Lactobacillus plantarum 70810 from Chinese paocai as a potential source of β-galactosidase for prebiotic galactooligosaccharides synthesis

作者：Zhang, Hongzhi; Li, Wei; Rui, Xin; Sun, Xingmin; Dong, Mingsheng^*

来源：European Food Research and Technology, 2013, 236(5): 817-826.

DOI：10.1007/s00217-013-1938-5

• Lactobacillus plantarum 70810
• beta-Galactosidase
• Chinese paocai
• Transgalactosylation
• Galactooligosaccharides

A novel food-grade strain Lactobacillus plantarum 70810 producing beta-galactosidase with high transgalactosylation activity was isolated from Chinese paocai. The galactooligosaccharides (GOS) were synthesized by using this enzyme with a maximum yield of 44.3 % (w/w) from 400 g/L lactose at 45 A degrees C for 10 h. The beta-galactosidase from this strain was purified to homogeneity by ammonium sulfate precipitation, anion exchange chromatography and gel filtration chromatography. It was a heterodimer arrangement of approximately 105 kDa composed of two subunits of 35 and 72 kDa. The optimal pH of the purified beta-galactosidase was 8.0 for both o-nitrophenyl-beta-d-galactopyranoside (oNPG) and lactose hydrolysis, and optimal temperature was 60 A degrees C and 55 A degrees C, respectively. Its K (m) and V (max) values for oNPG and lactose were 0.89 +/- A 0.05 mM, 194 +/- A 3.0 mu moL/min/mg protein, and 9.88 +/- A 0.16 mM, 15.88 +/- A 0.21 mu moL/min/mg protein, respectively. This enzyme was slightly inhibited by the hydrolysis products, that is, glucose and galactose. Since the beta-galactosidase from L. plantarum 70810 exhibited higher transgalactosylation activity, strong affinity for lactose and low end-product inhibition, it was suggested to be a potential candidate for the synthesis of prebiotic GOS.

• 出版日期2013-5
• 单位南京农业大学