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Novel insight into the role of thiamine for the growth of a lichen-associated Arctic bacterium, Sphingomonas sp., in the light
Korean J. Microbiol 2019;55(1):17-24
Published online March 31, 2019
© 2019 The Microbiological Society of Korea.

Nhung Pham, Khoi Pham, ChangWoo Lee, and Sei-Heon Jang*

Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan 38453, Republic of Korea
Correspondence to: E-mail:; Tel.: +82-53-850-6462; Fax: +82-53-850-6469
Received January 28, 2019; Revised March 14, 2019; Accepted March 14, 2019.
Bacteria in the polar region are under strong light and ultraviolet radiation. In this study, we investigated the effects of light on the growth of a psychrophilic bacterium, Sphingomonas sp. PAMC 26621, isolated from an Arctic lichen Cetraria sp. The growth of the strain in the light was lower than that in the dark. Surprisingly, thiamine increased the growth of Sphingomonas sp. PAMC 26621 in M9 minimal medium under light conditions. Thiamine increased the growth of the strain in a concentration-dependent manner along with ascorbic acid. N-acetylcysteine had no effect on the growth of the strain in the light. Thiamine and ascorbic acid also increased the activities of glucose-6-phosphate dehydrogenase and superoxide dismutase. The results of this study indicate that thiamine provided by the lichen symbiosis system plays an important role in light-induced oxidative stress in this Arctic bacterium as an antioxidant. Our study provide insight into the biochemistry and physiology of Arctic bacteria under strong light and ultraviolet radiation.
Keywords : Sphingomonas sp. PAMC 26621, ascorbic acid, light, NADPH, thiamine

March 2019, 55 (1)