Fig. 2

Dot activity assay on glycol chitin gels to detect chitinase activity. I Five μL of cell extract (A) and supernatant (B) from C. glutamicum WT (pEKEx3) (1) and C. glutamicum WT (pEKEx3-chiB) (2) are spotted on the glycol chitin gel. One μL of purified ChiB from S. marcescens with a specific activity of 28.8 mU mL⁻¹ was spotted as a positive control (C1). ChiB activity is clearly seen in the cell extract of C. glutamicum overexpressing ChiB, while no activity is detected on the supernatant of this strain or in the wildtype. II Triplicates (1–3) of one μL of concentrated (Amicon 30 K) culture supernatant (A) and 5 μL of non-concentrated supernatant (B) of C. glutamicum WT (pEKEx3-SP0955-chiB) and the empty vector control C. glutamicum WT (pEKEx3) (A4) were spotted on the glycol chitin gel