Wide-range antifungal antagonism ofPaenibacillus ehimensisIB-X-b and its dependence on chitinase and β-1,3-glucanase production

Abstract

Previously, we isolated a strain of Bacillus that had antifungal activity and produced lytic enzymes with fungicidal potential. In the present study, we identified the bacterium as Paenibacillus ehimensis and further explored its antifungal properties. In liquid co-cultivation assays, P. ehimensis IB-X-b decreased biomass production of several pathogenic fungi by 45%-75%. The inhibition was accompanied by degradation of fungal cell walls and alterations in hyphal morphology. Residual medium from cultures of P. ehimensis IB-X-b inhibited fungal growth, indicating the inhibitors were secreted into the medium. Of the 2 major lytic enzymes, chitinases were only induced by chitin-containing substrates, whereas beta-1,3-glucanase showed steady levels in all carbon sources. Both purified chitinase and beta-1,3-glucanase degraded cell walls of macerated fungal mycelia, whereas only the latter also degraded cell walls of intact mycelia. The results indicate synergism between the antifungal action mechanisms of these enzymes in which beta-1,3-glucanase is the initiator of the cell wall hydrolysis, whereas the degradation process is reinforced by chitinases. Paenibacillus ehimensis IB-X-b has pronounced antifungal activity with a wide range of fungi and has potential as a biological control agent against plant pathogenic fungi.

Cooperative Degradation of Chitin by Extracellular and Cell Surface-Expressed Chitinases from Paenibacillus sp. Strain FPU-7

“…Recently, their biocontrol potential against bacteria and fungi has attracted considerable notice, owing to the production of antimicrobial substances and cell wall-degrading enzymes (27,(46)(47)(48)(49). Molecular biological information regarding Paenibacillus chitinases is, however, scarce, and their amino acid sequences mostly remain to be determined.…”

Biochemical and genetic characterization of β-1,3 glucanase from a deep subseafloor Laceyella putida

“…β-1,3-Glucanase (EC 3.2.1.39) is produced by various organisms (BRENDA, http://www.brenda-enzymes.org/) and is known to be a biological control enzyme with a chitinase (EC 3.2.1. 14) in the lysis of cell walls of plant pathogenic fungi (Mauch and Staehelin 1989;El-Katatny et al 2001;Aktuganov et al 2008). Indeed, both enzymes are induced simultaneously by pea tissue (Mauch et al 1988), tobacco explants (Neale et al 1990), tomato seeds and leaves (Wu and Bradford 2003), grapevine (Aziz et al 2003), Trichoderma harzianum (De la Cruz et al 1993;El-Katatny et al 2000, Bacillus sp.…”

“…Indeed, both enzymes are induced simultaneously by pea tissue (Mauch et al 1988), tobacco explants (Neale et al 1990), tomato seeds and leaves (Wu and Bradford 2003), grapevine (Aziz et al 2003), Trichoderma harzianum (De la Cruz et al 1993;El-Katatny et al 2000, Bacillus sp. (Helistö et al 2001), and Paenibacillus ehimensis (Aktuganov et al 2008). β-1,3-Glucanase is useful for preparation of biologically active β-1,3-oligomers and protoplast of fungi and yeast cells and production of bioethanol from brown algae (Story et al 2014;Gouveria et al 2010).…”

Molecular characterization of an endochitinase from Bacillus thuringiensis subsp. konkukian

“…Chitinases have immense potential for biotechnological applications and may be used as biocontrol agents against phytopathogenic fungi as well as on important agricultural pest and vectors of diseases (Aktuganov et al 2008;Chernin et al 1995Chernin et al , 1997Kobayashi et al 2002;Liu et al 2008;Pan et al 2006). Several genera of bacteria, including Serratia (Mehmood et al 2009;Suzuki et al 2002;Watanabe et al 1997), Enterobacter (Chernin et al 1995), and Aeromonas (Wang et al 2003;Li et al 2007;Mehmood et al 2010) produce high levels of chitinolytic enzymes.…”