Mc. Manca et al., CHEMICAL-COMPOSITION OF 2 EXOPOLYSACCHARIDES FROM BACILLUS-THERMOANTARCTICUS, Applied and environmental microbiology, 62(9), 1996, pp. 3265-3269
The thermophilic bacterium Bacillus thermoantarcticus produces two exo
cellular polysaccharides (EPS 1 and EPS 2), which can be obtained from
the supernatant of liquid cultures by cold-ethanol precipitation, in
yields as high as 400 mg liter(-1). The EPS fraction was produced with
all substrates tested, although a higher yield was obtained with mann
ose as the carbon and energy source, The EPS content was proportional
to the total biomass. On a weight basis, EPS 1 and EPS 2 represented a
bout 27 and 71%, respectively, of the total carbohydrate fraction, EPS
1 is a sulfate heteropolysaccharide containing mannose and glucose in
a relative molar proportion of 1.0 and 0.7, respectively, EPS 2 is a
sulfate homopolysaccharide containing mannose as the major component.
The absolute configurations of hexoses were shown to be D for both EPS
s, Nuclear magnetic resonance spectra confirmed the presence of alpha-
D-mannose and beta-D-glucose in EPS 1 and only alpha-D-mannose in EPS
2, In addition, H-1 nuclear magnetic resonance analysis and chemical a
nalysis indicated the presence of pyruvic acid in EPS 2.