The alkali-soluble glucan of the yeast cell wall contains β-(1,3)- and (1,6)-D-linkages and systemically enhances the immune system. To isolate Saccharomyces cerevisiae mutants producing glucan with a high degree of β-(1,6)-D-glycosidic bonds, a wild-type strain was mutagenized with ultraviolet light. The mutants were then selected by treatment with 1.0 mg laminarinase, endo-β-(1,3)-D-glucanase/ml. The alkali-soluble glucan was extracted by modified alkali ysis followed by the Cetavlon method and concanavalin-A chromatography. The prepared alkali-soluble glucans from the wild-type and the mutants were compared with respect to yield and polymer structure using gas chromatography, 13C-NMR spectrometry, high performance liquid, and multi-angle laser light scattering and refractive index detectors. The results indicated that the S. cerevisiae mutants had ten-fold more alkali-soluble glucan than the wild-type. Structural analysis revealed that the alkali-soluble glucan from the mutants also had a higher degree of β-(1,6)-D-linkage than that from the wild-type.
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Acknowledgement This study was supported by Ministry of Health and Welfare, Republic of Korea, project No. HMP-97-D-4–0017, and we thank Professor Sang-Duk Kim for her careful advice.
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology