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Abstract:
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Pyocyanin is a versatile and multifunctional phenazine, widely used as a bio-control agent. Besides its toxicity in higher concentration, it has been applied as bio-control agents against many pathogens including the Vibrio spp. in aquaculture systems. The exact mechanism of
the production of pyocyanin in Pseudomonas aeruginosa is well known, but the
genetic modification of pyocyanin biosynthetic pathways in P. aeruginosa is not yet
experimented to improve the yield of pyocyanin production. In this context, one of
the aims of this work was to improve the yield of pyocyanin production in P.
aeruginosa by way of increasing the copy number of pyocyanin pathway genes and
their over expression. The specific aims of this work encompasses firstly, the
identification of probiotic effect of P. aeruginosa isolated from various ecological
niches, the overexpression of pyocyanin biosynthetic genes, development of an
appropriate downstream process for large scale production of pyocyanin and its
application in aquaculture industries. In addition, this work intends to examine the
toxicity of pyocyanin on various developmental stages of tiger shrimp (Penaeus
monodon), Artemia nauplii, microbial consortia of nitrifying bioreactors (Packed Bed
Bioreactor, PBBR and Stringed Bed Suspended Bioreactor, SBSBR) and in vitro cell
culture systems from invertebrates and vertebrates. The present study was undertaken
with a vision to manage the pathogenic vibrios in aquaculture through eco-friendly
and sustainable management strategies with the following objectives:
Identification of Pseudomonas isolated from various ecological niches and its antagonism to pathogenic vibrios in aquaculture.,Saline dependent production of pyocyanin in Pseudomonas aeruginosa originated from different ecological niches and their selective application in aquaculture,Cloning and overexpression of Phz genes encoding phenazine biosynthetic pathway for the enhanced production of pyocyanin in Pseudomonas aeruginosa MCCB117,Development of an appropriate downstream process for large scale production of pyocyanin from PA-pUCP-Phz++; Structural elucidation and functional analysis of the purified compoundToxicity of pyocyanin on various biological systems. |