Antibacterial Activity of Cell Suspension Cultures of Castor (Ricinus communis L. cv. Roktima)

Aims: The study was conducted to develop the protocol for callus culture, cell suspension culture and to determine antibacterial activity of Ricinus communis L. cv. Roktima in cell extract.

Study Design: Hypocotyl segments used as explants in callus culture and agar disk diffusion method used for antibacterial activity test.

Place and Duration of Study: Institute of Biological Sciences, Rajshahi University, Rajshahi, Bangladesh during the period of 2010-2012.

Methodology: MS medium supplemented with different growth regulators were used for callus induction and cell culture and paper disc diffusion method was used for the determination of antibacterial activities. Growth inhibition was determined against five gram positive bacteria viz., Sarcina lutea, Staphylococcus aureus, Bacillus megaterium, Bacillus subtillus, Bacillus halodurans, six gram negative bacteria viz., Shigella sonnei, Klebsiella species, Proteus species, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi by using disc diffusion and micro broth dilution techniques.

Results: Auxins NAA, 2,4-D and IAA played a great role in callus induction but 2.0 mg/L BAP + 0.5 mg/L NAA and 2.0 mg/L BAP + 0.8 mg/L NAA concentrations proved to be most suitable combinations for induction of callus in R. communis L.cv. Roktima. Cells were cultured on the MS medium having 2.0 mg/L BAP + 0.2 mg/L NAA in which the rate of cell growth found highest and the cell continued to grow until 14 days. The peak period of cell growth was observed from 4th d to 6th d. Antimicrobial test with eleven bacteria demonstrated that the extracts of cell suspension culture of R. communis L .cv. Roktima holds the merit of antimicrobial activity and it was considered to be the potent source of antibacterial compounds and a possible source for obtaining the toxin ricin.

Conclusion: In summary, the results obtained in the present investigation demonstrated that the extracts of cell suspension culture of R. communis L. cv. Roktima had the antibacterial activity and considered to be the potent source of antibacterial compounds.