TABLE 1.

Steady-state levels of glycosyl hydrolases

Carbon source(s)	Glycosyl hydrolase activity (mean ± SD)
	α-Glucosidase (μmol of PNP/min/mg)	β-Glycosidase (μmol of PNP/min/mg)	α-Amylase (U/ml)
Sucrose	46 ± 2	607 ± 55	121 ± 20
Sucrose + yeast extract	13 ± 1	32 ± 2	<10
Sucrose + tryptone	35 ± 5	73 ± 5	37 ± 20
Sucrose + amino acidsa	10 ± 3	126 ± 7	55 ± 30
Tryptone	33 ± 2	151 ± 6	41 ± 4

^aThe amino acids included alanine, arginine, asparagine, aspartate, glutamate, glutamine, glycine, leucine, and histidine.