Production of a thermophilic maltooligosyl-trehalose synthase in Lactococcus lactis.
The thermoacidophilic archaeon Sulfolobus solfataricus MT4 encodes a maltooligosyltrehalose synthase (MTS), that catalyzes an intramolecular transglycosylation process converting the glycosidic linkages at the reducing end of dextrins from alpha-1,4 into alpha-1,1. In this research the gene encoding MTS was cloned and expressed in Lactococcus lactis NZ9000 using the so-called NICE system. Growth conditions of the recombinant strain were optimized in flask experiments in relation to enzyme production. Batch experiments in 2 L-fermenters were performed on the best identified semidefined medium and 256 U L(-1) of recombinant MTS were produced. Purified recombinant MTS shows its optimal activity at 70 degrees C and pH 5.5, prefers maltoheptaose and maltohexaose as substrates, and demonstrates minimal side hydrolytic activity.
Cimini
Donatella
D
Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, Faculty of Medicine and Surgery, Second University of Naples, via De Crecchio 7, Naples, Italy.
De Rosa
Mario
M
Panariello
Andrea
A
Morelli
Veronica
V
Schiraldi
Chiara
C
D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D015870:Gene Expression; D005964:Glucosyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D013294:Lactococcus lactis / Q000235:genetics* / Q000378:metabolism; D013379:Substrate Specificity; D048229:Sulfolobus solfataricus / Q000737:chemistry / Q000201:enzymology*
D001426:Bacterial Proteins; D005964:Glucosyltransferases; C099084:maltooligosyl trehalose synthase