Isolation and selection of Bacillus spp. as potential biological agents for enhancement of water quality in culture of ornamental fish
Article first published online: 25 APR 2007
© 2007 CSIR. Journal compilation © 2007 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 103, Issue 5, pages 1471–1479, November 2007
How to Cite
Lalloo, R., Ramchuran, S., Ramduth, D., Görgens, J. and Gardiner, N. (2007), Isolation and selection of Bacillus spp. as potential biological agents for enhancement of water quality in culture of ornamental fish. Journal of Applied Microbiology, 103: 1471–1479. doi: 10.1111/j.1365-2672.2007.03360.x
- Issue published online: 25 APR 2007
- Article first published online: 25 APR 2007
- 2007/0039: received 11 January 2007, revised 20 February 2007 and accepted 21 February 2007
- Bacillus spp.;
- bacterial pathogens;
- biological agent;
- water quality
Aims: To isolate, select and evaluate Bacillus spp. as potential biological agents for enhancement of water quality in culture of ornamental fish.
Methods and Results: Natural isolates obtained from mud sediment and Cyprinus carpio were purified and assessed in vitro for efficacy based on the inhibition of growth of pathogenic Aeromonas hydrophila and the decrease in concentrations of ammonium, nitrite, nitrate and phosphate ions. Based on suitability to predefined characteristics, the isolates B001, B002 and B003 were selected and evaluated in vitro in the presence of Aer. hydrophila and in a preliminary in vivo trial with C. carpio. The inhibitory effect on pathogen growth and the decrease in concentrations of waste ions was demonstrated. Based on 16S RNA sequence homology, the isolates were identified as Bacillus subtilis, Bacillus cereus and Bacillus licheniformis, respectively. Isolate B002 did not contain the anthrax virulence plasmids pOX1, pOX2 or the B. cereus enterotoxin.
Conclusions: Selected isolates effected synergistic reduction in pathogen load and the concentrations of waste ions in vitro and in vivo and are safe for use in ornamental aquaculture.
Significance and Impact of the Study: A new approach for assessment of biological agents was demonstrated and has yielded putative isolates for development into aquaculture products.