Structural analysis of an extracellular polysaccharide produced by a benzene tolerant bacterium, Rhodococcus sp. 33.
Rhodococcus sp. 33 can tolerate and efficiently degrade various concentrations of benzene, one of the most toxic and prevailing environmental pollutants. This strain produces a large quantity of extracellular polysaccharide (33 EPS), which plays an important role in the benzene tolerance in Rhodococcus sp. 33, especially by helping the cells to survive an initial challenge with benzene. This EPS has been reported to be composed of D-galactose, D-glucose, D-mannose, D-glucuronic acid, and pyruvic acid at a molar ratio of 1:1:1:1:1. To understand the protective effect of 33 EPS, we determined its chemical structure by using 1H and 13C NMR spectroscopy including 2D DQF-COSY, TOCSY, HMQC, HMBC, and NOESY experiments. The polysaccharide was shown to consist of tetrasaccharide repeating units with the following structure: [structure: see text].
Urai
Makoto
M
Laboratory of Molecular Microbiology, Department of Applied Biological Science, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa 252-8510, Japan.
Aizawa
Tomoko
T
Anzai
Hirosi
H
Ogihara
Jun
J
Iwabuchi
Noriyuki
N
Neilan
Brett
B
Couperwhite
Iain
I
Nakajima
Mutsuyasu
M
Sunairi
Michio
M
D001554:Benzene / Q000494:pharmacology*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D003470:Culture Media / Q000737:chemistry; D005110:Extracellular Space / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000378:metabolism*; D012240:Rhodococcus / Q000187:drug effects* / Q000378:metabolism*
D003470:Culture Media; D011135:Polysaccharides, Bacterial; D001554:Benzene