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The processes of lipid synthesis and decomposition in Aspergillus niger under conditions of heat shock (HS) were studied in a pulse-chase experiment with 14C-labeled sodium acetate. HS (60 min) resulted in the synthesis of phospholipids and sphingolipids intensified compared tothe.control, as was evident from incorporation of the labeled substrate. The same pattern was observed for neutral lipids, especially for triacylglycerides, while incorporation of the label into sterols remained almost the same. Further cultivation for 3 h in the medium without the labeled substrate resulted in a significant decrease of the label content in the membrane lipids of both the control and the experiment, although under HS conditions this decrease was much more pronounced, especially for phosphatidylcholines and phosphatidylethanolamines. A threefold increase of the label content in phosphatidic acids was observed only under HS conditions. These results indicate more intense metabolism of the membrane lipids under heat shock and suggest the degradation of the major cell phospholipids as the factor responsible for the increased level of phosphatidic acids in A. niger mycelium.

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Phosphatidylethanolamine is the main phospholipid of Agaricus bisporus basidiospores obtained under sterile conditions from young basidiomes with closed partial veils. Storing the basidiospores for five months at room temperature resulted in a complete loss of their germinating capacity. Conversely, storing them at a low temperature increased their germination rate by 15-20%. At both temperature levels, the phosphatidylcholine ratio significantly increased during storage to the level found in mature basidiospores. In addition, a drastic (8-10-fold) decrease in trehalose content occurred after two months of storage at room temperature. The trehalose content decreased only 1.5-fold at low temperatures. The involvement of trehalose and lipids in the retention of spore viability is discussed.

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It was demonstrated for the first time that the level of carotenogenesis by the heterothallic Blakeslea trispora strains intensively forming zygospores decreased under conditions of a surface cocultivation during their sexual interaction as compared with the strains grown separately. On the contrary, carotenogenesis was stimulated during a sexual interaction of the strains incapable of forming zygotes. In a submerged culture, the zygote-forming pairs of strains synthesized a considerably larger amount of trisporic acids but a smaller amount of carotenoids than the strains not forming zygospores. The discovered inverse dependence between zygote formation and carotenogenesis allowed us to suggest the inability to form zygotes as a criterion for selecting carotenogenic strain pairs.

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The change of the content and composition of the chitin-glucan complex (CGC) of the ascomycete Aspergillus niger during its development has been studied. In submerged mycelium, the complex is dominated by glucan, whereas chitin is predominant in sporophores and spores. The highest CGC content has been noted in sporophores in the terminal phase and in submerged mycelium in the idiophase; i.e., before the formation of dormant cells. On the grounds of the correlation of the content and composition of lipids, protecting carbohydrates, and CGC, it is suggested that cell wall structural polysaccharides are involved in biochemical adaptation to adverse factors.

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This article deals with the lycopene of mycelial fungi. It pays special attention to its physical and chemical properties, occurrence in nature, biological functions, and the biotechnology of lycopene production. Data are presented concerning the medically important properties of lycopene and the drug Mycolycopene prepared on its basis. Its prospective use in the therapy of prostate cancers is discussed.

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Lipid compositions in mycelium and spores of Blakeslea trispora heterothallic strains were studied. Distinctions between the strains in the ability to synthesize linolenic acid and in optimal growth temperature were demonstrated. The (-) strain grew at a higher temperature and was unable to synthesize linolenic acid, whereas the (+) strain accumulated this acid up to 20% of total fatty acids. The distinctions between the strains remained at different developmental stages (mycelium and spores). A higher thermophilicity of the (-) strain correlated with a high sterol content, which is typical of thermophilic fungi. The lipid compositions of heterothallic strains studied differed in lipid content, their fractional composition, the degree of unsaturation, and carotenoid composition.

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The role of lipids and carbohydrates in the adaptation of Flammulina velutipes to hyperthermia (5 to -5 degrees C) in natural environments has been studied for the first time. The main changes are were found to occur in membrane lipids: the levels of sterols and glycolipids decreased, and the proportion of phospholipids with a high degree of nonsaturation (2.2) increased, which was due to predominance of two fatty acids, linoleic (35% of the total) and linolenic (50%). Phosphatidylcholine became the major phospholipid. Under hypothermic conditions, glycerol, known to have antifreeze properties, accumulated in the cell cytosol along with arabitol and trehalose. The significance of this biochemical strategy in the resistance of the fungus to temperatures below zero (i.e., to cryobiotic conditions) is discussed.

