Determination of mycelium-bound Beta-N-acetyl-D-glucosaminidase activity from Aspergillus niger MYA 135 in submerged process.

COLIN VERÓNICA LETICIA; ROMERO CINTIA MARIANA; BAIGORÍ MARIO DOMINGO; PERA LICIA MARIA

Tafí del Valle-Tucumán, Argentina

Jornada; XXII Jornadas Científicas de la Asociación de Biología de Tucumán; 2005

Introduction: Filamentous fungi grow by apical extensión, localized apical synthesis that creates a tubular hyphal morphology. Besides linear tip extension, filamentous fungi branch to form new intercalary growing tips. Wall lytics enzymes have an important role in the process of apical growth. However, the events involves are still not clearly understood. One of the wall lytic enzymes is the activity b-N-acetyl-D-glucosaminidase (NAGase) that we use as a relative marker of the wall lytic potential. Objetive: Evaluation of NAGase activity during fungal development in submerged process. Materials and Methods: Aspergillus niger (ATCC MYA 135) was grown at 30º C in BM (g/l) sucrose 10.0; KH2PO4 1.0; NH4NO3 2.0; MgSO4. 7H2O 0.2; CuSO4. 5H2O 0.06; pH 5. NAGase activity was determined using 0.01 gof wet mycelium and p-nitrophenyl-N-acetyl-b-D-glucosaminidase as substrate. Results and conclusions: Both NAGase specific activity and branch frecuency increase during fungal growth. The maximun NAGase specific activity was 0.550  U per mg of dry weight. This work was supported by grant 693/04 CONICET.