Biology Bulletin Reviews最新文献

Abstract—The diversity of entomopathogenic fungi, including, inter alia, members of the genus Beauveria, has been assessed insufficiently in Northwestern Russia. With respect to the contemporary taxonomical changes based on molecular markers, the available data are poor and need to be improved. We have established the species and intraspecies diversity of sixty Beauveria spp. isolates obtained from dead insects collected in Leningrad (2017), Novgorod (2018), Vologda (2018), and Pskov (2013, 2018) oblasts and in the Republic of Karelia (2017). Most fungi were isolated from beetles of the subfamily Scolytinae. Beauveria pseudobassiana was the predominant species in the studied subset (with an occurrence of 75.0%). B. bassiana (13.3%) and B. caledonica (11.7%) were isolated in smaller quantities. The latter species was considered rare for Russia; only one finding has been registered up to this time. Molecular analysis of the Bloc and tef1α loci allowed the designation of a new broad clade within B. pseudobassiana, comprised of haplotypes that had not been published in the nucleotide sequence databases previously. All other clades of the found species have a broad geographical distribution.

Abstract—The genus Colletotrichum includes a number of plant pathogens of major importance, causing diseases in a broad variety of woody and herbaceous plants. Due to recent molecular analysis, Colletotrichum spp. have undergone many taxonomic changes, i.e., introduction of a significant number of new species and abolition of some old ones. The data on the species diversity, abundance and host specialization of species in this genus on the territory of Russia and neighboring countries are obviously far from being complete, do not correspond to the modern taxonomy of the genus and require substantial revision. In this work, the molecular genetic identification and pathogenicity assessment of 35 isolates, previously identified as Colletotrichum spp., from the European part of Russia, Ukraine, Siberia, and the Russian Far East were carried out. It has been found that 12 isolates obtained from wild plants and crops belong to the species Colletotrichum coccodes. The remaining isolates belong to destructivum (14 isolates) and dematium (9 isolates) species complexes. Among the members of the destructivum complex, it was possible to identify the species C. destructivum and C. lini. C. dematium, C. lineola and Colletotrichum cf. spinaciae were defined among the isolates of the dematium complex. Three isolates of C. destructivum from wild plants of Leningrad oblast and Kamchatka, to our knowledge, are the first findings of this species for Russia. According to the results of the pathogenicity assessment, three isolates assigned to the destructivum species complex may be of interest for the biocontrol of Galinsoga parviflora, and one isolate identified as С. coccodes may be potentially used for the control of Ambrosia artemisiifolia.

Abstract

The peculiarities of the influence of cytokines and metabolites of the systemic inflammatory reaction and stress-implementing and nutritional factors contributing to the transformation of the phenotype of the resident intestinal microflora with an increase in its virulence are described. From the perspective of expression of genes and conformations of proteins and phospholipids, the influence of temperature as a signaling factor in increasing the virulence of the intestinal microbiome is considered. Evolutionarily formed mechanisms of expression of the maximum pathogenic phenotype of microorganisms and, thus, achieving an increase in their biomass and maximum dissemination through the microorganism compartments increase the probability of the transmission of commensals to another biotope, i.e., increases the probability of their survival after the death of the host organism. To prevent bacterial translocation after the relief of critical conditions, early enteral administration of β-glucans in food mixtures, iron excretion, and relief of inorganic phosphate deficiency, including by induction of alkaline phosphatase synthesis, are substantiated.

Abstract

Antibiotics have been used in clinical treatment since the mid-20th century. With the use of antibiotics, infant mortality has decreased and average life has increased by about 20 years. However, since the early years of antibiotic use, bacteria have begun to change to reduce or eliminate the effectiveness of antibiotics. Antibiotic resistance is spreading rapidly, but the mechanisms of resistance acquisition, how resistance arises, and how it can be prevented are not clearly understood. The purpose of this review is to compile information on studies of antibiotic resistance and the prevention of resistance acquisition. Spontaneous mutations are an important cause of resistance acquisition in the presence of antibiotics. One of the most commonly used methods to study how these mutations arise is adaptive resistance experiments. Using the information obtained from these experiments, it has been determined that the SOS response plays an important role in the acquisition of resistance mutations. Therefore, the SOS response could be an important target for inhibiting the acquisition of antibiotic resistance.

Abstract

The study of soil microbial biomass and enzymatic activity of natural and anthropogenically transformed ecosystems was carried out. The catenas of virgin luvisols and chernozems of the Belogorye Natural Reserve and the catenas of arable soils were studied under similar geomorphological and lithological conditions. The activities of enzymes involved in the cycles of carbon (β-glucosidase and xylosidase), nitrogen (chitinase), and phosphorus (acid and alkaline phosphatase) was studied. It has been established that a decrease in soil microbial biomass as a result of plowing is not accompanied by an equivalent decrease in the enzymatic activity of the soil. Differences in the enzymatic activity of different soils types were revealed, which indicates differences in the structure of the microbial community and the type of phytocenoses. Patterns of changes in the enzymatic activity of soils in watershed areas, in the transit and accumulative parts of catenas, have been established. The values of specific activities of enzymes (enzymatic activities per unit of microbial biomass) were calculated. The obtained patterns of changes in the specific enzymatic activity of arable soils indicate that, despite the loss of organic matter and a decrease in microbial biomass as a result of plowing, the physiological efficiency of the microbial community of agrochernozem is higher than in virgin soil. High specific enzymatic activity in arable soils is associated with higher rate of enzyme production by soil microorganisms due to land use changes.

Abstract

Cabbage, Brassica oleracea, is the leafy vegetable of Brassicaceae family. Leafy vegetables are unique among the many vegetable groups due to their high carotene and ascorbic acid content. It is consumed all over the world. Cabbage’s high nutritional value makes it more herbivores, among them Pieris brassiace is major pest causing huge damage in seedlings, vegetative and flowering stages of plant. Leaves and head of cabbage are damaged thus interfering with the growth of the plant and marketability of the cabbage. But persistent usage of artificial chemical pesticides for pest control has a number of detrimental outcomes including harm to wild species and pest resistance development. Therefore, there is need of substitute methods that are used for management of such pest that are easily biodegradable, ecofriendly and cost-effective. So, for the continuing management of this pest, effective bio-control agents should be used in conjunction with the cultural control techniques in Integrated Pest Management (IPM) systems. IPM aids in minimizing ecological damage and reliance on chemical pesticides. IPM uses different methods for pest management, i.e., natural enemies, entomopathogenic organisms and botanical insecticides that are being, reported.