Acta Botanica Croatica, Vol. 32 No. 1, 1973.
Original scientific paper
Isolation and Characterization of a Phage of Bacillus thuringiensis
Ana Šarić
; Hrvatska
Mercedes Wrischer
; Hrvatska
Abstract
A phage isolated from insect pathogen and crystal forming bacteria Bacillus thuringiensis var. thuringiensis, serotype I, was characterized. The isolated phage, called BTK-2, belongs to Bradleys group A according to its morphological characteristics. It has a head with a hexagonal outline of 73 nm in diam. and a very short neck. The tail has a contractile sheath, 60 nm long and 19 nm wide. At the distal end of the sheath a terminal structure is visible. The total length of the phage is 219 nm. It produces small clear plaques up to 2 mm in diam; BTK-2 is not sensitive to chloroform.
The kinetics of growth was studied in the »one step growth experiment« (Adams 1966). BTK-2 has a latent period of 35 minutes and the average burst size of 120 virus particles per infected cell. The adsorption rate was estimated from the number of free unadsorbed phage particles according to Adams (1966). Only 50°/o of phages were adsorbed after an adsorption period of 5 minutes.
The phage was grown in nutrient broth with 0.001 M CaCl2. In all experiments the MOI was 0.1 or 1.0.
BTK-2 is a rather stable phage; it did not loose its infectivity after a six month storage at 4° C or after a three month storage at room temperature. Its stability was maximal at pH 7.0—7.5.
The isolated virulent phage BTK-2 seems to differ from previously reported virulent phage GV-6 (Colasito and Rogof f 1969a).
Keywords
Hrčak ID:
157239
URI
Publication date:
31.12.1973.
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