Expression and characterisation of neopullulanase from <Emphasis Type="Italic">Lactobacillus mucosae</Emphasis>

Objectives

To clone and express a neopullulanase gene from Lactobacillus mucosae LM1 in Escherichia coli and characterise the resulting recombinant neopullulanase.

Results

An ORF in L. mucosae corresponding to a neopullulanase was cloned and expressed in E. coli. The predicted amino acid sequence of the neopullulanase contained catalytic sites and conserved motifs that are present in members of the neopullulanase subfamily. The resulting recombinant neopullulanase was efficiently purified by Ni–NTA affinity chromatography. The purified enzyme optimally hydrolyses pullulan at 37 °C and pH 6.0, producing panose as the major reaction product.

Conclusions

To the best of our knowledge, this is the first report of the cloning, expression and characterisation of a neopullulanase gene from a lactic acid bacterium.