Purification of a chitinase from Trichoderma sp. and its action on Scierotium rolfsii and Rhizoctonia solani cell walls

The Journal of General and Applied Microbiology

Adrienne P. Fernandes²  Carlos R. Felix²  Cirano J. Ulhoa¹  Luzia H. C. Lima¹ 

[1] Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA/CENARGEN);Departamento de Biologia Celular, Universidade de Brasilia (UnB)

关键词: N-acetylglucosaminadase;    biological control;    chitinase;    chitobiase;    β-1;    3-glucanase;    Rhizoctonia solani;    Sclerotium rolfsii;    Trichoderma;   

DOI  :  10.2323/jgam.43.31

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

Trichoderma harzianum is an effective biocontrol agent of several important plant pathogenic fungi. This Trichoderma species attacks other fungi by secreting lytic enzymes, including β-1, 3-glucanase and chitinolytic enzymes. Superior biocontrol potential may then be found in strains having a high capacity to produce these enzymes. We have therefore evaluated the capacity of six unidentified Trichoderma spp. isolates to produce chitinolytic enzymes and β-1, 3-glucanases in comparison with T. harzianum 39.1. All six isolates demonstrated substantial enzyme activity. However, while the isolates hereafter called T2, T3, , T5, and T7 produced lower amounts of enzymes, the activity of isolates T4 and T6 were 2-3 fold higher than that produced by T. harzianum 39.1. A chitinase produced by the T6 isolate was purified by a single ion-exchange chromatography step and had a molecular mass of 46kDa. The N-terminal amino-acid sequence showed very high homology with other fungal chitinases. Its true chitinase activity was demonstrated by its action on chitin and the failure to hydrolyze laminarin and p-nitrophenyl-β-N-acetylglucosaminide. The hydrolytic action of the purified chitinase on the cell wall of Sclerotium rolfsii was convincingly shown by electron microscopy studies. However, the purified enzyme had no effect on the cell wall of Rhizoctonia solani.

【 授权许可】

Unknown