Problems 2018

The problems of the extramural stage of the International Student BioTournament 2018

Probiotics

According to WHO definition “Probiotics are live microorganisms which, when administered in adequate quantities confer a health benefit on the host”. However, at the present time there is insufficient scientific evidence proving the prevention of diseases or improving the health status of people from taking probiotics. Consider the mechanism of the therapeutic effect of probiotic drugs. Propose a scheme and, if possible, conduct an experiment demonstrating the mechanism of action of these drugs. Suggest ways to increase the therapeutic effect when taking probiotics.

Save at lunch

It looks promising to use microorganisms-producers to accumulate in the biomass the various valuable substances. To reduce the cost of such biotechnological processes waste from agricultural production is used. An example of a cheap substrate for microorganisms is the sunflower husk, which contains a large amount of cellulose. However, in the process of processing fiber in the biomass of microorganisms, toxic or allergenic for humans and animals components can be produced. Suggest ways of the biotechnological processing of sunflower husk and the use of the received nutrients in food and fodder products.

One thousand years of solitude

In the soils that develop on “permafrost”, in the zone of the tundra, various processes of cryogenic mass transfer are widespread. This is reflected in the violation of the vertical connection of soil horizons due to the formation of ice and a rather rapid burial of fragments of surface organogenic horizons deep into the profile. As a part of these fragments, migration of representatives of soil microfauna (flagellates, infusorians, amoebae, nematodes) from the surface deep into the soil can occur, where they enter the near-zero temperature regime, and sometimes enter a permafrost state.

It is known that the resting stages of a number of organisms are capable of carrying a long (hundreds and thousands of years) cryopreservation in the low-temperature conditions of deep horizons of polar soils. However, studies have shown that only certain species from the communities of the modern soil microfauna can sustain viability under such conditions.

Identify differences between species that are capable of long-term viability in low-temperature conditions and species that do not possess this capacity. Identify the factors that prevent the long-term survival of species in the community of “living fossil” organisms.