The capacity of Amy A, a alpha-amylase from the hyperthermophilic bacteria Thermotoga maritima to carry out transfer reactions in addition to hydrolysis was investigated. Amy A is a saccharifying enzyme that catalyzes the hydrolysis of internal alpha-1,4 linkages Of glucose polymers generating low molecular weight products (G1-G7); however, in the long term it is capable of producing glucose and maltose exclusively. It was shown that Amy A is able to transform maltose to higher molecular weight oligosaccharides like maltoheptaose, through a combination of transfer and hydrolysis reactions: the fact that the enzyme can use maltose to generate higher molecular weight products is an almost unique property among alpha-amylases, with neotrehalose as one of the products of the transglucosylation activity. Amy A is also capable of efficiently performing alcoholysis reactions from starch and maltodextrins to methanol and butanol, generating alkyl-glycosides. This is the first report in the scientific literature concerning the synthesis of neotrehalose by an alpha-amylase. (C) 2009 Elsevier Inc. All rights reserved.