Antifungal Activity Screening of Antarctic Actinobacteria Against Phytopathogenic Fungi

Abstract

The extreme weather conditions in the Antarctic have exerted selective pressures favoring differential features in bacteria to survive this untapped environment (i.e., antibiotic molecules). Notably, higher chances of antibiotic discovery from extremophiles have been proposed recently. Althoughnew organic and environmentally friendly sources for helping in the control of plant pathogenic fungi are necessary, the information about anti-phytopathogenic applications of extremophile microorganisms from untapped environments is limited. In this study, we determined the antifungal effect of actinobacterial strains isolated from Antarctic soils and sediments. Co-culture inhibition assays and Minimum Inhibitory Concentration (MIC) determination revealed that all Antarctic strains (x28) can inhibit the growth of at least one phytopathogenic fungi including Fusarium oxysporum,Rhizoctonia solani,Botrytissp. and Phytophthora infestans. Additionally, new novel antagonistic relationships are reported. Our work establishes a precedent on Antarctic actinobacteria strains with the capacity to produce antifungal compounds, and its potential for developing new fungicides or biocontrol agents solving current agriculture problems.

Genome-Based Characterization of Plant-Associated Rhodococcus qingshengii RL1 Reveals Stress Tolerance and Plant–Microbe Interaction Traits

“…Members of the genus Rhodococcus have been reported to show antifungal activity in vitro against plant-pathogenic fungi ( Chiba et al, 1999 ; Iwatsuki et al, 2007 ; Santos et al, 2020 ) and RL1 reduced growth of F. oxysporum in vitro , but showed no inhibition against R. solani and F. culmorum ( Supplementary Figure 4 ). Further studies using model plants will reveal the full potential of RL1 as biocontrol agent against plant pathogenic fungi.…”

Biological and chemical characterization of antimicrobial activity in Arthrobacter spp. isolated from disease‐suppressive compost

“…Although the inhibitory effect of cell‐free filtrates from A. humicola and A. psychrophenolicus had not been shown before this study, previous work reported the inhibition of two aquatic pathogenic fungi, Saprolegnia australis and Mucor hiemalis , by the cell‐free supernatant of A. stackerbrandtii and A. psychrolactophilus [33]. Furthermore, the cell‐free supernatant of A. polychromogenes inhibited the growth of F. oxysporum , Botrytis sp., R. solani , and Phytophthora infestans [34]. In the same study investigating Antarctic actinobacteria, A. globiformis , A. psychrolactophilus , A. scleromae , and an Arthrobacter sp.…”

Mechanistic insights into the role of actinobacteria as potential biocontrol candidates against fungal phytopathogens

“…Since then there are numerous reports on the potential of actinobacteria, mainly Streptomyces spp. (isolated from diverse sources) as potent biocontrol tools in the control of various phytopathogens, especially phytopathogenic fungi [11,33,[37][38][39][40][41][42][43][44][45][46][47][48].…”