Trehalose synthase (TSase) possess the catalysis ability for the reversible conversion of maltose to trehalose by intrarnolecular transglucosylation.Recently,a new recombinant Picrophilus torridus TSase (PTTS) gene has been identified and synthesized from a hyperacidophilic,thermophilic archaea by using overlap extension PCR,and then transformed into Escherichia coli for protein expression.The substitution of proline residue with ten amino acid sites of PTTS was obtained by using sequence alignment compared with two identified TSase.