. Carnegie Institution of Washington publication. 242 BACTERIA IN RELATION TO PLANT DISEASES. - » »» »â .. Fig. 129.* Growth on cooked carrots looks yellowish at first. After some days there is a dis- agreeable odor. On cooked radish there is a sharp odor in i to 2 weeks and the tissue is then disorganized. The organism makes only a slight growth in Uschinsky's solution. The optimum temperature is about 320 C. Methylene blue (1 per cent) in bouillon is reduced. Litmus is reduced. Nitrate is reduced to nitrite (tested with meta- phenyldiamin, also sulphanilic acid + a-naphthylamin). In youn
. Carnegie Institution of Washington publication. 242 BACTERIA IN RELATION TO PLANT DISEASES. - » »» »â .. Fig. 129.* Growth on cooked carrots looks yellowish at first. After some days there is a dis- agreeable odor. On cooked radish there is a sharp odor in i to 2 weeks and the tissue is then disorganized. The organism makes only a slight growth in Uschinsky's solution. The optimum temperature is about 320 C. Methylene blue (1 per cent) in bouillon is reduced. Litmus is reduced. Nitrate is reduced to nitrite (tested with meta- phenyldiamin, also sulphanilic acid + a-naphthylamin). In young cultures in peptone-water or bouillon, indol was detected in small quantity. In 10 days in 5 per cent peptone-water the cultures became so black that indol could not be detected. Hydrogen sulphide is produced. The organism was found in the earth of a tobacco field to the depth of decimeters. Uyeda has the following on enzymes. Invertase is formed (the filtrate from a bouillon-culture passed through a Chamberland bougie inverted saccharose in one day). A very slight quantity of diastase appears to be excreted. Cytase is believed to be produced. Tyrosinase was detected in fresh agar-streak-cultures and in bouillon-cultures by the addition of paraphenyl- endendiamin and /3-naphthol (Spitzer's reagent). With this there developed a pale red stain soon becoming black. If one adds a 1 to 5 per cent solution of tyrosin to a cul- ture of this bacillus the red-black color increases more rapidly than without it. Trypsin is also produced. This was demonstrated in gelatin-cultures several weeks old by adding some drops of chlorine-water (Neumeister's tryptophan reaction), the color changing to a red. In the same way bromine gives a violet color. The organism grew as well (luxuri- antly) in an asparagin-dextrose solution as in a peptone-dextrose solution. Bacil- lus nicotianae did not grow in a mineral solution (KH2P04 , MgS04 , NaCl per cent) with dextrose or glyce
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