%0 Journal Article
%T Biocatalytic synthesis of lactosucrose using a recombinant thermostable ¦Â-fructofuranosidase from Arthrobacter sp. 10138
%A Chunmei Chen
%A Guocheng Du
%A Huazhong Li
%A Jianghua Li
%A Jieying Deng
%A Long Liu
%A Xueqin Lv
%J Bioengineered
%D 2020
%R https://doi.org/10.1080/21655979.2020.1739404
%X ABSTRACT As a prebiotics, lactosucrose plays an important role in maintaining human gastrointestinal homeostasis. In this study, a thermostable enzyme from Arthrobacter sp. 10138 was screened from six ¦Â-fructofuranosidase-producing strains for the lactosucrose production and the coding gene was heterologously expressed in Escherichia coli for efficient expression. Recombinant ¦Â-fructofuranosidase was purified and biochemically characterized by MALDI-TOFMS spectrometry. The transfructosylation product by this recombinant enzyme was determined to be lactosucrose rather than other oligosaccharides or polysaccharides by HPLC and LC-MS. Efficient extracellular secretion of ¦Â-fructofuranosidase was achieved by the optimization of signal peptide and induction conditions. It was found that with the signal peptide torT, the highest extracellular activity reached 111.01 U/mL, which was 38.4-fold higher than that with the OmpA signal peptide. Under the optimal conditions (pH 6.0, temperature 50¡ãC, enzyme amount 40 ¦Ìg/ml, sucrose 150 g/L and lactose 150 g/L), 109 g/L lactosucrose was produced with a molar conversion ratio of 49.3%. Here the thermostable ¦Â-fructofuranosidase from Arthrobacter sp. 10138 can be used for efficient synthesis of lactosucrose, and this provides a good startpoint for the industrial production of lactosucrose in the future. GRAPHICAL ABSTRAC
%U https://www.tandfonline.com/doi/full/10.1080/21655979.2020.1739404