Diffusible Compounds Produced by Hanseniaspora osmophila and Gluconobacter cerinus Help to Control the Causal Agents of Gray Rot and Summer Bunch Rot of Table Grapes

Abstract

Gray and summer bunch rot are important diseases of table grapes due to the high economic and environmental cost of their control with synthetic fungicides. The ability to produce antifungal compounds against the causal agents Botrytis, Aspergillus, Penicillium, and Rhizopus of two microorganisms isolated from table grapes and identified as Hanseniaspora osmophila and Gluconobacter cerinus was evaluated. In dual cultures, both biocontrol agents (together and separately) inhibited in vitro mycelial growth of these pathogens. To identify the compounds responsible for the inhibitory effect, extractions were carried out with organic solvents from biocontrol agents separately. Through dual cultures with pathogens and pure extracts, only the hexane extract from H. osmophila showed an inhibitory effect against Botrytis cinerea. To further identify these compounds, the direct bioautography technique was used. This technique made it possible to determine the band displaying antifungal activity at Rf = 0.05–0.2. The compounds present in this band were identified by GC-MS and compared to the NIST library. The most abundant compounds, not previously reported, corresponded to alkanes, ketones, alcohols, and terpenoids. H. osmophila and G. cerinus have the potential to control the causal agents of gray and summer bunch rot of table grapes.

Recruiting grape‐isolated antagonistic yeasts for the sustainable bio‐management of Botrytis cinerea on grapes

“…Additionally, all yeasts produced diffusible inhibitory compounds on B. cinerea (Table 2). Olivera et al (2021) identified the diffusible compounds produced by Hanseniaspora osmophila against grey rot of table grapes were identified as ketones, alcohols, alkanes, and terpenoids. Another study specified the diffusible antifungal compounds involved in the biocontrol of grey mould as 3-amino-5-methylhexanoic acid, biphenyl-2,3-diol, sinapaldehyde, piperideine, phenylpropanoid hydrolytic enzymes, and pulcherriminic acid (Chen et al, 2018;Sipiczki, 2006).…”

Back to the holobiont: ecophysiological and systemic responses of rooted-cuttings inoculated with a synthetic community

“…In the present study, the potential of bacterial endophytes as biocontrol agents in agriculture was mirrored by the fact that about 50% of the tested isolates exhibited a pathogen growth inhibition rate higher than 45% towards at least one of the four tested pathogens. Since no VOC activity was detected by means of septate-petri dish assay, such inhibition was probably due to diffusible compounds (Wan et al, 2008; Olivera et al, 2021). Although the main objective was the development of a customized SynCom formed by biocontrol agents able to trigger direct and indirect defence responses against grape pathogens, the seven isolated strains were also screened for some of the main PGP traits, such as nitrogen fixation, phosphate and starch solubilization or siderophore production, IAA production and ACC-deaminase activity.…”

Plant Beneficial Bacteria and Their Potential Applications in Vertical Farming Systems

“…Hydrogen cyanide has been observed to inhibit various pathogens including the ascomycete Thielaviopsis basicola in tobacco plants [ 130 ], Agrobacterium tumefaciens and the nematode Meloidogyne javanica in tomato [ 131 ], and even the insect Galleria mellonella [ 132 ]. Diffusible antibiotics, on the other hand, are solid or liquid compounds at an atmospheric temperature and pressure, and may include 2,4-diacetylphloroglucinol (DAPG), phenazines (PHZ), alkanes, and hexanoic acid [ 122 , 133 ]. PHZs, as an example, have been shown to compromise the cell membranes of plant pathogens [ 134 ], and hexanoic acid has been shown to inhibit Botrytis cinerea in tomato [ 135 ].…”