Abdelrahim H. Hassan ^1,2 Maria G. Maridueña Zavala ^3,4* Emad A. Alsherif ⁵ Abeer Aloufi ⁶ Shereen Korany ⁷ Mohammad Aldilami ⁸ Nahla A. Bouqellah ⁹ Hamada AbdElgawad ^1,4,5

• ¹ Department of Food Safety and Technology, Faculty of Veterinary Medicine, Beni-Suef University, Egypt, Beni-Suef, Egypt
• ² School of Biotechnology, Nile University, Giza, Giza, Egypt
• ³ Biotechnology Research Center of Ecuador (CIBE), Guayaquil, Ecuador
• ⁴ Laboratory for Integrated Molecular Plant Physiology Research, Department of Biology, Faculty of Sciences, University of Antwerp, Antwerp, Belgium
• ⁵ Department of Botany and Microbiology, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
• ⁶ Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia, Riyadh, Saudi Arabia
• ⁷ Department of Plant and Microbiology, Faculty of Science, Helwan University, Cairo, Egypt
• ⁸ Department of Biology, Faculty of Sciences, King Abdulaziz University, Jeddha, Saudi Arabia
• ⁹ Department of Biology, College of Science, Taibah University, Medina, Saudi Arabia

Plant growth-promoting bacteria (PGPB) are considered a promising tool for triggering the synthesis of bioactive compounds in plants and to produce healthy foods. This study aimed to demonstrate the impact of PGPB on the growth, accumulation of primary and secondary metabolites, biological activities, and nutritional qualities of Eruca sativa (arugula), a key leafy vegetable worldwide. To this end, Jeotgalicoccus sp. (JW0823), was isolated and identified by using partial 16S rDNA based identification and phylogenetic analysis. The findings revealed that JW0823 significantly boosted plant biomass production by about 45% (P<0.05) and enhanced pigment content by 47.5% to 83.8%. JW0823-treated plants remarkable improvements in their proximate composition and vitamin contents, with vitamin E level increasing by 161.5%. JW0823 induced the accumulation of bioactive metabolites including antioxidants, vitamins, unsaturated fatty acids, and essential amino acids, thereby improving the nutritional qualities of treated plants.An increase in the amounts of amino acids was recorded, with isoleucine showing the highest increase of 270.2%. This was accompanied by increased activity of the key enzymes involved in amino acid biosynthesis, including glutamine synthase, dihydrodipicolinate synthase, cystathionine γ-synthase, and phenylalanine ammonia-lyase enzymes. Consequently, the total antioxidant and antidiabetic activities of the inoculated plants were enhanced. Additionally, JW0823 improved antimicrobial activity against several pathogenic microorganisms. Overall, the JW0823 treatment is a highly promising method for enhancing the health-promoting properties and biological characteristics of E. sativa, making it a valuable tool for improving the quality of this important leafy vegetable.