ANNUAL REPORT - Department of Biotechnology

Oligonucleotide probe for monitoring vibrio
counts in hatcheries
Vibrio sp including luminous V. harveyi, V. vulnificus
and V. parahaemolyticus are major bacterial
pathogens of shrimp larvae. Monitoring Vibrio counts
in hatchery water and larval samples would be an
important aspect in health management. To
overcome the problem and get a realistic estimate of
Vibrio counts, an oligonucleotide probe binding to a
region of gyrB gene of all Vibrio spp has been
designed. When labeled with alkaline phosphatase,
this label could be used for enumeration of Vibrio spp
in hatchery environments by colony hybridization
technique.
Colonies of Vibrio spp hybridizing with alkaline phosphatase labeled
oilgonucleotide probe.
Genetic characterization of marine organisms
Studies on genotypic characterization of antagonistic
and detritus degrading bacteria based on their 16S
rDNA sequence ere carried out and partial
sequences of 6 organisms were deposited in
DBT Annual Report 2006-07
92
Genbank. Molecular characterization of
antimicrobial peptides in shrimp and their enhanced
production was undertaken, which showed broad
antimicrobial activity. Studies on novel drugs targeted
at Vibrios from marine microorganisms were
undertaken and an antivibrio compound produced by
Pseudomonas was identified as pyocyanin. A
bioprocess technology for large-scale production of
marine yeast Candida sake as single cell protein was
programmed and executed. An isolate was identified
as the source of alkaline protease for industrial
applications. The crude enzyme was partially purified
and found to have blood stain removal property from
fabrics in the absence of any detergent. A training
programme in Marine Biotechnology was initiated.
Genetic marker for population of cultured animals
would be important for genetic selection of
populations with commercially important traits like
fast growth and disease resistance. Using
microsatellite enrichment techniques, two DNA
microsatellites were identified in genome of
freshwater prawn, Macrobrachium rosenberii . The
sequences of these microsatellites, (CA) repeats,
13
(GA) and (GA) repeats have been deposited in
38 30
GenBank with accession number DQ793216 and DQ
793215. Primers binding to flanking region of these
microsatellites were designed and evaluated in
population of M. rosenbergii from Kerala and
Karnataka. The discriminative ability of microsatellite
was very good with heterogeneity index of 0.27 ±
0.32 and 0.92 ± 0.29 respectively. Shannon index for
these microsatellites were 0.6161 ± 0.2310 and
0.6619 ± 0.2276 respectively.
Organ Development
Aspects of in vitro organ development and
differentiation were undertaken through regeneration
and stem cell biology to search for novel
biomolecules from hitherto untapped sources that
will be useful in the differentiation and regeneration of
vertebrate organs. Preliminary studies showed that
perivitelline fluid (PVF) of Indian Horse Shoe Crab
influences early vertebrate development. Chick
embryo explants cultured in vitro were used as a