Mycelium

About: Mycelium is a research topic. Over the lifetime, 8923 publications have been published within this topic receiving 170993 citations.

Estimation of fungal biomass in a solid substrate by three independent methods

Abstract: Dry matter increase of Agaricus bisporus mycelium in liquid culture, was found to be directly proportional to quantities of fungal derived chitin and extracellular laccase for up to 28 days following inoculation. Fungal ergosterol showed a similar relationship to mycelial growth which was sustained for 56 days of culture. In cultures grown on autoclaved rye grain a correlation was found between the three biochemical indices and linear extension of the mycelium. Each method gave a similar biomass estimate for cultures grown on cereal grains.

Oxalic acid synthesis by the mycorrhizal fungus paxillus involutus (batsch. ex fr.) fr.

Abstract: Summary Oxalic acid produced by an isolate of the mycorrhizal fungus Paxillus involutus (Batsch. ex Fr.) Fr. in still broth culture was assayed using high-performance liquid chromatography. Production of oxalic acid per unit of mycelium was influenced by nitrogen source and concentrations of exogenous calcium and bicarbonate ions. Nitrate-grown mycelia produced large quantities of oxalic acid; ammonium-grown mycelia produced small quantities regardless of what other ions were present. Calcium concentrations between 10 and 50 meq 1−1 slightly enhanced oxalic acid production in the presence of nitrate; concentrations between 250 and 500 meq 1−1 depressed production. Small additions of bicarbonate ions substantially increased oxalic acids production when nitrate was present. When calcium was present, most of the oxalic acid was associated with the mycelium, probably as calcium oxalate. In the absence of calcium, most of the oxalic acid occurred free in the culture medium. It is concluded that in calcareous soils, bicarbonate and nitrate are more important than calcium in stimulating oxalate production. The significance and underlying mechanisms of oxalate production are discussed.

Functional diversity of arbuscular mycorrhizal fungal isolates in relation to extraradical mycelial networks

Abstract: Summary •W e investigated the functional significance of extraradical mycorrhizal networks produced by geographically different isolates of the arbuscular mycorrhizal fungal (AMF) species Glomus mosseae and Glomus intraradices . •A two-dimensional experimental system was used to visualize and quantify intact extraradical mycelium (ERM) spreading from Medicago sativa roots. Growth, phosphorus (P) and nitrogen (N) nutrition were assessed in M. sativa plants grown

An Antifungal Exo-α-1,3-Glucanase (AGN13.1) from the Biocontrol Fungus Trichoderma harzianum

Abstract: Trichoderma harzianum secretes α-1,3-glucanases when it is grown on polysaccharides, fungal cell walls, or autoclaved mycelium as a carbon source (simulated antagonistic conditions). We have purified and characterized one of these enzymes, named AGN13.1. The enzyme was monomeric and slightly basic. AGN13.1 was an exo-type α-1,3-glucanase and showed lytic and antifungal activity against fungal plant pathogens. Northern and Western analyses indicated that AGN13.1 is induced by conditions that simulated antagonism. We propose that AGN13.1 contributes to the antagonistic response of T. harzianum.

Hopanoids are formed during transition from substrate to aerial hyphae in Streptomyces coelicolor A3(2).

Abstract: Streptomyces coelicolor A3(2) contains a cluster of putative isoprenoid and hopanoid biosynthetic genes. The strain does not produce the pentacyclic hopanoids in liquid culture but produces them on solid medium when sporulating. Mutants defective in the formation of aerial mycelium and spores (bld), with the exception of bldB, do not synthesize hopanoids, whereas mutants, which form aerial mycelium but no spores (whi), do. The membrane condensing hopanoids possibly may alleviate stress in aerial mycelium by diminishing water permeability across the membrane.