Fungi lyophilization

Packaged as a commercial product, NPVs have a remarkable shelf life. The occluded virions, within the protective inclusion-body protein, are among the most stable entomopathogens, compared with other microorganisms and microparasites, such as bacteria, fungi, protozoa, and nematodes. In the laboratory, lyophilized, frozen, or simply refrigerated NPV inclusion bodies, stored in darkness, remain active for many years, even decades... 

Intensity of luminescence of cultures A. isolated in Krasnoyarsk area in 2007 was higher in comparison with the cultures from the Mushrooms Collection of BIN. We studied the effect of different concentrations (from 10 6 mg/mL to 1 mg/mL) of organic and inorganic toxicants on culture luminescence of 3 species of luminous fungi A. borealis, A. mellea and L. japonicus. It was shown that the mushroom A. mellea were more sensitive to action of toxicants than A. borealis and L. japonicus. The minimal concentration of benzoquinone resulted in a 21 % decrease in luminescence in comparison with the initial value, and a decrease in luminescence on 73 % was found at higher concentrations. The lowest concentration of copper ions which could be determined using this system was 10 5 mg/mL (19 % decrease in luminescence and a concentration 10"4 mg/mL caused a 33 % reduction of luminescence in comparison with the initial value) (Fig. 1,2). Lyophilized bioluminescent bacterial biosensors are popular nowadays because they are very sensitive even to micro-quantities of toxicants, and are very simple to... 

A complex is Formed with and cysteine. This complex is methylated by methylcobalamin in the presence of methionine in two steps, to yield methylmer-cury thiomethyl. Vonk and Kaars Sispesteijn (1973, 1974) found that in certain fungi the toxicity of mercury(II) chloride is greatly increased by methionine. According to these authors, this is due to the synthesis of CHjSHg— or (CHjS)jHg compounds. Synthetic methylthiomercury compounds are actually more toxic because their stronger lyophilic character enables easier penetration of the cell membrane. 

Because lichen fungi grow slowly, cultures can be kept for months or even several years before they are transferred. Vegetative mycelia have been lyophilized successfully and stock cultures of representative lichen fungi are being maintained by the American Type Culture Collection, 12301 Park-lawn Drive, Rockville, Maryland 20852. 

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