Molecular characterization of native isolates of lactic acid bacteria, bifidobacteria and yeasts for beneficial attributes

In a changing scenario of food habits being
associated with wellness factors through the concepts of
probiotics and prebiotics, an attempt has been made to
characterize on molecular basis, the desirable benefits
associated with natural isolates of lactic acid bacteria,
bifidobacteria, and yeasts. From a diverse range of foods
and related samples, based on conventional microbiological
protocols, three well-characterized natural isolates of
Lactobacillus plantarum MTCC 5422, Bifidobacterium
adolescentis MTCC 5423 and Saccharomyces cerevisiae
MTCC 5421 were selected. The cultures of L. plantarum
and B. adolescentis showed positive polymerase chain
reaction (PCR) amplification with oligonucleotide primers
targeting genus-specific 16 S rRNA for Lactobacillus and
fructose-6-phosphate phosphoketolase for Bifidobacterium.
Similarly, species-specific positive amplification in PCR
was observed with primers of phytase (acid phosphatase) in
S. cerevisiae and α-D-galactosidase and bile salt hydrolase
in L. plantarum and B. adolescentis. The cultures of
L. plantarum and B. adolescentis exhibited a broad
spectrum antibacterial activity against selected foodborne
pathogenic bacterial species and tolerance to acid and bile.
Gene sequence of respective PCR-amplified products
confirmed the genetic identity of the isolated cultures as
L. plantarum and B. adolescentis showing 99% homology
with the documented sequence of established gene bank.