THE VEWEZUELAN SALT-FISH INDUSTRIES 



Cultural and Morphological Characterlstlce 



In standard nutrient agar containing 5 percent salt, growth was smooth, raised, en- 

 tire and the color ranged from pale pink to transparent cherry-red. Single colonies in 

 plates occurred as ovoid, aaoeboid, mycelioid, and irregular forms. In standard nutrient 

 broth the characteristics were: no surface growth, moderate clouding, flocculent sediment 

 and slight "musty" odor. 



The organisms occurred as rods or spheres, were I>am negative and motile, and were with- 

 out spares. Organisms from primary transplantations intp agar frequently had one or two 

 dark spots at the ends, resenU>ling spores, Harrison and Kennedy (1922) attribute this to 

 transitions from cylindrical to round foraui. 



Optimum Salt Concentration for Growth 



To ascertain the optimum salinity of the reddening organism. Inoculations were made 

 from a 24-hour old nutrient agar culture containing 5 percent salt to media containing con- 

 centrations of chemically pure sodium chloride varying from to 30 percent. One percent 

 agar was added to the media containing the higher salt concentrations (over 5 percent) to 

 prevent solidification at the temperature at which agar is generally poured (45°C.). It 

 was determined (Table 2) that optimum salt concentration for growth was 5 percent. The 

 organism grew slightly in 15 percent salt but did not grow at concentrations of 20, 25 and 

 30 percent. 



Table 2 - Growth of Reddening Organisms at Dif^'erent Salt Concentrations 1 



1^0 growth observed in concentrations of 20, 25 and 30?. 

 2 /Pink color more pronounced in media contadning 5? salt. 



It was thought that the successive transplantings through the 5 percent salt medium 

 might have acclimatized the organism to that concentration. Accordingly a new series of 

 media was prepared in the same manner as the previous series, with the salt concentrations 

 ranging from to 30 percent. However, this series was inoculated with organisms that had 

 not been artificially cultured. These were obtained from a pink brine containing 29 per- 

 cent Venesuelan salt. In spite of having taken the inoculatory material directly from the 

 29 percent brine, growth occurred only in the media containing 0, 5, and 10 percent salt, 

 respectively. (Table 2) 



To detenaine whether the organic matter, or other impurities, in the sea-salt might 

 stimulate the growth of the red organism, a series of media of varying concentrations of 

 solar and chemically pure salt was prepared for comparative studies. The impure salt evi- 

 dently had no promotive effect, no growth being observed in the concentrations over 10 per- 

 cent. (Table 2) 



These trials led to the conclusion that a 3 percent salt concentration produced optimum 

 growth of the reddening organism under the laboratory conditions used. These were 48 hours 

 incubation at 42°C. in nutrient agar containing 5 percent salt. 



The results of these experiments on salt tolerance confim previous studies by Stuart, 

 Frey and James (1933) who reported that inoculums from young cultures derived from crude 

 solar salts grew well in media containing to 10 percent salt, but were retarded by con- 

 centrations of 12 to 16 percent, and were completely inactivated by concentrations of 24 



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