Mycelia of ABPU/A2 grown in MM supplemented with 2% glucose for 48 h were transferred to MM supplemented with different carbon sources, and cultivation was continued for 36 h (Fig.  5 ).

Western blot analysis showed strong ChiB signals in cell extracts prepared from mycelia incubated with no carbon source or with colloidal chitin (Fig.  5 a, lanes 2, 6), as well as in culture supernatants prepared with no carbon source (Fig.  5 c, lane 2).

Correspondingly, intracellular and extracellular chitinase activities increased simultaneously (Fig.  5 b, d; lanes 2, 6).

After 36 h incubation, levels of ChiB and chitinase activities were analyzed (Fig.  5 ; lanes 7, 8, 9).

In cell extracts and culture supernatants, levels of ChiB and chitinase activity did not increase when mycelia were incubated in MM supplemented with chitin plus glucose or with chitin plus galactose (Fig.  5 ; lanes 7, 8).

The combination of colloidal chitin with glycerol, which is a non-carbon catabolite repressing carbon source (Arst and Bailey 1977 ), showed the same effect as the combination with glucose or galactose (Fig.  5 ; lane 9).

Second, ChiB was strongly induced upon carbon source deprivation (Fig.  5 ).

In the present study we show that ChiB production was very low when ABPU/A2 was grown in the medium containing glucose, galactose, or glycerol, but increased by the deprivation of carbon sources (Fig.  5 ).

However, as shown in Fig.  5 , ChiB production and chitinase activity in cell extracts and culture supernatants did not increase when glucose or galactose was included in the media containing colloidal chitin.

nidulans could hardly grow in the medium containing chitin as sole carbon source, but the effect of chitin on the ChiB production is less efficient than that of no carbon source (Fig.  5 ; lanes 2, 6).