title: Adaptive response of Amphibacillus xylanus to normal aerobic and forced oxidative stress conditions.
abstract: Amphibacillus xylanus grows at the same rate and with the same cell yield under aerobic and anaerobic conditions. Under aerobic conditions, it exhibits vigorous oxygen consumption in spite of lacking a respiratory system and haem catalase. To understand the adaptive response of A. xylanus to oxidative stresses, a genomic analysis of A. xylanus was conducted. The analysis showed that A. xylanus has the genes of four metabolic systems: two pyruvate metabolic pathways, a glycolytic metabolic pathway and an NADH oxidase (Nox)-AhpC (Prx) system. A transcriptional study confirmed that A. xylanus has these metabolic systems. Moreover, genomic analysis revealed the presence of two genes for NADH oxidase (nox1 and nox2), both of which were identified in the transcriptional analysis. The nox1 gene in A. xylanus was highly expressed under normal aerobic conditions but that of nox2 was not. A purification study of NADH oxidases indicated that the gene product of nox1 is a primary metabolic enzyme responsible for metabolism of both oxygen and reactive oxygen species. A. xylanus was successfully grown under forced oxidative stress conditions such as 0.1 mM H2O2, 0.3 mM paraquat and 80 % oxygen. Proteomic analysis revealed that manganese SOD, Prx, pyruvate dehydrogenase complex E1 and E3 components, and riboflavin synthase β-chain are induced under normal aerobic conditions, and the other proteins except the five aerobically induced proteins were not induced under forced oxidative stress conditions. Taken together, the present findings indicate that A. xylanus has a unique defence system against forced oxidative stress.
authors.affiliation: Department of Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Mochizuki
authors.affiliation: Department of Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Arai
authors.affiliation: Department of Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Masazumi
authors.initials: M
authors.lastname: Asano
authors.affiliation: Department of Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Natsuki
authors.initials: N
authors.lastname: Sasakura
authors.affiliation: Department of Food Science and Technology, Tokyo University of Agriculture, Abashiri, Hokkaido 099-2493, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Nodai Genome Research Center, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Yuh
authors.initials: Y
authors.lastname: Shiwa
authors.affiliation: National Institute of Technology and Evaluation, Nishihara, Shibuya, Tokyo 156-0066, Japan.
authors.forename: Sanae
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: National Institute of Technology and Evaluation, Nishihara, Shibuya, Tokyo 156-0066, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Katano
authors.affiliation: National Institute of Technology and Evaluation, Nishihara, Shibuya, Tokyo 156-0066, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Fujinami
authors.affiliation: National Institute of Technology and Evaluation, Nishihara, Shibuya, Tokyo 156-0066, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Fujita
authors.affiliation: Department of Ophthalmology, Sapporo Medical University, Hokkaido 060-8556, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Abe
authors.affiliation: Department of Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Sato
authors.affiliation: Department of Food Science and Technology, Tokyo University of Agriculture, Abashiri, Hokkaido 099-2493, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Nakagawa
authors.affiliation: Department of Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Youichi
authors.initials: Y
authors.lastname: Niimura
mesh_terms: D000332:Aerobiosis; D001406:Bacillaceae / Q000235:genetics / Q000502:physiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006019:Glycolysis; D053858:Metabolic Networks and Pathways / Q000235:genetics; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D054464:Peroxiredoxins / Q000378:metabolism; D020543:Proteome / Q000032:analysis; D019289:Pyruvic Acid / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological
chemical_list: D004269:DNA, Bacterial; D009097:Multienzyme Complexes; D020543:Proteome; D017382:Reactive Oxygen Species; D019289:Pyruvic Acid; D054464:Peroxiredoxins; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D010100:Oxygen