This study describes the isolation of a phage, using mitomycin C and u.v. light, from each of four strains (HD67, HD130, HD228 and HD248) of Bacillus thuringiensis H-serotype 7 (var. aizawai). It also describes the isolation of two indicator strains (12.13 and HD102) for these phages (phi HD67, phi HD130, phi HD228 and phi HD248) and the ideal conditions, using these indicator strains, for maximum phage production.

Of 36 strains of the ‘aizawai’ variety of Bacillus thuringiensis (H‐serotype 7) 16 were naturally associated with bacteriophages, 11 of which were isolated at titres of 106 plaque‐forming units/ml and above. These 11 phages had varied host ranges among Bacillus cereus and five strains of the ‘aizawai’ variety of B. thuringiensis. Host range, plaque morphology and differences in cold lability indicated dissimilarities between the phages, which could be used taxonomically to differentiate between strains of this bacillus.

The essential oils obtained by hydrodistillation of the fresh leaves and mature fruits of Pittosporum viridulum were analyzed by GC and GC/MS. Fifteen components comprising 85.4% of the leaf oil and twenty-six components comprising 94.5% of the fruit oil have been identified. The major components of the leaf oil were spathulenol (28.4%), caryophyllene oxide (17.6%), and α−cadinol (9.0%), whereas germacrene D (28.6%), α−cadinol (13.0%) and δ−cadinene (9.4%) were the major components in the fruit oil. The oils showed moderate antibacterial activity against the Gram-positive bacteria Staphylococcus aureus and Salmonella typhi.

J.R.M. INAL. V. KARUNAKARAN AND H.D. BURGES. 1992. Four temperate phages, ØHD67, ØHD130, ØHD228 and ØHD248, which were isolated from Bacillus thuringiensis H‐serotype 7 strains, were tested for their ability to mediate transduction within H‐serotype 7 and also between H‐serotype 7 and 3a3b. The optimum conditions to facilitate transduction were determined. The four phages successfully mediated transduction within serotype 7 of all five auxotrophic markers tested and thus seem to have the ability to mediate generalized transduction. The phages also mediated transduction between H‐serotype 7 and H‐serotype 3a3b of 10 of 11 auxotrophic markers tested.

The temperate, generalized transducing phage 4HD248 from Bacillus thuringiensis subsp. aizawai (H-serotype 7) was shown previously to mediate transduction within subsp. aizawai and between subsp. aizawai and subsp. kurstaki (H-serotype 3a3b). Here it was found to have a broad host range, plating on 7 out of 14 H-serotypes tested. Cotransduction analysis using 4HD248 revealed two linkage groups in H-serotype 7 : bio-24is-2-met-l-cit-1-a~-2-lys-3 and trp-9-purCl-thi-I. Preliminary characterization of the 4HD248 genome revealed a linear double-stranded DNA of 47.15 kb. A restriction site map is reported including a total of 10 sites for the enzymes BamHI, Bg/ll, Sall and Sstl. Enzyme Sah was found to have a unique cleavage site which if not located in an essential region could be used as a cloning site. The 4HD248 genome was also shown to lack cohesive ends and appears to have a partial circular permutation.