In fisheries, antibiotics are usually used to prevent infections. However, their use leads to the emergence of strains of bacteria resistant to them. This is a potential threat not only to fish but also to humans – in case that antibiotic-resistant bacteria begin to be transmitted from person to person. Researchers are looking for alternative drugs suitable for use in ichthyology.
Morteza Yousefi, a biologist from the RUDN University, and his colleagues investigated the properties of Zizyphus (Zizyphus jujube), known as "Chinese date" and found that it can be used as an antimicrobial agent for fish.
Morteza Yousefi tested the immunostimulatory properties of this plant on carp (Cyprinus carpio). The biologists gave the fish a solution of ethanol and distilled water with Ziziphus fruit juice with a concentration of 0.25%, 0.5%, and 1%. Then they took samples from the fish mucosa and monitored how immune parameters change: the number of antibodies, the activity of enzymes – proteases and the expression of genes of signaling molecules – cytokines, which, in particular, trigger phagocytosis, that is, the destruction of bacteria.
Analysis of the data showed that carp, which were given a solution of the fetus with a concentration of 0.5%, increased the number of antibodies. The more antibodies in the blood, the more extraneous compounds – antigens – they can "catch".
Besides, ichthyologists have found a connection between the extract of dates in the diet of fish and the presence of cytokines. The experiment showed that the concentration of the solution is 0.25% does not change the immune reactions of carp, but 0.5% and 1% solution increases the expression of cytokine genes and the activity of protease enzymes that are involved in the "digestion" of killed pathogenic bacteria and in triggering the processes of extraneous cells death (apoptosis).
The results are published in the journal Fish and Shellfish Immunology.
A chemist from RUDN University has developed a catalyst for the production of eugenol acetate, a substance that destroys the larvae of mosquitoes transmitting dangerous diseases, being a safe chemical for human health.
RUDN soil scientists have revealed a direct correlation between the rate of soil formation of carbon dioxide, called CO2 emissions, and the content of microbial biomass in it. It is known that CO2 emission from soil is mainly conditioned by respiration of soil microorganisms and plant roots. The more CO2 soil emits, the more microbial biomass it usually contains. It was shown that CO2 emission by chernozem of different ecosystems (or different types of land use) correlates with the content of microbial biomass, and most closely with the rate of its microbial respiration. And the soil with good microbial properties has the “best quality”, is more fertile, provides the highest yield of crops and other plant biomass.
A RUDN chemist has synthesized a catalyst for the production of gamma-valerolactone — an energy-intensive “green” biofuel. The catalyst based on zirconium dioxide and zeolite has shown high efficiency in converting the waste of wood plant materials — methyl levulinate — to gamma-valerolactone.