Screening and ecological optimization of tannase produced from Lactobacillus spp. isolates from breastfeeding infant stool

Abstract

In this study, twenty stool samples have been collected from 1-4 months old infants, and thirteen Lactobacillus spp. have been isolated out of these isolates were 9 Lactobacillus plantarum and 4 Lactobacillus acidophilus. Semi-quantitative and quantitative analyses were used to screen for tannase production, The results indicated that 9(69%) of all collected isolates were tannase producers by semi-quantitative method and by quantitative screening method the isolates revealed specific activity ranged from 8.83 to 12.26 U/mg and L.plantarum S8 had the highest specific activity, and was chosen as the highest producing isolate. When this isolate was grown under ideal circumstances, its tannase activity reached its peak which is consisted of Muller Hinton broth medium supplemented with 0.6% pomegranate peel and 1.5% sodium nitrate at pH 6, inoculated with 1% of bacterial culture and incubated at 37°C for 72 hours which resulted in activity and specific activity of 45.68U/ml and 46.15U/mg, respectively