This review deals with characteristics of peptidases of fungi whose life cycles are associated with insects to varying degrees. The review examines the characteristic features of the extracellular ...peptidases of entomopathogenic fungi, the dependence of the specificity of these peptidases on the ecological characteristics of the fungi, and the role of peptidases in the development of the pathogenesis. Data on the properties and physiological role of hydrolytic enzymes of symbiotic fungi in “fungal gardens” are also considered in detail. For the development of representations about mechanisms of control over populations of insect pests, special attention is given to analysis of possibilities of genetic engineering for the creation of entomopathogens with enhanced virulence. Clarification of the role of fungi and their secreted enzymes and careful environmental studies are still required to explain their significance in the composition of the biota and to ensure widespread adoption of these organisms as effective biological control agents. The systematization and comparative analysis of the existing data on extracellular peptidases of insect-associated fungi will help in the planning of further work and the search for markers of pathogenesis and symbiosis.
•Features of the peptidases of fungi whose life cycle is associated with insects.•The relationship between the activity of peptidases, trophic behavior and virulence.•Trypsin-like peptidases as markers of the pathogenesis.•Physiological role of the peptidases of symbiotic fungi in the “fungal gardens”.•Biocontrol of insects by creation of entomopathogens with increased virulence.
•Extracellular peptidases can serve as markers of ecological features of fungi.•Asco- and basidiomycetes secrete mainly serine and metallopeptidases, respectively.•The species of pathogenic fungi ...secrete trypsin-like peptidases.•The role of secreted enzymes in proteolysis depends on community composition.
Fungi produce extracellular peptidases to break down proteins and polypeptides into smaller soluble molecules. These molecules are subsequently transported into the fungal cell, supplying osmotrophic nutrition. Although a variety of extracellular peptidases have been isolated from numerous fungal species, it remains largely unknown how the spectrum of secreted peptidases correlates with fungal ecology and taxonomy. In this study, we cultivated 17 fungal species on protein-enriched medium to compare the spectra of secreted peptidases produced by the fungi belonging to different ecological groups (pathogens, saprotrophs, symbionts) and taxonomic phyla (Ascomycota and Basidiomycota). Basidiomycetes predominantly produced metallopeptidases with neutral pH optima, while the species of ascomycetes secreted serine peptidases with alkaline pH optimum, mostly of the subtilisin-type. Fungal species with dominant activity of serine peptidases had, in general, much higher peptidase activity and were better adapted to growth on protein medium compared to the species with dominant metallopeptidase activity. Pathogenic fungi effectively cleaved the synthetic substrate specific for trypsin-like peptidases, while saprotrophic species were characterized by a relatively high aminopeptidase activity. Nevertheless, fungi have numerous genes encoding various types of peptidases, the spectra of fungal enzymes secreted on cultivation medium were to a major extent represented by the production of one class of peptidases that correlated with fungal taxonomic phylum. We suppose fungal strategies for cleaving polypeptides in experimental conditions are largely predetermined both by trophic status and phylogeny.
Proline-specific peptidases (PSP) play a crucial role in the processing of fungal toxins, pheromones, and intracellular signaling. They are of particular interest to biotechnology, as they are able ...to hydrolyze proline-rich oligopeptides that give a bitter taste to food and can also cause an autoimmune celiac disease. We performed in silico analysis of PSP homologs in the genomes of 42 species of higher fungi which showed the presence of PSP homologs characteristic of various kingdoms of living organisms and belonging to different families of peptidases, including homologs of dipeptidyl peptidase 4 (DPP4) and prolyl aminopeptidase 1 found in almost all the studied fungal species. Homologs of proliniminopeptidases from the S33 family absent in humans were also found. Several studied homologs are characteristic of certain taxonomic groups of fungi. Phylogenetic analysis suggests a duplication of ancestral DPP4 into transmembrane and secreted versions, which predate the split of ascomycete and basidiomycete lineages. Comparative biochemical analysis of DPP4 in alkaliphilic and alkali-tolerant strains of fungi showed that, notwithstanding some individual features of these enzymes, in both cases, the studied DPP4 are active and stable under alkaline conditions and at high salt concentrations, which makes them viable candidates for biotechnology and bioengineering.
We analyzed the problems of water supply for the population of global scale and regional importance. A method for the electrolysis-structural activation of water oriented on the use of initial fresh ...rainwater or desalinated membrane technology of sea water in a mix with biologically purified household sewage waters. This method can be used on sea vessels, in arid regions of the planet, and in areas with saline groundwater. Activation of water is achieved by mixing biologically purified wastewater obtained by technology that ensures the quality of purified water at the level of requirements for release in a fishery pond and desalinated water (rainwater) or obtained by reverse osmosis in a ratio of their volumes not more than 10:1
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