Environmental Technology & Innovation 17 (2020) 100594 Contents lists available at ScienceDirect Environmental Technology & Innovation journal homepage: www.elsevier.com/locate/eti Augmentation of stimulated Pelomonas aquatica dispersible granules enhances remediation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) contaminated soil Mohd Aamir Khan a , Sonal Yadav a , Ranju Sharma a , Manu Dalela b , S. Mary Celin c , Abhishek Sharma d,∗ , Satyawati Sharma a a Centre for Rural Development and Technology, Indian Institute of Technology Delhi, New Delhi 110016, India b Stem Cell Facility (DBT—Centre of Excellence for Stem Cell Research), All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India c Centre for Fire, Explosives and Environment Safety, Defence Research & Development Organization, Brig. Mazumdar Road, Delhi 110 054, India d Amity Food and Agriculture Foundation, Amity University Uttar Pradesh, Noida 201313, India article info Article history: Received 27 July 2019 Received in revised form 6 December 2019 Accepted 20 December 2019 Available online 23 December 2019 Keywords: Biodegradation RDX Pelomonas aquatica Biostimulation Water dispersible granules abstract In this study, we explored the hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) degradation potential of a gram-negative bacterium Pelomonas aquatica strain 12868. The microbe eliminated 80.68% of RDX by utilizing the explosive as a nitrogen source. FTIR study and nitrite assay confirmed the degradation of RDX into non-toxic metabolites in an RDX-succinate aqueous medium. The isolate showed an improved RDX degradation when formulated into water dispersible granules (WDG) using soy flour as a nutrient source. The WDG formulation not only achieved 6.53% enhanced RDX degradation but also stabilized the microbe as only a 24.37% decrease in cfu count was observed after a storage period of six months at 30 o C. During the microcosm experiments, RDX degradation followed first-order kinetics with a half-life of 13.9 and 19.04 days in a soil biostimulated by sucrose and wheat straw, respectively. P. aquatica with sucrose as added carbon source effectively degraded 50.91% more RDX compared to unstimulated control after 30 days of treatment. These data imply that microbial formulation mediated RDX reduction coupled with biostimulation has the potential to become a swift and sustainable clean-up approach for RDX contaminated environments. © 2019 Elsevier B.V. All rights reserved. 1. Introduction Hexahydro-1, 3, 5-trinitro-1, 3, 5-triazine (RDX) is a toxic explosive contaminant indiscriminately used in both military and civil operations around the world (Jugnia et al., 2017). Owing to the moderate solubility, RDX easily contaminates surface and groundwater (Kwon and Finneran, 2006). This cyclic nitramine explosive is carcinogenic and highly persistent thereby posing grave concern for humans and the surrounding environment (Chatterjee et al., 2017). RDX is gradually being considered as a toxic soil contaminant. In one of the studies, the soil was found contaminated with RDX in the ∗ Corresponding author. E-mail address: asharma5@amity.edu (A. Sharma). https://doi.org/10.1016/j.eti.2019.100594 2352-1864/© 2019 Elsevier B.V. All rights reserved.