Abstract
In 3 investigations, Loeffler, 1 Robinovitsch, 2 and Day and Gibbs 3 found that living tubercle bacilli were killed in about 48 hours when mixed with pancreatic enzymes. According to Loeffler, the live bacilli were digested, according to Day and Gibbs they were not. None of the foregoing papers records the use of quantitative biochemical methods for detecting tubercle bacillus digestion. Nor was consideration given to the possibility that this might take place without complete dissolution of the bacterial cell.
One of the objects of the present work was to determine by quantitative methods, the extent to which tubercle bacilli undergo digestion by pancreatic enzymes acting together. In all the experiments, human and bovine strains grown on Long's synthetic agar medium were used. The nearly dry masses of bacilli were easily lifted off the agar, weighed and mixed at once with commercial pancreatic enzyme preparations.
Digestible Carbohydrate. Series of June, 1928-May, 1929. Suspensions of tubercle bacilli in chloroform Ringer solution were incubated with and without the addition of pancreatic enzyme powder. In most of the experiments sufficient chloroform and toluol was added to promptly kill the bacilli. At convenient intervals of a few days, reducing sugar was determined in the filtrates by adaptations of Folin's 4 methods. In 30 experiments the added enzyme preparations caused an increase in reducing sugars followed by their gradual disappearance. An occasional failure to digest occurred. Calculated as dextrose, the digestible carbohydrate in 1 gm. tubercle bacilli varied up to 3 mg., depending upon the digestion period and other factors.
Digestible Fat. Series of May, 1930-June, 1931. Acid liberated from 1 gm. portions of tubercle bacilli by autolytic and by pancreatic enzymes was titrated with N/20 sodium hydroxide, with phenol red indicator.
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