Diffusible and volatile compounds produced by an antagonistic Bacillus subtilis strain cause structural deformations in pathogenic fungi in vitro

Abstract

An efficient antagonistic strain of Bacillus subtilis, originally isolated from the rhizosphere of established tea bushes, was found to cause structural deformities in six pathogenic fungi under in vitro culture conditions. This effect was attributed to the production of diffusible and volatile antifungal compounds. Out of the selected test fungi four were phytopathogenic, while the remaining two were of clinical importance. The bacterial strain successfully restricted the growth of all test fungi in dual cultures, and induced morphological abnormalities such as mycelial and conidial deviations. The inhibitory effect caused by volatiles was greater than that by diffusible compounds.

The growth of fungi andArabidopsis thalianais influenced by bacterial volatiles

“…[11][12][13] Organic compounds such as allyl alcohol inhibit germination of S. sclerotiorum, benzothiazole, cyclohexanol, n-decanal, dimethyl trisulfide, 2-ethyl-1-hexanol and nonanal of pseudomonades inhibit mycel growth of S. sclerotiorum, or not further identified compounds of B. subtilis caused structural deformations of pathogenic fungi. 8,14,15 Our survey supports and extends the previous observations that rhizobacteria produce biologically relevant organic volatile compounds. Beside pseudomonades and B. subtilis particularly potent volatiles are emitted by Serratia odorifera, S. plymuthica, Stenotrophomonas maltophilia, S. rhizophila and Burkholderia cepacia.…”

Plant growth promotion abilities and formulation of Bacillus megaterium strain B 388 (MTCC6521) isolated from a temperate Himalayan location

“…Studies in various ecological niches have indicated that the relative proportion of different microbes and dominance of a particular group of microorganism (species or strains) depend upon various environmental factors. The soils of temperate and alpine climates have been reported dominated by species of Bacillus and Pseudomonas [10,14]. Specifi c protocols must be followed to identify locally adapted benefi cial microbes according to their tolerance to environmental stresses, soil types and crop under consideration.…”

“…Biocontrol properties of the bacterium Production of diffusible and volatile antifungal compounds by the bacterium was evaluated following dual cultures using standard methods as described in Chaurasia et al [10] using Alternaria alternata (ITCC 4215) and Fusarium oxysporum (ITCC 4219) as test isolates. Reduction in fungal biomass was determined in broth assays [11].…”

Identification of Volatile Metabolites from Fungal Endophytes with Biocontrol Potential towards <i>Fusarium oxysporum</i> F. sp. <i>cubense</i> Race 4

“…Antimicrobial compounds are produced in either volatile or nonvolatile forms (Brooks et al, 1994;Cazar et al, 2005;Chanway, 1996;Chaurasia et al, 2005). The nonvolatile compounds are often detected using simple plate assay (Chaurasia et al, 2005) and the filtrates can be easily extracted, purified and characterized (Liu et al, 2007).…”