Detection and purification of tannase produced by clinical isolates of Lactobacillus spp.

Abstract

The current study included thirty Lactobacillus spp. isolates obtained from breastfeeding infant stool and women vagina. They were seventeen   Lactobacillus plantarum and thirteen Lactobacillus acidophilus. The screening for tannase producing isolates was done using semi-quantitative and quantitative methods, and the findings showed that 17/30 (56.66%) of the acquired isolates were tannase producers via the semi-quantitative method and all the producers were Lactobacillus plantarum. However, quantitative screening found that only 12 out of 30 isolates established specific activity ranging from (7.9 – 12.26 U/mg ), the highest specific activity was for Lactobacillus plantarum S8, which was chosen as the best producing isolates. Tannase was purified using precipitation by ammonium sulfate and organic solvents followed by gel filtration chromatography.  The results revealed that ammonium sulfate was superior to the organic solvents, with optimum saturation ratio for tannase precipitation was at 60% ammonium sulfate, which is considered a partial purification and yielded 122.77U/mg of tannase specific activity. Finally, the specific activity of a pure tannase reached 228.04 U/mg with 4.79 fold of purification and 49.57% yield was obtained by application to gel filteration chromatography