Studies on the Discrimination of SCP-related Yeast by Proton Magnetic Resonance Spectroscopy: Structural Changes in Cell Wall Mannan of Candida subtropicalis Grown in Different Media

Applicability of PMR spectroscopy to the discrimination of the SCP-related yeast was investigated because the yeast was inactivated by heat treatment. When Candida subtropicalis was cultured in a medium containing glucose as a sole source of carbon, its cell wall mannan (mannan A) showed a PMR spectral pattern characterized by three intense peaks at δ: 4.97, 5.10, 5.29 and two small peaks at δ: 4.90, 5.19. Mannan (mannan B) from the yeast cultured in a medium containing n-pentadecane and triton X–100 showed a different spectral pattern in which the signals were observed at δ: 4.97, 5,10, 5.29, the intensity ratios of the signals were also different from those of mannan A. Acetolysis mannan was analyzed to compare the difference between two specified structures by using a gel elution method, methylation analysis and PMR spectra. Mannan B contained a less amount of the a (1→3) linkage than mannan A did, and differed from mannan A in its distribution pattern of side chain units. Our previous results together with the present ones proved the PMR method to be effective for the discrimination of the yeast.