Burkholderia cepacia XXVI siderophore with biocontrol capacity against Colletotrichum gloeosporioides

Abstract

Colletotrichum gloeosporioides is the causal agent of anthracnose in mango. Burkholderia cepacia XXVI, isolated from mango rhizosphere and identified by 16S rDNA sequencing as a member of B. cepacia complex, was more effective than 6 other mango rhizosphere bacteria in inhibiting the model mango pathogen, C. gloeosporioides ATCC MYA 456. Biocontrol of this pathogen was demonstrated on Petri-dishes containing PDA by > 90 % reduction of surface colonization. The nature of the biocontrol metabolite(s) was characterized via a variety of tests. The inhibition was almost exclusively due to production of agar-diffusible, not volatile, metabolite(s). The diffusible metabolite(s) underwent thermal degradation at 70 and 121 °C (1 atm). Tests for indole acetic acid production and lytic enzyme activities (cellulase, glucanase and chitinase) by B. cepacia XXVI were negative, indicating that these metabolites were not involved in the biocontrol effect. Based on halo formation and growth inhibition of the pathogen on the diagnostic medium, CAS-agar, as well as colorimetric tests we surmised that strain XXVI produced a hydroxamate siderophore involved in the biocontrol effect observed. The minimal inhibitory concentration test showed that 0.64 μg ml(-1) of siderophore (Deferoxamine mesylate salt-equivalent) was sufficient to achieve 91.1 % inhibition of the pathogen growth on Petri-dishes containing PDA. The biocontrol capacity against C. gloeosporioides ATCC MYA 456 correlated directly with the siderophore production by B. cepacia XXVI: the highest concentration of siderophore production in PDB on day 7, 1.7 μg ml(-1) (Deferoxamine mesylate salt-equivalent), promoted a pathogen growth inhibition of 94.9 %. The growth of 5 additional strains of C. gloeosporioides (isolated from mango "Ataulfo" orchards located in the municipality of Chahuites, State of Oaxaca in Mexico) was also inhibited when confronted with B. cepacia XXVI. Results indicate that B. cepacia XXVI or its siderophore have the potential to be used as a biological control agent against C. gloeosporioides; thus diminishing environmental problems caused by the current practices to control this disease.

Microbial diversity in leaves, trunk and rhizosphere of coconut palms (Cocos nucifera L.) associated with the coconut lethal yellowing phytoplasma in Grand-Lahou, Cte dIvoire

“…Species of Burkholderia included B. cepacia and B. nodosa, known as plant growth promoters, nitrogen-fixing enhancers, and siderophore producers have been used for soil bioremediation for better water management, and biocontrol of soil-borne plant pathogenic fungi (de los Santos-Villalobos et al, 2012;Parke, 2000) and bacteria (Nion and Toyota, 2008). Although it is not clear its role, the fact that Burkholderia was mostly isolated from symptomless and S1-like symptom bearing palms suggests it as a candidate to further assess as a possible biocontrol against the CILY phytoplasma.…”

Plant-Associated Symbiotic Burkholderia Species Lack Hallmark Strategies Required in Mammalian Pathogenesis

“…Examples are B. vietnamiensis , which fixes nitrogen in association with rice roots in Asia [11], and B. cenocepacia and other BCC bacteria, which have been suggested for use as BCA because they kill pathogenic fungi [12]. However, major concerns about putting opportunistic pathogens into the soil have been voiced [13], [14] because some species, e.g., B. vietnamiensis , are common inhabitants of the lungs of cystic fibrosis (CF) patients [15], [16].…”

In vitro antagonism of five rhizobacterial species against athelia rolfsii collar rot disease in soybean

“…Isolate SYP31 was able to produce IAA in the media without tryptophan addition, while other isolates did not produce IAA in the media without tryptophan (Table 4 a large number of commercially hydrolytic enzymes and bioactive substances which are beneficial for plant growth and health (Eberl and Vandamme 2016). B. cepacia is a ubiquitous soil organism which has been effectively used as a biocontrol agent against many plant pathogenic fungi such as Colletotrichum gloeosporioides (de Los Santos-Villalobos et al 2012), Pythium-induced dampingoff, Aphanomyces-induced root rot of pea, Rhizoctoniainduced root rot of Poinsettia and other fungal diseases (Parke et al 1991;King and Parke 1993;Cartwright and Benson 1994;Fridlender et al 1993). In the USA, several strains of B. cepacia have been registered by The United States Enviromental Protection Agency (EPA) as biocontrol agents against plant pathogenic fungi (Eberl and Vandamme 2016;Rai 2006).…”