ANNUAL REPORT - Department of Biotechnology

probiotic selected strains of Lactobacilli to colonize
in vagina for reproductive health of women have
been initiated, to determine whether Lactobacilli can
colonize in vagina of women depleted of such
organisms. The safety, lack of side effects and
efficacy of replenishment for preventing episodes of
vaginosis are being determined.
d) Bacteriocins from Probiotics: Natural
isolates of lactic acid bacteria isolated from the
rhizosphere were screened for bacteriocin
production and , strain LR/14 has been found to be
potential bacteriocin producer. This strain was
identified as Lactobacillus plantarum LR/14 by
biochemical tests and 16SrDNA sequencing. The
crude bacteriocin of strain LR/14 was heat and pH
stable with shelf-life upto 2 years was checked. The
mode of action was observed to be bactericidal with
broad host range against related as well as some
food-borne pathogens like Listeria monocytogenes,
Staphylococcus and Salmonella.
E-Test (VA & CIP) - probiotic [C]
e) Probiotics as Potential Source of Vitamin
B12: Various Propionibacteria are being explored as
potential source of Vitamin B12 and functional
probiotic ingredient in a dairy based nutraceutical
formulation. Twenty two cultures were identified as
dairy Propionibacteria. Molecular Characterization
with the help of genus-specific primers from the 16S-
23S rRNA intergenic spacer regions for dairy
propionibacteria, isolated organism are under
process. The estimation of Vitamin B12 in milk has
been standardized using immunosorbent method.
Using ELISA kit, the values of vitamin B12 in cow
milk, buffalo milk and goat milk were observed to be
DBT Annual Report 2006-07
144
4.91 ± 0.40, 21.68 ± 2.69 and 3.91 4.91 ± 0.26 ppb,
respectively. Further work on the validation of
ELISA method with microbiological assay employing
Lactobacillus leichmannii as an assay organism is in
progress.
f) Food mixtures with Probiotics:
Standardization and quality evaluation of banana
based probiotic fermented food mixtures are being
accomplished. Initial standardization of the 14
different combinations of food mixtures based on raw
banana flour, defatted soya flour, green gram flour,
tomato, papaya and mango have been carried out.
Banana flour was the main ingredient in the food
mixture which ranged from 50 to 70% in all
combinations. A total of 56 food mixtures with the
above raw ingredients were developed and
subjected to organoleptic evaluation and out of this,
14 combinations were selected based on their
sensory qualities, for further studies.
Nutraceuticals
a) Reduced calorie fats: Various novel
reduced calorie fats have been developed. The
conditions for the transesterification were optimized
at laboratory scale and further upscaled. In a typical
reaction, sunflower oil was transesterified with ethyl
behenate in presence of specific enzyme
Lipozyme. Reaction products from five similar
reactions were pooled and distilled. Various
structural lipids have been prepared and the
products have been analyzed for RP-HPLC and
physico-chemical properties.
b) Tea Polyphenols: Theaflavins, (TF) is a
high valued neutraceutical found in Black Tea in
limited amounts, through the bioconversion of
catechins from tea by the immobilized polyphenol
oxidase (PPO) enzyme system native to tea.
Identification of suitable matrix for the enzyme
immobilization, isolation of tea PPO, kinetic studies
of the immobilized enzyme system, number of
turnovers of immobilized enzyme system to
Theaflavins, stability of the immobilized enzyme
matrix, isolation of tea PPO in soluble form, alogwith
characterization of Theaflavins product through UV,
IR and mass spectrometery, were completed. 100%
conversion of tea catechins to Theaflavins were
achieved with the system with repeated turnover of