Myrothecium
Myrothecium is a plant pathogen.Myrothecium verrucaria is common throughout the world. It has frequently been found on materials such as paper, textiles, canvas and cotton. It is an extremely potent cellulose decomposer. It has been formulated into a pesticide for control of nematodes and weeds. This pesticide active ingredient is a mixture of the killed fungus, Myrothecium verrucaria, and the liquid in which the fungus was grown. This dead fungus kills specific parasitic microscopic pests called nematodes, which attack plants, usually through their roots. The active ingredient is specific, being effective only against nematodes that parasitize plants; it does not harm free-living nematodes. Because the mixture may be toxic to aquatic organisms, it is not approved for use in or near bodies of water. No harmful effects to humans are expected as long as applicators protect their eyes and skin from contact with pesticide products that contain this active ingredient. Spores of the fungus Myrothecium verrucaria are cryptic to maltose and isomaltose. Induction of a transport system can be effected by several sugars whose order of effectiveness is: turanose > maltulose > sucrose > D-arabinose, D-fructose, nigerose, maltotriulose, kestose > melezitose, raffinose, nystose, and stachyose. The transport system is not specific to maltose and isomaltose, and it is apparently identical to an induced trehalose permease described previously. Induction of the permease is markedly influenced by spore age—older spores being more responsive. Pure maltose is not absorbed by spores. Absorption of commercial reagent-grade maltose is due to permease induction by maltulose as an impurity. Maltulose contamination of maltose was demonstrated by charcoal column chromatography and comparison of its physical, chemical, and permease-inductive properties with those of authentic maltulose. Maltose accumulates temporarily in spores after absorption and then decreases, although no conversion to glucose can be detected. Although spores contain small quantities of maltase, metabolism of maltose may be via some nonhydrolytic pathway.