Phlebia Tremellosa Research Articles

Nutritional regulation of synthetic lignin (DHP) degradation by Phlebia (Merulius) tremellosa: effects of nitrogen

Supplementary nitrogen added to cultures of Phlebia tremellosa in a nitrogen-limited synthetic medium delayed the appearance of lignin-degrading activity. It also accelerated the consumption of the carbon (energy) source by the cultures, decreasing the amount of cosubstrate available to support lignin biodegradation. Ammonium chloride, glutamate, albumin, and yeast extract all had similar effects, with small differences in the timing and extent of the lignin degradation that they allowed. Key words: lignin biodegradation, cosubstrate, nitrogen, selectivity.

Optimization of solid-state fermentation for selective delignification of aspen wood with Phlebia tremellosa

The white-rot fungus Phlebia tremellosa can delignify aspen wood and increase the accessibility of its polysaccharides to enzymatic hydrolysis, under solid-state fermentation conditions. Fermentations at the 50 g scale were conducted to provide information for the design of larger fermentations. Agitation was not required. Forced aeration was needed for delignification of wood layers more than a few millimeters thick, but air circulation between the particles was not blocked by mycelium. Shavings were the best particles size. Sterilization of the wood was essential, but preadaptation of the inoculum to growth in wood was not. Inoculum levels as low as 2% were adequate.

Antibiotics from basidiomycetes: Part 23. 1 Merulidial, an isolactarane derivative from [formula omitted][formula omitted

The structure of merulidial ( 1a), a sesquiterpenoid antibiotic produced by cultures of Merulius tremellosus has been elucidated by spectral investigations and conversion into several derivatives.

Cultivation of wood-rotting fungi on agricultural lignocellulosic materials for the production of crude protein

Ten wood-decaying fungi, eight of which were white-rot fungi, were cultivated on various agricultural wastes including straw, alkali-treated straw, straw cobs supplemented with molasses and urea, and granary waste. In submerged agitated cultures crude protein (6·25 × N) concentrations varied between 19 and 29% on granary waste, 11 and 20% on straw cobs, 6 and 20% on alkali-treated straw, 1 and 3% on newspaper, and 3 and 4% on Solka Floc cellulose, depending on the fungus. The highest protein concentration, 29·2%, was obtained with the the white-rot fungus Fomes fomentarius 80 when cultivated on granary waste. In this case, protein levels were doubled compared with the starting material. Protein concentrations of alkali-treated straw increased 7·8-fold and 7·1-fold after 10 days cultivation of the non-white-rot fungi Cylindrobasidium evolvens 58 and an Agaricales species, strain 153, respectively. The protein concentrations of residues were lower in solid-state fermentations where extracellular (enzyme) proteins were removed by extraction. The initial protein concentration of a sample of alkali-treated straw (rye straw, 2·4% NaOH) increased from 3·5 to 9·1% after treatment with the white-rot fungus Merulius tremellosus 136. In conclusion, agricultural lignocellulosic materials enriched with fungal protein may be valuable by-products if the wood-rotting fungi are used for production of extracellular enzymes.

Effect of an atmosphere of oxygen on growth, respiration, and lignin degradation by white-rot fungi

Lignin degradation by the white-rot fungi Phanerochaete chrysosporium, Coriolus versicolor, Pycnoporus cinnabarinus, Lentinus edodes, Grifola frondosa, Polyporus brumalis, and Merulius tremellosus was faster in an atmosphere of oxygen than in air. Gloeoporus dichrous, Pleurotus ostreatus, and Bondarzewia berkeleyi degraded lignin at equal rates in oxygen and in air. Increased oxygen partial pressure also stimulated carbohydrate consumption by most of the fungi. In liquid shake culture, the fungi grew as well under an atmosphere of oxygen as air. However, respiration was faster under oxygen, suggesting that the fungi required more energy for growth and maintenance in oxygen. On delignified wood, most of the fungi grew equally rapidly in air and oxygen. Apparently, the growth of these fungi in wood in air is limited by the rate of lignin degradation.

Antibiotics from Basidiomycetes. V merulidial, a new antibiotic from the Basidiomycete Merulius tremellosus Fr.

Merulidial, a new antibiotic, was isolated from the culture fluid of the Basidiomycete Merulius tremellosus Fr., strain No. WQ 568. Merulidial inhibits a variety of bacteria and fungi. In cells of the ascitic form of EHRLICH carcinoma, DNA synthesis is inhibited at lower concentration as compared to RNA and protein synthesis. Merulidial shows mutagenicity when incubated with the his-mutant TA 100 for Salmonella typhimurium (B.N.AMES). The molecular formula as determined by high resolution mass spectrometry is C15H20O3.

