Characterisation of microbial fructosyltransferase produced extracellularly from <i>Bacillus siamensis</i> GO6 for prebiotic production

The present study aimed to characterise bacterial Fructosyltransferase (FTase; EC 2.4.1.9) from <i>Bacillus siamensis</i> GO6 isolated from <i>Allium fistulosum</i>. The FTase producing potential of <i>B. siamensis</i> is being reported for the first time in this study. Fructosyltransferase production of <i>B. siamensis</i> GO6 was enhanced by optimisation of growth parameters. Maximum Fructosyltransferase activity 134.75 U/ml was recorded in nutrient broth supplemented with tryptone, 60% sucrose at 72 h with an optimised pH of 6.0 at 40 °C. Partial purification of FTase was achieved at 30-60%. FTase titres after partial purification were 175 U/ml with specific activity 484.76 U/mg, and 77% recovery. Partially purified FTase was active in a temperature range 30 °C and 80 °C and in pH 5.0 to 9.0. FTase was found stable at -20 °C for 45 days. The results showed that the <i>B. siamensis</i> GO6 represents a hopeful source for FTase enzyme that can be efficiently utilised for prebiotic production.