June 9, 1923 
Substrate and Hydrogen-Ion Concentration 
877 
concentration tested. On the other hand, it was secreted in sweet- 
potato decoction at all concentrations tried. 
(7) The best growth as measured by the dry weight of the mycelium 
took place at the lowest hydrogen-ion concentration. 
(8) The amount of glucose consumed in Czapek’s solution is correlated 
with the amount of mycelium produced. 
(9) The substrate influences the production of pectinase; the hydrogen- 
ion concentration does not. The results indicate a well-marked qualita¬ 
tive action of the substrate on the production of the macerating enzym, 
in that when vegetable decoctions which probably contain pectin are 
used and when nutrient solutions to which pectin is supplied as a source 
of carbon is employed pectinase is produced. 
LITERATURE CITED 
(1) BiERRY, H. 
1912. DIE ROLLE DER EEEKTROLYTE BEI DER WIRKUNG EINIGER TlER- 
ISCHEN PERMENTE. In Biochem. Ztschr., Bd, 40, p. 357-3^9* 
Bibliographical footnotes. 
(2) Brown, William. 
1915. STUDIES IN THE PHYSIOLOGY OP PARASITISM. I. THE ACTION OP 
BOTRYTis ciNEREA. In Ann. Bot., v. 29, p. 313-348. References, 
p. 348. 
(3) Brunton, T. Lauder, and MacFAYDEN, A. 
1890. THE PERMENT ACTION OP BACTERIA. In Proc. Roy Soc., [London], 
V. 46, 1889, p. 542-553- 
(4) Currie, James N. 
1917. THE CITRIC ACID PERMENTATION OP ASPERGILLUS NIGER. In Jour. 
Biol. Chem., v. 31, p. 15-37, 2 fig., 2 pi. 
(5) Dox, Arthur Wayland. 
1910. THE INTERCELLULAR ENZYMES OP PENICILLIUM AND ASPERGILLUS, 
WITH SPECIAL REPERENCE TO THOSE OP PENICILLIUM CAMEMBERTI. 
U. S. Dept. Agr. Bur. Anim. Indus. Bui. 120, 70 p. Bibliography, 
p. 66-70. 
(6 ) Duclaux, E. 
1899. trait^ de microbiologie. t. 2. Paris. 
(7) Grace, Linwood G., and HighbErger, Florence. 
1920. acid production by streptococcus viridans in mediums op 
dipperEnt hydrogen-ion concentration. In Jour. Infect. Dis¬ 
eases, V. 26, p. 451-456. 
( 8 ) Harter, L. L. 
1921. amylase op rhizopus tritici, with a consideration op its 
SECRETION and ACTION. In Jour. Agr. Research, v. 20, p. 761-786. 
Literature cited, p. 784-786. 
(9) -and WeimER, J. L. 
1921. STUDIES IN THE PHYSIOLOGY OP PARASITISM WITH SPECIAL REPER¬ 
ENCE TO THE SECRETION OP PECTINASE BY RHIZOPUS TRITICI. 
In Jour. Agr. Research, v. 21, p. 609-625. Literature cited, p. 624-625. 
(10) Hunt, Charles H. 
1918. A method por PREPARING PECTIN. In Science, n. s., v. 48, p. 201-202. 
(11) Jones, Horry. 
1920. SOME PACTORS INPLUENCING THE PINAL HYDROGEN-ION CONCENTRA¬ 
TION IN BACTERIAL CULTURES WITH SPECIAL REPERENCE TO 
STREPTOCOCCI. In Jour. Infect. Diseases, v. 26, p. 160-164. 
(12) Karrer, Joanne L. 
1921. STUDIES IN THE PHYSIOLOGY OP THE PUNGI. XIII. THE EPPECT OP 
hydrogen-ion concentration UPON THE ACCUMULATION AND 
ACTIVATION OP AMYLASE PRODUCED BY CERTAIN PUNGI. In Ann. 
Mo. Bot. Gard., v. 8, p. 63-96, 14 fig. Bibliography, p. 95-96. 
(13) - and Webb, Robert W. 
1920. TITRATION CURVES OP CERTAIN LIQUID CULTURE MEDIA. In Ann. 
Mo. Bot. Gard., v. 7, p. 299-305. Literature, p. 305. 
(14) Katz, J. ^7 
1898. DIE REGULATORISCHE BILDUNG VON DIASTASE DURCH PILZE. In 
Jahrb. Wiss. Bot. [Pringsheim], Bd. 31, p. 599-618. 
