title: Thermus thermophilus as source of thermozymes for biotechnological applications: homologous expression and biochemical characterization of an α-galactosidase.
abstract: BACKGROUND
  The genus Thermus, which has been considered for a long time as a fruitful source of biotechnological relevant enzymes, has emerged more recently as suitable host to overproduce thermozymes. Among these, α-galactosidases are widely used in several industrial bioprocesses that require high working temperatures and for which thermostable variants offer considerable advantages over their thermolabile counterparts.
  
  
  RESULTS
  Thermus thermophilus HB27 strain was used for the homologous expression of the TTP0072 gene encoding for an α-galactosidase (TtGalA). Interestingly, a soluble and active histidine-tagged enzyme was produced in larger amounts (5 mg/L) in this thermophilic host than in Escherichia coli (0.5 mg/L). The purified recombinant enzyme showed an optimal activity at 90 °C and retained more than 40% of activity over a broad range of pH (from 5 to 8).
  
  
  CONCLUSIONS
  TtGalA is among the most thermoactive and thermostable α-galactosidases discovered so far, thus pointing to T. thermophilus as cell factory for the recombinant production of biocatalysts active at temperature values over 90 °C.
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cinthia, 80126, Naples, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Aulitto
authors.affiliation: Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Fusco
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cinthia, 80126, Naples, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Fiorentino
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cinthia, 80126, Naples, Italy.
authors.forename: Danila
authors.initials: D
authors.lastname: Limauro
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cinthia, 80126, Naples, Italy.
authors.forename: Emilia
authors.initials: E
authors.lastname: Pedone
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cinthia, 80126, Naples, Italy.
authors.forename: Simonetta
authors.initials: S
authors.lastname: Bartolucci
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cinthia, 80126, Naples, Italy. contursi@unina.it.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Contursi
mesh_terms: D055162:Biocatalysis; D001709:Biotechnology / Q000379:methods; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D016963:Thermus thermophilus / Q000201:enzymology*; D000519:alpha-Galactosidase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D000519:alpha-Galactosidase
keywords: Recombinant expression; Themostability; Thermozymes; Thermus thermophilus; α-Galactosidase