Fructan-exopolysaccharides (fructan-EPS) (inulin and levan) and their oligosaccharides (fructooligosaccharides, FOS) have drawn considerable interest in the food and pharmaceutical industries. EPS-producing lactic acid bacteria have been reported to produce β-fructans (inulin and levan), as well as α-glucans, by the function of sucrase enzymes, i.e., fructansucrase and glucansucrase. A fructansucrase ftfCNC-2(1) gene from Weissella confusa strain MBFCNC-2(1) was previously cloned in Escherichia coli. In this study, we aimed to express the ftf[CNC-2(1)] gene in Bacillus subtilis to obtain the active form of the extracellular recombinant protein FTF[CNC-2(1)]. This cloning was achieved by inserting the gene in-fusion with the signal sequence of the B. subtilis subtilisin E. SDS-polyacrylamide gel electrophoresis analysis and in situ activity assay with Periodic Acid-Schiff staining revealed that the recombinant FTF[CNC-2(1)] was successfully expressed as an extracellular protein from B. subtilis DB403 in its active form, which was confirmed using sucrose and raffinose.
Keywords: Bacillus subtilis; Fructansucrase; Fructosyltransferase; Inulosucrase; Weissella confusa; ftf.
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