2019  1,023
2018  0,932
2017  0,977
2016  0,799
2015  0,662
2014  0,740
2013  0,739
2012  0,637
2011  0,658
2010  0,654
2009  0,570
2008  0,849
2007  0,805
2006  0,330
2005  0,435
2004  0,623
2003  0,567
2002  0,641
2001  0,490
2000  0,477
1999  0,762
1998  0,785
1997  0,507
1996  0,518
1995  0,502
Vol 54(2020) N 5 p. 757-768; DOI 10.1134/S0026893320050040 Full Text

D.S. Karpov1*, P.G. Osipova2, A.I. Domashin2, N.B. Polyakov3,4, A.I. Solovyev3, M.V. Zubasheva3, V.G. Zhukhovitsky3,5, V.L. Karpov1, S.V. Poddubko2, N.D. Novikova2

Hyper-Resistance of the Bacillus licheniformis 24 Strain to Oxidative Stress Is Associated with Overexpression of Enzymatic Antioxidant System Genes

1Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991 Russia
2State Scientific Center of the Russian Federation, Institute of Bio-Medical Problems, Russian Academy of Sciences, Moscow, 123007 Russia
3Gamaleya National Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, 123098 Russia
4Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow, 119334 Russia
5Sechenov First Moscow State Medical University, Ministry of Health of the Russian Federation, Moscow, 119991 Russia

Received - 2020-04-20; Revised - 2020-05-15; Accepted - 2020-05-15

At the International Space Station (ISS), artificial living conditions are created and maintained to satisfy human needs, these conditions are also favorable for the growth of numerous microorganisms, molds and bacteria. Among the microorganisms detected on the ISS are those from the automicroflora of crew members, and a significant number of spore-forming bacteria. In most cases, this group of microorganisms gives rise to strains that are able to colonize, grow and reproduce on interior materials and equipment of stations, and may be involved in biodestructive processes. These bacteria show increased resistance to various stress factors, for example, DNA-damaging and oxidizing agents. The molecular mechanisms of this resistance to stress are poorly understood. As part of the sanitary-microbiological monitoring of the ISS habitat, the Bacillus licheniformis 24 strain was isolated. Here, we demonstrated that this strain has increased resistance to hydrogen peroxide and Paraquat when compared to the "terrestrial" B. licheniformis B-10956 strain. B. licheniformis 24 overexpressed genes encoding enzymes that neutralize reactive oxygen species, such as KatX catalase and the superoxide dismutases SodA and SodF. Apart from this, in comparison with B. licheniformis B-10956, of B. licheniformis 24 cells had lower hydrogen sulfide production that was associated with sharply reduced expression of the cysIJ operon that encodes sulfite reductase. The results indicate that enzymatic antioxidant protective systems make a more significant contribution to the hyper-resistance of Bacillus strains to oxidizing agents than components of non-enzymatic systems, such as hydrogen sulfide.

Bacillus licheniformis 24, international space station, oxidative stress, hydrogen sulfide