Applied Microbiology and Biotechnology

, Volume 87, Issue 1, pp 225–233

Cloning, expression, and characterization of a thermostable glucoamylase from Thermoanaerobacter tengcongensis MB4

Biotechnologically Relevant Enzymes and Proteins

DOI: 10.1007/s00253-010-2439-0

Cite this article as:
Zheng, Y., Xue, Y., Zhang, Y. et al. Appl Microbiol Biotechnol (2010) 87: 225. doi:10.1007/s00253-010-2439-0


A thermostable glucoamylase (TtcGA) from Thermoanaerobacter tengcongensis MB4 was successfully expressed in Escherichia coli. The full-length gene (2112 bp) encodes a 703-amino acid polypeptide including a predicted signal peptide of 21 residues. The recombinant mature protein was partially purified to 30-fold homogeneity by heat treatment and gel filtration chromatography. The mature protein is a monomer with the molecular weight of 77 kD. The recombinant enzyme showed maximum activity at 75 °C and pH 5.0. It is the most thermostable bacterial glucoamylase described to date with nearly no activity loss after incubation at 75 °C for 6 h. TtcGA can hydrolyze both α-1, 4- and α-1, 6-glycosidic linkages in various α-glucans. It showed preference for maltooligosaccharides over polysaccharides with specific activity of 80 U/mg towards maltose. Kinetic studies revealed that TtcGA had the highest activity on maltooligosaccharide with four monosaccharide units. The cations Ca2+, Mn2+, Co2+, Mg2+, and reducing agent DTT showed no obvious effects on the action of TtcGA. In contrast, the enzyme was inactivated by Zn2+, Pb2+, Cu2+, and EDTA.


GlucoamylaseThermoanaerobacter tengcongensisRecombinant expressionThermostable

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.State Key Laboratory of Microbial Resources, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
  2. 2.The Graduate SchoolChinese Academy of SciencesBeijingChina
  3. 3.Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjinChina
  4. 4.Lehrstuhl für BiotechnologieRWTH Aachen UniversityAachenGermany