BACTERIOLOGY OF .SARDINES 197 



SESSIONAL PAPER No. 38a 



Temperature Regulations : — 



Thermal death point. — Some variation has been exhibited and further tests require 

 to be made; tests performed up to the present indicate the T.D.P. to be 

 around 60* C, exposed for 10 minutes in nutrient broth. 



Optimum temperature. — Cultures incubated at room temperature and at S7° C. 

 grow well; most satisfactory growth at 37° C. 



Vitality on culture media. — The culture survives several months on artificial 

 medium, agar or gelatine. 



Relation to Oxygen: — 



The culture is a facultative anaerobe; incubated for 36 hours at 37° C. under 

 anaerobic conditions moderate growth on slope of glucose agar; medium 

 cracked and split by gas bubbles, much froth in tube and heavy clouding of 

 condensation water. The organism appears to grow equally well in the 

 presence or in the absence of oxygen. 



Biochemical Reactions: — 



Indol production: Indol not produced. 

 Reduction of nitrates: Nitrates reduced to nitrites. 

 Voges Proskauer reaction : Negative. 

 Methyl red reaction : Alkaline. 



Fermentation of Carbohydrates. — The action of this culture on lactose is feeble 

 and slow, gas not appearing until the second day; dulcite is but slightly 

 fermented to acid and no gas is produced. Aesculin is fermented to acid and 

 gas in 24 hours and in 9 days the Andrade indicator reduced to a lemon 

 yellow turbid iridescent colour, while no reduction is noted in the case of 

 salicin. All the other test substances are fermented to acid and to gas rapidly 

 with profuse frothing and heavy turbidity within 24 hovirs. 



Glucose. Lactose. Saccharose. Mannite. Dulcite. 



++ ++ ++ ++ +- 



Adonit. Raffinose. Arabinose. Xylose. Salicin. 



++ ++ ++ + + 



Aesculin. Glycerin. Inulin. 

 + + + + + + 



+ = acid. 

 -H- = acid and gas. 

 Culture SJ/-. 



Source: Can. II., Ser. I., Packer A. 



Morphology. — Microscopically varying from coccus forms to short rods; the majority 

 8-1 fji long and twice as long as broad, many thinner; stains unevenly with 

 Kiihne's methylene blue; Gram negative*; from old agar cultures no evidence of 

 spores. 



Motility. — In hanging drop occurring singly and in twos ; actively motile. 



Cultural Characteristics: — 



Agar slope. — 36 hours at 37° C, moderate along track of needle, glistening irides- 

 cent, bluish by transmitted light, gas bubbles in medium presumably due to 

 fermentation of the muscle sugar in beef extract. In agar culture 2 months 

 old distinct sliminess has been noted. 



