title: Production of a thermophilic maltooligosyl-trehalose synthase in Lactococcus lactis.
abstract: 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.
authors.affiliation: 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.
authors.forename: Donatella
authors.initials: D
authors.lastname: Cimini
authors.forename: Mario
authors.initials: M
authors.lastname: De Rosa
authors.forename: Andrea
authors.initials: A
authors.lastname: Panariello
authors.forename: Veronica
authors.initials: V
authors.lastname: Morelli
authors.forename: Chiara
authors.initials: C
authors.lastname: Schiraldi
mesh_terms: 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*
chemical_list: D001426:Bacterial Proteins; D005964:Glucosyltransferases; C099084:maltooligosyl trehalose synthase