Selective Degradation of Wood Components by White‐Rot Fungi

AbstractIn order to find naturally occurring white‐rot fungi which preferentially degrade lignin. 25 different species of such fungi were cultivated on pine wood blocks and on kraft lignin agar plates with and without cellulose. Due to differences in phenol oxidase reactions on the kraft lignin agar plates, the 25 fungi could be divided into two groups, 1 and 2, which also differed in other properties. The three Group I fungi Sporotrichum pulverulentum, Phanerochaete sp. L1 and Polyporus dichrous produced high levels of endo‐l,4‐β‐glucanase and cellobiose:quinone oxidoreductase in shaking cellulose flasks and a low level of phenol oxidase in standing wood meal flasks, The four fungi Merulius tremellosus, Phlebia radiata, Pycuoporus cinnabarinus and Pleurotus ostreatus from Group 2, on the other hand, produced low levels of endo‐1,4‐β‐glucanase and cellobiose:.quinone oxidoreductase in the cellulose. flasks and a high level of phenol oxidase in the wood meal flasks.Analyses of pine wood blocks degraded by the above‐mentioned fungi in the presence of either malt extract, asparagine or NH4H2PO4 revealed that malt extract gave good lignin degradation. In the presence of this nutrient source. P. cinnabarinus, at 3.4% weight loss, even degraded 12.5% lignin without loss of cellulose or mannan. No common degradation pattern was, however, obtained using mall extract, asparagine or NH4H2PO4, It is suggested that while‐rot fungi, which preferentially degrade lignin, may be found among Group 2 fungi producing large amounts of phenol oxidases.

Organic acid production by Basidiomycetes. 3. Cultural conditions for L-malic acid production.

Cultural conditions were examined for the purpose of increasing yields of l-malic acid by the Basidiomycetes Schizophyllum commune and Merulius tremellosus, which have the ability to produce this acid as a main product in CaCO(3)-containing medium in shaken culture. The most favorable nitrogen sources selected were 0.3% (NH(4))(2)SO(4) and 0.18% NH(4)Cl. Effective combinations of inorganic salts in the medium were 0.1% KH(2)PO(4), 0.05% MgSO(4).7H(2)O, and 0.05% KCl, and suitable concentrations of glucose were 5 to 10%. Several nonionic surface-active agents promoted the filamentous mycelial growth of these strains and increased acid production. In particular, Tween 80 in 0.3% concentration markedly stimulated malic acid production by S. commune, and yields greater than 50% based on available glucose, were obtained after 10 to 14 days. Acid production by M. tremellosus was stimulated most with 0.5% Carbowax 4000 (polyethylene glycol), and the resultant yields were more than 40%.

Organic acid production by Basidiomycetes. I. Screening of acid-producing strains.

Sixty-seven strains belonging to 47 species of Basidiomycetes were examined for their acid-producing abilities in glucose media, in both the presence and absence of CaCO(3), in stationary and shake cultures. Some strains were found to produce large quantities of oxalic acid. The oxalic acid-producing strains could be separated into two groups. Strains of one group (mostly brown-rot fungi) were able to produce oxalic acid, regardless of whether CaCO(3) was present in the medium. Strains of the other group (mostly white-rot fungi) were characterized by their ability to produce oxalic acid only when CaCO(3) was added to the medium. With the latter group, shake-culturing was generally more effective than stationary culturing in respect to acid production. In the CaCO(3)-containing media, Schizophyllum commune, Merulius tremellosus, and Porodisculus pendulus were found to produce substantial amounts of L-malic acid as a main metabolic product, along with small quantities of oxalic and other acids in shake cultures. Especially, S. commune and M. tremellosus may be employed as malic acid-producing species.

Organic Acid Production by Basidiomycetes

Sixty-seven strains belonging to 47 species of Basidiomycetes were examined for their acid-producing abilities in glucose media, in both the presence and absence of CaCO3, in stationary and shake cultures. Some strains were found to produce large quantities of oxalic acid. The oxalic acid-producing strains could be separated into two groups. Strains of one group (mostly brown-rot fungi) were able to produce oxalic acid, regardless of whether CaCO3 was present in the medium. Strains of the other group (mostly white-rot fungi) were characterized by their ability to produce oxalic acid only when CaCO3 was added to the medium. With the latter group, shake-culturing was generally more effective than stationary culturing in respect to acid production. In the CaCO3-containing media, Schizophyllum commune, Merulius tremellosus, and Porodisculus pendulus were found to produce substantial amounts of L-malic acid as a main metabolic product, along with small quantities of oxalic and other acids in shake cultures. Especially, S. commune and M. tremellosus may be employed as malic acid-producing species.