Mycelium

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

Symbiotic Status, Phosphate, and Sucrose Regulate the Expression of Two Plasma Membrane H+-ATPase Genes from the Mycorrhizal Fungus Glomus mosseae

Abstract: The establishment of the arbuscular mycorrhizal symbiosis results in a modification of the gene expression pattern in both plant and fungus to accomplish the morphological and physiological changes necessary for the bidirectional transfer of nutrients between symbionts. H + -ATPase enzymes play a key role establishing the electrochemical gradient required for the transfer of nutrients across the plasma membrane in both fungi and plants. Molecular analysis of the genetic changes in arbuscular mycorrhizal fungi during symbiosis allowed us to isolate a fungal cDNA clone encoding a H + -ATPase, GmPMA1 , from Glomus mosseae (BEG12). Despite the high conservation of the catalytic domain from H + -ATPases, detailed analyses showed that GmPMA1 was strongly related only to a previously identified G. mosseae ATPase gene, GmHA5 , and not to the other four ATPase genes known from this fungus. A developmentally regulated expression pattern could be shown for both genes, GmPMA1 and GmHA5. GmPMA 1 was highly expressed during asymbiotic development, and its expression did not change when entering into symbiosis, whereas the GmHA5 transcript was induced upon plant recognition at the appressorium stage. Both genes maintained high levels of expression during intraradical development, but their expression was reduced in the extraradical mycelium. Phosphate, a key nutrient to the symbiosis, also induced the expression of GmHA 5 during asymbiotic growth, whereas sucrose had a negative effect. Our results indicate that different fungal H + -ATPases isoforms might be recruited at different developmental stages possibly responding to the different requirements of the life in symbiosis.

Nutrient compositions of culinary-medicinal mushroom fruiting bodies and mycelia.

Abstract: Mushrooms (including fruiting bodies and mycelia) are a food with high nutritional value. This article summarizes the results of proximate composition studies of 38 fruiting bodies and 19 mycelia of 32 species of culinary-medicinal mushrooms from genera Agaricus, Agrocybe, Antrodia, Auricularia, Boletus, Clitocybe, Coprinus, Cordyceps, Trametes, Dictyophora, Flammulina, Ganoderma, Grifola, Hericium, Hypsizygus, Inonotus, Lentinus, Morchella, Pleurotus, Sparassis, Termitomyces, Tremella, and Tricholoma. Based on the proximate composition, most fruiting bodies and mycelia are low in fat and rich in protein and dietary fiber (DF); however, some are rich in soluble polysaccharides and others are rich in crude fiber. Due to the high amount of DF present, the energy provided by 100 g of dry fruiting bodies and mycelia is 46.96-292.37 kcal and 195.84-373.22 kcal, respectively. The energy (100 g) is classified into four levels: first level of >300 kcal, second level of 200-300 kcal, third level of 100-200 kcal, and fourth level of <100 kcal. Most fruiting bodies are listed in the third level; nine mycelia are listed in the first level and ten in the second level. Overall, the information about the proximate composition and energy are of great interest for fruiting bodies and mycelia to be used as foods or food-flavoring materials or in the formulation of health foods.

Studies on the methylation of mercuric chloride by pure cultures of bacteria and fungi

Abstract: Small amounts of methylmercury were produced during 7 days aerobic growth in the presence of sublethal amounts of mercuric chloride by the following bacterial species studied:Pseudomonas fluorescens, Mycobacterium phlei, Escherichia coli, Aerobacter aerogenes, Bacillus megaterium. Under the same conditions methylmercury was also formed by mycelium of the fungi investigated:Aspergillus niger, Scopulariopsis brevicaulis andSaccharomyces cerevisiae. The concentration of the methylmercury produced by the various organisms did not vary much and was of the same order of magnitude as that found in Swedish experiments with lake sediments. In bacteria most of the methylmercury formed was present in the culture liquid, whereas the remainder was in or on the cells. In contrast, methylmercury formed by fungi was for the greater part present in the mycelium. The production of methylmercury byE. coli andA. aerogenes was lower under anaerobic conditions than under aerobic conditions.

Measuring external mycelia production of ectomycorrhizal fungi in the field: the soil matrix matters.

Abstract: Summary • Assessing mycorrhizal fungi production in field settings has been hindered by the inability to measure external mycelia. Recently, external mycelia production was measured in the field using a novel in-growth core technique with acid-washed sand as the in-growth matrix. Here, we tested the assumption that external mycelia production in acid-washed sand is representative of that in native soil. • External mycelia production was estimated as the difference in fungal growth between closed (allowing only saprotrophic fungal production) and open (allowing mycorrhizal and saprotrophic fungal production) cores using a factorial design of soil matrices (acid-washed sand vs native) and fertilization treatments (control vs nitrogen (N)) in a longleaf pine (Pinus palustris) plantation. • In native soils, the ectomycorrhizal to saprotrophic fungal biomass signal was strong and consistent facilitating the assessment of external mycelia production, which was 300% higher than corresponding rates in acid-washed sand and inversely correlated with soil N. • These results demonstrate the efficacy and importance of using native soil as the in-growth matrix to measure ectomycorrhizal fungi external mycelia production in field settings.