Induction of L-form Bacteria from Bacillus thuringiensis

Induction of L-form bacteria from Bacillus thuringiensis was investigated with the long-term view of their use as targeted biological control agents within plants. L-forms were successfully induced from B. thuringiensis subspecies israelensis 36-3 by preparing pour plates of exponential cultures in L-phase medium (LPM) containing μg ml-1 cephalosporin C. The induced L-forms were then subcultured and maintained in L-phase medium supplemented with inactivated mycoplasma screened 5% (v/v) horse serum (5HS) with a combination of 225 μg ml-1 cephalosporin C and 0.6 mg ml-1 penicillin G, using the push block method. Induced L-forms showed typical features with pleiomorphic cells that contained granular particles and small vacuoles but no parasporal bodies. These L-forms were capable of growing on solidified media but failed to grow in liquid media. Ceylon Journal of Science (Bio. Sci.) 41 (2): 137-144, 2012 DOI: http://dx.doi.org/10.4038/cjsbs.v41i2.5383