Figure 2

Growth of the enrichment culture in medium containing 4-aminopyridine. Growth and degradation of 4-aminopyridine. The enrichment culture was cultivated in medium containing 2.13 mM 4-aminopyridine (0.02% wt/vol) at 30°C with shaking. Growth was determined by measuring the optical density at 660 nm (OD₆₆₀) (open squares); the residual 4-aminopyridine (filled triangles, 4-AP) was measured using HPLC as described in the text; the released ammonia (open circles) was measured using the indophenol method [21]; and total protein in the culture (filled circles) was measured using the modified Lowry method, independently performed twice.