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Title: Enzymatic hydrolysis of whey lactose to glucose for alcohol production. Final report, September 1, 1979-August 31, 1981

Technical Report ·
OSTI ID:5721996

This report covers the initial phase of a whey-to-glucose-to-alcohol process via an immobilized beta-galactosidase reactor in series with a fermentor. The first stage takes pure lactose and its hydrolysis with a soluble enzyme system. This stage involves the development of an assay to assess conversion in the hydrolysis reaction and the selections of the best reaction conditions for the enzyme selected. For the Embiozyme Lactase enzyme, the best conditions are 45/sup 0/C and pH 6.5. Thus, this enzyme would be more applicable to sweet whey systems rather than to acid whey. In the range of 1.0 to 3.0 g/l enzyme concentration, increased conversion is seen with increased enzyme concentration; however, the economics need to be studied to determine the optimum enzyme level taking into account cost and yield considerations. Some substrate or product inhibition is seen and is especially apparent above 50 g/l substrate concentration. Inhibition needs to be studied in more detail. Stability seems to be a problem with the Embiozyme Lactase enzyme. This may lead to problems in the future immobilization. Alternate processing conditions may have to be determined giving stability considerations the highest priority. Alternate suppliers of lactase can also be investigated. Acid denaturation seems to be more reliable than heat denaturation. Whether buffer or water is used in enzyme reconstitution makes little short-term difference in conversion. However, there may be an effect on long-term stability. 33 refs., 8 figs., 13 tabs.

Research Organization:
Hirasuna (Thomas J.), Yonkers, NY (USA)
DOE Contract Number:
FG42-79R205032
OSTI ID:
5721996
Report Number(s):
DOE/R2/05032-T1; ON: DE85013559
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English