Effect of carbohydrate composition of the cytosol of Aspergillus niger conidia on their viability during storage

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.     

The correlation between the synthesis of beta-carotene and zygote formation by Blakeslea trispora heterothallic strains

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.     

Fungal lycopene: the biotechnology of its production and prospects for its application in medicine

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.     

The Use of Micromycetes for Cleaning Parts of Aircraft Engines

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 operation 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 cleaner than contemporary chemical methods. Scanning microscopy was suggested for estimating the degree of decarbonization of PAE surfaces.     

Germination of Basidiospores of Agaricus bisporus

The type of dormancy and conditions necessary for germination of Agaricus bisporus basidiospores were studied. Basidiospores failed to germinate on starvation agar and required the presence of carbon and nitrogen sources (asparagine and/or glucose) in the medium. Upon 3-week storage, basidiospores germinated after 4–5 days. Heat shock (20 min at 45°C) and 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 basidiospores differing from zygospores of Mucorales. Basidiospores contained 17–19% lipids with a composition of fatty acids differing from those of the 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 basidiospores stored at 2°C, basidiospores stored for 5 months at 20°C lost their ability to germinate, which correlated with a decrease in the content of trehalose.     

Carbohydrate Spectrum of Extremophilic Yeasts <Emphasis Type="Italic">Yarrowia lipolytica</Emphasis> under pH Stress

Alterations in the concentrations of cell cytosol carbohydrates of polyextremophilic yeasts Yarrowia lipolytica under stresses of diverse nature were observed. Under pH stress, mannitol was the main storage carbohydrate (up to 89% of the total cytosol carbohydrates), while arabitol, glucose, and inositol were present in insignificant amounts (3 to 6%). Experiments with inhibition of de novo mannitol synthesis by bis(p-nitrophenyl) disulfide revealed that the cytoprotective effect of mannitol was most noticeable in the cells grown under acidic conditions (pH 4.0), while the role of catalase and superoxide dismutase, the enzymes of the first line of antioxidant protection, increased under alkaline conditions (pH 9.0). The constitutively high mannitol content in Y. lipolytica cells was hypothesized to be a part of the core mechanism of stress resistance in this yeast species.     

Gene structure,transcripts and calciotropic effects of the PTH family of peptides in <Emphasis Type="Italic">Xenopus</Emphasis> and chicken

Background  

Parathyroid hormone (PTH) and PTH-related peptide (PTHrP) belong to a family of endocrine factors that share a highly conserved N-terminal region (amino acids 1-34) and play key roles in calcium homeostasis, bone formation and skeletal development. Recently, PTH-like peptide (PTH-L) was identified in teleost fish raising questions about the evolution of these proteins. Although PTH and PTHrP have been intensively studied in mammals their function in other vertebrates is poorly documented. Amphibians and birds occupy unique phylogenetic positions, the former at the transition of aquatic to terrestrial life and the latter at the transition to homeothermy. Moreover, both organisms have characteristics indicative of a complex system in calcium regulation. This study investigated PTH family evolution in vertebrates with special emphasis on Xenopus and chicken.     

Trisporoids and carotenogenesis in Blakeslea trispora

The recent data on the pathways of carotenoid biosynthesis, which resulted in revision of the earlier concepts, are analyzed. Trisporoid diversity and their role in the sexual process of mucoraceous fungi, resulting in formation of sexual cells (zygospores) are discussed. Special attention is paid to the role of trisporic acids in carotenogenesis of combined culture of the (+) and (?) strains, in which zygospores are not formed.     

Different mechanisms of the biochemical adaptation of mycelial fungi to temperature stress: Changes in the cytosol carbohydrate composition

The effect of temperature stress on the cytosol carbohydrate composition of fungi belonging to various systematic groups was investigated. InMucorales representatives (subkingdomEomycota, phylumArchetnycota, classZygomycetes), adaptation to hypo- and hyperthermia occurs via the regulation of trehalose synthesis, although inositol is also involved in these processes inBlakeslea trispora. InAscomycota (subkingdomNeomycota), oversynthesis of mannitol and glycerol occurs under hypothermia, whereas oversynthesis of trehalose and inositol takes place under hyperthermia.Basidiomycota (subkingdomNeomycota) use two pathways of biochemical adaptation, depending on the cytosol carbohydrate composition. In the absence of sucrose, glycerol and arabitol are involved in the adaptation to hyperthermia; trehalose accumulates under hypothermic conditions (type I of regulation). Type II regulation (revealed inPleurotus ostreatus) involves sucrose rather than glycerol or arabitol. The data obtained are discussed in terms of fungal systematics and phylogeny.