TABLE 4.

Changes in concentration of inorganic phosphate and activity of exo-β-d-galactofuranosidase as a function of culture age and initial phosphate concentration^a

Culture age (days)	Inorganic phosphate concn (mM) in the presence of an initial phosphate concn of:		Exo-β-d-galactofuranosidase activity (U h−1 ml−1) in the presence of an initial phosphate concn of:
	2.0 mM	20 mM	2.0 mM	20 mM
2	0.42	19.8	ND	ND
3	0.40	19.2	ND	ND
5	0.38	17	ND	ND
7	0.33	16	ND	ND
9	0.20	15	ND	2.2
14	0.13	15	ND	1.0
17	<0.05	9.6	ND	ND

^aApproximately 3 ml of culture filtrate was collected through sintered glass and centrifuged for 4 min at 4,000 × g to pack any particulate material. Sample volumes ranging from 20 to 300 μl of culture filtrate were reacted with ammonium molybdate (38), and the A₈₂₀ was compared with that of reference concentrations ranging from 0.05 to 1.0 μmol of KH₂PO₄. One milliliter of culture filtrate was added to 60 ml of 50 mM sodium acetate (pH 4.3) in H₂O containing 20 mg of pP_xGM. This reaction mixture was placed in a Rudolph polarimeter cell, and an optical rotation of 0.74 millidegrees was obtained. The reaction mixture was maintained at 25°C, and the observed optical rotation was measured again after 4 hr. ND, none detected.