SUGAR UTILIZATION AND ITS CONTROL IN HYPERTHERMOPHILES

Many hyperthermophilic microorganisms show heterotrophic growth on a v ariety of carbohydrates. There has been considerable fundamental and a pplied interest in the utilization of glucose and its alpha- and beta- polymers by hyperthermophiles. While glycolysis by Bacteria at high te mperatures shows conventional characteristics, it has been found that glucose catabolism by hyperthermophilic Archaea differs from the canon ical glycolytic pathways, involves novel enzymes, and shows a unique c ontrol. This review addresses these aspects with specific attention to Pyrococcus furiosus, which is one of the best studied hyperthermophil ic Archaea, has the capacity to grow on a variety of sugars including the marine beta-(1,3)-linked glucose polymer laminarin, and has been f ound to contain three novel glycolytic enzymes, two ADP-dependent kina ses, and a ferredoxin-dependent glyceraldehyde-3-phosphale oxidoreduct ase.