Bright Singh, I S; Vijayan, K K; Jayaprakash, N S; Alavandi, S V; Somnath Pai, S; Preetha, R; Rajan, J J S; Santiago, T C(Elsevier, October 2, 2005)
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Abstract:
A Pseudomonas sp PS-102 recovered from Muttukkadu brackish water lagoon, situated south of Chennai, showed significant
activity against a number of shrimp pathogenic vibrios. Out of the 112 isolates of bacterial pathogens comprising Vibrio harveyi, V.
vulnificus, V. parahaemolyticus, V. alginolyticus, V. fluvialis, and Aeromonas spp, 73% were inhibited in vitro by the cell-free culture
supernatant of Pseudomonas sp PS-102 isolate. The organism produced yellowish fluorescent pigment on King's B medium,
hydrolysed starch and protein, and produced 36.4% siderophore units by CAS assay and 32 μM of catechol siderophores as
estimated by Arnow's assay. The PS-102 isolate showed wide ranging environmental tolerance with, temperatures from 25 to 40 °C,
pH from 6 to 8, salinity from 0 to 36 ppt, while the antagonistic activity peaked in cultures grown at 30 °C, pH 8.0 and at 5 ppt saline
conditions. The antagonistic activity of the culture supernatant was evident even at 30% v / v dilution against V. harveyi. The
preliminary studies on the nature of the antibacterial action indicated that the antagonistic principle as heat stable and resistant to
proteolytic, lipolytic and amylolytic enzymes. Pseudomonas sp PS 102 was found to be safe to shrimp when PL-9 stage were
challenged at 107 CFU ml−1 and by intramuscular injection into of ∼5 g sub-adults shrimp at 105 to 108 CFU. Further, its safety in a
mammalian system, tested by its pathogenicity to mice, was also determined and its LD50 to BALB/c mice was found to be 109 CFU.
The results of this study indicated that the organism Pseudomonas sp PS 102 could be employed as a potential probiont in shrimp
and prawn aquaculture systems for management and control of bacterial infections
Bright Singh, I S; Jayaprakash, N S; Preetha, R; PhIlip, R(The Society for Applied Microbiology, July 20, 2006)
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Abstract:
Aim: To develop a new medium for enhanced production of biomass of an
aquaculture probiotic Pseudomonas MCCB 103 and its antagonistic phenazine
compound, pyocyanin.
Methods and Results: Carbon and nitrogen sources and growth factors, such as
amino acids and vitamins, were screened initially in a mineral medium for the
biomass and antagonistic compound of Pseudomonas MCCB 103. The selected
ingredients were further optimized using a full-factorial central composite
design of the response surface methodology. The medium optimized as per the
model for biomass contained mannitol (20 g l)1), glycerol (20 g l)1), sodium
chloride (5 g l)1), urea (3Æ3 g l)1) and mineral salts solution (20 ml l)1), and
the one optimized for the antagonistic compound contained mannitol (2 g l)1),
glycerol (20 g l)1), sodium chloride (5Æ1 g l)1), urea (3Æ6 g l)1) and mineral
salts solution (20 ml l)1). Subsequently, the model was validated experimentally
with a biomass increase by 19% and fivefold increase of the antagonistic
compound.
Conclusion: Significant increase in the biomass and antagonistic compound
production could be obtained in the new media.
Significance and Impact of the Study: Media formulation and optimization are
the primary steps involved in bioprocess technology, an attempt not made so
far in the production of aquaculture probiotics
Description:
Journal of Applied Microbiology 102 (2007) 1043–1051
This study shows that the disease resistance and survival
rate of Penaeus monodon in a larval rearing systems
can be enhanced by supplementing with antagonistic
or non-antagonistic probiotics. The antagonistic mode
of action of Pseudomonas MCCB 102 and MCCB 103
against vibrios was demonstrated in larval mesocosm
with cultures having su⁄cient concentration of antagonistic
compounds in their culture supernatant. Investigations
on the antagonistic properties of Bacillus
MCCB 101, Pseudomonas MCCB 102 and MCCB 103
and Arthrobacter MCCB 104 against Vibrio harveyi
MCCB111under in vitro conditions revealed that Pseudomonas
MCCB 102 and MCCB 103 were inhibitory to
the pathogen.These inhibitory propertieswere further
con¢rmed in the larval rearing systems of P. monodon.
All these four probionts signi¢cantly improved larval
survival in long-term treatments as well as when challengedwith
a pathogenic strain ofV. harveyiMCCB111.
We could demonstrate that Pseudomonas MCCB 102
andMCCB103 accorded disease resistance and a higher
survival rate in P. monodon larval rearing systems
throughactive antagonism of vibrios,whereas Bacillus
MCCB 101 and Arthrobacter MCCB 104 functioned as
probiotics through immunostimulatory and digestive
enzyme-supporting modes of action.