Vol.15, No 3, 2008 pp. 97 - 102
UC 613.2:639.3
PROBIOTIC EFFECT OF LACTOBACILLUS ISOLATES
AGAINST BACTERIAL PATHOGENS IN CLARIAS ORIENTALIS
Dharumaduari Dhanasekaran1, Subhasish
Saha, Noorudin Thajuddin1, Annamalai Panneerselvam2
1Department of Microbiology, School
of Life Sciences, Bharathidasan University, Tiruchirappalli, 620 024
2P.G. & Research Department of
Botany & Microbiology, A.V.V.M. Sri Pushpam College, (Autonomous),
Poondi, 613 503 Thanjavur District, Tamil Nadu, India
E-mail: dhansdd@yahoo.co.in
Summary. About 59 Lactobacillus isolates were isolated from 5 different
fresh water sites such as Cat fish (Clarias orientalis), Hari fish (Anguilla
sp), Rohu fish (Labeo rohita), Jillabe fish (Oreochromis sp) and
Gende fish (Punitus carnaticus). Among the 59 isolates only 4 Lactobacillus
isolates were selected for further study. Based on morphological, biochemical
characteristics, the isolates were identified as Lactobacillus sp. The
pathogens were isolated, characterized and identified as Vibrio parahaemolyticus,
Aeromonas sp and Aeromonas salmonicida. The Lactobacillus isolates were
screened for antagonistic activity against Aeromonas, Vibrio sp. by agar
diffusion assay. Among the 4 isolates, Lactobacilli RLD2 showed significant
antagonistic activity against Aeromonas and Vibrio sp alone. This isolate
was further evaluated by standard plate count assay for the viability of
pathogen. The isolate was multiplied and the fish feed was supplemented
with Lactobacillus isolates. The results reveal that the size and weight
of the fish statically increased in comparison to that of control fish.
The present study concluded that the Lactobacillus isolates will be used
as probiotic bacteria in aquaculture, to manage aeromonasis.
Key words: Probiotic bacteria,
Lactobacillus, Antagonistic activity, Aeromonas, Vibrio
PROBIOTSKO DEJSTVO IZOLATA LACTOBACILLUS
NA BAKTERIJSKE PATOGENE CLARIAS ORIENTALIS
Kratak sadržaj: Na 5 slatkovodnih lokacija, izolovano je oko 59
izolata Lactobacillus-a, kod riba kao što su som (Clarias orientalis),
jegulja (Anguilla sp), Rohu šaran (Labeo rohita), tilapija (Oreochomis
sp) i vrsta zrakoperki (Puntius carnaticus). Od 59, samo je 4 Lactobacillus
izolata odabrano za dalja proučavanja. Na osnovu morfoloških i biohemijskih
karakteristika, izolati su identifikovani kao Lactobacillus sp. Izolovani
patogeni su karakterizovani i identifikovani kao Vibrio parahaemolyticus,
Aeromonas sp i Aeromonas salmonicida. Pmoću agar difuzije testirana je
antagonistička aktivnost Lactobacillus izolata na Ae4romonas, Vibrio sp.
Od 4 izolata, Lactobacilli RLD2 je pokazao značajnu antagonističku aktivnost
samo na Aeromonas i Vibrio sp. Ovaj izolat je dalje testiran klasičnom
metodom brojanja (SPC-standard plate count) u cilju odredjivanja sposobnosti
opstanka patogena. Izolat je umnožen a riblja hrana je obogaćena izolatima
Lactobacillus-a. Rezultati su pokazali da se veličina i težina riba statistički
povećala u odnosu na kontrolnu grupu. Ova studija zaključuje da će se
Lactobacillus izolati koristiti kao probiotska bakterija u akvakulturi,
u cilju sprečavanja aeromonaze.
Ključne reči: probiotska
bakterija, Lactobacillus, antagonistička aktivnost, Aeromonas, Vibrio
