TABLE 2.

Comparison of the number of copies of pAS, the specific refolding activities, and the levels glucoamylase secreted by A. niger AB4.1, AS1.1, and AS2.2 grown in ACMS/N/P^a

A. niger strain	No. of copies of pAS	Specific refolding activity at 44 h (U/mg)	Level of glucoamylase at 72 h (mg/liter)
AB4.1	0	1.4 ± 0.1	166 ± 7
AS1.1	6–10	0.7 ± 0.1	58 ± 6
AS2.2	4–6	1.0 ± 0.1	65 ± 6

^aRefolding activities are presented in units per milligram of microsomal protein. Levels of glucoamylase secreted were assayed from the supernatant of 72-h cultures grown in ACMS/N/P. Values represent the average ± the SEM from triplicate experiments.