XXII. BIOCHEMICKÝ ZJAZD - Jesseniova lekárska fakulta

Posters
87.
MULTIPLE prOTEaSES are SECrETED BY vEGETaTIve TrIChoderma
VIride MYCELIUM CULTIvaTED WITH prOTEIN INDUCEr
Martin Šimkovič, Anita Gdovinová, Zuzka Zemková and Ľudovít Varečka
Department of biochemistry and microbiology, Faculty of chemical and food
technology, Slovak Univerzity of Technology, Radlinského 9, 81237 Bratislava
The cultivation of Trichoderma viride mycelium with purified protein substrate (bovine
serum albumin, ovalbumin) resulted in the secretion of protease activity into the medium
under submerged conditions. The secretion began within 30 h and the greatest secretion
activity was observed after 72 h cultivation. The secretion continued upon the prolonged
cultivation (up to 8 d) with lower secreted proteolytic activity. Gelatine zymography of
the secreted protease revealed high-molecular weight protease(s) (~200 kDa) with high
autolytic activity as the only secretory product. Low-molecular weight protease(s) involved
in the mycoparasitic activity of Trichoderma spp. was seen after prolonged cultivation
only, as a band with m.w. about 30 kDa. Expression of known Trichoderma spp. genes
encoding secreted proteases Prb1, ProA showed that only Prb1 was expressed after 3-4
days of cultivation, i.e., after fading out the early secretion phase. The secretory activity
of the earlier phase was impaired by tunicamycin and brefeldin A and was significantly
stimulated by uncoupler. The existence of biphasic fungal secretory response represents
a yet not recognized process. The structure and the biological role of secreted proteases
should be elucidated in the future.
Acknowledgements: This work was supported by the VEGA Grant Agency project (No.
1/0434/08) and by the Science and Technology Assistance Agency under the contracts
Nos. APVV-0642-07, APVT-20-003904 and VVCE-0064-07.
210 XXII. Biochemistry Congress, Martin