Isolation and identification of Bacillus subtilus as) probiotic ) from intestinal microflora of common carp Cyprinus carpio L.

Jamal K.H Faragi

doi:10.30539/iraqijvm.v36i0e.443

Abstract

The presence of Bacillus species Were investigated in the intestine of 50 fish specimens common carp Cyprinus carpio weigh range between 1400-1500g in weigh were obtained from commercial farms in north of Baghdad through period of September to December 2010.The result revealed presence of gram positive, rod shape bacteria grow in the mesosphilic temperature range. The optimal temperature was 25-35C° facultative aerobes and produce catalase an enzyme. The bacterial antagonist activity was tested with fish culture pathogenic bacteria. The modified antagonistic method results showed that Bacillus subtilus could inhibit Aeromonas hydrophila after 24 hours. The highest level of antibacterial substances of this bacillus was produced in 48 hours. The aim of this study is to isolate and identify the Bacillus spp. and study its efficacy as probiotic against A. hydrophila in a fish culture.

Highlights

The increasing in aquaculture is said to be paralleled with a corresponding increasing in the occurrence of infectious diseases resulting often from high stocking densities and stress conditions that favour the occurrence and spread of pathogens
Isolate bacteria was capable of utilizing glucose, xylose, sucrose, mannitol, arabinose, and fructose as carbohydrate sources for growth and grew at pH levels of 5, 8, 9, and 11 and salinities of 3%, 6%, and 8%, but not 10%
The results showed that Bacillus subtilis could produce antibacterial substance at highest level in 2 days that was 4.8mm (Fig 2) but there were no different from 3 and 4 days as measured by size of clear zone (Fig 3) and lower level in 1 day(fig 1) (Graph 2)

Summary

Introduction

The increasing in aquaculture is said to be paralleled with a corresponding increasing in the occurrence of infectious diseases resulting often from high stocking densities and stress conditions that favour the occurrence and spread of pathogens. Cultured fish suffer a wide variety of bacterial, viral, parasitic and fungal diseases [1]. The diseases caused by motile aeromonads Aeromonas hydrophila are wide spread and affect a wide Range of mostly freshwater species. Motile aeromonads are implicated in a number of disease conditions including hemorrhagic septicemia, ulcerative conditions, abdominal distensions, fin/tail rot and exophthalmia [1]. Disease management strategies were based mainly on chemotherapy [2]. The emergence of drug resistance in pathogens, problems associated with drug residues in cultured fish, and awareness towards environmental pollution problems emanating from the use of chemotherapeutants have led to greater focus on alternative methods of disease management [3]. Disease prevention by means of optimal husbandry and use of vaccines, immunostimulants and probiotics has been increasingly recognized [4, 5]

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Conclusion