• Korean Journal of Microbiology
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• v.24 no.2
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• pp.161-167
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• 1986

Some of the physiological properties of Sp816 bacteriophage of Bacillus subtilis SNU816 were characterized. It could form plaques on either B. subtilis SNU816 or B. natto 8102, but not on any other bacillus strains investrgated. Its plaque morphology was circular with a diameter of less than 1.0mm and had a narrow halo surrounding the clear center. Its latent period was 34-36 min and had a burst size of 547. It was most stable at pH 6.0, and rapidly inactivated at $60^{\circ}C$ with a initial deaty rate of -0.216 $min^{-1}$. Host range, thermal inactivation rate at $60^{\circ}C$, pH stability, and UV sensitivity revealed that SP816 was quite different from any other phages investigated together but seemed to be rather related to B. natto phages.

• Korean Journal of Microbiology
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• v.22 no.2
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• pp.111-118
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• 1984

The changes of susceptibility of Bacillus subtilis SNU816 to bacteriophage SP816 were investigated. When B. sutilis SNU816 cells were infected by the phage during vegetative growth, rapid lysis was observed. But when they were infected after late logarismic phase, they were resistant to phage infection. Since asporogenic culture of this strain was invariably lysed regardless of time of infection, the arrest of phage multiplication seemed to be caused by sporulation. In reality, the arrest of phage multiplication occurred at early stage of sporulation. Electron microscopy revealed that the arrest of phage multiplication occurred just prior to or during septum formation (stage II sporulation).

• Korean Journal of Microbiology
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• v.16 no.2
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• pp.71-78
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• 1978

Bacillus subtilis var. 816 was used for manufacturing fermented soybean which in turn is used as flavoring agent. Fermentation of soyebean or flat wheat was occasionally failed. It was elucidated that failure was due to the presence of bacteriophage. According to Hemphill and Whitely (1975), this bacteriphage might be belonged to the viulent phage group I as it is similar to SP82G, ${\phi}25$. In fact, the phenomena of the increase of moisture, disappenarance of mucin and existence of undersirable bacteria was attributed to the contamination of the above phage during the course of fermentation of soybean or flat wheat. Particularly disapparance of mucin was sufficiently correlated by the replication of the bacteriophage. The above phage can grow in the range of $30^{\circ}C\;to\;70^{\circ}C$. The optimum temperature was $40^{\circ}C{\sim}50^{\circ}C$. The optimum pH range was between pH 7.4 and pH 8.0. It is noticeable that staphylococci was replicating simultaneously with the phage. The head of 816 phage is hexagonal with a diameter of $10{\times}165{\sim}10{\times}240\;nm$. The end of the tail is enlaged. It has a size of 25 nm and this end areas are spreaded widely as fingers.