Comparative Studies of Yeast and Sugarcane Invertase

Abstract

Comparative studies of sugarcane invertase and a commercial yeast invertase were conducted. There were two objectives: 1, To identify specific enzyme types on the basis of action patterns against a series of substrates; and 2, to determine whether cane invertase, derived from a highly developed plant species, is identical with the invertase of a primitive plant form. Cane invertase was prepared from lyophilized immature storage tissues, while yeast invertase was obtained commercially as a desiccated extract of yeast cells. Substrates included sucrose, raffinose, stachyose, melibiose, inulin, and soluble potato starch. The cane-invertase complex gave evidence of three carbohydrases: ß-fructosidase, α-galactosidase, and α-glucosidase. Yeast invertase gave only ß-fructosidase activity. Both types of invertase were readily inhibited by silicon, and possible modes of silicon action are discussed. Similarities were noted between sugarcane invertase and sugarcane amylase. The two cane systems appear more nearly identical than cane and yeast invertase. Cane invertase, a more highly versatile enzyme complex than yeast invertase, apparently reflects the more complicated biochemical requirements of a higher plant species.