Siberian Federal University, 79 Svobodny pr, Krasnoyarsk 660041, Russia; Institute of Biophysics SB RAS, Federal Research Center “Krasnoyarsk Science Center SB RAS”, 50/50 Akademgorodok, Krasnoyarsk 660036, Russia
Aleksey V. Demidenko
Siberian Federal University, 79 Svobodny pr, Krasnoyarsk 660041, Russia; Institute of Biophysics SB RAS, Federal Research Center “Krasnoyarsk Science Center SB RAS”, 50/50 Akademgorodok, Krasnoyarsk 660036, Russia
Ivan V. Nemtsev
Siberian Federal University, 79 Svobodny pr, Krasnoyarsk 660041, Russia; Federal Research Center “Krasnoyarsk Science Center SB RAS”, 50 Akademgorodok, Krasnoyarsk 660036, Russia; L.V. Kirensky Institute of Physics, 50/12 Akademgorodok, Krasnoyarsk 660036, Russia
Ekaterina I. Shishatskaya
Siberian Federal University, 79 Svobodny pr, Krasnoyarsk 660041, Russia; Institute of Biophysics SB RAS, Federal Research Center “Krasnoyarsk Science Center SB RAS”, 50/50 Akademgorodok, Krasnoyarsk 660036, Russia
Sabu Thomas
Siberian Federal University, 79 Svobodny pr, Krasnoyarsk 660041, Russia; International and Interuniversity Centre for Nano Science and Nano Technology, Mahatma Gandhi University, Kottayam 686560, India
Tatiana G. Volova
Siberian Federal University, 79 Svobodny pr, Krasnoyarsk 660041, Russia; Institute of Biophysics SB RAS, Federal Research Center “Krasnoyarsk Science Center SB RAS”, 50/50 Akademgorodok, Krasnoyarsk 660036, Russia
The features of the degradation of the ''green'' plastic poly(3-hydroxybutyrate) [P(3HB)] in the soil of various geographical regions were studied: in red ferralitic soil under tropical conditions (Kerala, India) and in chernozem soil under conditions of a sharply continental climate (Eastern Siberia, Russia). Significant differences in the chemical composition, temperature, and humidity of the studied soils were revealed. The number of bacteria and mycelial fungi in the Siberian chernozem was higher than in the red soil of India, from 2-3 to 10 or more times. The degradation of P(3HB) films in the chernozem occurred faster than in the red soil, which was drier, with a low content of humus and minerals, and fewer microorganisms than the chernozem. The half-life of polymer samples in Siberia and India was 64.8 and 126.4 days, respectively. During degradation, a decrease in the molecular weight and an increase in the degree of crystallinity of polymer samples were revealed, which indicates a more active biodegradation of the amorphous phase of the polymer by soil microorganisms. The primary degraders of the polymer have been isolated and identified, and it has been shown that the complexes of degrading bacteria and fungi in different types of soils did not have common species. Despite the presence of species with pronounced depolymerase activity, the rate of film degradation in red ferralitic soils was slowed down by unfavorable environmental conditions. The obtained results confirm the importance of studying the process of PHA degradation in natural conditions.
