Antifungal potential of Lauraceae rhizobacteria from a tropical montane cloud forest against Fusarium spp.

Abstract

The occurrence of pests and diseases can affect plant health and productivity in ecosystems that are already at risk, such as tropical montane cloudforests.Theuseofnaturallyoccurringmicroorganismsisapromisingalternativetomitigateforesttreefungalpathogens.Theobjectives ofthisstudyweretoisolaterhizobacteriaassociatedwithfiveLauraceaespeciesfromaMexicantropicalmontanecloudforestandtoevaluate their antifungal activity against Fusarium solani and F. oxysporum. Fifty-six rhizobacterial isolates were assessed for mycelial growth inhibition of Fusarium spp.throughdualculture assays.Thirty-three isolates significantly reduced the growth of F. solani,while 21 isolates inhibitedthatofF.oxysporum.Theninebacterialisolatesthatinhibitedfungalgrowthbymorethan20%wereidentifiedthrough16SrDNA gene sequence analysis; they belonged to the genera Streptomyces, Arthrobacter, Pseudomonas,andStaphylococcus. The volatile organic compounds (VOC) produced by these nine isolates were evaluated for antifungal activity. Six isolates (Streptomyces sp., Arthrobacter sp., Pseudomonas sp., and Staphylococcus spp.) successfully inhibited F. solani mycelial growth by up to 37% through VOC emission, while only the isolate INECOL-21 (Pseudomonas sp.) inhibited F. oxysporum. This work provides information on the microbiota of Mexican Lauraceae and is one of the few studies identifying forest tree-associated microbes with inhibitory activity against tree pathogens.

Identification of Volatile Organic Compounds in Extremophilic Bacteria and Their Effective Use in Biocontrol of Postharvest Fungal Phytopathogens

“…Species of the genus Staphylococcus are mostly known to cause opportunistic human diseases, some of which are frequently found in rhizospheric soil. Although antifungal activity of the bacterium S. equorum against B. cinerea has been observed ( Sadfi-Zouaoui et al, 2008 ; Reverchon et al, 2019 ) to our knowledge, the VOCs produced by this bacterium have not previously been described. In our study, the antifungal activity of S. equorum strain EN21 against F. solani was found to be very low, with a reduction in fungal growth of only 2%.…”

“…In our study, the antifungal activity of S. equorum strain EN21 against F. solani was found to be very low, with a reduction in fungal growth of only 2%. Reverchon et al (2019) have shown that VOCs emitted by some Staphylococcus species, which are capable of inhibiting the growth of F. solani by over 20%, can, however, increase that of F. oxysporum .…”

Identification of Antifungal Compounds from Avocado Rhizobacteria (Bacillus spp.) against Fusarium spp., by a Bioassay‐Guided Fractionation Approach

“…This strain was isolated from chili pepper ( Capsicum annum L.) and has been used in our previous studies for screening bacterial strains with antifungal activity, as described in Guevara‐Avendaño et al [14] . and Reverchon et al [55] . The strain of F. kuroshium HFEW‐16‐ IV‐019 was provided by Dr. Clemente García‐Ávila (National Phytosanitary Reference Center (CNRF) of the National Health, Safety and Quality Service from Mexico), as described in Báez‐Vallejo et al [28] .…”

The Impact of Growth-Promoting Streptomycetes Isolated from Rhizosphere and Bulk Soil on Oilseed Rape (Brassica napus L.) Growth Parameters

“…According to data in the literature, all characterised species have already been confirmed as plant growth-promoting streptomycetes (PGPS). In the case of Streptomyces albidoflavus [41][42][43], Streptomyces sampsonii [44,45], Streptomyces puniceus [46], Streptomyces cirratus [47], Streptomyces flavovariabilis [48] and Streptomyces rishiriensis [49], there was a strong antagonistic activity against several phytopathogenic fungi such as Aspergillus niger, Microsporum gypseum, Trichopyton sp., Fusarium sp. and Alternaria solani.…”