TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preparation (claimed): Producing the recombinant polypeptide comprises: (a) providing a population of host cells comprising a vector, where the vector comprises a polynucleotide sequence encoding a polypeptide, the polypeptide comprising a Gly-Pro-Arg-His motif (SEQ ID NO: 9) and an Asp-Pro-Thr-Gx-Phe/Tyr motif (SEQ ID NO: 10), and where the polypeptide has lactonase activity; and (b) culturing the population of cells under conditions where the polypeptide of the vector is expressed. Preferred Polypeptide: The recombinant polypeptide comprises fully defined 390-400 amino acids (SEQ ID NO: 1, 2, and 3), given in the specification. Preferred Composition: The composition further comprises at least one additional polypeptide, where the additional polypeptide is cellobiose dehydrogenase (CDH). The additional polypeptide is glucose oxidase (GOX). Alternatively, the composition comprises the expression vector, and the host cell. Preferred Host Cell: The host cell is selected from a fungal cell, a yeast cell, a bacterial cell, an insect cell, and a mammalian cell. Preferred Method: In producing aldonic acid, the hexose- delta -lactone substrate is selected from cellobiono- delta -lactone, glucono- delta -lactone, and lactono- delta -lactone. In deconstructing biomass, the biomass comprises plant material. The plant material is selected from miscanthus, switchgrass, cord grass, rye grass, reed canary grass, common reed, wheat straw, barley straw, canola straw, oat straw, corn stover, soybean stover, oat hulls, oat spelt, sorghum, rice hulls, sugarcane bagasse, corn fiber, barley, oats, flax, wheat, linseed, citrus pulp, cottonseed, groundnut, rapeseed, sunflower, peas, lupines, palm kernel, coconut, konjac, locust bean gum, gum guar, soy beans, Distillers Dried Grains with Solubles (DDGS), Blue Stem, corncobs, pine, conifer softwood, eucalyptus, birchwood, willow, aspen, poplar wood, hybrid poplar, energy cane, short-rotation woody crop, crop residue, yard waste, or a combination. In the food processing, the digestible plant material is fed to animals. EXAMPLE - No suitable example given.