http://creativecommons.org/licenses/by/4.0/legalcode Environments volume: 12 number: 11 startpage: 409 info:eu-repo/semantics/article application/pdf 6591836 bytes Lazić, Sanja Berić, Tanja Milanović, Slobodan Medić, Olja Vemić, Aleksandar Stanković, Slaviša Rakonjac, Ljubinko Popović, Vladan Keywords: biofertilizer; Quercus petraea; physiological traits Abstract: Soil contamination is a major contemporary issue. In light of increasing efforts to align seedling production with the sustainable use and preservation of soil resources, this study aimed to explore the potential of selected plant-growth-promoting bacteria as natural alternatives to mineral fertilizers, a major soil pollutant in the forestry sector. The experiment involved inoculating one-year-old sessile oak (Quercus petraea) seedlings with multiple single bacterial treatments and a consortia derived from sessile oak rhizosphere and monitoring their effects on plant physiological parameters such as chlorophyll, carotenoid, and nitrogen content, along with selected parameters of the rapid chlorophyll a fluorescence induction curve (an OJIP curve). The results indicated that the selected bacterial strains improved specific plant physiological parameters at certain points during the monitoring period; however, further research is necessary to draw statistically significant conclusions. Although these bacteria did not directly enhance photosynthetic parameters, their potential remains evident and could be harnessed through improved application methods. Future studies should focus on identifying site conditions that support the proliferation of the introduced bacterial populations. MDPI https://unilib.phaidrabg.rs/o:8804 ISSN: 2076-3298 2025 Effect of Plant Growth-Promoting Bacteria on Photosynthetic Parameters of One-Year-Old Sessile Oak Seedlings eng