from indigenous fermented foods and human gut ... - Thapar University

3.1 Chemicals and Media
III. Materials and Methods
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Chapter III Material and methods
All chemicals and reagents used were of the highest analytical grade and purchased
from Sigma Aldrich (St. Louis, MO, USA) unless otherwise specified. Standard media
components were purchased from Fisher Scientific (USA) or Sigma Aldrich (St. Louis, MO,
USA) and Hi-Media (Mumbai, India). Chemicals of molecular biology grade were procured
from New England Biolabs, UK.
3.2 Collection of samples
A total of four hundred and thirty six samples were selected, 100 each of fruits pickle
mango and garlic–chilli samples were obtained from local market of Northern and North
Eastern India. Samples of Bhaati jaanr (fermented rice liquor) and Mahula liquor (from
fermented flowers of Madhuca longifolia) were obtained from local markets of Namchi;
Sikkim, Cuttack; Orissa and Sitamadhi; Bihar. Thirty six meconium samples of new born
babies were collected from Sehat Medicare, Patiala, Punjab (prior consent from parents was
taken). All samples were collected in pre-sterile poly-bags and screw capped bottles, kept in
an icebox and transported to the laboratory for analysis. Samples were processed within 6 h
of receipt in local laboratories.
3.3 Isolation, selection and identification of Lactobacillus strains
3.3.1 Isolation of bacterial strains
One gram of each sample were weighed aseptically and homogenized for 2 min in
stomacher lab-blender 400 (Seward, UK) in 9 ml Quarter-Strength Ringer’s Solution (QRS)
and diluted further in a ten-fold dilution series with the same. Freshly collected meconium (1
gm) from infants were suspended in 9 ml QRS and diluted further in a ten-fold dilution series
with QRS. Aliquots (100 µl) of suitable ten-fold dilutions were plated onto MRS and Rogosa