A thermostable formamidase from the aerobic hyperthermophilic archaeon Aeropyrum pernix was revealed a novel type II (+)-gamma-lactamase. This type II (+)-gamma-lactamase is only composed of 377 amino acid residues, in contrast to another thermostable (+)-gamma-lactamase from Sulfolobus solfataricus with 504 amino acid residues (type I). It is interesting that there are low identities between these two (+)-gamma-lactamases, and herein, we further proved that at least two types of (+)-gamma-lactamases exist in nature due to enzyme promiscuity. The gene of this thermostable (+)-gamma-lactamase was cloned, functionally expressed in Escherichia coli BL21, and purified by a simple yet effective heat treatment method. It showed incredible thermostability, retaining 100 % of its activity after 12 h at 100 A degrees C. The optimum temperature for this enzyme was supposed to be more than 100 A degrees C, and the optimum pH for this enzyme was about 9.0. The lactamase maintained its activity in the presence of most metal ions, except for Cu2+. This thermo- and alkaline-tolerant (+)-gamma-lactamase presents promising properties for the industrial application. Specifically, it could be used for the production of chirally pure (-)-gamma-lactam for the synthesis of well-known carbocyclic nucleosides like abacavir and peramivir. The optical purity of the chiral product reached over 97 % enantiomeric excess.