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Improving global food security by boosting crop production through environmentally friendly technology is critical in the fight against malnutrition. This study explores the use of green chemistry combined with nanotechnology to enhance seed germination. Silver nanoparticles (Ag NPs) were synthesized using a bacterial biosurfactant extracted from a newly discovered Klebsiellasp. strain RGUDBI03 found in a petroleum-contaminated site, employing a one-step method involving autoclaving. Electron microscopy analysis revealed well-dispersed Ag NPs ranging from 10–40 nm. X-ray diffraction (XRD) analysis confirmed the crystalline nature of the NPs with fcc lattice points of 111, 200, 220, and 311. Fourier-transform infrared spectroscopy (FTIR) spectra of the bacterial biosurfactant and Ag NPs showed the presence of C = C-H, C-H, and CH2groups, confirming the biosurfactant's role as a reducing and capping agent. Nano-treated seeds of chickpea (Cicer arietinum), and rice (Oryza sativa) exhibited enhanced water uptake rates and 99% germination under optimized condition as compared to that of the control (i.e., 78–80%). This led to a more than threefold increase in α-amylase activity in the treated seeds (i.e., 0.33 and 1.54 mg/g respectively for chickpea and rice seeds) as compared to their respective control (i.e., 0.12 and 0.48 mg/g), converting starch into soluble sugar and promoting germination and growth. Furthermore, the Ag NPs showed no cytotoxic effects on red blood cells and earthworms (Eudrilus eugeniae), with visibly healthy villi in the gut region of treated samples, demonstrating their non-cytotoxic and eco-friendly nature. Overall, this study provides a comprehensive depiction of biosurfactant-mediated Ag NPs synthesis, their application in seed germination and growth enhancement, the likely mode of action of Ag NPs, as well as cytotoxicity and eco-toxicity assessment. Additionally, biosurfactant extracted from a newly isolated Klebsiellasp. is reported for the first time for the synthesis of Ag NPs, implementing in enhancing seed germination rate up to almost one hundred percent with no sign of cytotoxicity.

Production of biosurfactant by a novel indigenous isolate Pseudomonas otitidisstrain DU13 and its role in bioremediation of petroleum hydrocarbon is reported. The identity of the isolate was confirmed by 16S rDNA gene sequencing analysis (Genbank accession: MK177190). The biosurfactant produced by the isolate could reduce the surface tension of petroleum supplemented medium by 46% just after 7 days of treatment. The emulsification index (E24) of the surfactant was found 37, 35, and 20%, respectively, against used motor oil, diesel, and kerosene. The FTIR spectrum of the crude biosurfactant showed the presence of υC–Hstretch, υCH2,υ-C=Cstretch and υC–Hbonding. The isolated strain could degrade 26% of TPH content of used motor oil in liquid culture. Whereas, ex situ pilot-scale field trial demonstrated very high bioremediation potential of the isolate in terms of germination rate of Vigna radiataand Cicer arietinumseeds and plant growth just after 20 days of treatment.