Mycelial structures

The perceived sensitivity of plant cells to the hydrodynamic stress associated with aeration and agitation conditions is typically attributed to the physical characteristics of the suspended cells, namely their size, the presence of a cell wall, the existence of a large vacuole, and their tendency to aggregate. Table 1 illustrates some of the differences between plant cells and other biological systems. Chalmers [19] attributed shear sensitivity in mammalian cultures at least in part to the fact that these cells occur naturally as part of a tissue, surrounded by other cells. The same is true for plant cells. The more robust microbial systems, on the other hand, exist in nature as single organisms or mycelial structures, very close to the forms they assume in submerged culture. 

There is quite a body of scientific literature that discusses the changes (increases and well as decreases) of psilocybin and psilocin content in mushrooms as a function of their nutrient diet. And, under the 4-HO-DET entry, I mentioned that the inclusion of an unnatural component into the diet just might produce an unnatural alkaloidal product, with an exploitation of the natural and available enzyme systems that are part of the mycelial structure. 

A compound of a very similar structure is phenazinomycin (67), which has been isolated from mycelial extracts of Streptomyces sp. WK-2057 by Omura et al. [69]. This compound possesses in vivo antitumor activity against experimental murine tumor cells and cytotoxic activity against adriamycin-resistant... 

The intensive search for new organic fungicides has continued for over 30 years. The technique employed in most laboratories is to make an extensive survey of various structures by empirical methods to locate materials that suppress spore germination on glass slides or prevent mycelial growth on nutrient agar plates or rolled tubes. Those materials having an ED ] (effective dose for 50% inhibition) in (he order of 10 ppm are further tested in use applications. 

Two types of viscous fermentations exist (a) Mycelial fermentations viscosity is due to microbial network structure dispersed in a continuous phase, (b) Polysaccharide fermentation viscosity is due to polymer in an aqueous phase-homogeneous viscous liquid. 

The dioxonine subunit is a core of UK-2A, dilactone which was isolated along with the structurally similar congeners, from the mycelial cake of Streptomyces sp. 517-02 <1998TL4363, 1998T12745>. 

The rapid allocation of trace quantities of to external AM fungal hyphae provides independent support for the observations by Johnson et al. (2002a, b) that carbon transfer to mycorrhizas occurs very quickly. Staddon et al. (2003b) concluded that the turnover rate of AMF hyphae was likely to be just 5-6 days. This corresponds well with the turnover rates by absorptive hyphal structures of 5-7 days observed in Artemisia triden-tata and Oryzopsis hymenoides communities (Friese Allen, 1991). However, it is not known from the Staddon et al. (2003b) study if the carbon allocated to the AMF was used for production of mycelial biomass or allocated into compounds that are rapidly respired, in accordance with the observations of Johnson et al. (2002a, b). 

Fig. 7.2. The structure of the translocation pathway in mycelial cords. (A) Hyphae fanning out at the distal end of a cord of Phanerochaete velutina (scanning electron microscopy by A. Yarwood) (B) Internal structure of a cord of Serpula lacrymans, showing vessels and cytoplasm-filled hyphae and extracellular matrix material. (C) Diagram of the components of the translocation pathway (adapted from Cairney, 1992) V, vessel hypha f, foraging front a, anastomosis (D) A cord system in beech woodland showing both corded mycelium and diffuse growth in contact with the wood substrate.

Cairney, J. W. G., Jennings, D. H. Veltkamp, C. J. (1989). A scanning electron microscope study of the internal structure of mature linear mycelial organs of four basidiomycete species. Canadian Journal of Botany, 67, 2266-71. 

Whole cell catalysts do not need immobiUzation, especially when mycelial micro-organisms are involved, since their morphological structure allows for easy filtration and re-utihzation. Carboxylesterases bound to the mycelia of molds have been advantageously employed as biocatalysts in water and/or organic solvents the first report of the use of fungal myceha in organic solvent dates back to 1978... 

We are so used to food that has a fibrous texture that when it is homogeneous fibres have to be added. An example is Quorn , a mycoprotein produced from Fusarium, a mycelial fungus. The threads or hyphae are about 5 pm in diameter and very thin-walled. So they hardly register as giving texture. Since they can be given a variety of flavours, it makes sense to complete the illusion with texture. One way is to align the hyphae in a shear field, add some egg albumen and fix the structure with heat. Although this does not produce a hierarchical structure, and so is more similar to chicken or fish than mammalian muscle, it is nonetheless very acceptable. 

A further series of hydroxyanthraquinones were isolated by Raistrick at the same time from Helminthosporium species. These organisms are found on cereals and grasses. When Helminthosporium gramineum, the causative organisms of a leaf stripe disease of barley, was grown on a Czapek-Dox medium it imparted a deep-red colour to the medium. Under some conditions the underside of the mycelial mat was partially covered with dark-red needle-shaped crystals. The main constituent was a trihydroxyanthraquinone, helminthosporin (7.8). Its structure was... 

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