Antimicrobial Effect of Biosynthesized Silver Nanoparticles Using Rosemary (Rosmarinus officinalis) Extract on Some Soft Rot Bacteria in Storage Condition

Subject Areas : Food Microbial Contamination

Esmaiil Torkabadi ¹ , Zeinab Fotoohiyan ² , fatemeh shahdadi ³

1 - Jiroft Branch, Islamic Azad University, Faculty of Sciences, Department of Microbiology
2 - Jiroft Branch, Islamic Azad University, Faculty of Agriculture, Department of Plant pathology
3 - food science department/faculty of agriculture/university of jiroft/jiroft/Iran

Received: 2020-08-19 Accepted : 2020-11-19 Published : 2021-05-22

Keywords: silver nanoparticles, antimicrobial effect, Soft rot bacteria. Aqueous extract, of Rosemary,

Abstract :

Nowadays, use of plants in the synthesis of metal nanoparticles, which have antimicrobial activity, is considered. The aim of present study was evaluating biosynthesis of silver nanoparticles from aqueous extract of rosemary and then investigating the effect of these nanoparticles and mancoseb toxin on soft rot bacteria isolated from carrots, potatoes and onions during storage. The biosynthesized silver nanoparticles were analyzed by ultraviolet and FTIR spectroscopy. Soft rot bacteria were isolated and identified using selective and specific culture media from carrots, potatoes and onions. A pathogenic isolate from each sample with the highest pathogenicity was selected for the tests and their minimum inhibitory concentration (MIC) was evaluated against the experimental treatments. The MIC of the pathogen isolates against the 2580 mg/ml of silver nanoparticles and 1000 ppm of mancoseb were 88.88% and 100%, respectively. The mean percentage of vegetable contamination with pathogen isolate in the presence of silver nanoparticles in the third month of storage was 70%, 80% and 70% for onions, potatoes and carrots, respectively, and average percentage of vegetable contamination with pathogenic isolates in the combined control of bacteria with silver nanoparticles and mancoseb toxin at the third month of storage for onion, potato and carrot were 45, 40 and 40%, respectively. According to obtained results, the combined control of biosynthesized silver nanoparticles and Mancoseb can be used to control of soft rot bacteria in carrot, potato and onion.