Sugary-2 maize starch

A starch-debranching isoamylase, obtained from sugary 1 (sul) maize, has been cloned by James et al.70 and found to have 32% sequence identity with Pseudomonas isoamylase. Other isoamylases or starch debranching enzymes have been isolated from Cytophaga sp.,71 Streptomyces sp.,72 Flavobacterium sp.,73 a yeast, Lipomyces kononenkoae,74 potato tubers,75 B. circulans76 and an alkaline isoamylase with a pH optimum of 9 from an alkalophilic Bacillus sp.77... 

James, M. G., Robertson, D. S and Meyers, A. M. 1995. Characterization of the maize gene sugary 1, a determinant of starch composition in kernels. Plant Cell 7,417-429. 

Sweet maizes have recessive genes (sugary 1 or sul, sugary 2 or su2) that causes an alteration in the endosperm that results in higher levels of soluble sugars and reduced levels of starch in the kernel. Sweet corn hybrids have been developed specifically to produce corn with desirable color, sweetness, and tenderness. 

Sweet corn Type of maize that contains high levels of soluble sugars and lower levels of starch due to recessive genes (sugary 1 or sul and/or sugary 2 or su2). It is usually consumed on the cob or processed by the canning industry. 

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