mucidin powerfully during later phases of the fermentation.

Alkenes↗
PubMed1982

Effect of glucitol on the production of mucidin in Oudemansiella mucida.

When studying the biosynthesis of mucidin under production (glucose as the main carbon source) and non-production (glucitol as the main carbon source) conditions it could be shown that the producer, Oudemansiella mucida, utilizes glucitol both for growth and for mucidin biosynthesis. However, the production of mucidin is 10 times lower than on glucose. When the culture was preincubated on glucose and transferred to non-production conditions the negative effect of glucitol could not be demonstrated. Biosynthesis of mucidin is influenced by the used carbon source already at an early stage of the cultivation.

Agaricales↗
PubMed1978

Biosynthesis of fatty acids and sterols in relation to the antibiotic formation in Oudemansiella mucida.

The production of mucidin by the basidiomycete Oudemansiella mucida was negatively influenced by the application of D-glucitol as the main carbon source, the effect being independent of the growth rate of the mycelium. The rate of fatty acid synthesis was measured by incorporation of 1-14C-acetate. After 8 days of cultivation, the amount of fatty acids was approximately half that synthetized during cultivation on glucose. The specific rate of incorporation reached its maximum after seven days of cultivation. Incorporation of 2-14C-MEValonate into sterols was the same under the two sets of cultivation conditions. Acetate units from the degraded fatty acids are probably also utilized for antibiotic synthesis.

Acetates↗
PubMed1976

Composition of lipids and production of mucidin in a submerged culture of the basidiomycete Oudemansiella mucida.

Mycelial lipids of the submerged culture of Oudemansiella mucida contain acylglycerols, free and esterified sterols. Free fatty acids are not present. Development of the culture is associated with an increased content of unsaturated fatty acids and, on the contrary, with a decreased content of saturated fatty acids. Content of total lipids depends on age of the culture and is inversely related with production of the antibiotic mucidin.

Antifungal Agents↗
PubMed1975

Lipids in fruiting bodies of the basidiomycete Oudemansiella mucida.

Dried fruiting bodies of the basidiomycete Oudemansiella mucida contain 29.1% total lipids. Their qualitative analysis revealed the presence of mono-, di-, triglycerides, sterols, free fatty acids and sterolesters. Quantitatively most significant were triglycerides (37.9%) and free fatty acids (29.7%). The phospholipid fraction contained phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidic acid. Gas chromatography showed the presence of a broad spectrum of fatty acids. The ratio between the neutral and polar fractions was 6 : 1, both having linoleic acid as the main component.

Anti-Bacterial Agents↗