110 CHEMISTRY OF BACTERIA AND THEIR PRODUCTS 



action of bacteria is not constantly related to their gelatin-dissolving 

 property, the hemolysis probably is produced by other means than 

 the proteolytic enzymes. ^^ A few pathogenic bacteria (anthrax, 

 cholera and some strains of hemolytic streptococci^^) digest starch" 

 and B. pyocyaneus, StapJnjlococcus pyogenes aureus, and B. prodigiosus 

 all produce fat-splitting enzymes demonstrable by tliis method."'* 

 B. pyocyaneus, Eijkman found, digested elastic tissue readily," as also 

 did a bacillus resembling B. subtilis obtained from the tissue of a gan- 

 grenous lung. 



Rennin is produced by many bacteria, as is shown by their coagu- 

 lating milk, independent of any acid reaction," and protease from 

 pyocyaneus causes "plastein" formation in albumose solutions (Zak),^^ 

 Bacteria which give negative results by the plate method may con- 

 tain active lipase demonstrable in killed bacteria by direct action 

 upon fats and esters, these lipases behaving exactly like the lipase of 

 animal tissues (Wells and Corper);" staphylococcus and pyocyaneus 

 are more actively lipolytic than B. coli, B. dysenierice and B. tuber- 

 culosis. Urease seems to be widespread." Tubercle bacilli contain 

 enzymes resembling lipase, trypsin, erepsin, nuclease and urease, 

 but not amylase,- elastase or invertase.^° 



Schmailowitsch^^ stated that the amount and nature of enzymes 

 produced by bacteria is modified by the amount and nature of their 

 food, but Jordan found that gelatinase is produced by bacteria grow- 

 ing on non-protein media; he failed entirely to support the statement 

 of Abbott and Gildersleeve^^ that bacteria grown on gelatin produce 

 much more active gelatin-dissolving enzyme than do bacteria grown 

 on bouillon. Diehl^^ found that bacteria grown on media containing 

 no organic nitrogen produce no proteolytic enzymes, and the enzyme 

 content of bacteria is much modified by the composition of the media, 

 depending on the character of the amino-acids present rather than the 

 proteins themselves. Jacoby'*'* has made extensive studies on the 



^' See Jordan, Biol. Studies by the pupils of W. T. Sedgwick, 1906, p. 124. 



" Tongs, Jour. Aincr. Med. A.ssoc., 1919 (73), 1277. 



'•' In relation to carbohydrate enzymes, the extensive studies of Kendall (Jour. 

 Biol. Chem., 1912, vol. 12) should be consulted. He emphasizes especially that as 

 a rule bacteria ferment carboliydrates in preference to attacking proteins when 

 both foodstuffs are available. 



" See Buxton (American Med., 1903 (0), 137) concerning enzymes of numerous 



Dfl.ctiGri&i 



"> Cent. f. Bakt.. 1903 (35), I. 



" Contradicted by DcWacle, Cent. f. Bakt., 1905 (39), 353. 

 " llofmeister's Beitr., 1907 (10), 287. 



"Jour, infect. Dis., 1912 (11), 388; literature on bacterial lipases. See also 

 Kendall." 



'" See Jacoby, Biochem. Zeit., 1917 (80), 357. 



80 Corper and Sweany, Jour, liact., 1918 (3), 129. 



«' Wratschel)naja Cazetta, 1902, p. 52. 



«2.Jour. Med. Re.seareli, 1903 (10), 42. 



«Mour. Infect. Dis., 1919 (21), 347. 



«♦ Biochem. Zeit., 1917 (83), 74. 



