Biochemical characterization and antifungal activity of an endo-1,3-β-glucanase of Paenibacillus sp. isolated from garden soil

Abstract

A 44-kDa 1,3-beta-glucanase was purified from the culture medium of a Paenibacillus strain with a 28-fold increase in specific activity with 31% recovery. The purified enzyme preferentially catalyzes the hydrolysis of glucans with 1,3-beta-linkage and has an endolytic mode of action. The enzyme also showed binding activity to various insoluble polysaccharides including unhydrolyzable substrates such as xylan and cellulose. The antifungal activity of this Paenibacillus enzyme and a previously purified 1,3-beta-glucanase from Streptomyces sioyaensis were examined in this study. Both enzymes had the ability to damage the cell-wall structures of the growing mycelia of phytopathogenic fungi Pythium aphanidermatum and Rhizoctonic solani AG-4. Nonetheless, the Paenibacillus enzyme had a much stronger effect on inhibiting the growth of fungi tested.

Carbohydrate-binding properties of a separately folding protein module from β-1,3-glucanase Lic16A of Clostridium thermocellum

“…This enzyme degrades b-1,3-linkages in glucans, e.g. in laminarin and curdlan (Hong & Meng, 2003). It has a multimodular structure remarkably similar to Lic16A (see Fig.…”

Plant defense-related enzymes against pathogens: a review

“…The induction of β-glucanase as part of the hypersensitive reaction is a stereotypic response; the pattern of induction is similar for viral, bacterial, and fungal pathogens. It creates resistance against various fungi such as Aspergillus parasiticus, A. flavs, Blumeria graminis, Colletotrichum lagenarium, Fusarium culmorum, Fusarium oxysporum, fusarium udum, Macrophomina phaseolina and Treptomyces sioyaensis (Rezzonico, 1998;Wu and Bradford, 2003;Hong and Meng, 2004;Wrobel-Kwiatkowska et al, 2004, Liang et al, 2005Roy-Barman et al, 2006).…”

Diversity and Characterization of Endophytic Bacteria Associated with Tidal Flat Plants and their Antagonistic Effects on Oomycetous Plant Pathogens

“…Chitinase activity was tested as described previously (Singh et al, 1999) with some modification by using 1/2 R2A agar medium containing 0.5% (w/v) colloidal chitin. The presence of a clear zone around the colony was detected after 7 days incubation at 28 o C. Protease activity was checked by using 0.5% (w/v) skim milk in 1/2 R2A agar media and the activity was determined by checking for the formation of a clear zone around the colony after 5 days incubation at 28 o C. Secretion of β-1,3-glucanase was tested by streaking bacterial strains on 1/2 R2A agar media containing pachyman (0.2%, w/v) and aniline blue (0.005%, w/v), on which the positive bacteria formed a clear halo around the colony (Hong and Meng, 2003).…”