Potential of biosynthesized silver nanoparticles using Stenotrophomonas sp. BHU-S7 (MTCC 5978) for management of soil-borne and foliar phytopathogens

Abstract

Stenotrophomonas sp. is emerging as a popular microbe of global concern with various potential ecological roles. Biosynthesis of gold and silver nanoparticles (AgNPs) using this bacterial strain has shown promising applications in life sciences. However, there is no report on efficient agricultural applications of biosynthesized AgNPs using Stenotrophomonas sp. In this regard, successful biosynthesis of AgNPs using Stenotrophomonas sp. BHU-S7 (MTCC 5978) was monitored by Uv-visible spectrum showing surface plasmon resonance (SPR) peak at 440 nm. The biosynthesized AgNPs were spherical with an average mean size of ~12 nm. The antifungal efficacy of biosynthesized AgNPs against foliar and soil-borne phytopathogens was observed. The inhibitory impact of AgNPs (2, 4, 10 μg/ml) on conidial germination was recorded under in vitro conditions. Interestingly, sclerotia of Sclerotium rolfsii exposed to AgNPs failed to germinate on PDA medium and in soil system. Moreover, AgNPs treatment successfully managed collar rot of chickpea caused by S. rolfsii under greenhouse conditions. The reduced sclerotia germination, phenolic acids induction, altered lignification and H2O2 production was observed to be the probable mechanisms providing protection to chickpea against S. rolfsii. Our data revealed that AgNPs treated plants are better equipped to cope with pathogen challenge pointing towards their robust applications in plant disease management.

Advancements in Plant and Microbe-Based Synthesis of Metallic Nanoparticles and Their Antimicrobial Activity against Plant Pathogens

“…The AgNPs were biosynthesized using the culture supernatant of Stenotrophomonas sp. BHU-S7, which was isolated from agricultural farm soil [28]. The synthesis of gold NPs (AuNPs) using Bacillus subtilis isolated from Hatti Gold Mine was reported in a study.…”

Biological synthesis and characterisation of silver nanoparticles using Pseudomonas geniculata H10 for pharmaceutical activity

“…This difference is due to the fact that the particle size thus obtained is substantially increased by the hydrated capping agents and surface water. That is, biomolecules, such as proteins, surrounding the NPs form a highly hydrated layer, and consequently, larger hydrodynamic diameters were obtained [38, 39]. Zeta potentials provide a means of characterising NP surface charges and stabilities in aqueous suspensions, and usually NPs with zeta potential >±30 mV are considered to be stabilised [34].…”

Silver nanoparticles coated with chitosan against Fusarium oxysporum causing the tomato wilt

“…Similarly that AgNP were effective against various phytopathogens such as Alternaria alternata, Botrytis cinerea, F. oxysporum and Pythium spinosum (Kim et al, 2012). Mishra et al (2017) showed the antifungal activity of AgNPs against foliar and soil-borne phytopathogens. The inhibitory impact of different silver concentrations (2, 4, 10 μg/mL) on conidial germination was recorded under in vitro conditions.…”