Quitinase classe I do látex de Ficus benjamina L. purificação caracterização e ação contra fungos fitopatogênicos de interesse agronômico

Abstract

A class I chitinase from F. benjamina latex designated FbLx-Chi-1 was purified to homogeneity after ammonium sulfate precipitation of the latex proteins (LP) and affinity chromatography of the 30-60% fraction on a chitin column. FbLx-Chi-1 has a 30 kDa molecular mass as estimated by SDS-PAGE, an optimal pH and temperature for full enzyme activity of 5.5 and 60 ºC, respectively. It presented significant thermoresistance to denaturation as it retains 100% activity after incubation at 60 ºC for 30 min, and remarkable pH stability preserving 100% activity after incubation at pH range of 2-10, for 30 min at 37 ºC, and salinity tolerance up to 250 mM NaCl. In addition, FbLx-Chi-1 activity enhanced in the presence of Ca2+ and Mg2+, but Mn2+ and Al3 inhibited it. Importantly, FbLx-Chi-1 exhibited antifungal activity against the phytopathogenic fungi Fusarium pallidoroseum and Fusarium oxysporum revealing biotechnological potential to control these phytopathogens in agriculture.