Johns Hopkins University

Novo Nordisk A/s

Novo Nordisk-a/s Novo Alle

Robert M Kelly

Stephen H Brown

Robert L Starnes

Christian B Anfinsen

Ilse I Blumentals

Anne K Robinson

Henry R Costantino

It has been found that produces several starch hydrolyzing enzymes, both extracellularly and intracellularly, which retain their activity for several hours at or above 100&deg; C. These comprise an &agr;-glucosidase, which has been highly purified, and amylolytic enzymes including an amylase and a pullulanase. In addition, at least one thermostable enzyme activity from that is useful in the process of degradation of cellulose to D-glucose has also been found, namely a &bgr;-glucosidase, which is also active up to at least 95&deg; C.

Saccharification enzymes from hyperthermophilic bacteria and processes for their production

Cell-free extracts from Pyrococcus furiosus were found to possess unusually high levels of proteolytic activity as measured by hydrolysis of azocasein; loss in activity was only 30% after incubation for 24 hours at 98.degree. C. and the half-life of proteolytic activity at that temperature was about 60 hours. Furthermore, cell-free extracts incubated at 98.degree. C. in 1% sodium dodecyl sulfate (SDS) for 24 hours yielded an SDS-resistant protease having a temperature optimum of at least 100.degree. C. The enzyme retained at least 40% of its activity when tested at 98.degree. C. by azocasein hydrolysis in the presence of 4M urea, 2M guanidinium chloride, 10 mM dithiothreitol or 150 mM .beta.-mercaptoethanol. The protease was found to have a pH optimum of 6.8 at 98.degree. C. and retained more than 45% of its activity at pH 9.3 and 82% of its activity at pH 4.5 in assays performed at those values. The protease was classified as a metalloprotease through inhibitor studies, and peptide hydrolysis showed trypsin-like cleavage with additional activities.

Proteolytic enzymes from hyperthermophilic bacteria and processes for

This invention is in the field of glucose isomerization enzymes. More specifically, the invention is directed to a novel xylose isomerase, a process for the preparation of this enzyme, the use of this enzyme in glucose isomerization processes, and glucose isomerization processes. The enzyme is preferrably derived from Thermotoga maritima or Thermotoga neapolitana. The enzyme has a temperature optimum above 90.degree. C., pH optimum in the range of from 6 to 7 and a residual activity at 90.degree. C. of more than 40% after 30 minutes and/or residual activity at 98.degree. C. of more than 20% after 30 minutes. The enzyme can also be in immobilized form.

Method for glucose isomerization using xylose isomerase purified from

This invention is in the field of glucose isomerization enzymes. More specifically, the invention is directed to a novel xylose isomerase, a process for the preparation of this enzyme, the use of this enzyme in glucose isomerization processes, and glucose isomerization processes. The enzyme is preferably derived from Thermotoga maritima or Thermotoga neapolitana. The enzyme has a temperature optimum above 90.degree. C., pH optimum in the range of from 6 to 7 and a residual activity at 90.degree. C. of more than 40% after 30 minutes and/or residual activity at 98.degree. C. of more than 20% after 30 minutes. The enzyme can also be in immobilized form.

Growing community of inventors

Ellicott City, MD, United States of America

Robert M Kelly