Bouquet of ions: glowing bacteria will allow you to choose the radiation level for animal growth

Russian scientists have proposed a new way to determine safe doses of ionizing radiation for animals. In small quantities, it can stimulate a number of physiological processes, which opens up prospects for the use of technology in agriculture. However, a positive effect is achieved only in a narrow range of doses, which can be determined by bacteria: the intensity of their glow varies depending on the level of radiation. At the same time, the complexity of the animal's body and individual reactions to low-dose exposure may make it difficult to implement the technology on an industrial scale, experts warned.

Why low radiation can be useful

Scientists from the Institute of Biophysics of the Siberian Branch of the Russian Academy of Sciences, Siberian Federal University and Krasnoyarsk State Agrarian University have proposed a rapid bacterial test to determine the optimal levels of ionizing radiation to animals.

As the researchers explained, exposure in the range of tens to hundreds of milligrees (mGr) can activate a number of physiological processes, including metabolism, growth and accumulation of biomass. The use of such technologies can open up new perspectives in animal husbandry, veterinary medicine and related fields. However, exceeding the permissible doses, on the contrary, leads to functional depression. The development will make it possible to identify such risks in a timely manner and prevent them.

— Stimulation by small amounts of stress factors is described by the hormesis model. This is a process in which organisms, reacting to external influences, strive to find a new balance and bring the system into balance," Nadezhda Kudryasheva, a leading researcher at the Siberian Branch of the Russian Academy of Sciences, Professor of the Department of Biophysics at SibFU, told Izvestia.

According to her, this ability underlies the vital activity of the body: as long as it is able to compensate for external loads, it remains viable. With age, these opportunities decrease. Therefore, in the practical application of small doses of radiation, it is important not to exceed the thresholds after which the toxic effect begins.

In the experiment, experts compared the effects of radiation on bacteria and rabbit cells. The source of the radiation was tritium water, a liquid whose molecules contain radioactive isotopes of hydrogen. Marine luminous bacteria were used as a test system: the intensity of their glow varies markedly depending on the level of radiation exposure.

How to choose a safe radiation dose

As a result of the study, scientists have established that animal blood cells and bacteria react in a similar way to radiation exposure. In particular, the activity of leukocytes, white blood cells whose activity serves as one of the main indicators of the immune response, varied according to the same pattern as the intensity of the glow of bacteria: activation was observed at low doses, and suppression was observed with increasing radiation levels. At the same time, the bacteria reacted to significantly lower doses of radiation than animal cells.

— We compared the reactions of bacteria and higher organisms. It turned out that their cellular processes follow common patterns. This means that a quick bacterial test can serve as an early indicator of risks," explained Nadezhda Kudryasheva.

According to experts, the development will make it possible to quickly select safe stimulating radiation doses for farm animals. However, at the current stage, due to the fundamental differences between bacteria and complex organisms, the possibilities of the method should be limited to predicting cellular processes. For example, it can be used to assess how radiation will affect the activity of immune cells. In the future, the method can also be adapted for environmental monitoring and prevention of consequences of radiation accidents.

— Low-dose radiation technologies are actively used to reduce the bacterial load on food products in order to increase their shelf life, as well as to sterilize products. The possibilities of using radiation exposure to reduce the germination time of plants are being explored," explained Deputy General Director for Science of JSC NIITFA (part of Rosatom) to Izvestia Marat Ismagilov.

According to the expert, it is safe if the established requirements are met. Before the industrial application of radiation treatment, the effects on products, including their taste, smell and structure, are investigated. The technology is put into industrial operation only after confirming the absence of risks to consumer health and significant changes in product characteristics.

— The word "radiation" is strongly associated with a threat. Overcoming this fear requires explanatory work. The safety of meat and milk obtained using such stimulation is a well—studied issue. It is important to understand that there is no conversion of stable elements into radioactive elements (induced radioactivity) during irradiation. This effect is possible only when exposed to very high—energy particle fluxes," said Lyudmila Komarova, Head of the Department of Biology at the Obninsk Institute of Atomic Energy at the National Research Nuclear University MEPhI.

According to her, extensive evidence has been accumulated that low and medium levels of ionizing radiation can stimulate the growth and survival of plants, bacteria, insects and mammals, as well as enhance the immune response and resistance of organisms to mutagenic factors.

However, there is still little data on the use of such technologies in animal husbandry. One of the difficulties lies in the unpredictability of the positive effect: it is necessary to get into a narrow range of doses, which must be determined separately for each type. So far, low-dose radiation stimulation is inferior to traditional methods such as breeding and fertilization.

According to Sergey Titov, Head of the Department of Zoology and Ecology at Penza State University, the main problem is related to the individual reactions of organisms to low-dose radiation. Therefore, it will be difficult to achieve the same result in industrial applications.

— Bioassays on luminous bacteria are effective primarily as a tool for rapid primary screening. They are used in pharmacology, radiobiology and water quality control. They are sensitive, relatively inexpensive, easily standardized, and allow for simultaneous examination of a large number of samples," he noted.

However, bacteria and mammalian cells differ in their metabolism, DNA repair mechanisms, and other parameters. In this regard, the high sensitivity of the test does not mean that the forecast is accurate. In addition, the intensity of the glow can be influenced by temperature, acidity and composition of the medium, as well as the state of the bacterial culture. Thus, the dose range determined by the test will need to be further checked and refined on animal cells.