Ca2+-induced sporulation in Achlya bisexualis: reserve 1,3-beta-glucans provide both carbon and phosphorus

摘要

Reserve water-soluble 1,3-beta-glucans represent some 13% (wt/wt) of the mycelial dry weight of Achlya, and consist of a small neutral form and a very large phosphorylated one. The phosphoglucan appears to be formed via aggregation of neutral molecules by phosphodiester linkages. Asexual sporulation in Achlya bisexualis, induced by 0.5 mM Ca2+, was accompanied by a 43% reduction in total glucan after 4 h, and the ratio of neutral glucan to phosphoglucan changed between 4 and 12 h. Phosphate content of the phosphoglucan declined by 50%, but the molecular size remained large and the ratio of mono- and diester linkages changed only slightly Appropriate enzyme activities of beta-glucanase and phosphoesterases capable of releasing both glucose and phosphate were found, and are described. [References: 17]