An antifungal chitinase produced by Bacillus subtilis using chitin waste as a carbon source

Abstract

The production of inexpensive chitinolytic enzymes is an element in the utilization of shellfish-processing waste. In this study, shrimp and crab shell powder, prepared by treating shrimp-and crab-processing waste by boiling and crushing, was used as a substrate for the isolation of an antifungal chitinase-producing microorganism. Bacillus subtilis NPU 001, a strain isolated from soil samples, excreted a chitinase when cultured in a medium containing 2% (w/v) shrimp and crab shell powder as the major carbon source. The chitinase, which was purified by sequential chromatography, had a Mw of 31 kDa and a pI of 5.4. The purified chitinase (2 mg ml -1 ) inhibited hyphal extension of the fungus Fusarium oxysporum. Compared with other known bacterial chitinases, the unique characteristics of NPU 001 chitinase include antifungal activity against plant-pathogenic fungi and the production of chitotriose as the major enzymatic hydrolysate from colloidal chitin.

Bacillus spp. en el Control de la Marchitez Causada por Fusarium spp. en Capsicum chinense

“…Las cepas CBMT2 y CBMT51, fueron las únicas que presentaron halos de inhibición del crecimiento micelial en confrontación contra F. equiseti con halos de 3.76 y 6.37 mm, respectivamente, que corresponden al 18.3 y 31.5 % de inhibición (Figura 1). La actividad antagónica de Bacillus se debe a varios mecanismos como competencia por la colonización de la rizosfera (Compant et al, 2005), producción de lipopéptidos como Iturina, Fengicina y Surfactina (Kim et al, 2010), y producción de enzimas líticas (Pleban et al, 1997;Chang et al 2010). La cepa B. subtilis Pla10 produce antibióticos de la familia Iturina A y Surfactina, las fracciones purificadas mostraron Fengycin, and Surfactin (Kim et al, 2010), and the production of lytic enzymes (Pleban et al, 1997;Chang et al 2010).…”

“…Therefore, an alternative for biological control is the use of antagonistic rhizobacterias, capable of exerting control over pathogens (Guillén et al, 2006). This antagonism is attributed in part to the production of chitinases (Chang et al, 2010) and lipopeptides such as: iturin, surfactin, fengycin, and bacillomycin (Ramarathnam et al, 2007). The most commonly used rhizobacterias belong to the genus Bacillus.…”

“…Por ello una alternativa de control biológico es el empleo de rizobacterias antagonistas, capaces de ejercer un control de patógenos (Guillén et al, 2006). Este antagonismo se atribuye en parte a la producción de quitinasas (Chang et al, 2010) y lipopéptidos como: iturina, surfactina, fengicina y bacilomicina (Ramarathnam et al, 2007). Las rizobacterias más utilizadas son del género Bacillus.…”

Vanilla Rhizobacteria as Antagonists against Fusarium oxysporum f. sp. vanillae

“…In the present study, we used culture media with added crab shell as an alternative to selecting bacterial strains capable of producing extracellular enzymes to hydrolyze the chitin present in the cell walls of fungi (Chang et al, 2003;Wang et al, 2006;Chang et al, 2009;Wang et al, 2009;Wang et al, 2010) where certain strains of Bacillus cereus and B. subtilis, when grown in media with crab and/or shrimp shells, produce chitinolytic enzymes efficient for the in vitro inhibition of F. oxysporum, F. solani and Pythium ultimum.…”

“…Obtaining strains of Sphingobacterium, Psychrobacter, Pseudomonas, Serratia, Staphylococcus and Stenotrophomonas from other plant species using culture media with crab and/or shrimp shells as the only carbon source has been reported (Wolf, 2002;Chang et al, 2003;Ribbeck-Busch et al, 2005;Wang et al, 2006;Chang et al, 2009;Wang et al, 2009;Zachow et al, 2009). Likewise, strains of these genera have been reported as rhizobacteria with in vitro antagonistic activity against phytopathogenic fungi, including F. oxysporum, but not for the strain vanillae.…”