An endophyte Paenibacillus dendritiformis strain APL3 promotes Amaranthus polygonoides L. sprout growth and their extract inhibits food-borne pathogens

Abstract

Green leafy vegetables are rich sources of antioxidants and minerals, which prevent food-borne pathogen infections during our diet. This study was aimed to isolate and identify the plant growth-promoting endophytic bacterium from several plant species to enhance the growth of Amaranthus polygonoides L. and their antimicrobial potential against food-borne pathogens. Seven endophytic bacterial isolates were tested on two Amaranthus species to identify the suitable beneficial bacterium. The antioxidants capacity and antimicrobial activity of bacterial isolate (APL3) treated plants were analyzed. The bacterial isolate, APL3 showed a significantly higher growth of A. polygonoides L. than other isolates. It was identified as Paenibacillus dendritiformis strain APL3 by 16S rRNA gene sequencing and phylogenetic analysis. The endophyte (APL3) treated A. polygonoides L. sprouts had higher antioxidants potentials and significantly inhibited the growth of Escherichia coli, Salmonella sp., Staphylococcus sp. and Pseudomonas sp. The results of the present study suggest that utilization of P. dendritiformis strain APL3 triggers the growth of A. polygonoides L. and induces metabolic changes in plants to improve their antimicrobial properties to prevent foodborne pathogens.