ABSTRACT
Trehalose is a naturally occurring non-reducing disaccharide. This sugar has been known as a protector of biomembrane and macromolecules. And it has been widely used in foods, medicines, cosmetics. Trehalose synthase (TreS) is an intramolecular transglycosylase. It can catalyze the conversion of maltose into trehalose in one step. As the simple protocol and cheap substrate, it is very prospect in the industrial production. Here we have discussed the properties, catalytic mechanism and gene-engineering of TreS, and also proposed some solutions to its present research problems.
ABSTRACT
A PCR method was used to amplify the sequence encoding the mature peptide of?-mannanase of Bacillus subtilis. The gene was inserted into the Pichia pastoris vector pPIC9K, downstream of?-factor signal peptide sequence. The resultant recombinant plasmid pPIC9K-MAN was lineared by BglII digestion and introduced into the host Pichia pastoris GS115 by PEG method. After screen, the recombinant P. pastoris strain MAN22 was obtained and fermented in large scale 5L fermenter. The recombinant mannanase activity could reach to 1102IU/ml. The properties of the recombinant mannanase were characterized.