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Evidence obtained with industrial beta-carotene-superproducing (+)T and (-)T strains, which fail to form zygotes, suggests that the lipids in the mycelium of the (-) strain of Blakeslea trispora lack linolenic acid. This circumstance apparently accounts for the fact that the (+) and (-) strains of B. trispora use different adaptive mechanisms to cope with an increase or decrease in cultivation temperature. In the (+) strain, temperature adaptation is based on changes in the ratio between linoleic and linolenic acyls and, also, involves shortening of acyl chains. In addition, the (+) strain contains a larger amount of protective carbohydrates, such as arabitol and trehalose. This strain is characterized by the presence of glycerol, a cryothermoprotector that protects fungal cells at low temperatures. The (-) strain lacks these biochemical mechanisms, but its neutral lipids contain a comparatively high amount of sterols and their esters. These facts enable us to interpret the enhanced thermotolerance of the (-) strain and its capacity to grow at high temperatures in terms of biochemical adaptation. In the light of the data obtained with wild-type and industrial strains, it is suggested that the lack of linolenic acid in the lipids should be considered an essential sex-specific property of the heterothallic strains of Blakeslea trispora.

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It is shown that the rate of sporogenesis, the appearance of low-molecular-weight thiols, and the activation of carbohydrate synthesis in spores adversely affected the viability of Aspergillus niger conidia during storage. Conversely, the prevalence of trehalose over mannitol and the absence of glycerol, erythritol, and glucose in carbohydrate composition facilitated viability of conidia. The data obtained are discussed in regard to the biochemical criteria that may be used to characterize quiescent state of fungi and retaining the viability of the inoculum.

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The type of dormancy and conditions necessary for germination of Agaricus bisporus basidiospores (BS) were studied. BS failed to germinate on starvation agar and required the presence of carbon and nitrogen (asparagine and/or glucose) sources in the medium. Upon 3-week storage, BS germinated after 4-5 days. Heat shock (20 min at 45 degrees C) and the decreased temperature facilitated activation of germination. Heterocyclic compounds stimulating germination of endogenously dormant spores, such as furfural, failed to activate germination. The data obtained suggested an endogenous dormancy of A. bisporus BS differing from zygospores of Mucorales. BS contained 17-19% lipids with a composition of fatty acids differing from those of pileus and stipe of the fruiting body. The soluble carbohydrates of the cytosol amounted to 12% dry spore weight and consisted of mannitol (74%) and trehalose (26%). Unlike BS stored at 2 degrees C, the BS stored for 5 months at 20 degrees C lost their ability to germinate, which correlated with a decrease in the content of trehalose.

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Changes associated with zygospore formation in the mucorous fungus Blakeslea trispora were studied. Zygospores are dormant cells with thickened cell walls and large central lipid vacuoles containing large amounts of lycopene. We established for the first time that B. trispora gametangia of different sexes differ in their carotenoid content and revealed that zygote formation involves a novel structure that consists of densely intertwined hyphae. Using inhibitory analysis (blocking beta-carotene synthesis with diphenylamine and 2-amino-6-methylpyridine), we showed that suppression of carotene production results in the inhibition of zygote formation. Hence, we established a manifest dependence of zygote formation on beta-carotene synthesis.

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Data on the lipid composition and carbohydrate composition of Aspergillus niger conidia make it possible to characterize the individual germination stages and differentiate between the conidia capable of germination and those that lost the germination capacity. The following criteria are proposed: the ratio of phosphatidylcholine and phosphatidylethanolamine, the ratio of mannitol and arabitol, and the levels of sterols and free fatty acids. The role of these compounds in the biochemical background of cell transition from dormancy to active metabolism and their use as indices of the quality of inocula in biotechnological processes are discussed.

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We revealed differences in the lipid and carbohydrate composition between cells of mucorous fungi during endogenous and exogenous dormancy. Endogenous dormancy (zygospores) is characterized by high contents of phosphatidylcholine (about 70% of total phospholipids) and triacylglycerol (over 90% of total neutral lipids). By contrast, exogenous dormancy (sporangiospores) is accompanied by elevated amounts of sterols, sterol esters, and free fatty acids, which account for over 70% of total neutral lipids. We established for the first time significant differences in the phospholipid composition between sporangiospores obtained from stylosporangia and sporangioles. Based on the data obtained, we regard the retardation of life-sustaining activities as a biochemical adaptation based on the dormancy state. We also discuss the taxonomical position of B. trispora.

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The mycelial Fungi Penicillium funiculosum, P. citrinum, P. expansum, P. chrysogenum, Aspergillus ochraceus, A. alliaceus, A. luchaensis, A. flavus, and A. niger were isolated from enrichment cultures. These fungi actively destruct carbon deposits formed during exploitation of aircraft. A biotechnological method for removing fouling from parts of aircraft engines (PAE) was developed. This method is less laborious, more rapid and ecologically clean than contemporary chemical methods. Scanning microscopy was suggested to use for estimating the degree of decarbonization of PAE surfaces.

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