invertase

Invertase, also known as beta-fructofuranosidase, is an enzyme that catalyzes the hydrolysis of sucrose into glucose and fructose. It is a glycoside hydrolase classified in family GH32 and occurs in a range of organisms, including yeasts, plants, and some bacteria.

In yeast, invertase is encoded by SUC genes (SUC2 in Saccharomyces cerevisiae) and exists in secreted and cell-wall–associated forms. In plants, invertases reside in the apoplast, vacuoles, and cytosol, and there are two main classes distinguished by pH: acid invertases (including cell-wall and vacuolar invertases) and neutral/alkaline invertases.

Biological roles: In plants, invertases influence carbon partitioning and sink strength, affecting phloem unloading, fruit ripening, and seed germination. In yeast and other microbes, invertase supports fermentation by providing glucose and fructose from sucrose.

Industrial use: Invertase is employed to produce invert sugar syrups, which blend glucose and fructose to yield higher sweetness and greater hygroscopicity and to reduce sugar crystallization in confectionery, baking, and beverages. Industrial enzymes are produced by fungi such as Aspergillus niger or by yeasts, and may be used in free or immobilized form.

Measurement and regulation: Enzyme activity is typically assayed by monitoring the release of reducing sugars, using methods such as the DNS assay or glucose assays. Activity depends on temperature, pH, and ionic conditions, with different sources showing different optima.